Journal Article

Characterizing Spatiotemporal Dynamics of Methane Emissions from Rice Paddies in Northeast China from 1990 to 2010

Zhang, Yuan, Su, Shiliang, Gao, Wei, Zhang, Feng, Shi, Runhe

2012

Overview

Rice paddies have been identified as major methane (CH(4)) source induced by human activities. As a major rice production region in Northern China, the rice paddies in the Three-Rivers Plain (TRP) have experienced large changes in spatial distribution over the recent 20 years (from 1990 to 2010). Consequently, accurate estimation and characterization of spatiotemporal patterns of CH₄ emissions from rice paddies has become an pressing issue for assessing the environmental impacts of agroecosystems, and further making GHG mitigation strategies at regional or global levels. Integrating remote sensing mapping with a process-based biogeochemistry model, Denitrification and Decomposition (DNDC), was utilized to quantify the regional CH(4) emissions from the entire rice paddies in study region. Based on site validation and sensitivity tests, geographic information system (GIS) databases with the spatially differentiated input information were constructed to drive DNDC upscaling for its regional simulations. Results showed that (1) The large change in total methane emission that occurred in 2000 and 2010 compared to 1990 is distributed to the explosive growth in amounts of rice planted; (2) the spatial variations in CH₄ fluxes in this study are mainly attributed to the most sensitive factor soil properties, i.e., soil clay fraction and soil organic carbon (SOC) content, and (3) the warming climate could enhance CH₄ emission in the cool paddies. The study concluded that the introduction of remote sensing analysis into the DNDC upscaling has a great capability in timely quantifying the methane emissions from cool paddies with fast land use and cover changes. And also, it confirmed that the northern wetland agroecosystems made great contributions to global greenhouse gas inventory.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Agricultural ecology / Agricultural ecosystems / Agricultural production / Agriculture / Agroecosystems / Air pollution / Analysis / Biogeochemistry / Biology / Carbon footprint / Chemistry / China / Clay soils / Climate change / Computer Science / Computer simulation / Crop production / Denitrification / Earth Sciences / Education / Emergency preparedness / Emission analysis / Emission inventories / Emissions / Environmental assessment / Environmental impact / Fluxes / Geographic information systems / Global warming / Greenhouse Effect / Greenhouse gases / Information science / Laboratories / Land use / Methane / Methane - analysis / Methane emissions / Mitigation / Organic carbon / Organic soils / Oryza - chemistry / Oryza - metabolism / Oxidation / Remote sensing / Reproducibility of Results / Respiration / Rice / Rice fields / River ecology / Rivers / Satellite navigation systems / Science / Social and Behavioral Sciences / Soil carbon / Soil properties / Spatial distribution / Spatial variations / Studies / Time Factors / Wetlands