1981～2000年中国陆地生态系统NPP时空变化特征分析

利用GLO-PEM模型估算了1981~2000年中国陆地生态系统植被净第一性生产力（NPP）。结果表明：1981~2000年中国总NPP呈现增加趋势,从1981年的2.82 PgC/a增加到2000年的3.13 PgC/a,年均增加0.0155PgC/a,20 a间NPP的平均值为2.98 PgC/a,约占全球NPP总量的4.7%~5.0%。NPP积累主要发生在4~10月,春季、夏季、秋季、冬季NPP量分别占全年总量的15.68%,54.54%,25.50%,4.2%。其中夏季NPP增长最快,占全年NPP增长的64.14%。全国NPP年均值从西北向东南方向呈逐步增加趋势,不同植被类型中,常绿阔叶林年均NPP最高,达745.68 gC/m2,除农业植被外各种植被类型的月均NPP最大值都出现在7月,最小值都出现在1月。经向剖线NPP变化规律不明显。纬向40°N线是南北分界线,往南随着纬度的降低,剖线平均NPP逐渐升高,往北随着纬度的增加,剖线平均NPP逐步变大。纬向剖线NPP均值最高的是20°N线,异质性最高的是30°N线。

Spatiotemporal pattern of NPP in terrestrial ecosystem of China from 1981 to 2000

GLO-PEM model was applied to estimate Net Primary Productivity（NPP） of terrestrial ecosystems in China from 1981 to 2000.The results indicated that the NPP increased from 2.82 PgC/a in 1981 to 3.13 PgC/a in 2000 in China.The mean NPP was 2.98 PgC/a,making up nearly 5.0% of the global NPP.NPP was accumulated during April to October within a year.The NPP in summer increased rapidly,accounting for 64.14% of the total of annual NPP.The annual NPP increased gradually from northwest to southeast in the distribution, and that in evergreen broad-leaved forest was the highest among different vegetation types, reaching 745.68 gC/（m^2·a）. Monthly average NPP of all vegetation types except agricultural vegetation reached the maximum in July and the minimum in January. Meridional NPP changed irregularly. 40°N latitude was the North-South demarcating line, and mean zonal NPP in the south of the line increased gradually as the latitude lowered. The mean zonal NPP reached the peak value in the 20°N latitude while there was the highest heterogeneity in the 30°N latitude.