title: Effects of shrub encroachment on soil organic carbon in global grasslands.
abstract: This study aimed to evaluate the effect of shrub encroachment on soil organic carbon (SOC) content at broad scales and its controls. We conducted a meta-analysis using paired control data of shrub-encroached grassland (SEG) vs. non-SEG collected from 142 studies worldwide. SOC contents (0-50 cm) were altered by shrub encroachment, with changes ranging from -50% to + 300%, with an effect size of 0.15 (p < 0.01). The SOC contents increased in semi-arid and humid regions, and showed a greater rate of increase in grassland encroached by leguminous shrubs than by non-legumes. The SOC content decreased in silty and clay soils but increased in sand, sandy loam and sandy clay loam. The SOC content increment was significantly positively correlated with precipitation and temperature as well as with soil bulk density but significantly negatively correlated with soil total nitrogen. We conclude the main effects of shrub encroachment would be to increase topsoil organic carbon content. As structural equation model revealed, soils properties seem to be the primary factors responsible for the extent of the changes, coarse textured soils having a greater capacity than fine textured soils to increase the SOC content. This increased effect appears to be secondarily enhanced by climate and plant elements.
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: He
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Haihua
authors.initials: H
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Leiyi
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Taoyu
authors.initials: T
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Luhong
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|Inner Mongolia Prataculture Research Center, Chinese Academy of Sciences, Hohhot, 010031, China.
authors.forename: Pujin
authors.initials: P
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|Department of Ecology, College of Urban and Environment, and Key Laboratory of Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China.
authors.forename: Jingyun
authors.initials: J
authors.lastname: Fang
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002980:Climate; D065948:Grassland; D009584:Nitrogen / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D013696:Temperature
chemical_list: D012987:Soil; D002244:Carbon; D009584:Nitrogen