基于变异系数的植被NPP人为影响定量研究——以石羊河流域为例  

The impact of human activities on net primary productivity based on the coefficient of variation: A case study of the Shiyang River Basin

作　　者：李传华[1] 赵军[1] 师银芳[1] 胡秀芳[1] 

机构地区：[1]西北师范大学地理与环境科学学院,兰州730070

出　　处：《生态学报》2016年第13期4034-4044,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(41261104)

摘　　要：人类活动是NPP变化的重要影响因子,定量计算NPP人为影响值具有较重要的意义。提出基于变异系数法的NPP人为影响模型,对其基本概念、理论基础、计算流程等进行了阐述,并以石羊河流域为研究区,分析该流域NPP人为影响分布规律。研究结果表明:(1)该模型基于一种间接计算的思想回避了人为作用的复杂过程,模型理论科学,以变异系数为参数,所需参数少,技术可行,计算结果为NPP值,易于定量评价。(2)2000—2010年期间,石羊河流域人类活动对植被NPP的影响广泛而严重,年均影响值大于40g C m^(-2)a^(-1)的面积占96.21%,影响程度严重以上占26.94%。NPP人为正负影响均较大,正影响年均为1.63×106g C m^(-2)a^(-1),负影响年均为1.21×106g C m^(-2)a^(-1),年均净增加4.20×105g C m^(-2)a^(-1);正向平均影响强度为136.84 g C m^(-2)a^(-1),负向平均影响强度为100.32 g C m^(-2)a^(-1),全流域表现为正影响。(3)凉州区是人为影响最为剧烈的地区,表现为强烈正影响;其次是天祝县,为强烈负影响;接下来是民勤县,表现为正影响;其它县区依次是永昌、古浪、肃南和金昌。(4)2000—2010期间,NPP人为影响值变化较大,人为活动减弱面积占53.90%,增加占46.10%;影响值正向减弱8.12×105g C m^(-2)a^(-1),负向减弱8.07×105g C m^(-2)a^(-1),正向增强8.02×105g C m^(-2)a^(-1),负向增强3.94×105g C m^(-2)a^(-1),人为活动影响净减少4.25×105g C m^(-2)a^(-1),人为作用总体呈减弱趋势。Human activities can heavily influence changes in net primary productivity （NPP）, and for this reason, the quantitative calculation of NPP as influenced by humans （NPPH ） has a vital significance. In this paper, a model of human impact on NPP is proposed based on the coefficient of variation. The basic concept, theoretical foundation, and calculation are discussed, and the distribution and variation of NPPHin the Shiyang River Basin are analyzed. The following conclusions were made. （ 1 ） The model is based on the indirect method, which avoids the complexities of human activity In addition, the NPPH model has other advantages, including its scientificity in theory, fewer input parameters as it uses only the coefficient of variation, feasibility and easy obtainability technology, and a straightforward quantitative evaluation of human activity on NPP. （2） The effect of human activity on NPP was widespread and severe in the Shiyang River Basin during 2000--2010. The area with an annual average NPPH value greater than 40 gC m^-2a^-1 was 96.21%, and the area with a degree of human impact greater than severe was 20%. There were two main features when the spatial distribution of the influence of human activil：ies on NPP was considered. The first was the intense positive influence of human activity on three oases （Minqin, Wuwei, and Jinchang） , where there is cultivated land, and the second is the strong negative influence on the junction of Sunan, Tianzhu, Gulang, and Yongchang, where the vegetation consists mainly of grassland and the predominant human-related activity is grazing. Thus, the human impact on NPP was both positive and negative, and significant for both. The average positive annual value as affected by humans was 1.63 ×10^6g C m^-2a^-1 , and the negative value was 1.21 ×10^6g C m^-2a^-1, producing a net value of 4.20 ×10^5g C m^-2a^-1. The positive effect averaged 136.84 gC m^-2a^-1 , and the corresponding negative effect was 100.32 gC m a ; therefore, overall, the Shiyang River Ba

关 键 词：净第一性生产力 变异系数 人为影响模型 石羊河流域 

分 类 号：Q948[生物学—植物学]