Fahmuddin Agus Indonesian Soil Research Institute Jl. Tentara Pelajar, No. 12, Cimanggu, Bogor 16114, Indonesia f_agus@litbang.pertanian.go.id MARCO Symposium 2015 Tsukuba International Congress Center, Tsukuba, Japan 26 28 August 2015
INTRODUCTION Coverage DISTRIBUTION, LAND USE AND LAND USE CHANGE PEAT DEGRADATION/COMPACTION SUSTAINABLE MANAGEMENT RESEARCH CHALLENGES
Multifunctional roles of peatland Environmental services: Water storage and regulator Carbon storage Niche of peatland specific biodiversity Agricultural production. Agricultural land is expanding rapidly on peatland, despite its suboptimal inherent fertility Need to balance the two roles, although in many cases they are mutually exclusive
The distribution of Indonesian peatland 14.9 Mha/186 Mha total land area
Peat C density (Agus et al. 2011)
Peat C stock Assume: Peat C density = 0.06 t/m 3 Average depth = 3 m C stock = 1800 t C/ha Biomass of undisturbed forest ~ 200 t C/ha The 14.9 Mha stores about 27 Gt C
Land cover changes of Indonesian peatland Modified from Gunarso et al. (2013) using Ritung et al. (2011) peatland map.
Pristine Peat Forest Stores C above and below ground Rich in biodiversity Regulates water Sembilang National Park, South Sumatra
Degraded forests/shrubs Prone to fire Affected by drainage emit CO2
Agriculture, low input
Intensive vegetable farming
Fruits
Plantations 13
Is peat farming profitable? Analysis using 10% df Land use Location NPV (USD/ha/yr) Oil palm Jambi 896 1.09 Oil palm Riau 2,421 1.21 Rubber C. Kalimantan 4,421 1.60 Maize pineapple W. Kalimantan 315 1.44 Sago palm Papua 478 1.40 Oil palm is the main driver of LUC, despite the higher NPV for rubber: Easy marketing Low labor requirement compared to rubber B/C
Opportunity costs of avoiding deforestation against oil palm development (Herman et al. 2009) Plantation model/ Stakeholder NPV (15% df) USD/ha/yr Opp. cost USD/t CO 2 e Nucleus estate (NE) 310 4.84 Plasma farmer 237 3.70 Nucleus 528 8.25 Large plantation 260 4.05 Assumptions: Mean CO2 emission under oil palm is 64 t CO 2 (ha yr) -1 and under forest it is zero Crude palm oil price was IDR 10,000 kg -1 ; palm kernel price was IDR 6,500 kg -1. df= discount factor
Peat soil degradation Main Indicator Peat subsidence Compaction (shrinkage and consolidation) Carbon loss due to CO 2 emissions heterotrophic respiration peat fire. Lubuk Ogong, Riau: Subsidence + 80 cm 2003-2012 (Photo: Maswar) Subsiden
What happens when the peat is drained? (Page et al. 2012)
What are behind the management of peat forests Management/use Positive impact Negative impact Land clearing New business/income opportunity Timber products Burning Easiest and cheapest clearing system Drainage Opportunity to grow aerobic crops Agriculture Source of income and economic development Improved social status and education Fertilization Increased production Decreased emissions per unit mass of product Biodiversity loss CO 2 emissions CO 2, CH 4, N 2 O emissions Smoke health, transportation problems CO 2 Emissions Fire risks Emissions CO 2, N 2 O N 2 O per unit area
What are the estimate of peat emission from decomposition?
IPCC (2014) Tier 1 (Mg CO 2 /ha/yr) Land cover class Emission factor 95% CI # of research sites 21 Drained peat forest or peat shrub 19 3 35 Long rotation plantation 55 37 77 Short rotation plantation, such as Acacia 73 59 88 Oil palm plantation 40 21 62 Plantations with <0.3 m drainage 6 8 20 Annual crops, bareland 51 24 95 Annual crop, paddy 34 1 73 Grassland 35 17 62 n.a. 13 10 5 10 6 n.a.
Mean +STD of CO 2 flux at different sites (Husnain et al. 2014) Land use Code Mean STD CO 2 flux (Mg CO 2 ha 1 year 1 ) Mean STD WT (cm) Mean STD temperature ( o C) 1 2 4 5 6 Oil Palm J OP 6 38±2 54±22 27.1±1.3 J OP 15 34±16 n/a 29.1±2.9 J OP 14 45±25 n/a 26.7±1.7 R OP 4a 66±25 72±37 30.6±2.7 Acacia R Ac 3 59±19 81±24 28.6±1.0 Secondary forest R SF 61±25 81±25 27.3±2.5 Rubber R Rb 6 52±17 67±25 28.6±2.8 Bareland R BL p 67±24 67±27 29.8±3.1 R BL q 56±26 74±23 30±3.2 R BL r 66±27 69±29 31±2.2 In column 2, research sites J = Jambi and R = Riau; land uses OP= Oil Palm, Ac = Acacia plantation, SF = Secondary forest, Rb = Rubber (Rb) and BL = Bareland; the numbers at the end of column 2 indicate plant age, where applicable. STD = standard deviation; WT = water table depth.
Water table effects (Hooijer et al. 2014)
Water table is associated with WFPS (Husen et al. 2014) A: surface peat samples (0-20 cm) B: subsurface peat samples (30-50 cm) Saturated condition had a greater effect in reducing microbial activity than dryer condition suggesting that water saturation is effective in peat emission reduction.
Peat fire emissions Fire is affecting AG vegetation Fire also burns peat layer IPCC (2006) IPCC (2014) Supplement to the 2006 IPCC Guidelines
Peat fire Forest fire Peat fire One of the major sources of emissions, but high uncertainty of activity data
Degraded peatland is a subscriber of peat fire 60 cm deep burn scar from 6 days event in Oct 2014, emitting about 300 ton CO 2 -C ha -1 or 1101 CO 2 ha -1 60 cm layer burnt in 6 days Photo: Maswar, 8 Oct 2014 Photo: Maswar, 8 Oct 2014
Eqn: 2.8 (IPCC 2014) L fire A M B C f G ef 10 3 L fire = amount of CO 2 or non CO 2 emissions, tonnes A = total area burnt annually, ha M B = mass of fuel available for combustion, tonnes ha 1 (i.e. mass of dry organic soil fuel) (default values in Table 2.6; units differ by gas species) C f = combustion factor (burning efficiency) ~1.0 G ef = emission factor for each gas, g kg 1 dry matter burnt (default values in Table 2.7)
Is the area of burnt scar easy enough to determine? Burn scar Peat dome Tier 1: Area of burn scar, usually based on MODIS hotspot. But high uncertainty in translating hotspot to fire and uncertainty differentiating fire from peat fire
How does the government deal with peat fire? Despite the uncertainty, the high emissions and air pollution from peat fire is certain. Regulations ban the use of fire and plantation companies are responsible to control fire
How to slow down the peat degradation
1. Avoid/minimize deforestation through regulatory measure (to large plantation) and incentive measures (to smallholders) 2. Ban the use of fire and fire control 4. Paludiculture 3. Minimize water table depth
Future research challenges Regionalized research for generating peat CO2 emission factors, especially on the relationship of water table depth and emissions Improved methodology of peat fire activity data determination Fire control technologies Exploration of economically competitive crops under undrained system (paludiculture)