Spatiotemporal evolution of vegetative net primary productivity and its
influencing factors in China's Yellow River Basin
Abstract
Ecosystem vulnerability in the Yellow River Basin (YRB) is a prominent
concern. Exploration vegetative net primary productivity (NPP) serve as
an important aspect of assessing and protecting ecosystem health. We
used a range of spatial analysis techniques, residual trend analysis,
and the cutting-edge computing-intensive variable importance
decomposition method to explore spatiotemporal changes and influencing
factors for vegetative NPP in the YRB from 2000–2015. The results found
that NPP showed a fluctuating growth trend over time, ranging from
165.9–227.7 gC∙m-2∙a-1, as well as a clear negative south-north spatial
gradient. Significant spatial agglomeration pattern was observed, with
Low-Low and High-High clusters being the dominated area classifications
at both scales of grid cells, counties and cities in the study area.
Foremost, we found that NPP was statistically significantly affected by
both natural factors, including climate and topography, and human
activities, whilst precipitation accounts for the most important factor,
explaining roughly 42% of the variability in NPP on average. Although
the impact of human activities on NPP was relatively low, human
activities tended to promote NPP on average, mainly due to the
implementation of the ecological restoration project in the region, such
as the Forest Protection and Grain for Green Project. Overall, this
study provides an improved technical framework for a comprehensive
analysis of spatiotemporal pattern of vegetative NPP and its influencing
factors at multiple-spatial scales.