Higher contribution of soil respiration (Rs) to ecosystem respiration (Re) in mixed deciduous forest compared to dry dipterocarp forest Apaporn Bulsathaporn1, Amnat Chidthaisong2 The Joint Graduate School of Energy and Environment (JGSEE) and Center of Excellence on Energy Technology and Environment, KMUTT, Bangkok, Thailand E-mail: apaporn.bul@gmail.com1, amnat_c@jgsee.kmutt.ac.th2 Montri Sanwangsri School of Energy and Environment (SEEN), University of Phayao, Phayao, Thailand, and The Joint Graduate School of Energy and Environment (JGSEE) and Center of Excellence on Energy Technology and Environment, KMUTT, Bangkok, Thailand E-mail: montri.sa@up.ac.th Samreong Panuthai Department of National Parks, Wildlife and Plant Conservation, Bangkok, Thailand E-mail: newsam@3bbmail.com Abstract-Absorbing CO2 from atmosphere into forest is an important ecosystem service from the global warming perspective. However, forest can be either a CO2 source or sink. Soil respiration (Rs) or soil CO2 emission which is a component of ecosystem respiration (Re) is one of the processes determining a sink-source capacity of a forest. In order to improve our understanding of forest carbon exchange, its source-sink capacity and its responses to climate change, enhancing accuracy in assessment of soil CO2 emission in forest is required. This study aims to measure soil CO2 by the newly established method using CO2 profile gradient and to study variations in soil CO2 effluxes in a dry dipterocarp forest (DDF) and a mixed deciduous forest (MDF). During the study periods in dry dipterocarp forest and in mixed deciduous forest for 181 days, we found that the average soil CO2 efflux was 1.9±0.8 and 4.8±2.3 μmol m-2 s-1, respectively. Accumulative soil CO2 emissions of 2.6 kg CO2 m-2 y-1 in DDF were much lower than those of MDF where these emissions reached 6.7 kg CO2 m-2 y-1. In line with this trend, Rs accounted for 44.6% of Re in DDF while reaching 70.9% of Re in MDF. The Rs values of MDF were about 2.6 times higher than those of DDF. This may indicate more active soil and forest floor process including a rapid turnover of carbon in mixed deciduous forest compared to dry dipterocarp forest. At both sites, Rs is strongly related to soil moisture: r2 = 0.61, P<0.01, n = 150 in DDF and r2 = 0.75, P<0.01, n = 136 in MDF. In addition, the soil CO2 probes also enabled us to detect the behavior of soil CO2 emissions during climate variability. Keywords: soil respiration, ecosystem respiration, dry dipterocarp forest, mixed deciduous forest Proceedings of the International Conference on Climate Change, Biodiversity and Ecosystem Services for the 151 Sustainable Development Goals (SDGs): Policy and Practice 27-29 June 2016, Cha-am, Phetchaburi, Thailand
Proceedings of International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals : Policy and Practice 27-29 June 2016 at the Sirindhorn International Environmental Park, Cha-am, Phetchaburi, Thailand
To see the actual publication please follow the link above