摘要
草地净初级生产力是生态系统碳循环的关键环节和重要组成部分。本研究使用分段线性回归分析和Pearson相关分析,分析了黄土高原2000—2015年间土地利用类型未改变的草地净初级生产力(NPP)的变化趋势及气候核心因子(年降水量、年强降水量、年有效降水日数、年平均温度、年最高温度、年最低温度)对NPP变化的影响,并借助增强回归树逐像素分析了草地NPP的驱动因素。结果表明:2000—2015年,研究区草地NPP总体呈增加趋势,显著增加区域占51.3%。年均NPP的变化速率从2000—2004年间的15.23 g C·m^(-2)·a^(-1)下降到2005—2015年间的3.58 g C·m^(-2)·a^(-1)。黄土高原草地NPP与降水指标呈显著正相关,与温度指标主要呈负相关。年降水量是研究区草地NPP变化最重要的驱动因素且具有最高的平均相对贡献率,年最高温度是高原中部草地NPP的主要限制因素,年最低温度主要影响高原西部高海拔地区的草地生长。
Net primary productivity(NPP)of grassland is a key link and important part of the ecosystem’s carbon cycle.We estimated the changes of NPP in grasslands of the Loess Plateau with unchanged land use types during 2000-2015 and analyzed its responses to the variation of main climate factors(annual precipitation,annual heavy rainfall,annual effective rainfall days,annual average temperature,annual maximum temperature,annual minimum temperature)using piecewise linear regression and Pearson correlation analysis.The driving factors of grassland NPP were further analyzed by pixel-by-pixel with boosted regression tree analysis.The results showed that annual mean grassland NPP in the Loess Plateau showed an increasing trend during the study period,with 51.3%of the total grassland area showing a significant increasing trend.The average increase rate of annual mean NPP declined from 15.23 g C·m^(-2)·a^(-1)in 2000-2004 to 3.58 g C·m^(-2)·a^(-1)in 2004-2015.There was a significant positive correlation between grassland NPP and precipitation,but negative correlation with temperature factors.Annual precipitation was the dominant climatic factor affecting NPP of the whole study area with the highest relative importance.Annual maximum temperature was the dominant driving force of grassland NPP of central Loess Plateau,while annual minimum temperature mainly affected the growth of grassland in high-altitude area of the western Loess Plateau.
作者
刘铮
杨金贵
马理辉
柯增鸣
胡宇美
岩晓莹
LIU Zheng;YANG Jin-gui;MA Li-hui;KE Zeng-ming;HU Yu-mei;YAN Xiao-ying(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,Shaanxi,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2021年第1期113-122,共10页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41671510)
陕西省重点研发计划项目(2020NY-155)资助。
