内蒙古NPP时空特征分析及多情景下的预测研究OA

Global warming caused by climate change currently exerts a profound impact on terrestrial ecosystem productivity.As a core indicator of the carbon sequestration capacity of vegetation,spatiotemporal changes in net primary productivity(NPP)directly influence regional carbon-sink functions and ecosystem stability.As an im-portant ecological security barrier in northern China,Inner Mongolia encompasses diverse ecosystems,such as grasslands,forests,and deserts.Its NPP is particularly sensitive to climate change,and any abnormal fluctuations may significantly compromise regional ecological balance and carbon cycling.This study integrated multimodel Coupled Model Intercomparison Project Phase 6(CMIP6)projections,the MOD17A3 NPP dataset,and ERA5-Land reanalysis temperature and precipitation data to systematically analyze spatiotemporal NPP patterns in Inner Mongolia(2001-2024),projecting trends(2025-2100)under four shared socioeconomic pathway(SSP)scenar-ios:SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5.We employed Sen's trend analysis to quantify historical changes and utilized the Delta downscaling method to enhance the accuracy and spatial resolution of CMIP6 cli-mate projections.We also applied Lasso regression to construct a robust multivariate NPP,namely the meteoro-logical relationship model.Taylor diagram analysis was used to identify EC-Earth3-Veg-LR as the best-perform-ing CMIP6 model for the region;this model was subsequently used to drive Lasso-based projections.Results indi-cated that the annual average NPP between 2001 and 2024 was 277.4 g C·m-2,exhibiting a distinct spatial pattern characterized by a"northwest-high,southwest-low"spatial gradient.NPP increased significantly(P<0.05)or ex-tremely significantly(P<0.01)across 20.7%of the region,driven mainly by climatic warming and humidifica-tion,particularly in eastern grasslands.Critically,Delta downscaling significantly resolved CMIP6 projections for regional-scale analysis.Additionally,our projections revealed an oscillatory increase in regional NPP across all four SSP scenarios,although with notable magnitude and spatial heterogeneity differences.The SSP1-2.6(sus-tainability)pathway projected the highest average NPP increase and the most balanced spatial growth across the region.The SSP2-4.5(middle of the road)scenario also showed substantial gains,albeit these were less uniform-ly distributed.The SSP3-7.0(regional rivalry)scenario exhibited the smallest area of significant NPP change,dominated primarily by fluctuation rather than strong upward trends.While the SSP5-8.5(fossil-fueled develop-ment)scenario projected an overall NPP increase,it was characterized by the most pronounced spatial disparities,potentially threatening regional ecosystem stability by exacerbating imbalances.This study quantifies NPP evolu-tionary trends,providing reliable scenario-prediction results based on climate-projection data,offering an impor-tant scientific basis for formulating climate-adaptive ecological management strategies,carbon sequestration plan-ning,and related policies in this ecologically sensitive and strategically significant region.