干旱对江西省森林生产力的影响特征

Characteristics of drought effects on forest productivity in Jiangxi Province

利用MODIS遥感数据等驱动生态过程模型,模拟分析了2000-2011年江西省森林总初级生产力(GPP)、净初级生产力(NPP)和净生态系统生产力(NEP)的时空变化特征及其对气象干旱的响应。结果表明,2000-2011年江西省受旱程度较之前的30 a有所加剧,2003,2004,2007,2009和2011等年份的干旱较为严重,其中,2003,2007和2011年遭受中度干旱以上地区分别占全省总面积的56.5%,73.3%和87.2%。2000-2011年间全省森林的平均年GPP的年际波动明显,略有下降;平均年NPP和NEP呈明显下降趋势(p=0.02,p=0.06)。森林生产力变化受干旱严重程度、干旱发生和持续时间等共同影响,轻度干旱不会导致森林生产力下降(2004年)、春旱(2011年)和夏旱(2003年)以及多季节干旱(2007年春旱和秋旱)则导致森林生产力降低。干旱对江西省森林生产力影响的时间效应较短,大部分地区的干旱会影响当月的NPP和NEP,仅在江西省东部和南部地区,干旱对森林NPP的滞后影响会达到3个月。

This paper simulates and analyzes spatiotemporal variation characteristics of gross primary productivity （ GPP）, net primary productivity （ NPP）, and net ecosystem productivity （NEP） of forest in Jiangxi Province dur- ing 2000 -2011 and their responses to meteorological drought by using remote sensing data and process-based mod- el. Results show that different degrees of droughts, as indicated by standard precipitation index （ SPI）, extensively hit forest ecosystems in Jiangxi Province during 2000 -2011, particularly in 2003, 2004, 2007, 2009 and 2011. The regional mean value of SPI was below than - 1.0 in 2003, 2007, and 2011, with 56.5%, 73.3%, and 87.2% areas hit by moderate drought. During the past 12 years, the mean annual GPP of forest in Jiangxi Province exhibited significant variations between years and negligible decreasing trend, while the mean annual NPP and NEP NEP of forest at current ere lagged effects reach 3