中国森林植被净生产量及平均生产力动态变化分析

Dynamic Change of Net Production and Mean Net Primary Productivity of China's Forests

根据1973—2008年间7次全国森林资源清查数据及中国森林植被分布特征,从不同森林类型和不同气候带定量分析中国森林植被净生产量及平均生产力动态变化规律。研究结果表明:中国森林植被净生产量和平均生产力总体呈增加趋势,植被净生产量由1973—1976年间的803.359×106t·a-1增加到2004—2008年间的1 478.425×106t·a-1,增加了84.03%;相应的森林植被平均生产力由7.302 t·hm-2·a-1增加到9.502 t·hm-2·a-1,增加了30.13%。不同森林类型中,阔叶混交林、杨桦林、落叶阔叶林和常绿阔叶林对中国森林植被净生产量贡献较大;热带林、阔叶混交林、常绿阔叶林平均生产力较高,油松林和马尾松林平均生产力相对较低。不同气候带中,热带地区森林植被净生产量呈波动中减少趋势,其它气候带呈增加趋势;1973—2008年间各气候带森林植被平均生产力为:热带(18.625 t·hm-2·a-1)>寒温带温带(9.610 t·hm-2·a-1)>亚热带(8.499 t·hm-2·a-1)>暖温带(7.800 t·hm-2·a-1)。

Based on data from the National Forest Inventory from 1973 to 2008, the net production and mean net primary productivity of China＇ s forests were estimated by various forest types and climatic zones. The results showed that, over the last 40 years, the total net production and mean net primary productivity of China＇ s forest was in- creasing. The total net production increased from 803. 359 × 10^6 t · a^-1（ 1973 to 1976） to 1 478. 425 × 106 t·a^-1 （2004 to 2008 ）, with an increase of 84.03%. The mean net primary productivity increased from 7. 302 t · hm^-2 a-1（ 1973 to 1976） to 9. 502 t · hm^-2 · a^-1 （2004 to 2008）, with an increase of 30.13%. The subtropical mixed evergreen-deciduous broadleaved forest, Betula and Populus forest, temperate typical deciduous broadleaved forest and subtropical evergreen broadleaved forest made a greater contribution to the net production of China＇ s forest. The tropical rainforest and monsoon forest, subtropical mixed evergreen-deciduous broadleaved forest and subtropical evergreen broadleaved forest had higher mean net primary productivity, while that of Pinus tabulaeformis forest and P. massoniana forest were lower. Among different climatic zones, the net production of forest vegetation reduced in fluctuations in the tropics, while it increased in all the other three climatic zones. From 1973 to 2008, the relations of the mean net primary productivity in different climatic zones are as follows： tropical （18. 625 t · hm^-2· a^-1） 〉 cold and temperate （9. 610 t· hm^-2 · a^-1） 〉 subtropical （8. 499 t · hm^-2 · a^-1） 〉 warm temperate （7. 800 t · hm^-2 · a^-l ）.