摘要
基于MODIS NPP、EVI遥感影像,采用MVC法、一元线性回归法与Pearson相关分析法,探讨天山北坡昌吉州草地植被时空动态及其对同期气温、降水的响应。结果表明:2000—2020年,草地植被NPP、EVI均为跃动式显著递增,2016年后呈逐年递减;NPP、EVI多年均值为0.095 kg C·m^(-2)、0.186;相较于2000年(NPP=0.077 kg C·m^(-2)、EVI=0.166),2020年NPP(0.099 kg C·m^(-2))、EVI(0.194)分别增长了28.57%、16.87%。草地NPP空间异质性显著增加并呈扩大趋势,EVI空间差异逐年递增,变化范围分别为0.038 kg C·m^(-2)(NPP)、0.059(EVI)。在空间上,NPP、EVI多年平均分布具有差异;总体上,NPP、EVI随海拔升高而增加,但绿洲边缘、古尔班通古特沙漠南缘分布有高位EVI,面积占比65.01%的NPP与21.93%的EVI显著递增。9种草地类型植被NPP、EVI与降水呈显著正相关的面积占比远大于同期气温,不同类型草地对降水的响应具有差异。降水是草地植被的重要影响因子,但高海拔区域的适度增温有益于草地植被生长。
As the most widespread ecosystem on Earth,grassland is vital for maintaining ecological security,sustainability,and human well-being.In this study,we used systemic methods of maximum synthesis,regression analysis,and partial correlation analysis to investigate the spatiotemporal dynamics of grassland and its responses to temperature and precipitation on the northern slope of the Tianshan Mountains in Changji Hui Autonomous Prefecture,Xinjiang,from 2000 to 2020.The research was based on remote-sensed time series images(e.g.,MODIS NPP and EVI)and related auxiliary data.The results indicate a significant increase in grassland NPP and EVI from 2000 to 2020,with temporal fluctuations.However,after 2016,both NPP,and EVI declined year over year.Over the past 20 years,the mean average NPP,and EVI of grassland vegetation were 0.095 kg C·m−2 and 0.186,respectively.In 2020,grassland NPP(0.099 kg C·m−2)and EVI(0.194)increased by 28.57%and 16.87%,respectively,compared to their values in 2000(NPP:0.077 kg C·m−2;EVI:0.166).The spatial heterogeneity of grassland vegetation NPP increased substantially and showed a trend toward expansion,while the spatial heterogeneity of grassland EVI increased annually.The range of variation observed during this research was 0.038 kg C·m−2 for NPP and 0.059 for EVI.Overall,the spatial distribution of grassland NPP and EVI was generally coherent,but variations also existed.Grassland NPP and EVI showed an upward trend with altitude,with an elevated EVI along the oasis edge and the southern edge of the Gurbantunggut Desert.In this study,we suggest that abundant water and heat induce the formation of vigorous layers of short-lived plants,resulting in higher coverage than other grassland plants after withering.These short-lived plants begin their life cycle in early spring,when hydrothermal conditions(e.g.,temperature,soil moisture,and root zone soil temperature)are favorable,and they complete their germination,growth,fruiting,and withering phases from April to June.The area percentages o
作者
陈春波
李均力
赵炎
夏江
田伟涛
李超锋
CHEN Chunbo;LI Junli;ZHAO Yan;XIA Jiang;TIAN Weitao;LI Chaofeng(State Key Laboratory of Desert and Oasis Ecology,Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;Joint Laboratory for Remote Sensing Observation of Grassland Ecosystem in Arid Area,Urumqi 830049,Xinjiang,China;Grassland Work Station of Changji Prefecture,Changji 831100,Xinjiang,China;Ruichang Design Institute Co.,Ltd.,Urumqi 830049,Xinjiang,China)
出处
《干旱区研究》
CSCD
北大核心
2023年第9期1484-1497,共14页
Arid Zone Research
基金
2020年自治区创新环境(人才、基地)建设专项-自然科学计划(自然科学基金)青年科学基金项目(2020D01B57)
天山英才科技创新团队(2022TSYCTD0006)
第三次新疆综合科学考察项目(2021XJKK1403)
2022年中央财政林业草原(草原生态修复治理补助)技术支撑项目(XJCYZZ202201)
2021年中央财政林业草原生态保护恢复资金(草原生态修复治理补助)项目(XJ⁃CYZZ202104)
2020年第一批中央财政林业草原生态保护恢复资金(草原生态修复治理补助)项目(XJCYZZ202001)
新疆维吾尔自治区草原总站草原生态修复治理补助监测及科技支撑项目(XJCYZZ202001)。
关键词
草地
短命植物
暖湿化
MODIS
NPP
MODIS
EVI
时空动态
天山北坡
grasslands
ephemeral plants
warm humidification
MODIS NPP
MODIS EVI
spatial-temporal dynamics
the northern slope of Tianshan Mountains
