基于CASA模型的古尔班通古特沙漠植被NPP预估

NPP prediction of vegetation in gurbantunggut desert based on CASA model

【目的】沙漠陆地生态系统在中国碳循环中发挥举足轻重的作用,预估植被净初级生产力(NPP)对于了解区域碳循环有着重要的指示意义。【方法】基于CASA(Carnegie-Ames-Stanford Approach)模型模拟中度发展情景(SSP245)和高度发展情景(SSP585)下2020—2099年古尔班通古特沙漠NPP,采用Sen+Mann-Kendall趋势分析和多元线性回归等方法探究未来NPP变化趋势及其影响因素。【结果】结果显示:在SSP245和SSP585下,2020—2099年古尔班通古特沙漠NPP呈现增加趋势,分别为1.70 gC/(m2·10 a)和4.36 gC/(m2·10 a),呈南高北低的空间格局;在SSP585下增幅更大,与基准期相比,近期(2020—2039年)、中期(2040—2059年)、中远期(2060—2079年)和远期(2080—2099年)的年均NPP将增加18.65%、53.43%、72.27%和93.44%;在SSP245情境下,平均气温、降水量和太阳辐射对植被NPP的贡献率分别为72.47%、13.26%和14.26%;在SSP585情境下,平均气温、降水量和太阳辐射对植被NPP的贡献率分别为77.68%、18.91%和3.41%。【结论】结果表明:在SSP245和SSP585下NPP总体呈现增加趋势,与区域气候暖湿化相关;与SSP245相比,SSP585下气温和降水量对NPP影响贡献率更大,而太阳辐射的贡献率降低。该研究结果能够为减缓和适应气候变化对植被的影响提供参考依据。

[Objective]Desert Terrestrial ecosystem plays an important role in China′s Carbon cycle,and estimating the net primary productivity(NPP)of vegetation is of great significance for understanding the regional Carbon cycle.[Methods]The actual NPP is estimated in Gurbantunggut Desert under the moderate development scenario(SSP245)and highly developed scenario(SSP585)from 2020 to 2099 using CASA model.Sen+Mann-Kendall trend analysis and other analysis method are used to further analyze the trend of future NPP and it′s influencing factors.[Results]Under SSP245 and SSP585,the NPP in Gurbantünggüt Desert show an increasing trend from 2020 to 2099,which are 1.70 gC/(m 2·10 a)and 4.36 gC/(m 2·10 a)respectively,showing a spatial pattern of high in the south and low in the north.Under the SSP585,the increase is even greater.Compared with the benchmark period,the multi-year average NPP of the near term(2020—2039),medium term(2040—2059),medium to long term(2060—2079),and long term(2080—2099)will increase by 18.65%,53.43%,72.27%,and 93.44%respectively.Under the SSP245 scenario,the contribution rates of temperature,precipitation,and solar radiation to NPP were 72.47%,13.26%,and 14.26%,respectively,while the contribution rates of temperature,precipitation,and solar radiation to NPP were 77.68%,18.91%,and 3.41%under the SSP585 scenario,respectively.[Conclusion]Under SSP245 and SSP585,the overall NPP shows an increasing trend,which is closely related to regional climate warming and humidification.Compared with SSP245,the contribution rate of temperature and precipitation on NPP under SSP585 is greater,while the contribution rate of solar radiation is lower.The research result aim to provide reference for mitigating and adapting to the impact of climate change on vegetation.