1981～2000年陕西省植被净初级生产力时空变化

为阐明陕西省植被净初级生产力(NPP)变化的整体状况,应用以遥感观测数据驱动的GLO-PEM模式模拟估计的NPP数据,对陕西省1981~2000年间的地表植被净初级生产力的空间分布及时间序列变化进行了综合分析.研究结果表明:(1)20年来,陕西省年NPP变化范围为687~858 g/(m2?a),平均值为749 g/(m2?a);(2)陕西省年平均NPP在波动中缓慢上升,NPP年增长幅度为3.248 2 g/(m2?a);(3)陕西省年平均NPP分布总体呈现从南到北递减的趋势,长城沿线风沙区NPP在200~400 g/(m2?a)之间,是陕西省NPP最低的地区;关中中东部NPP较高,大部在800 g/(m2?a)以上,NPP在1 200 g/(m2?a)以上的面积约占1/3,是全省NPP的高值区;(4)陕西省NPP基本不变(NPP变化百分率在-10%~10%之间)的面积占54.7%,NPP变化百分率增加10%以上的面积占40.5%,NPP变化百分率降低10%以下的面积仅占4.8%;(5)占陕西省总面积的77.3%的区域NPP变化不显著(P>0.05),NPP增加极显著(P<0.01)的区域占8.3%,增加显著(P<0.05)的区域占13.8%,NPP降低显著(P<0.05)和降低极显著(P<0.01)占0.7%.

Spatial and Temporal Patterns of Net Primary Productivity from 1981 to 2000 in Shaanxi Province

To clarify the overall NPP change trends in Shaanxi Province,we estimate the NPP distribution pattern and time series using GLO-PEM model driven by remote sensing observations.The results show:(1)The annual NPP ranged from 687 g/(m2·a) to 858 g/(m2·a),and the mean value was 749 g/(m2·a) from 1981 to 2000 in Shaanxi Province.(2)The annual NPP of Shaanxi Province increased slowly with fluctuation,on an average,3.248 2 g/(m2·a) annually.(3)The annual NPP declined from south to north.The minimum value of NPP was between 200 to 400 g/(m2·a) in the windy and sandy region along the Great Wall;The values of NPP in Central Shaanxi plain were higher,and most of them were above 800 g/(m2·a).The NPP above 1 200 g/(m2·a) accounted for one third,and was high value region.(4)The regions of NPP remained basically unchanged(change rates between-10% to 10%) were about 54.7% of total Shaanxi.The regions of NPP with an increase of over 10% were about 40.5%,and the regions of NPP reduced by 10% were only 4.8%.(5)The regions of NPP with no significant difference(P>0.05) were about 77.3% of total Shaanxi.The regions of NPP increased very significantly(P<0.01) were about 8.3%.The regions of NPP increased significantly(P<0.05) were 13.8%.The regions of NPP decreased significantly(P<0.05)and the regions of NPP decreased very significantly(P<0.01) altogether were 0.7%.