Environmental Control of Wood and Tracheid Properties in Norway Spruce (Picea abies (L.) Karst.)

Tuula JyskeHarri MäkinenPekka Saranpää

Pekka Saranpää 28/10/07

•Within annual rings: earlywood, Within annual rings: earlywood, latewoodlatewood

VARIATION OF WOOD PROPERTIESVARIATION OF WOOD PROPERTIES

•Between sites: fertilityBetween sites: fertility

•Between stems: genetic Between stems: genetic variation, effect of environmentvariation, effect of environment

•Within stems: juvenile Within stems: juvenile (core)wood, sapwood, heartwood(core)wood, sapwood, heartwood

Pekka Saranpää 28/10/07

Juvenile wood Earlywood

LatewoodCompression wood

_________

0,1 mm

Pekka Saranpää 28/10/07

1 m

4 m

8 m

R2 = 0,93

R2 = 0,95

R2 = 0,96

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140Distance from the pith, mm

mm

Tracheid length of Norway sprucefrom the pith to the bark

Pekka Saranpää 28/10/07

The variation of wood properties from the pith to the bark and from the base to the tree top

The effect of long-term fertilisation and thinning on:

»diameter growth, »wood density»tracheid dimensions?

Pekka Saranpää 28/10/07

Finland Finland –– Europe's most Europe's most densely forested countrydensely forested country

Suonenjoki

Parikkala

62°45'N, 27°00'E SuonenjokiSuonenjoki

ParikkalaParikkala

62°45'N, 62°45'N, 27°00'E27°00'E Suonenjoki

Parikkala61°36'N, 29°22'E61°36'N, 29°22'E

Pekka Saranpää 28/10/07

Thinning experiments

1970 1980 1990 2000

Sta

nd b

asal

are

a (m

2 ha-1

)

10

20

30

40

50

Low thinning intensityHigh thinning intensityNormal thinning intensity

1970 1980 1990 200010

20

30

40

50A Heinola B Punkaharju

Pekka Saranpää 28/10/07

Growth ring widthRing width in Punkaharju thinning experiment

0

1

2

3

4

5

6

7

1942 1952 1962 1972 1982 1992 2002

Year

Rin

g w

idth

(mm

)

Low thinning intensity High thinning intensity

Normal thinning intensity Onset of treatment

Pekka Saranpää 28/10/07

Thinning and fertilisationParikkala & Suonenjoki

• delayed first thinning

• normal first thinning• intensive first

thinning

• control• 150 kg N ha-1 / 5 v.• 300 kg N ha-1 / 5 v.1975 1980 1985 1990 1995

No.

ste

ms

(%)

0

20

40

60

80

100

Pekka Saranpää 28/10/07

Bas

al a

rea

of s

tudy

tree

s (c

m2 )

5

6

7

8

9

10

11

12

F0 F1 F2

Fertilised

control fertilised 1 fertilised 2

5

6

7

8

9

10

11

12

T0 T1 T2

delayed normal high

thinning intensity

Thinned

Pekka Saranpää 28/10/07

Thinning experiments Heinola & Punkaharju

over 50 % increase of growth rate in normally thinned stands compared to low thinning intensity (based on basal area of study trees)

ca. 70 % increase of growth rate in normally thinned stands compared to low thinning intensity

latewood proportion decreased by 8 % – 20 % in normal and intensively thinned trees compared to low thinning intensity

weight density decreased only 1 % – 4 % in normal and intensively thinned trees compared to low thinning intensity

Pekka Saranpää 28/10/07

intensively thinned trees showed 4 – 9 % shorter tracheids compared to low thinning intensity

intensive thinning resulted 3 – 12 % thinner cell walls compared to low thinning intensity

only slight change in tracheid diameter (1 – 3%)

Thinning experiments Heinola & Punkaharju

Pekka Saranpää 28/10/07

Thinning - fertilisation experimentsParikkala & Suonenjoki

normal fertilisation level increased ca. 40 % growth rate compared to unfertilised stand

intensive fertilisation level increased growth rate ca. 40 % compared to an unfertilised stand

normal thinning resulted an 8 % increase of growth compared to delayed thinning

Pekka Saranpää 28/10/07

intensive first thinning resulted an 30 % increase of growth compared to delayed thinning

differences in latewood proportion only 2 % – 9 %

weight density decreased only 2 % – 7 % by increasing thinning intensivity

Thinning - fertilisation experimentsParikkala & Suonenjoki

Pekka Saranpää 28/10/07

only slight differences in tracheid length ( 1 % – 2 %)

cell wall thickness decreased 1 % – 7 %

minor effect on lumen diameter (0 % – 2 %)

1

1.5

2

2.5

3

3.5

4

1945 1965 1985 2005Tr

ache

id le

ngth

, mm

ControlFertilised

Pekka Saranpää 28/10/07

Models to predict wood properties

Models to predict the effect of growth rate on wood properties- from stem base to the tree top- from the pith to the bark

Fibre properties- latewood proportion- wood density- fibre length- fibre diameter- cell wall thickness

Multivariate multilevel models, GLMM

Pekka Saranpää 28/10/07

Material Thinning intensity from below in Central and Eastern Finland

(Heinola ja Punkaharju, PURO)

Timing of first thinning, intensity of nitrogen fertilisation in Eastern Finland (Parikkala ja Suonenjoki, PURO)

Effect of nitrogen fertilisation in Southern and Northern Finland (Heinola ja Kemijärvi, IMWO)

Nutrient optimisation experiments in Southern and Northern Sweden (Asa and Flakaliden (ENWO)

Fast growing Norway spruce clones in Southern Finland (Nurmijärvi and Ruotsinkylä)

Pekka Saranpää 28/10/07

Models to predict wood properties Multivariate multilevel models, GLMM

Mäkinen et al. 2007 For Ecol Manag 241

Latewood proportion Weight density gm-3 Fibre length, mm

Fibre diameter, um Cell wall proportion

Pekka Saranpää 28/10/07

Weight density Tracheid length

Pekka Saranpää 28/10/07

Conclusions

Prevailing thinning intensities increase significantly growth rate of Norway spruce

However, thinning and fertilisation had a minor effect on wood properties like density and fibre dimensions

Within-tree and between-tree variation is the major source of variation

Limited material (altogether 109 stems from various experiments) and fibre measurements only at breast height

Pekka Saranpää 28/10/07

Thank you!

Foundation for Research of Natural Resources in Finland

Tuula Jyske Harri Mäkinen