Spatial pattern of net primary productivity and its relationship with climatic factors in Hilly Red Soil Region of southern China: A case study in Taihe county, Jiangxi province
植被净初级生产力(NPP)对气候变化的响应研究是全球变化研究的核心内容之一。在区域尺度上研究NPP年际间的空间变化规律,探究气候因子与植被生长的关系,是应对气候变化区域响应、探讨区域生态过程的科学基础。基于SPOT VEGETATION NDVI植被指数数据、气候和植被分类数据,利用光能利用率模型(CASA)估算了中国南方红壤丘陵区泰和县1998-2012年植被NPP,分析了NPP时空分布特征及其与气候因子的相关性。结果表明:①1998-2012年泰和县植被年均NPP为762 gC/m~2·a,不同植被类型差异明显,空间上表现出东西高、中间低的分布特征;②1998-2012年泰和县植被NPP总体呈增长趋势,年际波动较大,平均值为2.21 * 10~6 g C/a;③研究区NPP与年降水量呈不显著正相关关系,与年均气温呈显著负相关关系,表明温度是影响该地区植被NPP的主要气候因子。
英文摘要:
Net primary productivity (NPP) and its responses to climate change stand one of the focuses of global change research. At the regional scale, it is significant to investigate the annual spatial variation and the impact of climatic factors on vegetation. Based on SPOT VEGETATION NDVI data, vegetation classification data and meteorological data, the spatiotemporal pattern on the NPP of Taihe county during 1988-2012 was simulated by CASA model. Then, the relationship between NPP and climatic factors was investigated deeply. The results showed that average annual NPP from 1988 to 2012 was 762 gC/m~2 ? a in the study region. Spatial dimension is characterized by "high in the middle, but low in the east and west". There was a rising trend in the vegetation NPP during 1988-2012. The annual value fluctuated greatly. Mean NPP in the study area is 2.21 * 10~6 g C/a. It can be found that vegetation NPP showed a weak positive correlation to annual precipitation, while it showed a significant negative correlation to annual average temperature. So, it can be concluded that temperature is the dominant climatic factor affecting vegetation NPP in the study region.