title: Determining the contributions of urbanisation and climate change to NPP variations over the last decade in the Yangtze River Delta, China.
abstract: Terrestrial net primary production (NPP) is an important measure of global change, and identifying the relative contributions of urbanisation and climate change to NPP is important for understanding the impact of human and natural influences on terrestrial systems and the carbon cycle. The objective of this study was to reveal how urbanisation and climate drive changes in NPP. Satellite-based estimates of NPP collected over a 12-year period (1999-2010) were analysed to identify NPP variations in the Yangtze River Delta. Temporal and spatial analysis methods were used to identify the relationships among NPP, nighttime light urbanisation index values, and climatic factors from pixel to regional scales. The NPP of the entire Yangtze River Delta decreased slightly at a rate of -0.5 g C m(-2)a(-1) from 1999 to 2010, but this change was not significant. However, in the urban region, NPP decreased significantly (p<0.05) at a rate of -4.7 g C m(-2)a(-1) due to urbanisation processes. A spatially explicit method was proposed to partition the relative contributions of urbanisation and climate change to NPP variation. The results revealed that the urbanisation factor is the main driving force for NPP change in high-speed urbanisation areas, and the factor accounted for 47% of the variations. However, in the forest and farm regions, the NPP variation was mainly controlled by climate change and residual factors.
authors.affiliation: School of Geographic and Oceanographic Sciences, Nanjing University, 163 Xianlin Road, Nanjing, Jiangsu 210023, PR China. Electronic address: wsh@nju.edu.cn.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Wu
authors.affiliation: School of Geographic and Oceanographic Sciences, Nanjing University, 163 Xianlin Road, Nanjing, Jiangsu 210023, PR China.
authors.forename: Shenglu
authors.initials: S
authors.lastname: Zhou
authors.affiliation: School of Jinling, Nanjing University, 8 Xuefu Road, Nanjing, Jiangsu 210089, PR China.
authors.forename: Dongxiang
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Geographic and Oceanographic Sciences, Nanjing University, 163 Xianlin Road, Nanjing, Jiangsu 210023, PR China.
authors.forename: Zongqiang
authors.initials: Z
authors.lastname: Wei
authors.affiliation: School of Geographic and Oceanographic Sciences, Nanjing University, 163 Xianlin Road, Nanjing, Jiangsu 210023, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Dai
authors.affiliation: Department of Geography, University of Kansas, Lawrence, KS 66045, USA.
authors.forename: Xingong
authors.initials: X
authors.lastname: Li
mesh_terms: D002681:China; D057231:Climate Change / Q000706:statistics & numerical data*; D055669:Ecological and Environmental Phenomena; D004777:Environment; D004784:Environmental Monitoring; D045483:Rivers; D014197:Trees; D014507:Urbanization / Q000639:trends*
keywords: Climate change; NPP; Relative contributions; Urbanisation; Yangtze River Delta