摘要
植被净初级生产力(Net primary production,NPP)是陆地生态系统碳循环及能量流动的关键参数,表征生态系统质量状况。基于2001—2019年MOD13A1、MCD12Q1、TERRACLIMATE等数据,利用CASA模型,估算了近20 a来塔里木河下游生态输水条件下天然植被NPP的时空变化趋势;通过Slope趋势分析和Person相关分析法,从时空分布、不同植被类型和不同累积输水量方面分析了生态输水工程对塔里木河下游天然植被生长状况的影响。结果表明:(1)在近20 a间,塔里木河下游天然植被NPP整体呈上升趋势,其中极显著增加和显著增加的面积分别占总面积的31.93%(P<0.01)和11.49%(P<0.05),平均增速为0.40 g C·m^(2)·a^(-1)。(2)在横向上,塔里木河下游天然植被NPP随着与河道距离的增加而下降;纵向上,沿河道自上而下,天然植被NPP依次表现为:上段(28.21 g C·m^(2))>中段(18.70 g C·m^(2))>下段(13.55 g C·m^(2))。(3)对不同植被类型NPP而言,柽柳群落(57.37 g C·m^(2))>胡杨群落(29.29 g C·m^(2))>草本群落(23.23 g C·m^(2)),且柽柳群落在生态输水过程中NPP增幅也最大,增幅达350.20%。(4)地下水埋深和天然植被NPP均与累积3 a的生态输水量相关性显著,相关系数分别为:-0.70(P<0.01)、0.62(P<0.01),年内总输水量与下一年地下水埋深相关性明显高于与当年地下水埋深的相关性;此外,随地下水埋深持续稳定回升,2010—2019年天然植被NPP与地下水埋深相关性也明显增强(R^(2)=0.62)。
Vegetation net primary production(NPP)is a key parameter of the carbon cycle and energy flow in terrestrial ecosystems that characterizes the quality the latter.This article estimated the spatiotemporal of the NPP natural vegetation over the last 20 years under the condition of ecological water conveyance in the lower reaches of Tarim River,Xinjiang,China based on the CASA model.Meanwhile,the impact of ecological water conveyance projects on the growth of natural vegetation in the lower reaches of Tarim River was analyzed from the perspectives of spatiotemporal distribution,vegetation type,and cumulative water transfer through slope trend and Pearson correlation analyses.Several interesting results were obtained.(1)The NPP of natural vegetation in the lower reaches of Tarim River showed an overall upward trend,with an average growth rate of 0.40 g C·m^(-2)·a^(-1).Extremely significant increases,significant increases,and insignificant changes in the areas accounting for 31.93%(P<0.01),11.49%(P<0.05),and 52.03%,respectively.(2)Horizontally,the NPP of natural vegetation in the lower reaches of Tarim River decreased as the distance from the river channel increased in the following order:0-1000 m>1000-2000 m>2000-10000 m.From top to bottom along the river channel,the NPP of natural vegetation decreased in the following order:upper section(28.21 g C·m^(-2))>middle section(18.70 g C·m^(-2))>lower section(13.55 g C·m^(-2)),with the largest increase of 61.39%in the middle segment.(3)In terms of vegetation type,the NPP of natural vegetation decreased in the following order:Tamarix community(57.37 g C·m^(-2))>Populus euphratica community(29.29 g C·m^(-2))>herbal community(23.23 g C·m^(-2)).Among the vegetation types studied,the Tamarix community showed the greatest increase in NPP(350.20%)during ecological water conveyance.However,the characteristics of NPP changes in the Tamarix,P.euphratica,and herbal communities,the growth period of which is April-October,during the year were similar:NPP increased slowly from Apr
作者
张静静
郝海超
郝兴明
范雪
李远航
ZHANG Jingjing;HAO Haichao;HAO Xingming;FAN Xue;LI Yuanhang(State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;National Field Scientific Observation and Research Station of Akesu Oasis Farmland Ecosystem,Aksu 843017,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Life Sciences,Xinjiang Normal University,Urumqi 830054,Xinjiang,China)
出处
《干旱区地理》
CSCD
北大核心
2021年第3期708-717,共10页
Arid Land Geography
基金
中国科学院战略性先导科技专项(XDA20100303)
西部之光交叉团队项目(028410101)。
