鄱阳湖流域植被总初级生产力时空变化特征及其气候驱动因子分析

Spatial-temporal Change of Gross Primary Productivity in the Poyang Lake Basin from 2000 to 2013 and Correlation with Meteorologic Factors

植被总初级生产力(GPP)在陆地生态系统和全球气候变化研究中占有重要地位。基于MODIS GPP遥感数据产品、土地覆盖数据和气象观测数据,对2000–2013年鄱阳湖流域GPP的时空变化及其与气候因素的关系进行了分析。结果表明,鄱阳湖流域GPP的年总量变化介于88–2 493 g C·m^(–2)·a^(–1)之间,平均值为1 361 g C·m^(–2)·a^(–1);GPP年总量最小值出现在2002年,最大值出现在2004年。GPP年际变化呈现明显的上下波动现象,并呈缓慢增长趋势。近14年植被GPP年均值在空间分布上表现出由湖区中心向四周散射递增的特点,GPP显著增加的区域占全区总面积的40%,主要分布在研究区东北部。相关性分析显示,气温对GPP年际变化的影响程度强于降水。此外,火灾对GPP的年际变化也具有一定的影响。该研究可为了解研究区的植被生长状况和生态环境质量提供参考。

Study of vegetation gross primary production （GPP） is important for research of terrestrial ecosystems and global climate change. We used MODIS GPP products, land cover type data and meteorological data during 2000 to 2013 to analyze the spatial-temporal changes in GPP and the relation with climatic factors （air temperature and precipitation） in the Poyang Lake basin. The mean annual GPP was 1 361 gC·m^–2·a^–1 （range from 88 to 2 493 gC·m^–2·a^–1）. GPP in 2002 had the lowest mean value and in 2004 the largest. With respect to spatial distribution, GPP values showed a radiative increasing trend pattern, from the center to peripheral areas of the lake valley. The area with obvious GPP increase accounted for 40%, mainly in the northeast of the study region. Correlation analysis showed that air temperature had greater effect than precipitation on changes in annual GPP. As well, fires had some impact on GPP. This study was useful for providing a basis to understand the vegetative growth and monitoring the ecological environment in the Poyang Lake basin.