Topic C2. Carbon stocks assessment in tropical peat swamp forests

J Boone Kauffman and Mathew Warren

Topic C2. Slide 2 of 27   

Contents Introduction C stocks assessment scheme

• • • • •

General layout Aboveground biomass Belowground biomass Dead wood and litter sampling Soil sampling

Long-term monitoring

Topic C2. Slide 3 of 27    • • • • • 

Why do we care about peatlands?

Peatlands cover 3% of the earth’s land area but contain about 30% of the planet’s soil carbon (C) and about 20% of the earth’s terrestrial fixed C Ecosystem C pools of tropical peat forests are among the largest terrestrial C pools on earth; some sites exceed 2000 tC/ha Disturbances from land-use change and climate change in these unique ecosystems results in exceptionally high GHG emissions These unique ecosystems provide services, such as: biological diversity; maintenance of water quality and timing; forest and non-timber forest products; aesthetic and ecotourism values; carbon sinks (important for climate mitigation strategies).

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Forest carbon stocks

Sources: IPCC (2001); Donato et al. (2011)

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Threats to tropical peat swamp forests:

Deforestation, drainage and fire from land-use and land-use change

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Carbon stocks assessment scheme

Tropical peat forest ecosystem Aboveground pools

Trees >1.3m ht Palms Dead Live by species Shrubs >100 cm dbh 50-100 cm dbh 30-50cm dbh 10-30 cm dbh 0-10 cm dbh Seedlings Herbs Litter pneumatophores Downed wood 0.67cm diam 0.67-2.54 cm diam.

2.54-7.6 cm diam.

>7.6cm diam sound rotten

Belowground pools

Roots Peat soil 0-10cm depth 10-30 cm 30-50 cm 50-100cm 100-200 cm 300-500cm >500cm

Topic C2. Slide 7 of 27

General plot layout

General plot layout to quantify ecosystem C pools in tropical peat forests Trees >5 cm dbh measured in 10 m radius (all plots) D Wood debris transects (4 per plot, all plots) A Trees <5 cm dbh measured in 2 m radius (all plots)

R= 2m

Plot: 1 50m 2 50 m C B Understory/litt er sample (2 per plot, all 4 5 3 soil depth measurements and 1 nutrient core (all plots) 6

Topic C2. Slide 8 of 27

Trees

Topic C2. Slide 9 of 27

Trees >5 cm dbh measured in 10 m radius (all plots)

The circular plots

2 m

Trees <5 cm dbh measured in 2 m radius nested plots

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Tree diameter

a.

Normal tree: DBH is measured at 1.3 m from the surface ground Oblique tree. tree: DBH is measured at 1.3 m from closest surface ground, or parallel with the tilt of the c.

land: DBH is measured at 1.3 meter from the highest surface ground d.

Abnormal tree: if 1.3 meter exactly at the abnormal trunk (swollen), DBH is measured at the immediate normal part, above or below depends on which one is the closest . e.

the branch, DBH is measured below the V part that is normal. f.

Branches tree: if 1.3 meter above the V part, DBH is measured at 2 trunks and considered as 2 trees. g.

Tree with supporting root: DBH is measured 1.3 meter above the root h.

Buttress tree: DBH is measured 20 cm above the buttress.

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Tree biomass - allometric equations,

AGB= ρ

×

exp(-1.239 + 1.98ln(D) + 0.207(ln(D)) 2 -0.0281(ln(D)) 3 )

Source: Chave et al. (2005)

Topic C2. Slide 12 of 27

Belowground biomass

Following Cairns et al. (1997):

Root : shoot ratio for tropical forests biomass:

mean = 0.26; median = 0.21, LQ = 0.14, UQ = 0.31

Root biomass density for tropical forest biomass:

RBD = exp (-1.085+0.9256 (lnAGB))

; where AGB is aboveground biomass (Mg/ha).

Multiply belowground biomass by 0.39 to convert to belowground C stock.

Note: since the C fraction of belowground biomass is different from aboveground biomass, the simple root : shoot ratio

cannot

be applied to estimate belowground C directly.

Topic C2. Slide 13 of 27

Belowground carbon

Belowground C can be calculated directly using the equation:

BGC=AGC

×

0.216

Where: BGC=belowground C AGC=aboveground C, 0.216 is the ratio of BGC to AGC (Calculated from Cairns et al. (1997) default root:shoot of 0.26, default %C AGB=0.47 and default %C BGB=0.39)

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Dead trees

Live Status 1 Status 2 Status 3 For Status 1 and 2 trees, biomass lost from leaves (2.5%) or branches+leaves (15– 18%) is subtracted from the total tree biomass estimated using an allometric equation. Status 3 dead tree biomass and C are estimated using appropriate volumetric formulas (i.e. cylinder or frustrum of a cone) multiplied by wood density and C fraction.

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Dead wood

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Planar intercept

• • • •

Suggestions for wood debris

Measure only wood categories >7.6 cm diameter (2–14 m on tape) 2.5–7.6 diameter for 5 m (9–14 m) Small wood (<2.5 cm in litter plot) 0 m 2 m 9 m Pieces 2.5–7.6 cm measured here 14 m Pieces >7.6 cm measured here

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Dead or downed wood

Equation to determine volume of fine, small and medium wood size classes:

Volume (m 3 ha -1 ) = π 2

×

(N i * QMD i 2 / 8 * L)

Where N i = the count of intersecting woody debris pieces in size class i ; QMD i = the quadratic mean diameter of size class i (cm): QMD = L=transect length (m) Equation for calculating the volume of large (>7.6 cm diam.) downed wood: Where

Volume (m 3 ha -1 ) = π 2

×

(d 1 2 + d 2 2 + d 3 2 + …..d

n 2 / 8 * L)

d 1 , ..d

n , = diameters of intersecting pieces of large deadwood (cm). L = the length of the transect line for large size class (m). Woody debris mass is calculated as the volume multiplied by its mean specific gravity and converted to Mg ha -1 . Generally there will be specific gravity measurements for “sound” and “rotten” decay classes. Dead wood mass is multiplied by its C fraction to determine C stock.

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Litter

Three values are needed: Fresh weight of the litter sample (FW), Fresh weight of a litter subsample (FW s ) and Dry weight of the litter subsample (Dw s ). A moisture correction factor (M) is calculated based on the H 2 O (g) lost from the dried litter subsample:

(Dws/FwsxFW=DW)

. C stock is estimated as C litter =

DW

×

0.45

. Litter C stock must then be scaled to the standard unit Mg/ha by converting the area of the sampling frame to ha, and the weight of the sample to Mg. For example, a 250g dry litter sample from a 0.25m

2 (50cm × 50cm sampling frame) would scale to 10Mg/ha.

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Litter sampling in 2 microplots

• • • Two 50 x 50 cm micro-plots per subplot Includes identifiable organic materials e.g. leaves, twigs, wood/bark fragments, flowers, fruits, seeds, etc.

Usually collected 7 to 10 m away from plot center Wood debris transects (4 per plot, all plots) A D C B Understory/litter sample (2 per plot, all plots, if relevant)

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Soil

0–15 cm depth 15–30 cm 30–50 cm 50–100 cm 100–300 cm >300 cm

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Soil sampling

Soil depth are the Δ’s. The soil core is collected in an undisturbed place near the plot center.

• • • • • 3 soil depth measurements and 1 nutrient core (all plots) Shallow peats (<2 m) sample soil beneath peat; be sure to mark the peat depth Carefully label cans and collect samples Samples for bulk density/carbon concentration should be at least 50 g – about 5 cm in depth Samples should be collected at the mid point of the sample depth (e.g. 7.5 cm, 22.5 cm, 40 cm, 75 cm, 200 cm)

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A

Soil

Use an auger or sampling device designed to sample organic soils (Russian style or peat augers)

B C D

A: Measuring and cutting the sample from the core at the appropriate location. B: Carefully collecting the sample in a labeled aluminum tin. C: Collected 5 cm sample. D: Sample and tin are wrapped in aluminum foil and sealed in a labeled plastic bag.

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Soils are dried at 60

o

C in the lab

Important parameters: Soil Bulk Density (g cm -3 ), % Organic C content, Depth of peat layer Organic soil C stocks are estimated by calculating the C density (Cd) of soil samples (Cd = Bulk Density × %C) and scaling up to Mg/ha. Multiply the Cd of each soil sample by the volume of soil it represents per ha. For example, consider a soil sample from the 0–15cm increment, with BD=160 kg/m 3 and %C=48. Cd = 76.8 kg C/m 3 . Total soil volume per surface m 2 is 1m × 1m × 0.15m = 0.15m

3 , so 76.8 × for this layer 0.15 kg C/m 3 = 11.5 kg C per m 2 for the 0–15cm depth increment. Scaled up, the C stock of this layer is 115 Mg/ha. Sum the C stock from each soil layer to calculate the total soil C pool in Mg/ha.

Topic C2. Slide 24 of 27  

Other aspects for long-term

 

monitoring

GPS coordinates are critical Tree heights

 Hard to accurately and rapidly measure  To facilitate future monitoring via remote sensing tools (e.g. LIDAR, etc.)  So that diameter-height regressions can be built for all trees

Canopy cover

 Using a densiometer  Purpose: To monitor forest canopy cover and to intersect with remote sensing data

Photo documentation

 Systematic photopoints at center of each plot  Reporting purposes, visualization

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References

Chave J, Réjou-Méchain M, Búrquez A, Chidumayo E, Colgan MS, Delitti WB, Duque A, Eid T, Fearnside PM, Goodman RC, et al. 2014. Improved allometric models to estimate the aboveground biomass of tropical trees.

Global Change Biology.

Donato DC, Kauffman JB, Murdiyarso D, Kurnianto S, Stidham M, and Kanninen M. 2011. Mangroves among the most carbon-rich forests in the tropics.

Nature Geosciences

4:293–297. doi: 10.1038/NGEO1123.

Howard J, Hoyt, S, Isensee K, Telszewski M, Pidgeon E (eds.). 2014.

Union for Conservation of Nature.

Coastal Blue Carbon: Methods for assessing carbon stocks and emissions factors in mangroves, tidal salt marshes,and seagrasses

. Arlington, Virginia, USA: Conservation International, Intergovernmental Oceanographic Commission of UNESCO, International [IPCC] Intergovernmental Panel on Climate Change. 2003.

Good practice guidance for land use, land-use change, and forestry

. Penman J, Gytarsky M, Hiraishi T, Krug Thelma, Kruger D, Pipatti R, Buendia L, Miwa K, Ngara T, Tanabe K, et al, eds. Japan: Institute for Global Environmental Strategies.

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References

Kauffman JB, Arifanti VB, Basuki,I, Kurnianto S, Novita N, Murdiyarso D, Donato D, Warren MW (2015).

Swamp Fores

t. CIFOR Working paper (In preparation).

Protocols for the Measurement, Monitoring, & Reporting of Structure, Biomass and Carbon Stocks in Tropical Peat

Kauffman JB and Donato DC. 2012.

Protocols for the Measurement, Monitoring, & Reporting of Structure, Biomass and Carbon Stocks in Mangrove Forests

. Working Paper 86. Bogor: Center for International Forest Research.

Manuri S, Brack C, Nugroho NP, Hergoualc’h K, Novita N, Dotzauer H, Verchot L, Agung C, Putra S, and Widyasari E. 2014. Tree biomass equations for tropical peat swamp forest ecosystems in Indonesia.

Forest Ecology and Management

334(2014):241–253.

[UNEP] United Nations Environment Programme. 2014. The Importance of Mangroves to People: A Call to Action. van Bochove J, Sullivan E, Nakamura T, eds. Cambridge: United Nations Environment Programme World Conservation Monitoring Centre, Cambridge. Warren MW, Kauffman JB, Murdiyarso, D. Anshari G, Hergoulac’h K, Kurnianto S, Purbopuspito J, Gusmayanti E, Afifudin M, Rahajoe J, et al. 2012. A cost-efficient method to assess carbon stocks in tropical peat soil.

Biogeosciences Discuss

9:7049-7071. www.biogeosciences-discuss.net/9/7049/2012/ . doi:10.5194/bgd-9 7049-2012.

Thank you

The Sustainable Wetlands Adaptation and Mitigation Program (SWAMP) is a collaborative effort by CIFOR, the USDA Forest Service, and the Oregon State University with support from USAID.

How to cite this file

Murdiyarso M and Kauffman B. 2015. Carbon stocks assessment in tropical peat swamp forest [PowerPoint presentation]. In: SWAMP toolbox: Theme C section C2 Retrieved from

Photo credit

Boone Kauffman/Oregon State University, Daniel Murdiyarso/CIFOR, Matt Warren/USFS, Neil Palmer/CIAT.