Greenhouse gas emissions are affected by land use type in two agroforestry systems: Results from an incubation experiment

作者：Ping Li, Man Lang, Sixi Zhu, Edward W. Bork, Cameron N. Carlyle, Scott X. Chang · 发表于：Ecological Research · 年份：2020 · DOI：10.1111/1440-1703.12162 · 被引用次数：6 · 研究领域：Soil Carbon and Nitrogen Dynamics、Fire effects on ecosystems、Soil and Water Nutrient Dynamics

Abstract In order to better understand factors affecting greenhouse gas (GHG) emissions in Canadian agroforestry systems, we conducted a laboratory incubation study to assess N 2 O, CO 2 and CH 4 emissions from soils in response to land use (forestland vs. cropland) and agroforestry system type (hedgerow vs. shelterbelt) in central Alberta, Canada. Emissions of N 2 O were lower in soils from forestland than cropland, and forest soils acted as a net sink of atmospheric CH 4 while cropland soils were weak sources of CH 4 . However, the forest soil had higher CO 2 emission rates than the cropland soil within both agroforestry systems. Soil CH 4 oxidation was higher in soil from hedgerow (consisted of natural forest vegetation) than from shelterbelt system (planted forest vegetation), while the former also had lower N 2 O emissions. Overall, soil CO 2 emissions were significantly higher from hedgerow than from shelterbelt systems. Emissions of N 2 O were positively related with gross nitrification rates and soil pH, and negatively related with gross N immobilization rates. The CO 2 emissions were positively related with water‐soluble organic C contents, while CH 4 emissions were positively related with clay content, but negatively with gross N immobilization rates and soil organic C content. The global warming potential was higher in forestland soil than in cropland soil within agroforestry systems, and higher in forestland soil of the hedgerow compared to that in shelterbelts. O...