摘要
植被净生产力(Net Primary Productivity,NPP)变化机理是全球变化碳循环研究的重要内容。城市群地区人类活动与自然环境交互强度大,植被净生产力变化原因较为复杂,尚没有明确解析。本研究以京津冀城市群作为研究区,分别考虑林地、草地、耕地以及建成区的NPP,通过数理统计和土地转移矩阵方法,归纳了2001-2018年期间典型地物类别NPP的时空特征;识别了影响各土地类型NPP变化的主要因素;定量化阐明了土地类型转移导致的城市群各土地利用类型以及整个区域NPP的净变化。得出主要结果:(1)京津冀全域NPP总量随时间波动增加,各土地类型NPP总量增加。(2)耕地、草地NPP变化与降水相关性更高,林地NPP总量的提升主要是由于林地面积大幅增加,建成区NPP增加主要是由于城市植被绿度的增加。(3)林地单位面积均值最高(0.459 Kg C/m^2),其次是草地(0.4 Kg C/m^2)、耕地(0.337 Kg C/m^2),建成区最小(0.274Kg C/m^2)。因此,林地转出导致NPP减少0.062 Tg C,草地和耕地由于部分转为林地,转出NPP分别净增0.565和0.718 Tg C。(4)林地NPP转入量大,转出量小,林地NPP净增8.413 Tg C;草地转为林地面积较大,草地NPP净减5.467 Tg C,耕地转出量也大于转入量,NPP净减2.340 Tg C。建成区NPP净增0.625 Tg C;京津冀全域由于土地转化导致的NPP净增1.231 Tg C,主要由于林地的NPP增量不仅补偿了其他地类的净减量,还贡献了增量。本研究以定量的方法,较为详细地解释了土地转换过程和转换结果对城市群区域NPP总量变化的影响,可为在土地利用结构较为复杂的区域开展NPP变化机理研究提供参考。
Vegetation Net Primary Productivity(NPP)change is an important part for global change carbon cycle research.The interaction between human activities and the natural environment is very obvious in urban agglomerations,and the causes of changes in the net productivity of vegetation are more complex,which have not yet been clearly explained.In this paper,the Beijing-Tianjin-Hebei urban agglomeration was set as the study area,and the NPPs of forest land,grassland,arable land,and built-up areas are considered.Through mathematical statistics and land transfer matrix methods,the spatiotemporal characteristics of NPPs from 2001 to 2018 were summarized.The main factors influencing the change of NPPs were quantified;the net changes of NPP in the urban agglomeration caused by land transfer were quantified.The main results are as follows:(1)The total amount of NPP in the Beijing-Tianjin-Hebei region increased with time,and the total amount of NPP of each type also increased.(2)Changes in cultivated land and grassland NPP have higher correlations with precipitation.The increase in the total NPP of forest land was mainly due to the substantial increase of forest land,and the increase of NPP in built-up areas was due to the increase in urban vegetation greenness.(3)The average NPP of woodland was the highest(0.459 KgC/m^2),followed by grassland(0.4 Kg C/m^2),cultivated land(0.337 KgC/m^2),and the built-up areas(0.274 KgC/m^2).Therefore,the transfer of forest land caused a decrease of 0.062 TgC in NPP,and the conversion of grassland and cultivated land into forest land resulted in a net increase of 0.565 and 0.718 TgC in transferred NPP,respectively.(4)The amount of received NPP of forest was higher than the export NPP.Hence,the forest NPP increased by 8.413 TgC;many of grassland converted to the forest,which caused the grassland NPP decreased by 5.467 TgC.NPP of cultivated land showed the net reduction of 2.340 TgC.The NPP in built-up areas has a net increase of 0.625 TgC;as a whole,the land conversion caused the net increase of 1.231 TgC in BeijingTianjin-Hebei region.The increase in forest NPP not only compensates for the net decrease of other land types,but also contributes to the net increase of regional NPP.This study quantitative explained the impact of land conversion process and conversion results on the total change of NPP in urban agglomerations and could be the references for related NPP researches in urban area.
作者
孙涛
孙然好
陈利顶
SUN Tao;SUN Ran-hao;CHEN Li-ding(Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of the Chinese Academy of Sciences,Beijing 100049,China)
出处
《环境生态学》
2020年第4期1-8,17,共9页
Environmental Ecology
基金
国家重点研发计划课题(2016YFC0503001)资助。
