Presentation on theme: "Assessment of Soil Carbon in Forests, Plantations and Wastelands Dr. M.N.Jha Forest Research Institute Dehra Dun Workshop on “ Forestry and Climate Change."— Presentation transcript:
Assessment of Soil Carbon in Forests, Plantations and Wastelands Dr. M.N.Jha Forest Research Institute Dehra Dun Workshop on “ Forestry and Climate Change - Assessing Mitigation Potential and Costs”, Sept. 23 –24; 2002, India International Centre, New Delhi
SOC is the largest, ca 15X10 14 kg C reservoir at the earth surface. This reservoir responds positively to, Increased photosynthesis. Increased moisture. Directly to increased atmospheric CO 2 by decreasing the SOC decompositions rates. Increased temperature.
We have ignored SOC because we think it is dead biomass and is directly dependent on the amount of live biomass. It neglects following considerations : A. Increased oxidation of SOC to CO 2 by : - Cultivation of new lands (reduces SOC by1/3and converts it to CO 2 ) - Increased temperature which accelerates SOC decay rates. - Conversion of forests to other land uses. - Decreased rainfall will convert SOC to CO 2 by raising temperature and aerobiosis.
Conversely, soil can remove CO 2 from atmosphere by: B. Accumulating SOC beyond receiving increased NPP, via - Increased rainfall which lowers soil temperature and decreases O 2 diffusion rates thereby reducing oxidation rates. - Minimum-or no-tillage agriculture which should increase SOC. - Increasing atmosphere CO 2 can repress SOC degradation rates.
How might soil be affected by climate changes. Changing temperature Altered rate of microbial activity in soil Will cause break down of organic matter at faster rates Will result in greater release of CO 2
Carbon Stored in : Atmosphere1 unit Soil2 units Therefore, change in temperature and increased microbial activity can lead to significant increase of CO 2 in atmosphere
Soil organic carbon in plantations and natural forests Plantation:Soil Organic C (up to 30 cm depth) (age 16 years)(t/ha) Teak68.0 Chir pine57.2 Eucalyptus99.6 Khair79.6 Shisham98.4 Natural Forests: Deodar392.0 Chirpine338.8 Spruce 280.0 Kail272.8 Quercus360.0
Organic carbon store in some Indian Soils (up to 30 cm depth) Area SOC store Total SOC Store (m ha) (t/ha) (Gt) Red soil117.241.2 4.80 Laterite 11.7 120.4 1.40 Alluvial 58.4 32.4 1.90 Brown Forest 21.3 190.0 4.00 Saline/alkali 10.0 13.2 0.13 Black 64.5 18.0 1.10
Soil organic carbon store under different land uses in India Land use Area Organic CStore (up 30 cm depth) (m ha) (t/ ha ) Total Store (G t) Forests75.00120.09.00 Agriculture 150.00 40.0 6.00 Pastures 11.80 40.0 0.44 Barren land18.97 20.00.37
GHG mitigation potential of different land uses with barren land as base. Land useSOC store Mitigation potential (up to 30 cm depth) 1. Barren land20.0 t / ha1.00 2. Pasture40.0 t / ha2.00 3. Agriculture66.0 t / ha3.30 4. Plantations 80.5 t / ha4.02 5. Agroforestry83.6 t / ha4.18 6. Forest 120.0 t / ha 6.00
Carbon sequestration in the wasteland and improvement after afforestation C store (t/ha) C store (No afforestn.) (after 9 yrs. of afforestn.) C store (t/ha) % increase 19.4668.80253.14 Species: Dalbergia sissoo, Prosopis juliflora, Eucalyptus hybrid Site : Eastern U.P.
Sink Expansion Potential of Sodic Wastelands Sink expansion potential (m t) after 3 years6 years 9 years Prosopis49.6112.0252.8 Eucalyptus28.883.2179.2 Dalbergia 11.252.8158.4
Soil Carbon Estimates in Forest Soils Forest/Strata Soil Org. C store (m t) 1984 1994Change Conifers 943.70 969.95 26.25 Teak 765.64 755.09 - 10.55 Sal 905.46 899.86 - 5.60 Bamboo 182.53 181.22 - 1.31 Mangrove 35.86 39.23 3.37 Hollong 0.92 0.82 - 0.10 Khasi pine 17.41 17.30 - 0.11 Salai 13.79 13.93 0.14 Khair 10.86 10.45 - 0.41 Misc. 6555.60 6469.80 - 85.80 - ve changes in SC store has been due to – ve change in the area under different species except in conifers, Mangrove and Salai
Source of Soil Carbon estimates The SOC estimates are based on, - published Indian literature mainly on the work of - FRI, Dehra Dun and sister institutions under ICFRE - other research organizations
Proposal There is a need to formulate a strategy for more precise SOC estimates and monitoring thereafter under different forest covers and also under trees outside forest (TOF) etc.
Approach A joint field programme with Forest Survey of India for precise SOC estimates and monitoring, ensuring full correspondence between forest cover and land area.
Strategy - FSI Survey methodology - SOC estimates and monitoring as programmed by FSI for forest cover & TOF - Soil sampling and carbon estimations as per IPCC guidelines