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15 An Inventory of the Southern Coastal Plain Pine Forests, Belize
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Ministry of Overseas Development , i
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An Inventory of the Southern Coastal Plain Pine Forests,
Belize
by
M S Johnson and D R Chaffey
Land Resource Study No. 15
Land Resources Division, Tolworth Tower, Surbiton, Surrey, England, KT6 7DY
1974
*B2>»
THE LAND RESOURCES DIVISION-
The Land Resources Division of the Ministry of^Overseas Development a s s i s t s developing countr ies in mapping, inves t iga t ing and assessing land resources, and makes recommendations on the use of these resources for the development of ag r i cu l tu re , l ivestock husbandry and fores t ry , i t also gives advice on re la ted subjec ts to overseas governments and organisa t ions , makes s c i e n t i f i c personnel ava i l ab le for appointment abroad and provides l ec tu res and t r a in ing courses in the bas ic techniques of resource appra i sa l .
The Division works in close co-operation with government departments, research i n s t i t u t e s , u n i v e r s i t i e s and in te rna t iona l organisa t ions concerned with land resources assessment and development planning.
i i
CONTENTS
PART 1. INTRODUCTION
Page
Preface Acknowledgement s Abstract Resume Descriptors for Co-ordinate Indexing Summary of Results Summary of Conclusions
PART 2. THE PROJECT
Origin of the Project Procedure Team Composition
5 5 6
PART 3 . THE ENVIRONMENT
Physical Aspects
Location Climate Geology Topography Water Soils (by C J Birchall) Vegetation Fauna
7 7 10 11 13 13 14 17
Human Aspects
History Forest Exploitation Population Land Tenure Current Land Use Communications Markets
18
18 19 19 20 20 21 22
PART 4 . OBJECTIVES AND METHODS
Objectives Sampling Blocks and S t r a t a Sampling of Timber Stocking Regeneration Count Volume Measurements Other Observations
23
23 24 24 25 25 25
i n
Page
PART 5 . RESULTS OF THE INVENTORY 27
Forest/Vegetation types 27 Stand Tables 27 Standing Volume 27 Volume Table 35 Regeneration 37
PART 6. CONCLUSIONS 40
Exploitable Growing Stock 40 Seedling Regeneration 41 S i l v i c u l t u r e and Management 41
PART 7. REFERENCES AND RELATED WORKS 43
APPENDIXES 45
1. L i s t of common and l a t i n names of p l an t s mentioned in the t ex t 45 2. Volume figures for p r iva te lands 47
LIST OF TABLES
1. Summarised area statement for the whole project area 2
2. Mean numbers of stems of pine per uni t area 3
3. Standing volume of pine in project area 3
4. Mean annual r a i n f a l l at four s t a t i o n s 9
5. Mean annual maxima and mean annual minima and highest and lowest
temperatures at three s t a t ions 9
6. Mean annual r e l a t i v e humidity at two s t a t ions 9
7. Provisional f igures from 1970 population census for set t lements between
S i t t e e River and Deep River 20
8. Fores t /vegeta t ion types iden t i f i ed and mapped 24
9. Area statement showing areas of sampled pine-bearing fores t /vegeta t ion types 27 10. Stand t ab les showing numbers of stems of pine per uni t area and the d i s t r i bu t i on
according to s ize c lass in groups of fores t /vegeta t ion types 28 11. Standing volume of pine per uni t area, including defect ive timber, in groups
of fores t /vegeta t ion types 29
12. Standing net sound volume of pine per uni t area, assuming maximum defect, in groups of fores t /vegeta t ion types 30
13. Local volume t ab l e for Pinus caribaea 31
14. Standing gross volume of pine, including defect ive timber, in groups of fores t /vege ta t ion types 32
15. Standing net sound volume of pine, assuming maximum defect, in groups of fores t /vegeta t ion types 33
Page
16. Summary statement of standing gross volume of pine (defect ive timber included) 34
17. Summary statement of net sound volume of pine, assuming maximum defect 34
18. Pine volume t ab l e data: sample s i ze and incidence of defect 37
19. Regeneration of pine in f ive fores t /vege ta t ion type groups in Block 2 38
20. Regeneration of pine in f ive fores t /vege ta t ion type groups in Block 3 39
21. Hughes Estate: Standing gross volume of pine, including defective timber, in groups of fores t /vegeta t ion types 47
22. Hughes Esta te : Standing net sound volume of pine, assuming maximum defect, in groups of fores t /vegeta t ion types 48
23. The Stopper: Standing gross volume of pine, including defect ive timber, in groups of fores t /vegeta t ion types 49
24. The Stopper: Standing net sound volume of pine, assuming maximum defect, in groups of fores t /vegeta t ion types 50
LIST OF FIGURES
1. Monthly r a i n f a l l 1961-70 at Stann Creek, Savannah and Punta Gorda 11
2. Temperature at Stann Creek and Punta Gorda, based on years for which data are avai lable in the period 1933-70 12
3. Mean monthly r e l a t i v e humidity at Stann Creek and Punta Gorda, based on years for which data are avai lable in the period 1933-70 12
4. Defective t r ee s : rot as a percentage of t o t a l volume and i t s var ia t ion with t r e e s ize 36
L I S T OF MAPS
Text Map Location 8
Forest/Vegetation Maps 2 sheets 1:50 000 scale Separate sheets
v
PART 1. INTRODUCTION
PREFACE
The Southern Coastal Plain of Belize has in the past been a major source of Caribbean pine (Pinus caribaea)• With the recent renewal of emphasis on the development of the country's pine resources and the possibility of the re-introduction of pine-based industries, the contribution which could be made by the Southern Coastal Plain became a question of importance. This final report follows an inventory made in 1970 of the pine savannas between Sittee River and Deep River and is issued with the permission of the Belize Government to whom field maps and preliminary figures were presented in January 1971 and the full preliminary report in 1972.
Completion of the final report was delayed by a decision to await base material from a new edition of maps for the southern part of Belize. Production of these new edition maps was delayed for technical reasons and in 1973 the decision to await them was reversed and map production was put in hand using the existing base material. Most of the text of the report was drafted by D R Chaffey.
The project covered by this report was one of three forest inventories undertaken in Belize by the Land Resources Division between 1968 and 1971, the other two being of Chiquibul Forest Reserve and the Mountain Pine Ridge.
ACKNOWLEDGEMENTS
The authors record their appreciation for the assistance received from the Chief Forest Officers, the late R M Waters and his successor L S Lindo. The Forest Department' s Counterpart Officer, 0 Rosado, is particularly thanked for his contribution in helping with preparatory work and the organisation and execution of the fieldwork. The assistance of the former Divisional Forest Officer at Melinda Forest Station, E 0 Bradley, is also acknowledged. The junior staff and labourers engaged on the project gave cheerful and willing service under conditions which were at times trying. Dr H C Dawkins, MBE, of the Commonwealth Forestry Institute advised on statistical matters and assisted in the computation of data, for which he is accorded special thanks. Valuable help with the extraction and processing of data was given by staff of the Land Resources Division. Thanks are due to the Director of Overseas Surveys and to the Cartographic Unit of LRD for the preparation of maps and diagrams.
ABSTRACT
The results of an inventory of pine in 1 400 km2 (540 mi2) of the southern Coastal Plain are presented. The inventory included the assessment of the standing volume of wood and, in part of the project area, of the replacement stocking.
By the interpretation of aerial photography of scale 1:15 000, fourteen forest/vegetation types were identified and mapped. The map accompanies this report. Seven of the fourteen forest/ vegetation types were sampled. Six of the seven are pine or mixed pine/broadleaved forest types, distinguished from each other by pine canopy density. The seventh type is grassland with pine seedlings and/or very scattered overmature pine. Sampling of both standing timber stocking and regeneration was carried out in all seven of the forest/vegetation types sampled.
The project area was divided into three sampling blocks. The sampling results were computed separately for each forest/vegetation type sampled in each block.
As a background to the forest inventory, relevant aspects of the environment are described, with emphasis on soils and vegetation. The principal type of vegetation in the project area is savanna, the distribution of which depends on the incidence of fire as well as on climate and soil.
1
RÉSUMÉ
Les résultats d' un inventaire des pins contenus dans 1 400 km2 de la plaine cotiere meridionale sont présentés. L'inventaire comprenait 1' estimation du volume de bois sur pied et, pour une partie de la superficie couverte par Ie projet, 1' estimation du peuplement de regeneration.
Par 1'interpretation de photographies aeriennes a 1'échelle de 1/15 000, quatorze types de foret/ vegetation furent représentés'sur carte. La carte est annexée a ce rapport. Sept partni les quatorze types de foret/végétation furent échantillonnés au hasard. Six parmi les sept types sont des forets de pins ou des forêts a peuplement mélange de pins et d' arbres feuillus, se distinguant 1'une de 1'autre par la densité de cime des pins. Le septième type est^la prairie avec des sauvageons de pin et/ou des pins a maturité excessive tres disséminés. L' echantillonnage aléatoire des arbres sur pied ainsi que du peuplement de regeneration fut effectué dans tous les sept types de foret/végétation échantillonnés.
La superficie couverte par le projet fut divisée en trois bloes d' echantillonnage. Les résultats de 1' echantillonnage aléatoire furent calculés séparément pour chacun des types de foret/ vegetation dans chaque bloc.
Pour servir de fond a 1'inventaire forestier, des aspects du milieu biophysique sont décrits, en soulignant les sols et la vegetation. Le type principal de vegetation de la superficie couverte par le projet est la savane, dont la distribution dépend aussi bien de 1' incidence du feu que du climat et du sol.
DESCRIPTORS FOR CO-ORDINATE INDEXING
Climate/geology/geomorphology/pedology/soil description (morphology, survey and mapping)/photo-grammetric application/water quality/land use (current)/crown density/ forest classification/ forest inventory/forest mapping/forest mensuration/forest sampling/natural regeneration system/ natural stand/Pinus caribaea/stand density/tree individual measurement/tree volume measurement/ savanna/vegetation stratification/history/environment/Belize.
SUMMARY OF RESULTS
Area
Table 1 shows the total areas of the sampled forest/vegetation types in the project area.
TABLE 1 Summarised area statement for the whole project area
Sampled forest/vegetation types
Area Sampled forest/vegetation
types ha ac
Pine forest
Mixed pine/broadleaved forest
Grassland with pine seedlings and/or scattered overmature pine
14 815
5 219
25 466
36 608
12 896
62 927
Total 45 500 112 431
Timber Stocking
Because the lower size limit for trees enumerated was not uniform for all of the three forest blocks into which the project area was divided, results are summarised only for growing stock of d.b.h. 15.2 cm (6.0 in) and above.
2
TABLE 2 Mean numbers of stems of pine per unit area in Blocks l, 2 and 3
d.b.h. Number of stems
cm in ha ac
>15. 2
>25. 4
>6.0
>10.0
26
10
11
4
Stem Numbers Table 2 shows the number of stems per unit area, in two size classes, in the three blocks. The values shown are mean values and are not qualified by estimates of. precision.
Standing Volume Minimum estimates for the standing volume of pine in two size classes are shown in Table 3. Figures quoted are obtained by totalling reliable minimum estimates (at 95% probability) calculated separately for each of the three sampling blocks. The estimates given in Table 3 are therefore almost certainly very conservative.
TABLE 3 Standing volume of pine in the whole project area
d.b.h. Minimum estimate
cm in Defective timber included Defective timber excluded
>15. 2
>25. 4
>6.0
>10.0
n,3 f t3 m* ft»
>15. 2
>25. 4
>6.0
>10.0
307 040
185 240
10 871 500
6 537 900
275 150
156 410
9 739 400
5 517 800
Regeneration
Regeneration is taken to include pine of d.b.h. less than 5 cm (2 in). Reliable minimum estimates (at 95% probability) of regeneration stocking in the two blocks in which regeneration was sampled are low. The highest reliable minimum estimate obtained for any forest/vegetation type group in either block is only 353 stems/ha (143 stems/ac). A total of approximately 2 900 ha (7 100 ac), or roughly one-quarter of the total area sample for regeneration, carries a stocking of approximately 350 stems/ha (140 stems/ac). Reliable minimum estimates for the rest of the area sampled are well below 100 stems/ha (40 stems/ac).
SUMMARY OF CONCLUSIONS
1. The present low stocking of material exploitable for saw-timber will increase only slowly in the near future: in more than half of the total area sampled (i.e. in more than half of the pine-bearing land within the project area), it will take about 30 years to achieve the modest stocking of 50 exploitable trees per ha (20 stems/ac).
2. Foreseeable terminal rates of stocking from the naturally regenerated pine compare unfavourably with those to be expected from plantations.
3. The generally low stocking of regeneration in the areas sampled is attributable largely to inadequate fire control.
4. The area subject to fire control should be adjusted to match the actual fire-fighting capability with, possibly, some relocation of fire-fighting resources in order to concentrate activities on the areas of higher potential. Alternatively the fire-fighting capability should be adjusted to cover adequately the areas of higher potential.
3
5. The effectiveness of fire control should be monitored; this could be done by means of permanent sample plots.
6. The possibility of afforestation of the more fertile soils in the foothills edging the southern Coastal Plain, using fast-growing species such as Gmelina arborea, should be investigated.
7. Concerning the possible use of pine in the southern Coastal Plain for an industrial wood-based product such as pulp, the supply of wood available is such that any operation dependent for its raw material largely or entirely upon the project area would have to be of a type capable of economic production on a small scale.
4
PART 2. THE PROJECT
ORIGIN OF THE PROJECT
A request was made by the Belize Forest Department in 1969 to the Ministry of Overseas Development that a study be made of the feasibility of establishing a pine-based pulp industry. This request, which was subsequently withdrawn as being premature and replaced by one for a more widely based pre-feasibility forest utilisation study, was in accordance with recommendations made by Logan (1966) and followed preliminary observations by Waters (1969) on the desirability of introducing a pulp industry. The most suitable location for a pulp mill was thought to be in the vicinity of Deep River.
Necessary prerequisites to any further study were considered to be the investigation of the following'.
1. The suitability for industrial use of the locally grown Pinus caribeea
2. The local supply of pulpwood
The study of the pulping and other characteristics of Caribbean pine became the responsibility of the Tropical Products Institute, while the Land Resources Division undertook to carry out an inventory of the pine resource in the southern Coastal Plain. Other projects already being undertaken by the Land Resources Division were a survey of the agriculture and soils of the Belize Valley and forest inventories of the Chiquibul and Mountain Pine Ridge Forest Reserves.
The forest inventory had four broad objectives. These are described in detail in Part 4 but can be stated briefly as follows:
1. The estimation of the standing volume of pine
2. The assessment of pine regeneration (in part of the project area)
3. The construction of a volume table for pine to enable the volume of a standing tree to be estimated from simple field measurements
4. The mapping of the pine resource
PROCEDURE
June - December 1970 Airphoto interpretation, forest/vegetation type mapping, field sampling and preliminary calculations made as the fieldwork proceeded.
January 1971 Preliminary results presented to Belize Forest Department.
January 1971 - September 1972 Final computation and preparation of report.
The project area was divided into three enumeration blocks. Each block was subdivided, by stereoscopic examination of the relevant 1:15 000 air photography, into 14 forest/vegetation types, of which eight contained pine. Seven of these eight types in two of the three sampling blocks were randomly sampled for timber stocking and regeneration. In the third block, timber stocking only was sampled, as regeneration data were not required. No field sampling was carried out south of Deep River.
5
TEAM COMPOSITION
The project was carried out by three forest officers, assisted by four forest guards. Thirty-six labourers were engaged on the project, divided into six gangs. Two of the officers, M S Johnson, the Senior Forest Officer, and D R Chaffey, were from the Land Resources Division, and the third, 0 Rosado, was provided by the Forest Department as Counterpart Officer. The Forest Department were also responsible for the provision of junior staff and labour. The inventory was in the charge of R N Jenkin, LRD Project Manager. C J Birchall, who contributed the chapter on soils, was attached to the LRD Belize Valley Project under an Overseas Development Administration contract.
PART 3. ENVIRONMENT
PHYSICAL ASPECTS
LOCATION
The area included in the inventory is shown on the location map. The project area stretches from Sittee River in the north to first south of Deep River, a distance of rather less than 80 km (50 mi). Its eastern boundary is the coast. There is no well-defined western limit as this is the boundary between broadleaved forest and either savanna or mixed pine/broadleaved forest (Broken Ridge). This vegetational boundary coincides roughly with the edge of the plain, which varies in width from about 12 km (7.5 mi) in the north to about 32 km (20 mi) in the south. In the hills, west of the plain, considerable areas of Broken Ridge occur in a matrix of broadleaved forest and these were included or not, depending on their accessibility for exploitation.
The project area includes two forest reserves - Swasey-Bladen and Deep River - which have a combined area of 650 km2 (250 mi 2). The total project area is about 1 430 km2 (552 mi 2). A third former forest reserve, Mango Creek, with an area of 273 km (100 mi2) was de-reserved in 1969 but remains as Crown Land. No field sampling was done south of Deep River
The largest town in the area is Mango Creek, which is approximately 160 km (100 mi) from Belmopan, 240 km (150 mi) from Belize City and 80 km (50 mi) from Stann Creek Town It is adjoined'by the settlement of Independence. There is a small forest station at Savannah, 5 km (3 mi) from Mango Creek, a subsidiary to the Divisional Forest Office at Melinda, 16 km (10 mi) north of the project area boundary. The only other settlements of any size are the wastal settlements of Monkey River, Placentia and Seine Bight. The project area is traversed by several rivers in addition to the two already mentioned at its northern and southern extremities, of which the most important are South Stann Creek and the Swasey and Bladen Branches of Monkey River
CLIMATE
The southern Coastal Plain experiences a climate characterised by high temperatures and high rainfall. A distinct dry season occurs in the early months of the year, from February to May, and during this period the fire hazard is at its highest because of the prevailing combination of high temperatures, low rainfall and low relative humidity. The weather for much of the rest of the year tends to depend on whether the moist south-east Trade Winds or the cool drier northerly winds are dominant. The convergence of the two accounts for the rainfall peak in October. From June to November hurricanes may occur, and both Stann Creek and Punta Gorda (a town just south of the project area) have been destroyed by hurricanes, and subsequently rebuilt.
Climatic data are available from a number of stations in or close to the project area (Walker 1972). Data for four stations (Stann Creek Agricultural Station, Cabbage Haul Fire Look-out, Savannah Forest Station and Punta Gorda Agricultural Station) are quoted here. The first and last-named lie just outside the project area, north and south respectively, and a comparison of their data gives an indication of the variation in climate between opposite ends of the project area. Cabbage Haul is situated in the foothills at about 400 m (1 300 ft) a.m.s.l. while Savannah is on the plain near the centre of the project area.
The periods during which data have been recorded and the parameters measured are unfortunately not uniform for the four stations. Data for some parameters are fragmentary or missing.
7
TEXT MAP - LOCATION OF THE PROJECT 68*00 'Wei t of Greenwich
Scale 1:2.000.000 Appro*.
BAHiA Of OMOA
89*00' We i t of Greenwich
D.O.S. 3I52C
© C R O W N COPYRIGHT 1974
Complied and drawn by Directorate of Overseas Survey*
Rainfall
Table 4 gives an impression of the rainfall in the project area. Figure 1 compares histograms for Stann Creek, Savannah and Punta Gorda in the period 1961-70, showing the distribution of rainfall throughout the year. Cabbage Haul is excluded as data for only a few years are available. Data for Stann Creek and Punta Gorda are from the Belize Department of Agriculture, and for Cabbage Haul and Savannah from the Forest Department.
TABLE 4 Mean annual rainfall at four stations
Station Period Rainfall
Period Rainy days Station Period mm in
Period Rainy days
Stann Creek Cabbage Haul Savannah Punta Gorda
1931-70 1965-70 1950-70 1934-70
2 256 2 276 2 398 3 861
88.8 89.6 94.4 152.0
1951-70 1966-70 1951-70 1951-70
173 197 176 193
Temperature
Table 5 shows the range of temperature in the project area. Data are available for only three of the four stations mentioned above. Figure 2 compares graphically the parameters for two stations included in the table and shows their monthly variation throughout the year.
TABLE 5 Mean annual maxima and mean annual minima and highest and lowest temperatures at three stations
Station
Mean annual Highest maximum
Lowest minimum
Station Maximum Minimum Station
Period °C °F Period °C °F Period °C °F Period °C °F
Stann Creek
Savannah
Punta Gorda
1933-39 1945-70
1965-70
1935-39 1945-51 1955-67
30
31
30
86
88
86
1933-39 1945-70
1965-70
1935-39 1945-48 1955-66
21
23
20
70
73
68
1933-38 1946-52 1959-70
1966-70
1934-38 1946-51
41
39
41
105
102
105
1933-38 1946-52 1959-70
1966-70
1934-38 1946-48
10
10
6
50
50
42
Relative Humidity
An impression of mean annual relative humidity in the project area is given by Table 6. Data are available for only two stations. Figure 3 shows graphically the variation in relative humidity throughout the year.
TABLE 6 Mean annual relative humidity at two stations
Station Period r.h.(%)
Stann Creek Punta Gorda
1933-9; 1945-70 1935-9; 1945-51; 1955-66
79.2 80.6
Source: Belize Department of Agriculture
9
Wind
Prevailing winds are onshore from the east, from which direction persistent light winds blow throughout the dry season. During the middle months of the year the less stable conditions may produce winds of high velocity; tropical cyclones may occur with associated hurricane-force winds. From October until the end of the dry season, winds remain predominantly easterly to northeasterly, except for occasional spells lasting three-four days during which cool winds blow from the north. Wind is an important factor in fire hazard, and hurricanes can cause severe mechanical damage to forest trees.
GEOLOGY
The southern Coastal Plain is a wave-cut platform which is overlain by marine deposits of silt and medium to coarse sand derived from siliceous rocks of the Maya Mountains. According to Dixon (1956) the deposits north of the Swasey Branch are more recent than those to the south of it. As far south as the Swasey Branch, Dixon has not mapped the underlying rock. South of that, the coastal deposits are underlain by shales and sandstones.
True alluvium has been deposited in the shallow valleys cut by the water courses traversing the plain. Along the western edge of the plain where it adjoins the foothills are other alluvial deposits, the eroded remnants of old river fans.
A few limestone hills protruding above the surface of the plain are all that remain of the former limestone capping.
TOPOGRAPHY
The project area is a flat plain backed on the west by the foothills of the Maya Mountains and traversed by a number of streams and rivers flowing eastward from the mountains to the sea. The low land adjoining the coast consists of swamps and lagoons. Inland, the land surface rises gently along the alignment of a former shoreline to the main terrace which is about 15 m (50 ft) above sea-level. Inland again, both on the surface of the plain and at the base of the hills, there are more small changes in elevation associated with yet other old beach terraces.
Close to the hills the topography of the plain tends to be more undulating, especially near to where watercourses emerge from the hills and former alluvial fans have been subjected to peneplanation. The boundary between plain and foothills, about 30 m (100 ft) above sea-level, is abrupt, and the hills themselves are steep and dissected by deep valleys. The gradient in ground elevation from the coast to the base of the hills has been rendered virtually imperceptible over most of the plain by erosion and the levelling of the old beach terraces.
Apart from the shallow valleys cut by the watercourses, most of the plain proper is devoid of macrorelief. There are a few small limestone hills protruding steeply from the plain between the Swasey Branch and Deep River. A small group of these, called the Sierritas, includes one hill which rises to 210 m (700 ft). There are one or two instances of the peripheral erosion of a limestone hill having proceeded to a point below the level of the surface of the plain with the resulting formation of a moat-like depression around the base of the hill. Some more rolling hills which appear to be composed of or heavily overlain by gravel occur at Las Lomitas, just south of the Sierritas.
Drainage north of the Swasey Branch is mainly by means of small watercourses which rise in the foothills and form a subparallel pattern of drainage where they cross the plain. The valleys occupied by the smaller streams tend to be steep-sided while those of the one larger river -the South Stann Creek, which drains the eastern end of the Cockscomb Basin - is more gently sloping.
South of the Swasey Branch most of the smaller creeks have been captured by the major rivers traversing the plain. The density of drainage is lower than in the northern part and the pattern of drainage is typically subdendritic to centripetal. The Swasey Branch drains most of the Cockscomb Basin and the Bladen Branch drains the majority of the southern face of the Maya Mountains south of Richardson Peak. The third major river, Deep River, is fed partly from the foothills but largely from the plain itself.
10
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J I F I M I A I M ' J ' J I A ' S ' O ' N I D
Stann Creek Highest Max. Mean Max. Mean Min. Lowest Mln.
) I F I M I A | M I J I J I A , S | O ' N I D
Punta Gorda
Rgure 2 Temperature at Stann Creek and Punta Gorda, based on years for which data are available in the period 1933-70
r.h. %
1 0 0 - ,
9 0 -
6 0 -
5 0 -
3 0 -
10
J ' F ' M ' A ' M ' J ' J ' A ' S ' O ' N ' D
Stann Creek
r.h. %
100—1
9 0 -
70 —
10 -
J ' F ' M ' A ' M ' J ' J ' A ' S ' O ' N ' D
Punta Gorda
Rgure 3 Mean monthly relative humidity at Stann Creek and Punta Gorda, based on years for which data are available in the period 1933-70
D.O.S. 3152E Prepared by Directorate of Overseas Surveys 1974
Because of the prevailing flatness of the plain, microrelief has greater significance than it does in hillier terrain. There are numerous seasonal lagoons and swamps formed in depressions of about 1 m depth. In places a terraced microrelief has been produced by the movement and deposition of sand by surface runoff.
WATER
The rivers and streams in the southern Coastal Plain provide water of good quality throughout the year. There is no true watertable on the plain except at depth, only a perched watertable which may be absent during the dry season and at or above ground level during wetter periods of the year. The boundaries of the seasonal lagoons expand and contract according to the prevailing level of the perched watertable. The water in the lagoons and surface floodwaters, as is that in the rivers, is clean and potable.
Although the gradient of the land surface is slight, it is sufficient to ensure the gradual surface runoff of floodwater into creeks and swamps. The slow lateral movement of a large body of water causes sheet erosion. It may be a matter of days or weeks before floodwater drains off.
Because of the size and nature of their watersheds, the main rivers crossing the plain are liable to sudden and severe flooding. The swasey Branch, South Stann Creek and Sittee River appear to be most liable to flash-flooding.
SOILS (C J Birchall)
The soils of the southern Coastal Plain are formed on a variety of parent materials and have been classified and mapped by Wright et al. (1959). The area between Sittee River and Deep River is occupied mainly by soils of the Puletan suite developed on coastal deposits of sand and clay. Alluvial soils of the Monkey River, Melinda and Ossory suites have been developed in the valleys of streams flowing across this area. The area south of Deep River is occupied by soils of the Toledo suite developed on shale and sandstone. Towards the west of the project area small areas of soils formed on foothills of granite, quartzite, shale and limestone are found. The coastal fringe has soils associated with mangrove swamps behind discontinuous sand beaches.
The soils of the Puletan suite cover an extensive area of the southern Coastal Plain. They range from sands to clays, with the heavier textured types occurring in poorly drained low-lying areas of clay and silt alluvium, and comprising the Haciapina and Sennis sets. The sandier soils support a pine savanna vegetation, whereas soils with a clay texture are characterised by low broadleaved forest. Between these two extremes sandy clay loams and sandy clays support a variety of transitional vegetation types.
The sandy Puletan soils vary in texture from sand to sandy loam. They exhibit a two-decked profile typical of planosols, with a well-drained sand or sandy loam topsoil grading into a gritty clay impermeable subsoil at between 0.6 and 1.2 m (2-4 ft). The topsoils are leached and white or light grey in colour with a very thin accumulation of organic matter on the surface. The subsoil is strongly mottled light grey, red and yellow-brown. This marked differentiation within the profile is less pronounced in soils with a sandy-clay-loam texture and absent altogether in the clay soils. The latter are vertisols and tend to be dark in colour, with self-mulching properties giving rise to a hummocky microtopography and cracking surface horizons. The subsoil is poorly drained and strongly mottled, and slickensided surfaces are common. Better drained, i.e. silty soils, occur along minor creeks.
The fertility of the sandy Puletan soils has been much reduced by the leaching of nutrients. Clay, too, has been translocated, resulting in a very low cation exchange capacity. The reaction of the topsoil is acid and the soils are low in nutrients, particularly phosphate. Poor drainage in the subsoil gives rise to waterlogging and the soils are often flooded in the wet season, whilst in the dry season the topsoil rapidly dries out and becomes desiccated. Small-scale movement of soil material may occur during the wet season on gentle undulations due to sheet erosion. The clay soils of the Puletan suite have a neutral reaction and are low in nutrients, although they have not been leached. As they occur in lowlying sites and are slow to drain, these soils are usually flooded to a depth of several feet in the wet season.
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The alluvial soils, occurring in narrow bands moving north-west to south-east across the area, have been formed from a variety of parent materials. Soils of the Monkey River suite occur along the major drainage system of Monkey River and along minor creeks farther north. They are formed from recent and contemporary deposition of material derived from limestone, granite, shale and quartzite, and horizon differentiation is poorly developed. The soils are silty loam to sandy silt loam in texture, greyish brown to brown in colour with fair to good natural drainage and slightly acid reaction. Soils of the Hondo subsuite are developed on material still being laid down in ponded areas near the mouths of South Stann Creek and Monkey River. Although they have high fertility these silty clay loam soils are flooded during the wet season.
Soils of the Melinda suite occur in patches to the west of the project area and are formed on fan material derived from granite and shale. They are brown sandy loams with mottled gritty clay subsoils and acid reaction. Adjacent to South Stann Creek, soils of the Canquin set derived from quartzites, shale, sandstone and granite occur. They have a sandy silt loam to sandy clay loam texture and exhibit a fair degree of profile development. The soils are deep and drainage is mainly good, although nutrient reserves are only moderate.
Alluvial soils of the Ossory suite occur adjacent to the lower reaches of the Sittee River and are derived from quartzites. These fine sandy silt loams are freely drained and low in fertility. Soils of the Governor subsuite are found between the Trio and Bladen branches of Monkey Rivers. These soils are formed on a high terrace and fan from material derived from shales, quartzite and porphory. The soils are loam textured and show little profile development. Drainage is good, fertility moderate and reaction neutral. Granodoro sandy silty clays are formed on old alluvium between the Swasey and Bladen branches of Monkey River. These soils are leached and infertile with a poorly drained subsoil.
Soils of the Toledo suite occur in the southern part of the project area as the Machaca complex. These soils are generally of low natural fertility and are slow to drain. They vary from grey and brown sandy clay loams on sandstones to clays on shale. On higher areas better drained dull brown stony clay soils occur. Jacinto sandy clay loams of very low fertility and poor drainage occur in association with Machaca soils developed over non-calcareous sandstone.
On the foothills in the west of the project area, soils of the Stopper, Ossory and Cabro suites occur, formed on granite, quartzite and limestone respectively. The Stopper soils are coarse sandy clay loams, gritty clay loams, gritty loams and loams, and fertility is generally fairly high with adequate reserves of potash, although phosphate contents are low and reaction is acid. Drainage tends to be fairly slow because of the heavy texture, except in the Stopper loam where drainage is good. Soils of the Ossory suite are shallow stony and clay loams, are low in fertility and occur on acid rocks on steep and precipitous country. Shallow brown and grey stony clays of the Cabro set occur on steep rugged limestone country.
The coastal fringe is occupied by a narrow strip of discontinous Turneffe coarse sand similar to that present on offshore cays and other exposed areas. Behind this lie extensive areas of mangrove swamp with Ycacos sandy peat and peaty sand soils. The coarse sand soils are of low fertility and excessively drained whilst the mangrove soils are saline and permanently waterlogged.
VEGETATION
Three broad types of vegetation may be recognised in the southern Coastal Plain: savanna, broadleaved forest and mixed pine/broadleaved forest (locally called Broken Ridge). The coastal fringe vegetation is not discussed here as it has no relevance to the inventory of the pine resource.
Savanna
This consists typically of a coarse sward of bunch grasses and sedges with scattered overmature pine (Pinus caribaea); palmetto (Acoelorraphe wrightii) occurs singly or in clumps. Other small trees, shrubs and suffrutices may be present as a discontinuous understorey. Prominent among these are various species of the Melastomaceae, species of oak (Quercus spp.) and craboo
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(Byrsonima crassifolia). Other characteristic species, as recorded by Hunt (1970), include Savannah white poisonwood (Cameraria bclizensis), Coco plum (Chrysobalanus icaco). Calabash (Crescent ia cujete), Yaha (Curatella amer.icana), and (Ximcnia amcricana).
The floristic and physiognomic features of the pine savanna vary with a number of environmental factors, among which drainage and the incidence of fire appear to be the most important.
The most complete study of the Central American savannas is that by Beard (1953) who defines savanna as:
" a plant formation of tropical America, comprising a virtually continuous, ecologically dominant stratum of more or less xeromorphic herbs, of which grasses and sedges are the principal components, with scattered shrubs, trees or palms sometimes present The essential point is that the herb stratum is ecologically dominant."
Beard considers that the vegetation of all tropical American savannas is sufficiently homogeneous for them to be regarded as a single formation. He recognises four main phases, open, orchard, palm and pine, with two fringe types, sedge savanna and high grass savanna. Beard (1944, 1953), Hunt (1970) and others, observe that the distribution of the different savanna phases appears to be determined by the drainage characteristics of the site. This is in line with the comments made above on the Puletan soils of the southern Coastal Plain. Beard's orchard and pine phases are characteristic of the dry end of the spectrum and are found on the Puletan sands. The open and palm phases are associated with conditions of impeded drainage and correspond to the 'sabana' described by Bartlett; they occur on the Puletan sandy loams and clay loams. The pattern may be altered by fire. Hunt regards Beard's high grass savanna as transitional between savanna and broadleaved forest, as it occurs at the edges of forest and is less readily and less frequently burned than the other savanna phases.
Hunt comments on the misleading appearance of uniformity of the herb stratum which conceals a considerable variation in species composition, depending on drainage. Only the extremes of wet and dry conditions are conspicuous. The dry extreme is characterised by Trachypogon angust ifolius and Paspalum pect inatum and the wet extreme by Mesosetum f iIifolium and Rhynchospora globosa.
On the poorer drained savannas, pine is stunted and sparse and the frequency of other woody species is also much reduced, except for clumps or more extensive blocks of Acoelor raphe (Beard's palm phase), Quercus and locally abundant Cameraria. Bartlett (1935) suggests that the growth of pine may be inhibited by a high concentration of salt in the soil. The very open type of savanna occurs mainly along the eastern edges of the project area on the lower-lying terraces descending towards the sea.
Under conditions of better soil drainage and a lower incidence of fire, a denser stocking of both pine and other woody species occurs. Eventually this better stocked savanna (Beard's orchard and pine phases) merges into Broken Ridge. There are extensive areas of pine savanna that is savanna with a woody component predominantly of pine - although the density of pine is very low.
Orchard savanna is distinguished by having a considerable stocking of woody species other than pine. Two distinct variants are those described by Bartlett as 'nanzal' and 'encinal' . Nanzal is distinguished by the predominance of craboo (Byrsonima crassifolia). Encinal is pure oak woodland and occurs in the form of isolated, well-defined islands. The trees comprising the oak woodland may be of a considerable size with well-developed bushy crowns. Ground cover under the oak is sparse or absent and a considerable proportion of the ground surface consists of exposed white sand. Patches of encinal occur particularly in the vicinity of Mango Creek.
Broadleaved Forest
Strips of broadleaved gallery forest occupy the river valleys. The strips associated with the major rivers are substantial and extend as broad swathes several hundred metres wide. The riparian broadleaved forest on the plain merges with the more extensive blocks of broadleaved forest in the foothills.
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The physiognomic and floristic characteristics of the broadleaved forest are variable. At its most developed it is Cohune Ridge, that is, high forest dominated by the cohune palm (Orbignya cohune). This type of forest has an open structure near the ground, with few understorey and shrub species because of the shade cast by the top canopy. Cohune Ridge occurs along the major rivers, chiefly upstream towards the foothills of the Maya Mountains. At the other extreme, broadleaved forest may be only low thicket, with emergent small trees reaching a height of 10-15 m (30-50 ft). There may be a sparse herbaceous ground cover, and cutting grass (Scleria bracteata) is frequently present. This type of forest occurs along the western edges of the plain towards the foothills and on some of the alluvial fans, between the Trio and Bladen Branches, for example.
Merchantable species occurring in the broadleaved forest of the Coastal Plain include mahogany (Swietenia macrophylla) and rosewood (Dalbergia stevensonii), both of which are exploited on a small scale. Rosewood is of importance in the vicinity of the Bladen Branch of Monkey River and Deep River.
Mixed Pine/Broadleaved Forest
This type of vegetation (Broken Ridge) is transitional between broadleaved forest and pine savanna and falls within the marginal forest category described by Hunt (1970).
Broken Ridge occurs on the better drained soils which are capable of supporting both pine and broadleaved species, the balance between the two apparently being determined by fire. In the absence of fire, pine savanna becomes Broken Ridge which in turn becomes broadleaved forest. In physiognomy there is a gradation from the early transitional vegetation, having an open structure without canopy closure and with trees and shrubs of various sizes, to the more uniform and continuous broadleaved thicket and woodland with an overstorey of overmature pine.
Floristically, Broken Ridge is very variable, the species composition probably depending particularly upon soil drainage, as well as on other factors. More detailed descriptions of the various plant associations which are included in this category, and of the Coastal Plain vegetation in the Belize River area, are given by Jenkin et al. (in preparation). Common woody species, apart from pine and various Melastomes, are AcoeJorraphe wrightii, Byrsonima crassifolia and Quercus spp. As Broken Ridge develops, trees more typical of true broadleaved forest, such as negrito (Simaruba glauca), tend to emerge from the low canopy. Broken Ridge thicket does not cast a dense shade and is frequently laced with Scleria bracteata.
Savanna Development and the Role of Fire
The origin and maintenance of the Central American savannas has been the subject of considerable speculation and study. A frief review of the subject is given elsewhere by Johnson and Chaffey (1974) in relation to the Mountain Pine Ridge, which is the principal upland pine savanna in Belize. Repetition here is avoided except in so far as is necessary to draw inferences which relate specifically to the southern Coastal Plain.
Broadly, two main theories of savanna development have arisen. On the one hand, authors such as Charter (1941) and Beard (1953) have attemped to explain savanna as a consequence essentially of edaphic factors, especially soil drainage. In contrast and more recently, the pine savanna of the Miskito Coast - the largest area of Pinus caribaea savanna in Central America and similar in many respects to the Coastal Plain of Belize - has been described as a fire disclimax which, in the absence of fire, reverts to broadleaved forest (Munro, 1966; Taylor 1962). The same view is held by Luckhoff (1964) in relation to most of the Caribbean pine savannas in Central America, although he observes that the pine savanna of the Coastal Plain in Belize appears to be determined exclusively by soil characteristics. Budowski (1956) and Parsons (1955), the latter with reference to the Miskito Coast, envisage savanna development as a consequence of soil degradation which, in turn, is the result of the removal by fire of former broadleaved forest.
Authors subscribing to either view have tended to see fire as an influence of man and have discounted lightning as a cause. In Belize (and elsewhere in Central America, vide Beard, 1953) the degree of adaptation of the vegetation to fire is such that it seems doubtful whether it could have occurred wholly since man's arrival in the Americas, which Beard quotes as being
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between 10 000 and 25 000 years ago. In the uplands of Belize, it is well established by observation that lightning- caused fires are frequent in pine savanna and occur occasionally in broadleaved forest. Fire records are not available for the southern Coastal Plain, although Wolffsohn (1967) reports that lightning-caused fires are unknown there.
Over most of the southern Coastal Plain, where drainage is poor both externally and internally -the result of topography and the sand-over-clay savanna soils - it seems likely that fire is of much less significance in maintaining the savanna (whatever its origin) than on better sites. Certainly, for practical purposes, the immediate problem on these areas is not the possibility of a return to broadleaved vegetation but the failure to achieve regeneration of pine because of recurrent fire. On the more deeply draining soils on the plain and in the adjacent foothills, where fairly rapid invasion by broadleaved forest can occur, fire is probably of decisive importance. Here, Luckhoff' s conclusion that the development of Broken Ridge is the consequence of the prolonged absence of fire is almost certainly correct.
Butt and Stem Decay in Standing Pine
The pathology of Pinus caribaea in Belize has been discussed by Etheridge (1968) and by Johnson and Chaffey (1974). Of importance in relation to the present inventory of the southern Coastal Plain is the occurrence of stem and butt decay, the incidence of which is high in mature pine. Fire sears are the commonest site of infection. Williams (1965) records primary infection through fire scars by the fungus Lentinus pallidus, which causes cubical brown rot. Etheridge lists nine further species of wood destroying fungi isolated from pine in Belize. Rotten heartwood commonly becomes infested by the termite Coptotermes niger, primary termite attack being precluded by the high resin content of the wood.
FAUNA*
Among the larger mammals, the only species commonly seen on the open savanna is a deer,, (Odocoileus truei). This is hunted for meat, as are armadillo (Tatusia spp.), gibnut (Coelogcnys paca) and the two wild pigs, peccary (Dicotyles tajacu) and warrie (D. labiatus), all of which are found more commonly in the broadleaved forest and Broken Ridge. Four species of cat occur in the area and are hunted for sport, which is commercially organised. These are jaguar (Felis onca), puma (F. concolor) ocelot (F. padalis) and tiger cat (F. glaucula yucat.cn ica). Other mammals worthy of note are tapir (Tapirella bairdi), kinkajou (Potos flavus), quash (Nasua nasica), fox (Urocyon cinereo argentus), bush dog (Galictis barbara), various anteaters (Tamandua spp.) and oppossums of the genera Caluromys, Didelphis, Uarmosa and Philander ,
Birds which are hunted for meat are the curassow (Crax rubra rubra), guan (Penelope purpurasccns purpurascens) and chachalaca (Ortalis vetula intermedia). Two other conspicuous bird species are the oscellated turkey (Meliagris ocellata), which is protected (although formerly a game species), and the John Crow or turkey vulture (Cathartes aura).
Among insects, the termite Coptotermes niger is important in relation to pine, although termite infestation of trees is always secondary to fungal attack which is normally effected through fire scars (Williams, 1965).
Scolytid bark beetles are a serious pest of Pinus caribaea in Belize and neighbouring territories. The most important species is probably Dendroctonus frontalis Zimm. (Etheridge, 1968). The injurous effect of D. frontalis is due to the fungus Ceratocystis sp. which the insect transmits. Fungal infection of a tree cannot only prove fatal but also degrades the timber by staining the sapwood blue.
*The notes given here are based largely upon the authors' own observations and impressions and are not intended to be regarded as complete or authoritative. The principal source of specific names consulted in writing these notes is Wright et al. (1959).
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A shoot borer, Rhyaconia frustrana Comstock, is recorded as affecting P. caribaea in Belize by Loock (1950) and Browne (1968) but its importance, if any, in the Coastal Plain is not known.
Finally, no account of the fauna of the southern Coastal Plain would be complete without mention of the blackfly (Simulium sp.). Fortunately, although the superabundance of Simuliids can be very discomforting, the insect is not known to carry disease.
HUMAN ASPECTS
HISTORY
The infertility of the savanna soils discouraged cultivation of the project area during the period of the Maya civilisation (300 BC - 900 AD). Except for subsistence farming along the coastal settlements, the southern Coastal Plain remained largely uninhabited until the late 19th century.
Banana production was important in the early 20th century. Leafspot and Panama disease, marketing difficulties, and a shortage of land suitable for cultivation contributed towards a decline in the export crop in 1937.
The export of coconuts grew in importance along the coast during the early 20th century and continues to date.
Little use has been made of the foothills edging the Coastal Plain. The absence of limestone prevented their settlement by the ancient Mayas. In more recent times, the use of the foothills has been limited by the paucity of commercially desirable tree species. Early settlers ignored them because of the absence of logwood (Haematoxylon campechianum) and chicleros (tappers of chicle, an exudate from which chewing gum is made) have been similarly disinterested in the area because of the absence of sapodilla (Manilkara zapota). More recently the foothills have been exploited for the small stock of mahogany (Swietenia macrophylla).
Afforestation of the pine savanna by planting was started in the southern Coastal Plain in the late 1940s. Between 1949 and 1952 more than 90 ha (230 ac) was planted annually in the area which subsequently became the Mango Creek Forest Reserve, and afforestation at a rate of 40 ha (100 ac) per annum was maintained until 1959. Savannah Forest Station developed to serve both as a base for the planting programme and as a fire-fighting station.
Forest reservation dates from 1941, when the Deep River Forest Reserve was gazetted. Mango Creek and Swasey-Bladen Reserves followed in 1960. Fire protection was practised throughout these years, in so far as equipment and accessibility permitted, and by 1960 the whole of the southern Coastal Plain was subject to some degree of fire protection. Fire lookout stations had been constructed at six points and fire-fighting organisations had been established at Savannah Forest Station, inside the project area, and at Melinda, the Divisional Forest Office near Stann Creek. The policy towards fire control envisaged nuclei of manpower located at the fire lookouts with major support provided by the two forest stations, but this policy was never fully implemented. Following recommendations by Downie (1959) that the national allocation of funds to forestry should be halved, the fire control effort in the Coastal Plain was severely contracted. Newly built fire lookout stations which had had little or no use were abandoned. Fire control has never been particularly successful. Fire-fighting resources have been inadequate for the area involved and the local people' s habit of setting fire to the savanna in the dry season has never been successfully discouraged.
Air photography of most of the project area, at scale 1:16 000, was flown in 1956 and a forest-type map prepared from it. In the same year, ground enumeration was carried out and forest management plans prepared. Relevant records are no longer available.
In 1961, Belize was struck by Hurricane Hattie, which caused severe damage to the country's forests. Accounts are given in the 1961 Annual Report (British Honduras Forest Department, 1962) and by Lindo (1967).
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The eye of the hurricane, with wind speeds of 240-370 km/h (150-230 mi/h) moved south-west about 25 km north of Sittee River. Susceptible trees in the northern part of the project area had recently been blown over by two minor hurricanes. Pine trees up to 25 cm d.b.h. were sufficiently supple to survive the high winds. Damage was severe south of the Swasey Branch, where the pine was only then being exploited; here, windthrow averaged about 50% and was as much as 80% in places.
Debris left by the hurricane was such that the risk of fire was greatly increased and legislation was introduced to control entry into most of the southern Coastal Plain. North of the Swasey Branch, in the former Mango Creek Forest Reserve, controlled burning was conducted in order to pre-empt the possibility of uncontrolled fire (British Honduras Forest Department, 1963). Timber salvaging operations were encouraged by the temporary waiver of royalty, which resulted in a considerable increase in the output of sawn lumber.
In the late 1960s, horticultural operations were started near Savannah Forest Station, and in 1969 Mango Creek Forest Reserve was de-reserved in order to make the whole area available for horticulture.
FOREST EXPLOITATION
Exploitation of the southern Coastal Plain dates back to the 1920s, when pine was exported from All Pines, long since abandoned. Hummel (1921) attributes the reluctance to exploit pine at that time to the lack of knowledge of its qualities. Logging on a large scale, with sawmills at Mango Creek, started around 1945, and operations moved progressively southwards once the areas close to Mango Creek were logged out.
Quantitative records of timber removed are not available. Obtaining a sustained yield was not seriously attemped, partly because of a reluctance to impose restrictions upon a developing and successful industry. Such restrictions could have been effective if introduced in the late 1940s (British Honduras Forest Department). By 1961, the year of Hurricane Hattie, most of the southern Coastal Plain had been exploited. The last commercially exploitable stands were cut in 1966 (British Honduras Forest Department, 1967).
The question of the feasibility of establishing a pulp and paper industry, possibly based on pine in the southern Coastal Plain, was raised in the 1950s. From a brief survey, le Cacheux (1957) found that the existing pine resources were insufficient for such an industry. He concluded that supplies of pulp wood sufficient to maintain a pulp industry might become available in the late 1970s, provided that afforestation in the southern Coastal Plain continued as planned. In the event, the Downie report (1959), resulted in the abandonment of the planting programme.
In 1963, a wood naval stores industry was started at Big Creek, near Mango Creek. Resin was extracted from the pine stumps left by timber working and exported to the United States. For reasons which are not clear the enterprise was not as successful as had been anticipated and operation ceased in 1965. A lasting benefit is the road system which was constructed on the pine savannas and was subsequently of value for fire control.
In recent years only one small sawmill just south of the Swasey Branch has continued to take pine in the project area. Small volumes of rosewood are exported in the round, and other hardwoods are sawn at Medina Bank on Deep River.
POPULATION
Figures from the 1970 population census for settlements in the areas between Sittee River and Deep River are shown in Table 7. These figures relate to settlements of more than 50 persons and therefore slightly underestimate the population.
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TABLE 7 Provisional figures from 1970 population census for settlements between Sittee River and Deep River
Settlement Total population Males Females Households
Alabama
Independence
Mango Creek
Monkey River
Placentia
Savannah
Seine Bight
64
225
602
276
290
71
500
33
111
306
143
148
43
220
31
114
296
133
142
28
280
16
37
100
n. a.
56
17
118
Total 2 028 1 004 1 024 n. a.
n.a. = not available Source: Belize Ministry of Finance and Economic Development
Except for Alabama, which is a banana estate, and Savannah, a forest station, the settlements listed are coastal and their populations largely depend on agriculture and fishing. Placentia and Seine Bight village are effectively outside the project area as the narrow spit of land on which they are situated is separated for most of its length from the mainland by the Placentia Lagoon. The coastal town of Monkey River is effectively excluded from the project area by virtue of being readily accessible only by sea and having no significant contact with the pine savannas.
A preponderance of males in Savannah, but not in the other settlements listed in Table 7, reflects the tendency for Forest Department employees to commute to the forest station for work but to maintain a permanent home elsewhere.
LAND TENURE
Most of the project area is Crown Land but two privately owned estates included in the inventory include about 4 220 ha (10 400 ac) of pine land. South of the Swasey Branch, the Crown Land inventoried consists of forest reserves. North of the Swasey Branch the land remains in Crown ownership although it has been de-reserved and is leased for private use. Administration of the forest on Crown Land is the responsibility of the Forest Department.
CURRENT LAND USE
The principal uses of land in the project area are for agriculture and timber production. Hunting and recreation are secondary. (Timber production is discussed elsewhere).
Agriculture
The agricultural use of the area is of three basic kinds.
1. Subsistence agriculture by traditional methods of shifting cultivation, or 'milpa' .
2. Longer-term agriculture based on fruit, notably citrus and bananas.
3. Large-scale production of horticultural annual crops by shifting cultivation.
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Subsistence Agriculture Cultivation of both annual and perennial crops is practised along the lower reaches of Sittee River and Monkey River. Crops include rice, maize, beans, cassava, yam, coconut and mango.
Traditional farming is essentially on a subsistence basis although a small amount of surplus production may be sold for cash. This type of agriculture is restricted in its distribution by soil fertility and accessibility to areas other than those most important for timber production; there is therefore no conflict between the two uses in the demand for land. There is a problem, however, in the tendency for runaway milpa fires to spread to the forests on the savanna.
Coconuts are grown commercially on the coastal beaches for export by small-scale operators using traditional methods.
Fruit farming Citrus farming occurs around South Stann Creek and a sizeable mango estate has been established near Mango Creek. Although some fruit is sold for local consumption most citrus is taken by two citrus factories in Pomona Valley, near Stann Creek for the United States market.
Work is going ahead to revive the banana industry with a nucleus of operations at Cowpen, and new roads have been constructed to improve access to Riversdale for shipping. There is no conflict between fruit farming and forestry in the demand for land.
Horticulture There was considerable development in the production of cucumbers, water melons and tomatoes on the pine savanna soils until 1973. Crops were exported to the United States when home-produced crops of the same kind were in short supply there. As the market for the imported product lasted for only a short period each year, the timing of the operation was critical. The operation was abandoned in 1973.
Horticulture and timber production were competing for land, but in 1969 the former Mango Creek Forest Reserve was de-reserved and leased for the cultivation of horticultural crops.
Hunting and Recreation
Several animal species are hunted for meat which, with fish, forms an important item in the diet of the agricultural population. Conflict with timber production arises from the practice of subsistence farmers setting fire to the pine savanna in order to attract game animals to the fresh growth which follows a burn. If the dependence on wild animals as a source of meat could be reduced by greater reliance on domestic livestock, the fire hazard could be greatly reduced.
Jaguar and other cats are hunted commercially for sport. Other recreational use of the area is minimal, except where resort development has occurred along the coast at Seine Bight and Placentia.
COMMUNICATIONS
Road communications are poor. The area is traversed by the Southern Highway from Stann Creek to Punta Gorda, which remains passable for four-wheel drive vehicles throughout the year except for short periods, usually of a few hours' duration, when flooding occurs at river crossings.
During the dry season, access by vehicle is possible over much of the coastal plain. Logging roads dating from the 1950s, tracks made more recently for oil prospecting and old railway alignments all remain serviceable, and in places it is possible to drive across the open savanna. In wet seasons, vehicular access is complicated by surface floodwater. The ground surface is such that loss of traction in wet conditions is often less of a problem than mechanical failure.
The coastal settlements are readily accessible by sea but only those in the Mango Creek area can be easily reached from other parts of the mainland. The main rivers are navigable by dory (small canoe) across the width of the plain and for some distance into the foothills.
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There are airstrips suitable for light aircraft at Savannah Forest Station, Mango Creek and near Mango Creek. Savannah is served by scheduled daily flights between Belize City and Punta Gorda.
Radio communication is maintained by the Forest Department, with radio telephone equipment at Cabbage Haul Fire Lookout and Savannah. Cabbage Haul is the relay station for the Divisional Forest Office at Melinda and can communicate with Belize City, Belmopan, and the other Forest Department relay station at Cooma Cairn. Departmental vehicles are equipped with mobile radio telephone sets.
MARKETS
Markets for pine lumber are now exclusively local, although considerable quantities were previously exported. Sawn pine lumber was sold in May 1971 at a government-controlled price of 17 cents per bdft (i.e. S"72/m3, S2/ft3)*- The sawn lumber production from the one small pine mill still operating in the project area is disposed of in Stann Creek and Belize City. Hardwood production is also marketed locally, except for rosewood which is exported in the round.
• Bgl = £0.25
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PART 4. OBJECTIVES AND METHODS
OBJECTIVES
The broad objective of the forest inventory was to quantify the growing stock of pine in the project area. The type of information to be collected and the subsequent treatment of the data were governed by the generally low rate of stocking, which was evident from air photography, and by consideration of management and utilisation, the latter especially in relation to pulp. The detailed objectives are defined as follows.
A. Estimation of Standing Volume of Pine
1. To estimate the standing volume of pine in blocks specified by the Forest Department and in the project area as a whole. The precision of estimate required was + 20% at 95% probability, except where preliminary sampling revealed such a low stock that it was agreed with the Forest Department to curtail sampling and accept less precision.
The minimum size of material for which volume estimates were required, south of the Swasey Branch, was 7.6 cm (3.0 in) d.b.h. and north of the Swasey, 12.6 cm (5.0 in) d.b.h. The difference in the requirements for the two parts of the project a.rea was due to the recent de-reservation of the pine area north of the Swasey Branch (i.e. the former Mango Creek Forest Reserve). With the then possibility that much of this former reserve would in the near future be cleared for horticultural use, and assuming that a minimum commercially exploitable size for pulp of 25,4 cm (10.0 in) existed, the project only dealt with timber that was already or would very soon be exploitable for pulp. It was decided to quote volume estimates for the following size categories.
Block 1
d.b.h. >12.6 cm ( 5 0 in) d.b.h. >15. 2 cm ( 6 0 in) d.b.h. >25.4 cm (10 0 in)
Blocks 2 -3
d.b.h. > 7.6 cm ( 3 0 in) d.b.h. >15.2 cm ( 6 0 in) d.b.h. >25.4 cm (10 0 in)
On account of the high incidence of stem and butt rot the estimate of volume was required to incorporate some measure of defect, to permit the assessment of the standing volume of sound timber.
Private lands Separate volume figures were required for two areas of private land, the Hughes Estate and the Stopper, derived not from separate sampling of them but from the figures for the first blocks in which they lay. A third estate, Harvest Cay Works, was to be excluded in the presentation of results.
To show by means of stand tables the size class distribution for each of the four blocks. Stand tables were required particularly to indicate probable future recruitment of material to 25.4 cm (10.0 in) d.b.h. and above.
Assessment of Pine Regeneration
In order to assess the amount of pine regeneration by numbers of stems, classified by height, 'regeneration' was taken to comprise stems of less than 5 cm (2 in) d.b.h. The precision of estimate required was i 20% at 95% probability. For reasons given above, the area north of the Swasey was not sampled for regeneration..
Construction of a Pine Volume Table
To construct a single variable local volume table for Pinus caribaea.
23
D. Forest/Vegetation Type Mapping
To produce by airphoto interpretation a map of the project area showing the distribution of pine forest and pine regeneration according to a canopy density classification. The map was required both for planning the field sampling and for subsequent management.
SAMPLING BLOCKS AND STRATA
Originally the project area was divided into four blocks. It was agreed with the Forest Department that no field sampling should be done in Block 4 south of Deep River because of the paucity of pine and difficulty of access. Block 4 has therefore been merged into Block 3.
Vegetation type mapping was done by stereoscopic examination of air photographs of scale 1:15 000. Fourteen forest/vegetation types were recognised and mapped, of which seven were sampled. Pine forest types were distinguished on the basis of canopy density and by the presence or absence of a broadleaved understorey. The distinguishing characteristics of the forest/ vegetation types mapped are summarised in Table 8.
TABLE 8 Forest/vegetation types identified and mapped
Forest/vegetation type Distinguishing features
1. Pine forest
1. 1 1.2 1.3
( >70 Canopy closure % ( 40-70
( <40
2.1 Broadleaved forest* Without pine
2.2 Mixed pine/broadleaved forest
2.2/1.1 2.2/1.2 2.2/1.3 2.2/1.4*
( >r70 Pine canopy K 40-70 closure % ( ^4Q
Very scattered overmature pine overstorey
3. Grassland
3. 1* 3. 2
Without pine With pine seedlings and/or very scattered overmature pine
4. Swamp*
4.1* 4.2* 4.3*
Palmetto Grass Coastal and estuarine, including mangrove
5. Coastal strand* Beach vegetation, including coconut groves
'Types not sampled
SAMPLING OF TIMBER STOCKING
Sampling was carried out by means of randomly distributed sample plots. Each forest block was treated as a unit within which the sample plots were randomly arranged without consideration of their location within a particular forest/vegetation type, so permitting data to be subsequently combined in whatever ways might prove desirable for analysis.
The total number of plots sampled in each block was of the order of 100, each plot being 50 x 100 m (165 x 330 ft), having an area of 0.5 ha (1.2 ac) with the long axis aligned north-south.
24
Trees of all species were calipered and their d.b.h. recorded to the nearest millimetre as the mean of two measurements taken at right angles. In two of the blocks, trees of d.b.h. 5 cm (2 in) and over were recorded. In the third sampling block, from Sittee River to the Swasey Branch, trees of less than 12.6 cm (4.5 in) d.b.h. were not sampled.
It was agreed with the Forest Department that figures for the two areas of private land (the Hughes Estate and the Stopper) for which separate figures were required, should be derived from results obtained for the complete blocks of which they form a part, so they were not sampled as separate units. The approximate boundaries of the Hughes Estate, the Stopper and Harvest Cay works (to be excluded in presenting block volumes) are given on the forest 'type map.
REGENERATION COUNT
Pine regeneration of less than 5 cm d.b.h. was sampled by means of 0.1 ha (0.25 ac) plots, each 10 x 100 m (33 x 330 ft), aligned inside the western margin of the timber sampling plots. Stems were recorded and classified according to height. Three height classes were recognised, viz 0-1.5 m (0-5 ft), 1.5-3 m (5-10 ft) and over 3 m (10 ft).
Regeneration was sampled in only two of the three blocks sampled for standing volume. In Block 1 (Sittee River to Swasey Branch) regeneration was not sampled.
VOLUMETRIC MEASUREMENTS
Quantitative data for the construction of a local volume table for pine were collected from 167 randomly selected trees. Measurements were made of a sample of approximately 15 trees in each 5 cm (2.0 in) d.b.h. class up. to 70 cm (27.5 in) and the parameters measured as follows: diameter at breast height, butt diameter (15 cm, 5.9 in above ground), top diameter (10.0 cm, 3.9 in, overbark), mid-point diameter, height to top diameter and total height. Diameter measurements were made to the nearest millimetre, each measurement being taken both under and overbark, and recorded as the mean of two measurements at right angles, and height measurements to the nearest centimetre.
Allowance for the generally high incidence of butt and stem decay in the pine in the project area was effected through the volume table. Diameter measurements were made of rot, where it occurred, at each point at which stem diameter measurements were made. Rot diameters were similarly recorded as the mean of two measurements at right angles, and an estimate made of the length of stem affected by rot.
OTHER OBSERVATIONS
In addition to the quantitative sampling data collected at each sample point, stand condition, degree of canopy closure, situation, slope, aspect, drainage and underlying rock were also recorded.
25
PART 5. RESULTS OF THE INVENTORY
FOREST/VEGETATION TYPES
The distribution of the forest/vegetation types is shown on the maps accompanying this report and in Table 9.
TABLE 9 Area statement showing areas of sampled pine-bearing forest/vegetation types in three blocks
Forest/vegetation type
Block Pine forest Mixed pine/broadleaved forest Grassland
Block
1. 1 1. 2 1.3 2.2/1.1 2.2/1.2 2.2/1.3 3. 2
Block
ha ac ha ac ha ac ha ac ha ac ha ac ha ac
1* Sittee - Swasey 325 803 2 325 5 745 6 925 17 112 75 185 225 556 775 1 915 17 775 43 922
2 + Swasey - Bladen 25 62 325 803 2 525 6 239 75 185 350 865 825 2 039 1 800 4 448
3 Bladen - south of Deep River 208 514 327 808 1 830 4 522 942 2 328 725 1 791 1 227 3 032 5 891 14 557
Total all blocks 558 1 379 2 977 7 356 11 280 27 873 1 092 2 698 1 300 3 212 2 827 6 986 25 466 62 927
* including Hughes Estate and excluding Harvest Cay Works
+ including the Stopper
STAND TABLES
Stand tables showing numbers of stems per unit area and the distribution according to size class for grouped forest/vegetation types are given in Table 10. The forest/vegetation type groups used are the same as those used for computing standing volumes, described below. The d.b.h. classes shown in the tables each have a range of 5 cm (2 in). The smallest complete class for which figures are given for Block l is the 15 cm (5. 9 in) class which extends from 12. 6 cm (5.0 in) to 17.4 cm (6.9 in). For Blocks 2 and 3 the smallest complete class for which figures are given is the 10 cm (3.9 in) class (7.6-12.5 cm/3.0^4.9 in). Stems of 5.0-7.5 cm (2.0-3.0 in) d.b.h. are shown separately and are also included in the summary columns.
The 15 cm d.b.h. class is subdivided to show the numbers of stems equal to and above 15.2 cm (6.0 in) d.b.h. The 25 cm (9.8 in) class is subdivided to show the number of stems of 25.4 cm (10.0 in) d.b.h. and above. These subdivisions are necessary to permit the growing stock to be grouped into the imperial-unit size categories required for standing volume (described below); the size categories are included in the summary columns of the stand tables.
STANDING VOLUME
Volume figures are presented for three size categories of growing stock, as described in Part 4. Volumes were calculated for various groups of forest/vegetation types, rather than for each type separately, because of the large number of types identified. The three combinations of types for which results are presented are those found, by trial calculation, to give the lowest variance.
Tables 11 and 12 show the mean stocking for each group of forest/vegetation types. These figures are derived by converting stem numbers per unit area into volume per unit area by use of the local volume table (Table 13). Gross volume figures are given in Tables 14 and 15*.
*Mean volumes for Block 1 apply also to Harvest Cay Works (included in Block 1 for sampling purposes) The block area used to calculate gross volumes for Block 1 excludes Harvest Cay Works, which is thus excluded from the gross volumes given
27
TABLE 10 Stand tables showing numbers of stems of pine per unit area* and the distribution according to size class in groups of forest/vegetation types in three blocks*
Block Types Area ha
(ac)
d.b.b. c lass , cm (In) d. b. h., cm (in)
Block Types Area ha
(ac) d.b.h.
5.0-7.5 cm (2.0-3.0 in)
10 (3.9)
15 (5.9) 20
(7.9)
25 (9.8) 30
(U.8) 35
(13.8) 40
(15.8) 45
(17.7) 50
(19.7) 55
(21.7) 60
(23.6) 65
(25.6) 70
(27.6) 5.0 (2.0)
12.6 (5.0)
15.2 (6.0)
23.4 (10.0)
Block Types Area ha
(ac) d.b.h.
5.0-7.5 cm (2.0-3.0 in)
10 (3.9) «15.2
(6.0)
>(15.2) (6.0)
20 (7.9) <25.4
(10.0) >25.4 (10.0)
30 (U.8)
35 (13.8)
40 (15.8)
45 (17.7)
50 (19.7)
55 (21.7)
60 (23.6)
65 (25.6)
70 (27.6)
5.0 (2.0)
12.6 (5.0)
15.2 (6.0)
23.4 (10.0)
1 1.1:1.2; 1.3
9 575 (23 660)
n .s . n.s . 16.6 6.7
9.4 3.8
9.4 3.8
4.4 1.8
1.4 0.6
2.4 1.0
0.8 0.3
0.4 0.2
0.1 0.0
0.0 0.0
0.0 0.0
0.0 0.0
0.0 0.0
0.0 0.0
n.s . 45 18
28 11
5 2
1 2. 2/1. 1 2.2/1.2 2.2/1.3
1 075
(2 656)
n.s. n.s . 22.1
8.9
16.4
6.7
25.9
10.5
10.4
4.2
5.9
2.4
9.0
3.7
3.3
1.3
1.9
0.7
0.8
0.3
0.3
0.1
0.1
0.0
0.0
0.0
0.0
0.0
0.0
0.0
n.s. 96
39
74
30
21
9
1 3.2 17 775 (43 922)
n.s. n.s . 1.5 0.6
0.5 0 .2
0.7 0.3
0.5 0.2
0.7 0.3
0.5 0.2
0.8 0.3
0.0 0.0
0.0 0.0
0.0 0.0
0.0 0.0
0.0 0.0
0.0 0.0
0.0 0.0
n.s. 5 2
4 1
2 1
2 1. 1; 1. 2 2. 2/1.1 2. 2/1.2
775
(1 915)
71.9
29.1
60.9
24.6
18.9
7.6
12.4
5.0
30.0
12.1
11.9
4.8
10.0
4.0
18.1
7.3
7.0
2.8
4.5
1.8
1.5
0.6
0.5
0.2
0.9
0.4
0.3
0.1
0. 1
0. 1
0.0
0.0
249
101
177
72
97
39
43
17
2 1.3 2. 2/1. 3
3 350 (8 278)
77.0 31.2
63.0 25.5
8.0 3.2
4.6 1.8
10.4 4.2
5.4 2.2
4.2 1.7
6.3 2.5
2.2 0.9
1.3 0.5
0.6 0.2
0.3 0. 1
0.1 0.1
0 .1 0.0
0.0 0.0
0.0 0.0
183 74
106 43
35 14
15 6
2 3.2 1 800 (4 448)
14.7 6.0
6.8 2.8
1.3 0.5
0.8 0.3
2.5 1.0
2.2 0.9
1.0 0.4
2.4 1.0
0.8 0.3
0.4 0.2
0.2 0. 1
0.1 0.0
0.1 0.0
0.0 0.0
0.0 0.0
0.0 0.0
33 13
18 7
10 4
5 2
3 1. i; 1. 2; 1.3
2 365 (5 844)
47.3 19.1
67.5 27.3
13.8 5.6
9.0 3.7
12.9 5.2
6.8 2.8
4.5 1.8
6.6 2.7
4.2 1.7
1.5 0.6
0.8 0.3
0 .2 0.1
0.1 0.1
0.1 0.0
0.0 0.0
0.0 0.0
175 71
128 52
47 19
18 7
3 2. 2/1. 1 2.2/1.2 2.2/1.3
2 894
(7 151)
32.5
13.2
73.3
29.7
27.4
11.1
23.5
9.5
37.2
15.1
19.8
8.0
11.1
4.5
17.9
7.2
12.2
4.9
3.8
1.5
3.9
1.6
1.1
0.4
0.6
0.2
0.5
0.2
0.2
0.1
0.5
0.2
266
107
233
94
132
54
52
21
3 3.2 5 891 (14 557)
17.2 7.0
13.9 5.6
1.3 0.5
0.8 0.3
1.2 0.5
0.8 0.3
0.5 0.2
1.7 0.7
0.7 0.3
0 .2 0.1
0.1 0.0
0 .3 0. 1
0.2 0.1
0.1 0.0
0. 1 0.0
0.0 0.0
39 16
22 9
7 3
4 2
* Figures for both stems/ha and stems/ac have been rounded to the nearest 0. 1; th is accounts for some apparent anomalies in conversions of low stem numbers
x n.s. = not sampled
TABLE 11 Standing volume of pine per unit area, including defective timber, in groups of forest/vegetation types in three blocks*
Block Types Area
d . b . h . c l a s s *
Mean R e l i a b l e minimum e s t i m a t e
ha ac m 3 /ha f t 3 / a c m 3 /ha f t 3 / a c
b 9 .7 139 7.0 100
1 1. i ; l . 2; 1.3 9 575 23 650 c 8 .0 114 5 . 4 77
d 3 . 5 51 1.8 26
b 28.6 409 21 . 1 302
1 2 . 2 / 1 . 1 :2 .2 / 1 . 2 : 2 . 2 / 1 . 3
1 075 2 656 c 26. 1 373 18.7 267
17 775 43 922
d 15.7 223 9 .6 137
17 775 43 922 b 1. 8 26 0 . 5 7
1 3 .2 c 1.7 24 0 . 3 5
d 1.3 19 0 . 0 0
a 49.8 712 29.0 414
2 i - i ; i - 2 ; 2 . 2 / 1 . 1 - 2 . 2 / 775 1 915 c 4 5 . 5 650 25. 1 359 1.2
d 3 3 . 2 474 17.5 250 1.2
a 19. 2 274 15.3 219
2 1 . 3 : 2 . 2 / 1 . 3 3 350 8 275 c 15.8 226 12. 1 172
d 11. 1 159 8. 1 116
a 5 . 3 76 3 .6 52
2 3 . 2 1 800 4 448 c 4 .9 70 3 .2 46
d 3 .5 50 2. 1 30
a 24. 1 344 10.9 156
3 i . i ; i . 2 ; i . 3 2 365 5 844 c 19.9 285 7 . 4 106
d 13.7 196 5 .2 74
a 6 8 . 3 975 50 .8 726
3 2 . 2 / 1 . 1 : 2 . 2 / 1 . 2 : 2 . 2 / 1 . 3
2 894 7 151 c 6 2 . 3 890 4 6 . 2 660
d 44.0 629 30 .8 440
a 5 .2 74 2.8 40
3 3 . 2 5 891 14 557 c 4 .5 65 2 .2 32
d 3.9 56 2.0 28
* Figures This ac
for m3/ha have been rounded t counts for apparent anomalies
o the nearest 0. 1, thos m the conversions of s
»e for f t 3 / mall volun
'ac to the r aes
learest whole number.
X a > 7.6 cm (3.0 in) c > 15. 2 cm (6.0 in)
b > 12.6 en d > 25. 4 en
l ( 5.0 in) i (10.0 in]
29
TABLE 12 Standing net sound volume of pine per unit area, assuming maximum defect, in groups of forest/vegetation types in three blocks
R e l i a b l e Area Mean minimum
Block Types d . b . h . e s t i m a t e
ha ac \*± tXOO
tn3/ha f t 3 / a c m3/ha f t 3 / a c
b 9 . 2 131 6 .7 95
1 1. l ; l . 2 ; l . 3 9 575 23 660 c 7 . 5 107 5. 1 73
d 2.9 42 1.5 22
b 2 6 . 2 374 19.6 280
1 2 . 2 / 1 . l ; 2 . 2 / 1 . 2 : 2 . 2 / 1 . 3
1 075 2 656 c 24. 1 345 17.7 252
d 12.8 183 8 .0 114
b 1.6 23 0 . 5 7
1 3 .2 17 775 43 922 c 1.5 21 0 . 3 5
d 1. 1 16 0 . 0 0
a 4 4 . 2 632 25.9 370
2 1 . 1 : 1 . 2 : 2 . 2 / 1. 1 : 2 . 2 / 1 . 2
775 1 915 c 39 .9 571 22. 1 316
d 27.5 393 14.7 210
a 17.4 248 14.0 200
2 1 . 3 : 2 . 2 / 1 . 3 3 350 8 278 c 14.0 200 10.7 153
d 9 . 3 133 6 . 9 98
a 4 .8 68 3 . 3 47
2 3 . 2 1 800 4 448 c 4 . 4 62 2.9 41
d 3 .0 43 1.8 26
a 21.8 311 9 . 9 142
3 l . i ; i . 2 ; 1.3 2 365 5 844 c 17.6 252 6 . 5 93
d 11.4 162 4 . 3 61
a 60 .6 866 44. 1 630
3 2 . 2 / 1 . 1 : 2 . 2 / 1 . 2 : 2 . 2 / 1 . 3
2 894 7 151 c 55 .0 786 40 .7 582
d 36 .8 525 26 .3 376
a 4 . 4 63 2 . 3 33
3 3 .2 5 891 14 557 c 3 .8 54 1.8 25
d 3. 1 45 1.6 22
30
TABLE 13 Local volume for Pinus caribaea
d.b .h . Volume of
sound t rees* Confidence l i m i t s
for sound t r e e s Net sound volume
of defect ive t rees+
cm in m3 f t 3 ± m3 • ± ft3 ± m3 ± f t3
10
15
20
25
30
35
40
45
50
55
60
65
70
3.9
5.9
7.9
9.8
11.8
13.8
15.8
17.7
19.7
21.7
23.6
25.6
27.6
0.042
0. 112
0. 223
0.381
0.590
0.855
1. 177
1.562
2.011
2.528
3. 116
3.775
4.510
1.48
3.96
7. 87
13.45
20.83
30. 19
41.56
55. 15
71.01
89.26
110.03
133. 30
159. 25
0.005
0.014
0.027
0.055
0. I l l
0.204
0.341
0.18
0.49
0.95
1.94
3.92
7.20
12.04
0.376
0.512
0.690
0.912
1. 183
1.505
1.882
2.317
2.809
3.364
13.28
18.08
24.36
32.20
41.77
53. 14
66.45
81.81
99. 19
118.78
* Loge volume m3 underbark =2 .4 Loge d.b.h. cm overbark - 8.69
+ Defect volume = - 0.162 + 0.000267 (d.b.h. cm overbark)2
Defect negligible in trees of d.b.h. 25 cm (9.8 in)
The reliable minimum estimates quoted in Tables 11 and 12 and used to derive those given in Tables 14 and 15 are based on estimates of precision at 95% probability.
Separate estimates are given as follows:
i. Volume of standing timber, assuming all trees are sound ii. Net sound volume of standing timber, assuming maximum incidence of defect, obtained
by using the net sound volume figures for defective trees given in Table 13.
The reason for quoting both is that, although the conservative estimate of net sound volume may be the more useful statistic, the estimate which ignores defect is the more reliable of the two on account of the difficulty of adequately measuring defect in the field and the consequent absence of estimates of precision for net sound volume in the volume table.
Table 16 and 17 give summarised gross volumes for each block as a whole and for the three blocks combined. The minimum estimates given in Tables 16 and 17 are obtained by summing the reliable minimum estimates given in the preceding tables. The values obtained by summing reliable minimum estimates are almost certainly much lower than the actual values; true reliable minimum estimates for the project area as a whole have not been calculated because of the different combinations of forest/vegetation types used for calculation for the three blocks.
In Tables 16 and 17, the total project area volumes are given for two size categories only because of the difference between Block 1 and Blocks 2 and 3 in terms of the minimum size of tree measured.
31
TABLE 14 Standing gross volume of pine, including defective timber, in groups of forest/vegetation types in three blocks
Block Types
Diameter at breast height, cm (in)
Block Types Area Gross volume Reliable minimum estimate
Block Types Area >12. 6 (5.0) >15. 2 (6.0) >25. 4 (10.0) >12. 6 (5.0) >15. 2 (6.0) >25. 4 (10.0)
Block Types
ha ac ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3: '00 f t 3
1
1
1
2
2
2
3
3
3
1. l; 1.2 1.3
2 .2 /1 .1 2 .2 /1 . 1 2.2/1.2
3.2
1. l; 1.2 2 .2 /1 . 1 2.2/1.2
1.3 2.2/1.3
3.2
1. l; 1.2 1.3
2 .2 /1 . 1 2.2/1.2 2.2/1.3
3.2
9 575
1 075
17 775
775
3 350
1 800
2 365
2 894
5 891
23 660
2 656
43 922
1 915
8 278
4 448
5 844
7 151
14 557
9 288
3 075
3 199
32 887
10 863
11 420
7 660
2 806
3 022
26 972
9 907
10 541
3 351
1 688
2 311
12 067
5 923
8 345
6 703
2 268
889
23 660
8 021
3 075
5 171
2 010
533
18 218
7 092
2 196
1 723
1 032
0
6 152
3 639
0
1
1
1
2
2
2
3
3
3
1. l; 1.2 1.3
2 .2 /1 .1 2 .2 /1 . 1 2.2/1.2
3.2
1. l; 1.2 2 .2 /1 . 1 2.2/1.2
1.3 2.2/1.3
3.2
1. l; 1.2 1.3
2 .2 /1 . 1 2.2/1.2 2.2/1.3
3.2
9 575
1 075
17 775
775
3 350
1 800
2 365
2 894
5 891
23 660
2 656
43 922
1 915
8 278
4 448
5 844
7 151
14 557
>7.6 (3.0) >15. 2 (6.0) >25. 4 (10.0) >7.6 (3.0) >15. 2 (6.0) >25. 4 (10.0)
1
1
1
2
2
2
3
3
3
1. l; 1.2 1.3
2 .2 /1 .1 2 .2 /1 . 1 2.2/1.2
3.2
1. l; 1.2 2 .2 /1 . 1 2.2/1.2
1.3 2.2/1.3
3.2
1. l; 1.2 1.3
2 .2 /1 . 1 2.2/1.2 2.2/1.3
3.2
9 575
1 075
17 775
775
3 350
1 800
2 365
2 894
5 891
23 660
2 656
43 922
1 915
8 278
4 448
5 844
7 151
14 557
3 859
6 432
954
5 700
19 766
3 063
13 635
22 682
3 380
20 103
69 722
10 772
3 526
5 293
882
4 706
18 030
2 651
12 447
18 708
3 114
16 655
63 644
9 462
2 573
3 719
630
3 240
12 734
2 297
9 077
13 162,
2 224'
11 454
44 980
8 152
2 247
5 125
648
2 578
14 702
1 649
7 928
18 129
2 313
9 117
51 916
5 823
1 945
4 053
576
1 750
13 370
1 296
6 875
14 238
2 046
6 195
47 197
4 658
1 356
2 713
378
1 230
8 914
1 178
4 787
9 602
1 334
4 325
31 464
4 076
TABLE 15 Standing net sound volume of pine, assuming maximum defect, in groups of forest/vegetation types in three blocks
Block Types
Diameter at breast height, cm (in)
Block Types Area Gross volume Reliable minimum estimate
Block Types Area >12.6 (5.0) >15. 2 (6.0) >25. 4 (10.0) >12. 6 (5.0) >15. 2 (6.0) >25. 4 (10.0)
Block Types
ha ac ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 •00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3
1
1
1
2
2
2
3
3
3
1. l; 1.2 1.3
2 .2 /1 . 1 2.2/1.2 2.2/1.3
3.2
1. i; 1.2 2 .2 /1 . 1 2.2/1.2
1.3 2 .2/1 .3
3.2
1. l; 1.2 1.3
2 .2 /1 . 1 2 .2/1 .2 2 .2/1 .3
3.2
9 575
1 075
17 775
775
3 350
1 800
2 365
2 894
5 891
23 660
2 656
43 922
1 915
8 278
4 448
5 844
7 151
14 557
8 809
2 817
2 844
30 995
9 933
10 102
7 181
2 591
2 666
25 316
9 163
9 224
2 777
1 376
1 955
9 937
4 860
7 028
6 415
2 107
889
22 477
7 437
3 075
4 883
1 903
533
17 272
6 693
2 196
1 436
860
0
5 205
3 028
0
1
1
1
2
2
2
3
3
3
1. l; 1.2 1.3
2 .2 /1 . 1 2.2/1.2 2.2/1.3
3.2
1. i; 1.2 2 .2 /1 . 1 2.2/1.2
1.3 2 .2/1 .3
3.2
1. l; 1.2 1.3
2 .2 /1 . 1 2 .2/1 .2 2 .2/1 .3
3.2
9 575
1 075
17 775
775
3 350
1 800
2 365
2 894
5 891
23 660
2 656
43 922
1 915
8 278
4 448
5 844
7 151
14 557
>7.6 (3.0) >15. 2 (6.0) >25. 4 (10.0) >7.6 (3.0) »15. 2 (6.0) >25. 4 (10.0)
1
1
1
2
2
2
3
3
3
1. l; 1.2 1.3
2 .2 /1 . 1 2.2/1.2 2.2/1.3
3.2
1. i; 1.2 2 .2 /1 . 1 2.2/1.2
1.3 2 .2/1 .3
3.2
1. l; 1.2 1.3
2 .2 /1 . 1 2 .2/1 .2 2 .2/1 .3
3.2
9 575
1 075
17 775
775
3 350
1 800
2 365
2 894
5 891
23 660
2 656
43 922
1 915
8 278
4 448
5 844
7 151
14 557
3 426
5 829
864
5 156
17 538
2 592
12 103
20 529
3 025
18 175
61 928
9 171
3 092
4 690
792
4 162
15 917
2 239
10 935
16 556
2 758
14 727
56 207
7 861
2 131
3 115
540
2 696
10 650
1 826
7 526
11 010
1 913
9 467
37 543
6 551
2 007
4 690
594
2 341
12 763
1 355
7 085
16 556
2 091
8 298
45 051
4 804
1 713
3 585
522
1 537
11 779
1 060
6 051
12 665
1 824
5 435
41 619
3 639
1 139
2 311
324
1 017
7 611
943
4 021
8 112
1 156
3 565
26 888
3 203
TABLE 16 Summary statement of standing gross volume of pine in three blocks* (defective timber included)
Block
Diameter a t b r e a s t h e i g h t , cm ( i n )
Block Area Gross volume R e l i a b l e minimum e s t i m a t e
Block Area
»12.6 (5 .0 ) »15. 2 (6 .0) >25. 4 (10 .0) »12.6 (5 .0 ) »15.2 (6 .0 ) >25.4 (10 .0) Block
ha ac ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3
1 28 425 70 238 £5 562 55 170 13 488 47 420 7 350 26 335 9 860 34 756 7 714 27 506 2 755 9 791
2 5 925 14 641
»7 .6 (3 .0 ) >15. 2 (6 .0 ) »25 .4 (10 .0) »7 .6 (3 .0 ) »15. 2 (6 .0 ) >25.4 (10 .0)
2 5 925 14 641 11 245 39 697 9 701 34 269 6 922 24 463 8 020 28 370 6 574 23 159 4 447 15 723
3 11 150 27 552 28 529 100 597 25 387 89 761 18 271 64 586 18 929 66 856 16 416 58 050 11 322 39 865
T o t a l a l l b locks
45 500 112 431 55 336 195 464 48 576 171 450 32 543 115 384 36 809 129 982 30 704 108 715 18 524 65 379
* Area figures given are the combined areas of the forest /vegetat ion types sampled and are not t o t a l block areas
CO I»
TABLE 17 Summary statement of net sound volume of pine in three blocks*, assuming maxi^im defect
Block
Diameter a t b r e a s t h e i g h t , cm ( in )
Block Area Gross volume R e l i a b l e minimum e s t i m a t e
Block Area
»12.6 (5 .0) >15. 2 (6 .0 ) »25.4 (10 .0) >12.6 (5 .0) »15. 2 (6 .0 ) >25. 4 (10 .0) Block
ha ac ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 0 0 f t 3 ' 0 m3 ' 00 f t 3
1 28 425 70 238 14 470 51 030 12 438 43 703 6 108 21 825 9 411 32 989 7 139 26 161 2 296 8 233
2 5 925 14 641
»7 .6 (3 .0) »15 .2 (6 .0 ) »25.4 (10 .0) »7 .6 (3 .0 ) »15. 2 (6 .0 ) >25. 4 (10 .0 )
2 5 925 14 641 10 119 35 657 8 574 30 249 5 786 20 449 7 291 25 732 5 820 20 540 3 774 13 289
3 11 150 27 552 25 286 89 274 22 318 78 795 15 172 53 561 16 459 58 153 14 376 50 693 9 571 33 656
T o t a l a l l b locks
45 500 112 431 49 875 175 961 43 330 152 747 27 066 75 835 33 161 116 874 27 515 97 394 15 641 55 178
Private Lands
Volume figures for the private lands are given in Appendix 2. Tables 21 and 22 refer to the Hughes Estate in Block 1 and Tables 23 and 24 to the Stopper in Block 2. The volumes quoted are derived from the mean values for the forest blocks of which the private lands form a part, as given in Tables ll and 12. As the private lands were not sampled as seperate units, the volume calculated are approximate.
VOLUME TABLE
The local volume table for Pinus caribaea given in Table 13 is produced from a linear regression of sample tree volume against overbark diameter at breast height.
The volume table shows for each d.b.h. class:
i. The total volume of timber, whether defective or not, given as the volume of timber in a completely sound tree
ii. The net volume of sound timber in defective trees.
The computation of the volume table was made at the Commonwealth Forestry Institute, Oxford, the total volume of each sample tree calculated by Newton' s formula:
v = L (a + 4b + c)
where
v = stem volume L = stem length from butt (15 cm, 5.9 in, above ground) to top height a = cross-sectional area at top height b = cross-sectional area at middle c = cross-sectional area at base
The stem volume and the dimensions used to calculate it are all underbark.
For defective trees, the sound volume excluding defect was obtained for each d.b.h. class by subtracting from the total volume for the class the mean volume of rotten timber, calculated separately from the defective tree data.
Confidence limits quoted for total volume are at 95% probability. Confidence limits were not calculated for the net volume of sound timber because the estimation of rot in the trees sampled was partly a matter of judgement rather than of actual measurement, and because the often irregular shape of pockets of rot and cavities could not be adequately allowed for in the computation.
Table 18 shows the number of trees sampled in each diameter class in order to provide the volume table data. Also shown are the number of defective trees found in each class. The figures for defective stems probably reflect the fact that, in the course of the past exploitation of the project area, most of the sound trees of exploitable size were removed.
Figure 4 shows how, in defective trees, the volume affected by rot varies with tree size. Defective timber as a percentage of total volume (i.e. the volume of sound trees in Table 13) is plotted against diameter at breast height.
35
70 cm
Diameter breast height
5-9 7 9 I
9-8 I
11 9 I
13 8 I
15 8 177 _ |
21 7 23 6
| _ 2 5 4
I 27-6
I
Figure 4 Percentage of rotten timber in the rot-affected trees sampled and the variation of this percentage with tree size
D.O.S. 31S2F Prepared by Directorate of Overseas Surveys 1974
TABLE 18 Pine volume table data: sample size and incidence of defect
d.b.h. class No. of trees in sample
Defective trees in sample % defective
cm in
No. of trees in sample
Defective trees in sample % defective
15 5.9 15 0 0
20 7.9 15 1 7
25 9.8 17 4 24
30 11.8 13 5 38
35 13.8 15 7 47
40 15.8 17 12 71
45 17.7 14 10 71
50 19.7 15 8 53
55 21.7 15 13 87
60 23.6 14 10 71
65 25.6 9 8 89
70 27.6 8 7 88
The areas from which the sample trees were obtained had mostly been logged over previously. As a result of the selective removal of sound and slightly rotten stems, particularly in the larger diameter classes, the proportion of defective trees in the sample may be higher than in unexploited areas.
REGENERATION
Mean stocking rates for Block 2 are shown in Table 19 and those for Block 3 in Table 20, together with reliable minimum estimates at 95% probability. Regeneration figures are presented for five groups of forest/vegetation types. The combination of types used, which are the same for both blocks and which differ from those used for volume, are those found by trial calculation to give the lowest variance.
Stem numbers are given for the three height classes separately, and combined (total regeneration). The latter figures were calculated separately from those for the individual height classes, in order to reduce sampling errors. The reliable minimum estimates for total regeneration are therefore not the sum of those for the three height classes.
37
TABLE 19 Regeneration of pine in five forst/vegetation type groups in Block 2*
Types Area Height c l a s s * *
Mean R e l i a b l e minimum es t ima te+
1.1; 1.2
1.3
ha ac
a
b
c
d
a
b
c
d
s t e m s / h a s t e m s / a c s t e m s / h a s t e m s / a c
1.1; 1.2
1.3
350
2 525
865
6 239
a
b
c
d
a
b
c
d
166
174
130
470
325
177
50
552
67
70
53
190
132
72
20
223
0
0
0
16
177
90
23
346
0
0
0
6
72
36
9
140
l . l ; 1.2; 1.3 2 875 7 104
a
b
c
d
291
176
67
534
118
71
27
216
169
97
23
353
68
39
9
143
3 .2
2 . 2 / 1 . 1 :2 .2 / 1.2; 2. 2 / 1 . 3
1 800
1 250
4 448
3 089
a
b
c
d
a
b
c
d
170
41
5
217
62
33
42
137
69
17
2
88
25
13
17
55
40
6
1
64
0
0
0
0
16
2
0
26
0
0
0
0
All f igures rounded to nearest whole number
** a < l . 5 m (5 ft) b 1.5 - 3.0 m (5-10 ft)
c >3.0 m (10 f t) d t o t a l
+ Where sampling e r ro r s of 100% or higher were obtained, the r e l i a b l e minimum estimate i s zero
38
TABLE 20 Regeneration of pine in five forest/vegetation type groups in Block 3
Types Area Height class
Mei in Reliable minimum estimate
ha ac
a
stems/ha stems/ac stems/ha stems/ac
a 18 7 0 0
l. l; 1.2 535 1 322 b 40 16 5 2
c 12 5 0 0
d 70 28 5 2
a 40 16 5 2
1.3 1 830 4 522 b 49 20 10 4
c 24 10 2 1
d 112 45 36 15
a 36 14 7 3
l. l; 1.2; 1.3 2 365 5 844 b 47 19 16 6
c 22 9 4 2
d 104 42 43 17
a 20 8 3 1
3.2 5 891 14 557 b 22 9 8 3
c 15 6 2 1
d 57 23 21 9
a 8 3 0 0
2.2/1. 1:2.2/ 1.2:2.2/1.3
2 894 7 151 b 16 6 1 0
c 28 11 0 0
d 52 21 0 0
39
PART 6. CONCLUSIONS
EXPLOITABLE GROWING STOCK
Saw Timber
The stand tables given in Table 10 show that the present stocking of trees of exploitable size for saw timber (i.e. 107 cm, 42 in girth or 34 cm, 13 in d.b.h. and above) in terms of stems per unit area is very low. Mean values range from less than 1 stem/ha (0.4 stem/ac) to slightly more than 20 stems/ha (8 stems/ac). Mean stocking rates of exploitable timber in type 3.2 (grassland, with pine seedlings and/ or scattered overmature pine), which accounts for rather more than half of the total area of forest/vegetation types sampled, are in all three blocks less than 2 stems/ha (0.8 stems/ac).
Increment data for poor coastal plain sites are not available. Sample plot data recorded by the Forest Department from plantations on better sites in the southern Coastal Plain and further south at Machaca indicate a mean annual increment in d.b.h. of about 1 cm (0.4 in), which is similar to that for naturally regenerated pine in the Mountain Pine Ridge. Thus it takes at least five years for a tree to pass through a single 5 cm d.b.h. class. On the basis of this rate of growth, it follows from the present size class distributions given in Table 10 that it will take at least 10 years to achieve a stocking of, say, 50 exploitable trees per ha (20 stems/ac) in the best stocked areas and in the absence of exploitation. In the poorest stocked forest vegetation type (i.e. type 3.2) at least 30 years would be required to reach such a stock of exploitable trees. Type 3.2 has a negligible rate of recruitment to exploitable size, which will not start to increase significantly for 15-20 years.
On the basis of estimates of present growing stock, comparatively low terminal rates of stocking can be foreseen. If material presently below the 10 cm (3.9 in) diameter ;lass (recorded in only two of the three blocks) is taken into account, final rates of stocking well below 300 stems/ha (123 stems/ac) are foreseeable over most of the area. In type 3.2 (more than half the total area sampled), final stocking rates will probably be less than 50 stems/ha (20 stems'ac). These figures compare unfavourably with final stocking rates to be expected from plantations. *
It can be inferred from Table 18 that the incidence of butt and stem rot, in terms of numbers of trees affected, increases with tree size. This broad conclusion can be made with some confidence although, because of the small sample size, the figures quoted cannot be regarded as being accurate in themselves. The smoothness of the curve in Figure 4 suggests that, in defective trees, a significant relationship exists between the incidence of rot, in terms of volume, and tree size. Table 18 and Figure 4 taken together indicate that decay is, as might be expected, partly a function of age.
Figure 4 shows that, in the sample taken, the proportion of volume affected by rot in a defective tree rises from being negligible in material of 25 cm (9.8 in) d.b.h. and below to a constant level of approximately 25% in trees of 50 cm (19.7 in) and above. However since the sample was taken from an area previously culled for sound or slightly defective trees this level may be higher than would be encountered in defective trees in an unexploited stand.
The rot and the significant loss of increment which it represents in the larger material can be attributed indirectly to fire because of the known frequency with which decay organisms enter through fire scars. Failure to cut defective trees in the course of past exploitation is also a factor. The volume table sample to which Table 18 and Figure 4 refer represents the residual growing stock (at least as far as the larger trees are concerned) after selective cutting of sound stems.
As allowance for defect was made through the volume table, the data do not permit conclusions regarding variation with location in the incidence of defect. On the savanna areas, where there has been a history of recurring fire, the incidence of rot would probably be significantly higher
* Luckhoff (1964) quotes a final stocking rate of 321 stems/ha (130 stems/ac) for Pinus caribaea in plantations in South Africa.
41
than in some areas of Broken Ridge, where there is a well developed broadleaved understorey and fire has for some time been infrequent or absent. Similarly, in a few small areas which have not been cut over, apparently because of their inaccessibility, the incidence of defect in the larger trees is probably lower than it is in the rest of the project area. In fact, most unexploited areas are in Broken Ridge, so the two factors usually coincide. Such areas are, for example, the foothills in the vicinity of Silver Creek in Block 1 and the Broken Ridge west of the Sierritas in Block 2.
Pulp
The present stocking of material of 25.4 cm (10.0 in) d.b.h. and above is low in terms of the requirements of industrial wood use. The minimum estimate of sound timber represents about five months' supply for a pulp mill (using 295 t, 300 ton/day) or four year's supply for a particle board plant (using 30 t/day). The minimum estimate of the total standing volume of sound timber, including the smallest sizes measured, represents rather less than a year's supply for a pulp mill or nine years supply for a particle board plant. Thus the inventory results indicate that any industrial wood-using operation which might be introduced in the southern Coastal Plain would have to be of a kind capable of economic production on a small scale, if it was to be dependent for its raw material largely or entirely upon supplies from the project area.
Apart from the question of supply, prospects for industrial utilisation depend also on other factors. Among these, the chemical and structural characteristics of the locally grown pine and the market situation are important. As far as pulp is concerned, indications to date are that pulp made only from Belize pine is of rather poor quality (Chittendon and Palmer, 1959; Palmer, 1969). Moreover it seems probable that an export market for pulp (the internal market is negligible) might not exist because of adequate production elsewhere in Central America (Wyatt Smith, 1970)
SEEDLING REGENERATION
Tables 19 and 20 show that approximately one quarter of the area sampled for pine regeneration, or 2 900 ha (7 100 ac), carries a stocking of regeneration (i.e. stems <5 cm (2 in) d.b.h.) of the order of 350 stems/ha (140 stems/ac). It is significant that in both of the blocks in which regeneration sampling was carried out, the forest/vegetation type least stocked with larger trees (i.e. type 3.2) also has a very low stocking of regeneration. The paucity of regeneration.here can be attributed largely to fire. A measure of the seriousness of fire in the project area is given by the fact that type 3.2, which comprises land which could, but does not, support a significant stocking of naturally regenerated pine, accounts for 45% or 7 700 ha (19 000 ac) of the total area sampled for regeneration. The reliable minimum estimates of regeneration stocking obtained for types 1,1 and 1.2 may partly reflect the better stocking of larger material in those types (i.e. they have already passed through the regeneration phase), although the precision of estimate achieved in sampling those types is such that very much meaning cannot be attached to the results.
For the mixed pine/broadleaved forest types, both sample means and reliable minimum estimates are low. This probably reflects the inhibiting of pine regeneration by the understorey of broad-leaved herbaceous and woody species.
SILVICULTURE AND MANAGEMENT
If the establishment and maintenance of naturally regenerated pine forest is to continue to be an objective in the southern Coastal Plain, then the principal silvicultural requirement is fire control. Given the inadequacy of the existing fire fighting resources in relation to the task presented, two possible courses of action are:
1. To enlarge the present fire-fighting organisation and (possibly) disperse it so that it can cover areas remote from the two forest stations.
2. To reduce the area subject to fire protection so that it matches the actual fire control capability. This might involve the establishment of some scale of priority whereby certain areas would be recognised as being more worthy of fire protection than others.
42
Some relocation of fire-fighting resources to the south of the Swasey Branch might be worth considering, particularly bearing in mind that the area north of the Swasey has been dereserved.
A means of monitoring the effectiveness of fire protection is needed and the use of permanent sample plots would be appropriate. The plots, distributed throughout the savanna areas, would be enumerated at regular intervals, say every 2-3 years.
The data collected would indicate
i. whether the stocking of pine regeneration increases as fire control is improved
ii. whether the regeneration survives from one year to the next.
The second point is important in distinguishing between a situation wherein recurring regeneration is destroyed by recurring fire and one in which fire is prevented sufficiently to enable seedlings to reach a size at which they can withstand fire.
The futura of the areas of mixed pine/broadleaved forest does not appear promising from the point of view of pine production. Where the broadleaved component is continuous and well developed it has to be accepted that, except for such exploitation of the existing pine overstorey as may be economic, these areas no longer form part of the pine resource. In areas where the broadleaved understorey is less well defined and pine is or has until recently been regenerating, it may be feasible to remove the broadleaved growth, for example by controlled burning, although the diffi-fulties involved in doing so would be appreciable.
Development of broadleaved forest beneath mature and overmature pine, as has occurred in some areas of the project area, supports the view that the complete absence of fire may be as inimical to the growth of pine as is a situation of recurring, uncontrolled fire. It appears that, if pine regeneration can be established by means of fire protection, the use of controlled burning may then become necessary in order to prevent encroachment by weed species, at least on the better drained sites where the growth of broadleaved species is favoured.
A considerable amount of knowledge and experience has already been accumulated on the establishment of pine plantations at Savannah in the project area and of plantations of various broadleaved species in areas closely adjacent to the project area. The success of plantations of Gmelina arborea, Tectona grandis and Pinus caribaea on the better drained foothill soils at Silk Grass just north of the project area boundary is noted by Wyatt-Smith (1970). He recommends that a survey should be made of the extent of these more productive soils along the rest of the Coastal Plain foothills. This recommendation, and the possibility of further planting of fast-growing exotics such as Gmelina arborea, are worth pursuing.
43
PART 7. REFERENCES AND RELATED WORKS
BARTLETT H H 1935 A method of procedure for f i e ld work in t rop ica l American phytogeography based upon a botanical reconnaissance in p a r t s of Br i t i sh Honduras and the Peten fores t of Guatemala. Pubis Carnegie Instn 461, 1-25.
BEARD J S 1944 Climax vegetation in t rop ica l America. Ecology 25, 127-158.
BEARD J S 1953 The savanna vegetation of northern tropical America. Ecol. Monogr. 23, 149-215.
BRITISH HONDURAS FOREST DEPARTMENT
BRITISH HONDURAS FOREST DEPARTMENT
BRITISH HONDURAS FOREST DEPARTMENT
BRITISH HONDURAS FOREST DEPARTMENT
History of forestry in British Honduras. Internal Rep. For. Dep. Br. Honduras
1962 A. Rep. For. Dep. Rr. Honduras 1961.
1963 A. Rep. For. Dep. Rr. Honduras 1962.
1967 A. Rep. For. Dep. Rr. Honduras 1966.
BROWNE F G 1968 Pests and diseases of forest plantation trees. Oxford: Clarendon Press.
BUDOWSKI G 1956 Tropical savannas, a sequence of forest f e l l ing and repeated burnings. Turrialba 6 , 23-33.
CACHEUX P l e 1957 Report on a preliminary pulp and paper survey in Br i t i sh Honduras including p o s s i b i l i t i e s for wallboard manufacturing. Port of Spain: Caribbean Commission.
CHARTER C F
CHITTENDON A E and PAIMER E R
1941 A reconnaissance survey of the so i l s of Br i t i sh Honduras north of the cent ra l metamorphic and igneous massif with special reference to t h e i r u t i l i s a t i o n in agr icu l ture . Port of Spain: Government P r in t e r .
1959 Pulping t r a i l s on Pinus caribaea wood from Br i t i sh Honduras. For. Sei. 1, 22-40.
DIXON C G 1956 Geology of southern British Honduras. Belize: Government Printer.
DOWNIE J
ETHERIDGE D E
1959 An economic policy for British Honduras. Belize: Government Printer.
1968 Preliminary observations on the pathology of Pinus caribaea Morelet in British Honduras. Commonw. For. Rev. 47, 72-80.
45
HUMMEL C 1921 Report on the fores ts of Br i t i sh Honduras with suggestions for a far reaching forest pol icy. Belize: Government P r i n t e r .
HUNT D R 1970 Some observations on the pine savannas of British Honduras. Internal Rep. R. Bot. Gdns kcw.
JOHNSON M S and CHAFFEY D R
LINDO L S
1974 A fores t inventory of par t of the Mountain Pine Ridge, Belize. Land Resour. Study No. 13.
1967 The effect of hurricanes on the fores ts of B r i t i s h Honduras. Pap. 9th Commonw. For. Conf. New Delhi 1968.
LOGAN WEM
LOOCK E E M
LUCKHOPP H A
1966 Vis i t of Forestry Adviser to Br i t i sh Honduras. Tech. Asst. Rep. Minist, overseas Dev.
1950 The pines of Mexico and Br i t i sh Honduras. A report on the reconnaissance of Mexico and Br i t i sh Honduras during 1947. Bull. Dep. For. Un. S. Afr. No. 35.
1964 The na tura l d i s t r i bu t ion , growth and botanical va r i a t ion of Pinus caribaea and i t s cu l t iva t ion in South Africa. Annale Univ. Stellenbosch 39, 1.
MUNRO N
PALMER E R
PARSONS J J
STANDLEY P C and RECORD S J
TAYLOR B W
WALKER S H
WATERS R M
WILLIAMS R M C
W0LFFSOHN A L A
WRIGHT A V S ROMNEY D H ARBUCKLE R H and VIAL V E
WYATT-SMITH J
1966 The fire ecology of Caribbean pine in Nicaragua. Proc. 5th A. Tall Timb. Fire Ecol. Conf. Tallahassy, Florida 1966, 67-83.
1969 Pulp and paper prospects in British Honduras. Internal Rep. Trop. Prod. Inst.
1955 The Mi ski to pine savanna of Nicaragua and Honduras. Ann. Ass. Am. Geogr. 45, 36-63.
1936 The forests and flora of British Honduras. Field Mus. Nat. Hist. Bot. 12, 1-432.
1962 The status and development of the Nicaraguan pine savannas. Caribb. Forester 23, 21-26-
1972 Summary of climatic data for British Honduras. Suppl. Rep. Land Resour. Div. overseas Dev. Adm. No. 3.
1969 British Honduras: possibilities for pulp and paper: a preliminary study. Internal Rep. For. Dep. Br. Honduras
1965 Termite infestation of pines in British Honduras. Overseas Res. Publ. No. 11.
1967 Post-hurricane fires in British Honduras. Commonw. For. Rev. 46, 233-238.
1959 Land in British Honduras. Report of the British Honduras land use survey team. London: HMSO.
1970 Visit of Forestry Adviser to British Honduras (3-6 March 1970). Internal Rep. overseas Dev. Adm.
46
APPENDIX 1. LIST OF COMMON AND BOTANICAL NAMES OF PLANTS MENTIONED IN THE TEXT
COMMON NAMES
The common names given are those found by the authors to have wide local usage and/or are mentioned in the t ex t . More complete l i s t s of the common names of p lants in the southern Coastal Plain (and elsewhere in Belize) are given by Standley and Record (1936) and by Wright et al. (1959).
Calabash
Caoba
Caribbean pine
Cohune palm, corozo
Craboo
Cocoplum
Cutting grass
Mahogany, caoba
Negrito
Logwood
Oak
Palmetto, pimento
Pine, Caribbean pine pino
Rosewood
Sapodilla, sapote
Savanna white poisonwood
Teak
Yaha
Crescent ia cujete L.
see mahogany
see pine
Orbignya cohune (Mart.) Dahlgren
Byrsonima crassifolia (L.) DC.
Chrysobalanus icaco L.
Scleria bracteata Cav.
Swietenia macrophylla King
Simaruba glauca DC.
Haematoxylon campechianum L.
Quercus spp;
AcceI or raphe wright ii (Gris.) Wendl.
Pinuz caribaca Morelet var. hondarensis Barr, and Golf.
Dalbergia steiensonii Standi.
Manilkara zapota (L.) van Royen
Cameraria belizensis Standi.
Tectona grand is L.
Curatella americana L.
47
BOTANICAL NAMES
Acoelorraphe wrightii (Gris) Wendl.
Byrsonima crassifolia (L.) DC.
Cameraria bel izensis Standi.
Chrysobalanus icaco L.
Crescent ia cujete L.
Curate 11a americana L.
Dalbergia stevensonii Standi.
Gmelina arborea Roxb.
Haematoxylon campechianum L.
Lentinus pallidus Berk, and Curt.
Manilkara zapota (L.) van Royen
Mesosetum filifolium Hubbard
Orbignya cohune (Mart.) Dahlgren
Paspalum pectinatum Nees
Pinus caribaea Morel et var. hondurensis Barr, and Golf
Quercus spp.
Rhyncospora globosa Roem. & Schult
Scleria bracteata Cav.
Simaruba glauca DC.
Swietenia macrophylla King
Tectona grand is L.
Trachypogon angustifolius (Kunth) Nees
Ximenia americana L.
palmetto, pimento
craboo
savanna white poisonwood
cocoplum
calabash
yaha
rosewood
logwood
sapodi l la , sapote
cohune palm, corozo
Caribbean pine, pine, pino
oak
cu t t ing grass
negri to
caoba, mahogany
teak
48
APPENDIX 2. VOLUME FIGURES FOR PRIVATE LANDS
TABLE 21 Hughes Estate: Standing gross volume of pine, including defective timber, in groups of forest/vegetation types
Types
Diameter at breast height, cm (in)
Types Area Gross volume R e l i a b l e minimum e s t i m a t e Types Area
>12. 6 ( 5 . 0 ) >15. 2 (6 .0 ) >25. 4 (10 .0 ) >12.6 ( 5 . 0 ) >15. 2 (6 .0 ) >25. 4 (10 .0 )
Types
ha ac W '00 f t 3 ' 0 m3 '00 f t 3 ' O m 3 ' 00 f t 3 ' 0 m3 '00 f t 3 ' O m 3 '00 f t 3 ' 0 m3 '00 f t 3
1.1
1.2
1.3
940 2 323 912 3 229 752 2 648 329 1 185 658 2 323 508 1 789 169 604
2 . 2 / 1 . 1
2 . 2 / 1 . 2
2 . 2 / 1 . 3
26 64 74 262 68 239 41 143 55 193 49 171 25 88
3.2 2 365 5 844 426 1 519 402 1 403 307 1 110 118 409 71 292 0 0
To ta l
a l l t y p e s 3 331 8 231 1 412 5 010 1 222 4 290 677 2 438 831 2 925 628 2 252 194 692
TABLE 22 Hughes Estate: Standing net sound volume of pine, assuming maximum defect, in groups of fores t /vegetat ion types
Types
Diameter at b r e a s t h e i g h t , cm ( in)
Types Area Gross volume R e l i a b l e minimum e s t i m a t e Types Area
?12.<S ( 5 . 0 ) >15. 2 (6 .0 ) >25.4 (10.0) >12. 6 (5 .0 ) >15. 2 (6 .0 ) »25. 4 (10 .0 )
Types
ha ac ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3 ' 0 m3 '00 f t 3
1. 1
1.2
1.3
940 2 323 865 3 043 705 2 486 273 976 630 2 207 479 1 696 141 511
2 . 2 / 1 . 1
2 . 2 / 1 . 2
2 . 2 / 1 . 3
26 64 68 239 63 221 33 117 51 179 46 161 21 73
3.2 2 365 5 844 378 1 344 355 1 227 260 934 118 409 71 292 0 0
To ta l
a l l t y p e s 3 331 8 231 1 311 4 626 1 123 3 934 566 2 028 799 2 795 596 2 149 162 584
TABLE 23 The Stopper: Standing gross volume of pine, including defective timber, in groups of forest/vegetation types
Types
Diameter at breast height, cm (in)
Types Area Gross volume Reliable minimum estimate Types Area
>7.6 (3.0) >15. 2 (6.0) >25. 4 (10.0)' >7.6 (3.0) >15. 2 (CO) >25. 4 (10.0)
Types
ha ac W '00 f t 3 '0 m3 '00 f t 3 '0 m3 '00 f t 3 '0 m3 '00 f t 3 '0 m3 '00 f t 3 '0 m3 '00 f t 3
1. 1/1.2
2. 2/1. 1
2.2/1.2
194 479 966 3 410 883 3 113 644 2 270 563 1 983 487 1 720 339 1 197
1.3
2.2/1.3 531 1 312 1 020 3 595 839 2 965 589 2 086 812 2 873 643 2 256 430 1 522
3.2 160 395 85 300 78 277 56 197 58 205 51 182 34 119
Total
a l l types 885 2 187 2 071 7 305 1 800 6 355 1 289 4 553 1 433 5 061 1 181 4 158 803 2. 838
TABLE 24 The Stopper: Standing net sound volume of pine, assuming maximum defect, in groups of forest/vegetation types
Types
Diameter at breast height, cm (in)
Types Area Gross volume Reliable minimum estimate Types Area
>7.6 (3.0) »15. 2 (6.0) >25. 4 (10.0) >7.6 (3.0) >15. 2 (6. 0) >25.4 (10.0)
Types
ha ac '0 m3 '00 f t 3 w '00 f t 3 W '00 f t 3 '0 m3 '00 f t 3 'Om3 '00 f t 3 'Om 3 '00 f t 3
1. 1; 1. 2
2 .2 /1 . 1
2.2/1.2
194 479 857 3 027 724 2 735 533 1 882 502 1 772 429 1 514 285 1 006
1.3
2 .2/1.3 531 1 312 924 3 254 743 2 624 494 1 745 743 2 624 568 2 007 366 1 286
3.2 160 395 77 269 70 245 48 170 53 186 46 162 29 103
Total
a l l types 885 2 187 1 858 6 550 1 587 5 604 1 075 3 797 1 298 4 582 1 043 3 683 680 2 395
PUBLICATIONS OF THE LAND RESOURCES DIVISION
These publ ica t ions have a r e s t r i c t e d d i s t r i b u t i o n and are not ava i lab le to booksel lers . The Division makes a report on each completed pro jec t . The report i s published as a Land Resource Study or Technical Bulletin only with the consent of the government concerned. The abbreviated t i t l e s of the repor ts in the s t y l e of the 'World Lis t of Sc i en t i f i c Pe r iod ica l s ' a re Land Resour. Stud, and Tech. Bull. Land Resour. Div. overseas Dev. Admin.
RAWDEN M G and LANGDALE-BROW I
1961 An ae r i a l photographic reconnaissance of the present and poss ib le land use in the Bamenda Area. Southern Cameroons. *
BAWDEN M G and STOBBS A R
1963 The land resources of Eastern Bechuanaland.
LANGDALE-BROWN I and SPOONER R J
1963 The land use prospects of Northern Bechaunaland*
BAWDEN M G (Ed) 1965 Some s o i l s of Northern Bechuanaland with a descr ip t ion of the main vegetation zones.
LAND RESOURCE STUDIES
SPOONER R J and JENKIN R N
1960 The development of the Lower Mgeta River Area of the United Republic of Tanzania. Land Resource Study No. 1.
BAWDEN M G and TULEY P
BAWDEN M G and CARROLL D M
1966 The land resources of Southern Sardauna and Southern Adamawa Provinces, Northern Nigeria. Land Resource Study No. 2.
1968 The land resources of Lesotho. Study No. 3. *
Land Resource
JENKIN R N and FOALE M A
BLAIR RAINS A and McKAY A D
1968
1968
An inves t iga t ion of the coconut-growing po ten t i a l of Christmas Island.. Volume I. The environment and the p lan ta t ions . Volume 2. Appendixes. Land Resource Study No. 4.
The Northern Sta te Lands. Resource Study No. 5.
Botswana. Land
HILL I D 1969 An assessment of the p o s s i b i l i t i e s of o i l palm cu l t iva t ion in Western Division. The Gambia. Land Resource Study No. 6.
VERBOOM W C and BRUNT M A
1970 An ecological survey of Western Province, Zambia, with specia l reference to the fodder resources. Volume I , The environment, Volume 2, The grasslands and t h e i r development. Land Resource Study No. 8.**
AITCHISON P J BAWDEN M G CARROLL D M GLOVER P E KLINKENBERG K LEEUW P N de and TULEY P
1972 The land resources of North East Nigeria. Volume I, The environment! Land Resource Study No. 9.
* Out of print.
*• Land Resource Study No. 7 has not yet been published.
53
AITCHISON P J and GLOVER P E
BAWDEN M G CARROLL D M and TULEY P
LEEUW P N de LESSLIE A and TULEY P
TULEY P ed.
JOHNSON M S
BLAIR RAINS A and YALALA A M
BERRY M J and HOWARD W J
JOHNSON M S and CHAPPEY D R
JOHNSON M S and CHAFFEY D R
HENRY P W T
BERRY M J LAURENCE J F MAKIN M J and WADDAMS A E
1970 The land resources of North East Nigeria. Volume 2. Tsetse and trypanosomiasis. Land Resource Study No. 9*.
1972 The land resources of North East Nigeria. Volume 3. The land systems. Land Resource Study No. 9.
1972 The land resources of North East Nigeria. Volume 4. Present and potential land use. Land Resource Study No. 9.
1973 The land resources of North East Nigeria. Volume 5. Appendixes and tables. Land Resource Study No. 9.
1971 New Hebrides Condominium. Erromango Forest inventory. Land Resource Study No. 10.
1972 The Central and Southern State Lands, Botswana. Land Resource Study No. 11.
1973 Fiji Forest inventory. Volume 1, trhe environment and forest types; Volume 2, Catchment groups of Viti Levu and Kandavu; Volume 3, Catchment groups of Vanna Levu. Land Resource Study No. 12.
1973 A forest inventory of part of the Mountain Pine Ridge, Belize. Land Resource Study No. 13.
1973 An inventory of the Chiquibul Forest Reserve, Belize. Land Resource Study No. 14.
1974 Pine forests of the Bahamas. Land Resource Study No. 16.
1974 Development potential of the Nawalparasi Area of Nepal. Land Resource Study No. 17.
TECHNICAL BULLETINS
CARROLL D M and BASCOMB C L
PIGGOTT C J+
1967 Notes on the soils of Lesotho. Technical Bullet in No. 1.
1968 A soil survey of Seychelles. Technical Bulletin No. 2*.
LAND RESOURCE BIBLIOGRAPHIES
POSNETT N W comp. 1963
1971 POSNETT N W and REILLY P M comp.
POSNETT N W REILLY P M and WHITFIELD P comp.
1971
Bahamas. Land Resource Bibliography No. 1*.
Bahamas. Land Resource Bibliography No. 1. (Revised edition)
Nigeria. Land Resource Bibliography No. 2-
* Out of print.
54
POSNETT N W and 1973 Belize. (British Honduras). Land Resource REILLY P M comp. Bibliography No. 3.
POSNETT N W and 1973 Fiji. Land Resource Bibliography No. 4. REILLY P M comp.
GREENWAY M E 1974 New Hebrides and New Caledonia. Land Resource POSNETT N W and Bibliography No. 5. REILLY P M
* Out of print.
R 78857/10168/12 700 1/75 TP 55
