陕北风沙过渡带植被净初级生产力变化特征及原因  

Spatial and Temporal Patterns of Net Primary Productivity and Their Attribution in Wind Drift Sand Region in Northern Shaanxi

作　　者：倪向南 郭伟[1] 乔凯[1] Ni Xiangnan;Guo Wei;Qiao Kai(Department of Earth and Environmental Sciences,Xi ＇an Jiaotong University,Xi ＇an 710049,China)

机构地区：[1]西安交通大学地球环境科学系,陕西西安710049

出　　处：《中国沙漠》2018年第4期889-898,共10页Journal of Desert Research

基　　金：国家自然科学基金项目(41301007);中央高校科研支持计划项目(xjj2013079)

摘　　要：基于光能利用率原理,采用CASA(Carnegie-Ames-Stanford-Approach)模型,实现了2000—2014年陕北风沙过渡带地区植被净初级生产力(NPP)估算,对该地区NPP时空变化以及驱动机制进行了定量化分析。结果表明:(1)2000—2014年陕北风沙过渡带NPP为6.71×1012gC·a^(-1),单位面积值为202.57gC·m^(-2)·a^(-1),受地貌和气候特征影响,植被空间异质性强,黄土区植被明显优于风沙区;(2)近十几年来该区域植被得到明显改善,NPP总体增速为10.98gC·m^(-2)·a^(-1)(R=0.85,P<0.01),植被增速存在空间差异,东南部的黄土区植被增长较快,西北风沙区植被增长较慢;(3)2000—2014年,降水、气温和辐射与NPP的相关系数分别为0.54(P<0.05)、-0.25、0.35,三者对植被增长的贡献量分别为3.95、0.71、2.75gC·m^(-2)·a^(-1)。这说明降水是气候因素中影响陕北风沙过渡带植被变化的主要因素;(4)近15年的植被恢复过程中,气候和人类活动都是重要的驱动因素,气候因子对植被增长的贡献更大,相对作用达到67.49%。区域内部,不同地区植被的主要驱动源存在差异,东部地区植被受气候因子主导,西部地区植被受人类活动主导。Based on the principles of energy efficiency and the use of CASA model,this study estimated terrestrial net primary productivity（NPP）of the wind drift sand region in northern Shaanxi,to analyze the spatial and temporal patterns of NPP and its driving mechanisms during 2000—2014.The main conclusions are as follows：（1）The annual NPP of wind drift sand region in northern Shaanxi from2000 to 2014 was 6.71×1012 gC·yr^-1,the average unit area of NPP was 202.57 gC·m^-2·yr^-1.Spatial heterogeneity of vegetation was caused by differences of landform and climate.The vegetation of loess area had higher NPPthan that of sandy area.（2）NPPin study area showed a signal upward trend during 2000—2014（10.98 gC·m^-2·yr^-1,R=0.85,P〈0.01）.And NPPtrend had spatial heterogeneity in wind drift sand region in northern Shaanxi.Vegetation in loess area showed a higher upward trend than that in sandy area.（3）During 2000—2014,the correlation coefficient of precipitation,temperature and solar radiation with NPPover the entire region were 0.54（P〈0.05）,-0.25,0.35.And the contribution of precipitation,temperature and solar radiation to NPPtrend were 3.95,0.71 and 2.75 gC·m^-2·yr^-1.Precipitation was the climate factor with the greatest influence on NPPvariation.（4）Climate and human activity were both important driving factors of vegetation change in wind drift sand region in northern Shaanxi.The relative importance of climate factors and human activity were 67.49% and 32.51%,In eastern area,vegetation was mostly influenced by climate variations.And in west,the human activity was the leading factor.

关 键 词：NPP CASA模型 时空变化 驱动因素 

分 类 号：Q948.15[生物学—植物学]