ENHANCING ECOLOGICAL AND ECONOMICAL BENEFITS IN RUBBER (Hevea brasilensis) PLANTATION UNDER KYOTO PROTOCOL Syed Moazzam Nizami Key Laboratory of Tropical Forest Ecology XTBG- CAS, CHINA

* Increase in CO 2 Conc.(ppm) during the past 315ppm (in1958) to ppm in 2015 (NOAA, 2015) * Need to understand terrestrial global Carbon Cycle

Role of Forests and Plantations was identified in this context. Research revealed that among all the terrestrial ecosystems, forests contain the largest store of C (IPCC, 2000; Malhi, 1999). About 82% of the terrestrial plant biomass in forests is inter-linked with atmospheric CO 2 levels through the carbon cycle. (IPCC, 2001)

 Global Comprehension of importance of Forests/ Plantations  Kyoto Protocol_ An international Treaty for climate change on 11 December  Under Article 3.4 of the Kyoto Protocol the ratifying countries were bind to increase their carbon sinks by changing rotation of the forests to decrease CO 2 conc. in atmosphere.

So the present study was designed to determine the best and efficient Rotation Length (which gives maximum ecological as well as economical benefits) for managing the rubber (Hevea brasilensis) Plantation of Xishuangbanna SW China Objective of the study  Estimation of above and below ground C Stocks in rubber plantation at chronosequence.  Estimation of rubber production in Chronosequence.  Simulating C stocks using CO2Fix Model ver.3.2 for determining most efficient Rotation in light of Kyoto Protocol.

I) Study Site Experiment has been carried out in chronosequence stands of rubber planted in the year 2007, 2002, 1997,1990, 1982 and 1965 in Xishuangbanna, Yunnan South Western China. Lat/Long: 21 o 41`N, 101 o 25`E ; Elevation: 570m; MAR: 1496 mm Cool-dry season (November–February) 17 o C Hot-dry season (March–April) 22 o C and Rainy season (May–October) 25 o C (Cao etal., 1996)

Rubber Stand Established in 1965 (49 years old)

Rubber Stand Established in 1982 (32 years old)

Rubber Stand Established in 1990 (24 years old)

Rubber Stand Established in 1997 (17 years old)

Rubber Stand Established in 2002 (14 years old)

Rubber Stand Established in 2007 (7 years old)

ii) Study was based on: Field inventory in Chronosequence of rubber plantation in Xishuangbanna. Estimation of Diameter at breast height (DBH) and Height of trees. Estimation of volumes (m 3 ha -1 ). Investigation of the rubber production (Mg ha -1 yr -1 ) in the Chronosequence Then the C stocks Simulation using CO2 FIX Model.

ii) CO2FIX V 3.2- A modelling framework for quantifying carbon sequestration in forest ecosystems of the other tree compartments (foliage, branches and roots). Carbon stocks in living biomass are calculated as the balance between growth on the one hand and turnover and mortality on the other hand.  Based on Good Practice Guidance (GPG) on reporting greenhouse gases under 1996 Revised IPCC Guidelines.

The CO2FIX stand level simulation model is a tool which quantifies the C stocks and fluxes in the forest biomass and the soil organic matter. The model calculates the carbon balance with a time-step of one year. Basic inputs are stem volume growth and allocation pattern in the other tree compartments (foliage, branches and roots). Carbon stocks in living biomass are calculated as the balance between growth or turnover rate on the one hand and mortality on the other hand.

The Total Carbon Physically stored in the system at any time (CT t ) is considered as: CT t = Cb t + Cs t Where CT t is Total C stock in ecosystem ; Cb t is the C stock in biomass Cs t is Total C stock in soil; There are 2 Modules in the model: The Biomass Module and The Soil Module

ii) CO2FIX – Structure * Biomass Module Consider C stocks per unit area from biomass of stem, branches, foliage, roots and the mortality of the vegetation. Increase in biomass of each component is calculated in relative proportion to increase in stem growth. Turn over rates are also considered. The Total C Stock in biomass (Cb t )of the whole stand can be expressed as sum of biomasses of each component. Cb t = Ʃ Cb it Where Cb it is the carbon stored in living biomass of each component “i” at time “t” in “Mg ha -1 ”

Biomass Module

ii) CO2FIX – Biomass module So total carbon in vegetation biomass after one complete rotation is Cb it +1 = Cb it + K c [Gb it – Ms it - T it – H it - Ml it ] Where Cb it is the balance between the original biomass; K c is Constant convert biomass to C content (Mg C per t of dry biomass) Gb it is the biomass growth; (CAI) Ms it is the mortality rate due to senescence ( natural) T it is the turnover rate; H it is the mortality due to harvesting Ml it is the mortality due to logging.

ii) CO2FIX – Soil Module Soil C stocks dynamics in soil module is calculated by in built YASSO model in the CO 2 Fix. Yasoo, calculates the amount of soil carbon, changes in soil carbon and soil respiration. Basic Information required: climatic information and decomposition rates from biomass module. The soil module consists of three litter compartments ( Non woody litter ( fine wood litter and coarse woody litter ) and five decomposition compartments (extractives, celluloses, lignin-like compounds, simple humus and complicated humus).

Soil Module

Since the biomass module makes no distinction between fine and coarse roots, root litter is separated into fine and coarse roots according to the proportion between branch litter and foliage litter. Moreover the soil module calculate degree days and Potential evapotranspiration during the growing season from data input of monthly mean temperature ( o C) and growing season.

Model Parameterization For the present study field inventory was carried out to find: DBH(cm), Height (m), tree density (no. of trees ha -1 ), volume (m 3 ha -1 ) CAI ( m 3 ha -1 yr -1 ) was calculated after short field inventory and Generic turnover rate of branches, foliage and roots were taken from (Ren et al., 1999). Wood density (dry) of rubber (0.53 Mg m -3 ) was obtained from Gisel et al., (1992). Decomposition rate of Roots and leaf taken from Nizami et al., (2013)

Glimpse of Field Inventory

Model Parameterization Soil Module Climatic data of the study area i.e mean monthly temperature ( o C) and Precipitation(mm) was pooled from Deng and Tang, (2010). On the basis of mean monthly temperature and growing season the model automatically calculates degree days above zero ( o C) and Potential evapotranspiration in growing season(mm). Decomposition rates of leaf and roots taken from Nizami et al., 2013 and Turn over rates (1/year) of branches, foliage and roots in Rubber Plantation of Xishuangbanna were taken from Ren et al., (1999).

Results C Stocks of the Ecosystem in Chronosequence Highest ( Mg C ha -1 ) at rotation length of 45 years Least (89.86 Mg C ha -1 ) at rotation length of 25 years

Results Above and below ground Carbon dynamics across the different rotation lengths AGBG  25 years: 73.34% and 26.66%  30 years : 73.64% and 26.36%  35 years: 73.36% and 26.64%  40 years: 67.53% and 32.47%  45 years: 66.90% and 33.10%

Results Rate of C input (Mg C ha -1 yr -1 )in above and below ground biomass AG BG Total  45 years: 2.58 and 1.27 = 3.85  40 years : 2.86 and 1.37 = 4.24  35 years: 2.80 and 1.01 = 3.82  30 years: 2.64 and 0.94 = 3.58  25 years: 2.63 and 0.95 = 3.59 Here study revealed that at 40 years we can get maximum ecological benefit of carbon sink.

Results Simulations of C stocks for four consecutive cycles in extended rotations S.No Rotation Length (Yr) C stocks at end of 1 st cycle (Mg C ha -1 ) C stocks at the end of 4 cycles (Mg C ha -1 ) Initial and Final C stocks at four consecutive cycles of five different rotations lengths in Rubber Plantation are as folows:

Simulations of C stocks for four consecutive cycles Rotation 1 st 2 nd 3 rd 4 th

Economics and Ecology of the Rubber Plantation  Allometric model prepared from the data of Rubber production( Mg ha -1 yr -1 ) gathered from Farm Mgt. Committee for the 3-42 years old plantations.  A polynomial relation (R 2 =81) was found between rubber production and age.  Then production (Mg ha -1 yr -1 ) for each rotation was determined using this allometric model.

Economics and Ecology of the Rubber Plantation Here study revealed that 40 years is economically the best rotation age. S.No Rotation Length (Years) Rubber Production (Mg ha -1 yr -1 )

Discussion Reliability of the results Depends on i) how realistically CO2Fix model describes carbon cycling in forest and plantations ii) the parameter values used The data for the study was taken from:  Forest Inventory  Literature reviewed Biomass of branches, Foliage and roots : Deng and Tang (2010) Turn over rates : Ren et al., (1999) Decomposition rates: Nizami et al., (2013)

Discussion Finally we compared the results with the other studies in Xishuangbanna and different part of the world with same ecology Reference Study Area co-ordinates Age Above ground Biomass (Mg ha -1 ) Above ground C Stock (MgC ha -1 ) Soil C Stocks (MgC ha -1 ) (0-60cm) Present Study (2014)21 o 41`N 101 o 25`E Song and Zhang (2010) 21 o 08`N 99 o 56`E Jia et al., (2006)21 o 09`N `E Castillo and Reyes (2004) 14° 08′ N 12°12′ E Huber et al., (2005) 21 o 08`N 99 o 56`E Cotta (2005)20 o 48`S 42 o 52`W Song et al., (2013)21 o 55`N 101°15`E de Ble´court et al., (2013) 21 o 31`N 100 o 37`E Wauters et al., (2008)48 o 55` N 28 o 02`W Wu zhixiag et al., (2009) 19 o 31`N 09 o 28`E Sun (2013)21° 27′ N 100°25′E (at 1m)

Conclusions Annual rate of carbon input (Mg C ha -1 yr -1 ) was highest at the rotation of 40 years in Rubber Plantation. So this age is best in light of Article 3.4 of Kyoto Protocol to enhance carbon sinks in forests. To balance the economics and ecology, the total revenue/income that can be generated from the rubber production at different rotation lengths was determined using the present (Oct, 2014) market USD ha -1 The study revealed that at currently adopted, 35 years rotation length the income from the rubber production is USD ha -1 that can be increased to USD ha -1 by changing the rotation up to 40 years (1USD=6.13 CYN). So ecological maximum carbon input rate and economically maximum income from rubber production can be achieved at 40 years instead of 35 years.

Conclusions The results are thought provoking for policy makers and managers in the context of a potential REDD-plus scenario which a hot issue now a days which additionally considers: conservation of forest/plantation for carbon stocks sustainable management and enhancement of carbon stocks in developing countries.

Acknowledgement This study was supported by the NSFC ( ， U ， ） The "Strategic Priority Research Program" of the Chinese Academy of Sciences ， XDA ， XDA ， XDA ） and the CAS 135 program (XTBG-T03). Special gratitude's to Prof. Dr. Nabuurs & Prof. Dr. Mohren for provision of the CO2FIX Model software.

Nizami Syed Moazzam, Yiping Zhang, Liqing Sha, Wei Zhao, Xiang Zhang Managing Carbon Sinks in Rubber ( Hevea brasilensis ) Plantation by Changing Rotation length in SW China. PLOS ONE: 9(12):e doi: /journal. pone Thanks for your attention!