Carbon and tree diversity in agricultural systems in Nicaragua: do trees really make a difference?

www.ciat.cgiar.org Eco-efficient agriculture for the poor

Cali, 06th May 2015

Tree diversity & C sequestration in rural landscapes in sub-humid Central

America

P. Siles; D. Valbuena; A. Castro; O. Tellez; G. Bonilla; R. van der Hoek

Rural landscapes, degradation & eco-services

• Rural landscapes & soils are highly degraded in Central America (82% soils with erosion)

• Restoration of these landscapes are key for rural livelihoods & ES provision

• Need to co-develop farming systems & rural landscapes that account for ES

Constanza et al. 2014

The seasonally dry tropical forest

17 degrees Celsius rainfall ranging from 250 to 2000 a distinctive seasonality with 4 to 6 dry months

The seasonally dry tropical forest

2-3% of its original extentless of 0.5 % in protected areas20 percent of its original extent by the mid 1980’sExtensive agriculture 5000 years agoPasture, maize and beans the predominant agricultural land use

highly threatened ecosystem by human activity

Challenges in the Mesoamerican Region SDTF

Extensive agriculturePovertyFood security riskLandscape degradation Vulnerability with CC

Agroforestry systems

Coffee agroforestry systems

Cocoa agroforestry systems

High plant species richness

Provide product diversification for self-consumption and sale

play a very important role in the generation of provisioning ecosystem services

Cocoa - AFS

Coffee - AFS

Smallholder farms:

Multi-strata systems a Farmer’s technology

Very variable design and Composition

In the sub-humid areas some production systems provide ES

Traditional cropping systems

Silvopastoral systems

Fallows and secondary forestSlash and mulch agroforestry

In the sub-humid areas some production systems provide ES

In this study the objective was to assess carbon stock and tree diversity in different land uses

AFS with potential to generate ES (plot and landscape level)Carbon Storage and AFS as biological corridors

Carbon Stocks

Living biomass

Litter

Death wood biomass

Soil carbon

1 2 3 4 5 6 7 8 9 10 11 120

50

100

150

200

250

300

350

400

Somotillo

1 2 3 4 5 6 7 8 9 10 11 120

50

100

150

200

250

300

350

400

Condega PET 1450 mmPrec 850 mmP/PET=0.58

PET 1900 mmPrec 1700 mmP/PET=0.9

Field sites

• Micro watershed Río Pires (Condega): Potrerillos, Santa Teresa, Los Cerritos

• Micro watershed Río Tecomapa (Somotillo): La Danta y La Flor

• 8 Farms per site (Total 16)


Land usesT1 – Monocrop and burn T2 – Monocrop with traditional varietiesT3 – Monocrop + improved varieties

T7 – Naturalized pastureT8 – Improved pasture

T9 - Silvopastoril + Improved pasture

T4 – QSMAS+ traditional varietiesT5 - QSMAS+ improved varieties

T6 – Secondary forest

Land uses monitored for production and ESA farmer participative studyEvaluation and design of agroforestry systems Tree species selection

TCS

NP

SPS

QSMAS

SF


Field measurements

20 m

50 m

We identified and measured the diameter at breast height (DBH) of all living woody stems DBH > 2.5 cmWe also measured the total heightPlot of 0.1 ha

33 m

33 m

SF, NP and SPS

TCS and QSMAS


Death wood biomass

Field measurements

Litter biomass Soil sampling

Diameter of death woodin the transept

Herbs and litter in 0.25 m2

Soil samples 0-20 cm


Data analysis

Land Use Systems

TCS NP SPS QSMAS SF

Tre

e ric

hnes

s (s

peci

es 1

000m

-2)

0

5

10

15

20

25

Land Use Systems

TCS NP SPS QSMAS SF

Sha

nnon

Ind

ex H

'

0.0

0.5

1.0

1.5

2.0

2.5

Results

Across all sample sites, species richness ranged from 0 to 39 species/plotThe overall pattern of the the Shannon index was the same as that found for species richness

Number of samples

0 5 10 15 20

Sp

ecie

s ric

hnes

s

0

20

40

60

80

100TCSNPSPSQSMASSF

Number of individuals

500 1000 1500

(a) (b)

Results

SF and QSMAS with the highest species richness accumulationA total 110 tree species found

Results

A total 110 tree species foundFew species with high relative abundance

Species rank

0 10 20 30 40 50 60 70 80

Rel

ativ

e ab

und

ance

(%

)

0

5

10

15

20%P %SPS

Results

Species rank

0 10 20 30 40 50 60 70 80

Rel

ativ

e ab

und

ance

(%

)

0

5

10

15

20%P %SPS %QAS %SDF

A total 110 tree species foundFew species with high relative abundance

Results

Greatest similarity between the SF and QSMAS

Land Use Systems

TCS NP SPS QSMAS SF

Tot

al a

bove

grou

nd

Bio

mas

s (M

g ha

-1)

0

20

40

60

80

100

120

Land Use Systems

TCS NP SPS QSMAS SF

Tre

e B

iom

ass

(M

g h

a-1

)

0

20

40

60

80

100

120

Results

Tree biomass most important compartment in Total AGB

Tree stem density (Individuals ha-1)

0 500 1000 1500 2000 2500

Tre

e ae

rial b

iom

ass

(Mg

ha-1

)

0

20

40

60

80

100

120

140

160

Stem basal area (m2 ha-1)

0 10 20 30 40 50

(a) (b)

Results

Land Use Systems

TCS NP SPS QSMAS SF

Tre

e st

em d

ensi

ty (

Indi

vidu

als

ha-1

)

0

200

400

600

800

1000

1200

Land Use Systems

TCS NP SPS QSMAS SF

Tre

e ae

rial b

iom

ass

(M

g h

a-1

)

0

10

20

30

40

50

< 10 cm10-20 cm20-30 cm> 30 cm

Results

Land Use Systems

TCS NP SPS QSMAS SF

-60

-40

-20

0

Tot

al C

arbo

n st

orag

e (M

g C

ha

-1)

0

10

20

30

40

50

60

Results

Land Use Systems

TCS NP SPS QSMAS SF

-60

-40

-20

0

Tot

al C

arbo

n st

orag

e (M

g C

ha

-1)

0

10

20

30

40

50

60

14 Mg ha-1 33% of SF

Results

• Tree biodiversity• Small number of spp accounted for the majority of trees and

shrubs

• Differences among land uses in species richness and community structure, but QSMAS similar in composition to SF

• C stocks • Soils store a large portion of the carbon (even only 20 cm depth)• C stocks in woody biomass the largest compartment of AGB• Forest plots stored on average 46 Mg C ha-1, QSMAS only 33% of

SF• Between 30 to 40% of the biomass C was stored in the largest

trees (DBH> 30 cm)• Based on average values, C stocks could increase by about 14 Mg

C ha-1 by converting cropland to agroforestry

Conclusions

• AFS are promising land uses to restore rural landscapes in sub-humid tropics of Central America

• Maize-beans AFS plantations with higher C stocks, tree diversity and food production is possible, with no trade-offs

• Few examples of successful agroforestry systems in SDTF

• Increasing yield in these systems still a challenge

• High value products from trees are unexplored (reduce biodiversity and ecological complexity)

• Maize-beans AFS and SPS represent a wildlife-friendly farming strategy (corridor and landscape integrity)

Final remarks: agroforestry systems on the SDTF

• Compensations

• These results could assist to develop mechanism to promote an agriculture with trees

• But how to make PES likely in HN, NI or SV?

• Compensation through certification also challenging: no like coffee or cocoa (certification), but maybe livestock?

• Other mechanisms to incentive the AFS (credits)

Final remarks: up/out-scaling of agroforestry systems


Thanks!

Métodos: Parcelas de muestreo

20 m

50 m

Vegetacion de arbustos y arboles con dap > 2.5 cm

33 m

33 m

Vegetacion de arbustos y arboles con dap > 2.5 cm

Bosque, SSPP

SAQ, Agricultura


Data analysis


Métodos: Esquema general de trabajo

Field measurement

s

Tree measurements Soil and litter Dry Matter and SOM

Diversity analysis

Biomass stimation by allometric equations

Litter C estimation /ha

Soil Carbon estimation /ha

Total C stock /ha

Métodos: Muestreo de hojarasca y suelos

Fase de campo

Muestreo de raíces y hojarasca

Cinco puntos de muestreo de la hojarasca y las raíces finas por parcela

En cada punto de muestreo -Residuos en 0.25 m2 recolectado

Suelos 0-10 y 10-20 cm

Land Use Systems

Family Tree specie % of the total

TCS

Boraginaceae Cordia alliodora 26.3Bignonaceae Tecoma stans 21.1Burserac eae Bursera simarouba 15.8Fabaceae Gliricidia sepium 15.8

NP

Bignonaceae Tecoma stans 16.8Boraginaceae Cordia alliodora 15.6Mimmosaceae Acacia velutina 12.0Rhamnaceae Karwinskia calderonii 8.4

SPS

Rhamnaceae Karwinskia calderonii 18.6Rhamnaceae Tecoma stans 14.0Boraginaceae Cordia alliodora 8.4Simaroubaceae

Alvarodoa amorphiodes

6.5

QSMAS

Boraginaceae Cordia alliodora 15.0

Fabaceae Lonchocarpus minimifolius

14.5

Rhamnaceae Karwinskia calderonii 13.4Bignonaceae Tecoma stans 9.0

TSF

Mimmosaceae Lysiloma divaricatum 16.6Bignonaceae Tecoma stans 8.5Rhamnaceae Karwinskia calderonii 7.9Ebenaceae Diospyros salicifolia 7.8

Land Use Systems

TCS NP SPS QSMAS SF

Dea

th w

ood

Bio

mas

s (M

g ha

-1)

0

1

2

3

4

Land Use Systems

TCS NP SPS QSMAS SF

Litt

er +

her

bs B

iom

ass

(Mg

ha-1

)

0

1

2

3

4

Results

Science

Carbon and tree diversity in agricultural systems in Nicaragua: do trees really make a difference?