【摘要】 基于MODIS遥感数据、辐射传播模型和光能利用率模型,估算位于中高纬度的美国伊利诺伊州植被吸收的光合有效辐射（APAR）,结果较好地反映了该地区植被吸收的光合有效辐射的时空分布。2006-2016年该地区APAR年均值介于35. 10～39. 58 W·m^-2·a^-1,季节变化明显。夏季的APAR均值最高,集中在80～120 W·m^-2·d^-1,其次是春秋两季。基于Mann-Kendall非参数估计方法,模拟了伊利诺伊州地区2006-2016年不同季节平均APAR的变化趋势。夏季,中部、北部的APAR平均值升高幅度最大,为0. 6～1. 0 W·m^-2·a^-1,而南部的平均值呈较为明显的下降趋势;春季,中部范围APAR均值升高;秋季,南部的APAR均值升高幅度较大,而中部和北部变化幅度较小。通过水热条件变化等分析,该地区气温总体在升高,更利于中部、北部的植被生长分布,一定程度上延长了植被的生长季,而南部夏季在相对较高的温度基础上进一步升温,高温抑制植被对辐射的吸收,导致植被吸收的光合有效辐射呈下降趋势。更多还原

【Abstract】 Vegetation absorbed photosynthetic active radiation（ APAR） in Illinois,USA was estimated by CASA model,radiation transmission model and light use efficiency model. The results reflect the spatial and temporal distribution of photosynthetic radiation absorbed by vegetation in this region. From 2006 to 2016,the average annual APAR were between 35. 10 and 39. 58 W·m^-2·a^-1,and seasonal variation was evident. Among the four seasons,the APAR in summer was the largest,about 80-120 W·m^-2·d^-1,followed by spring and autumn. This paper also studied the distribution and variation characteristics over seasons of APAR by using Mann-Kendall method from 2006 to 2016 in this area. In north and middle area,the increased range of average summer APAR was the greatest,about 0. 6-1. 0 W·m^-2·a^-1,while the average summer APAR of south area deceased obviously. The average APAR in south area raised obviously in autumn,and also in middle area in spring. By hydrothermal condition change analysis,the temperature in the region was generally on the rise,which was good for the distribution and growth of vegetation in the middle and in the north and prolonged the vegetation growing season to some extent. However,in the south,temperature was relatively high in summer,temperature increasing inhibited vegetation to absorb radiation and led to APAR decreasing.更多还原