中国未来土地利用变化对地上植被生物量的影响

土地利用变化通过改变生态系统结构对植被生物量产生很大影响.采用土地利用动态模型模拟了沿历史趋势情景(未来土地利用面积变化由1988-2005年的历史趋势推衍而来)和规划情景下(未来土地利用面积变化基于国家尺度上的土地利用规划来制定)中国至2030年土地利用变化的时空分布格局,基于此格局并结合密度法估算了植被生物量空间分布.模拟结果表明:沿历史趋势情景下,森林面积将减少,但随着林龄的增长,森林生物量密度增加,至2030年中国植被生物量为14619 Tg,比2005年增加了251.19 Tg；规划情景下,森林面积将增加,至2030年中国植被生物量为15468Tg,比2005年增加了1100Tg.在规划情景下,由于人工林面积较大,林龄普遍较低,导致至2030年植被生物量密度低于沿历史趋势情景,因此规划情景下中国植被作为碳汇的潜力更大.

Effects of China future land use change on aboveground vegetation biomass

Land use change has significant effects on vegetation biomass via altering ecosystem structure.By adopting a spatially explicit land use change model,this paper simulated the spatiotemporal pattern of land use change in China till 2030,based on the historical scenario(in this scenario,the land use trend in 1988-2005 was extrapolated to obtain the area of each land use type in the future) and the planned scenario(in this scenario,the area of each land use type in the future was based on the national scale land use planning).On the basis of this simulation and using a biomass density approach,the spatial pattern of vegetation biomass change in China was estimated.The simulation showed that under the historical scenario,the forest area would be decreased but the forest age would be in adverse,and accordingly,the forest biomass density would have an increase.Till 2030,the overall vegetation biomass in China would be 14619 Tg,with an increase of 251.19 Tg as compared to the situation in 2005.Under the planned scenario,the forest area would be increased,and the overall vegetation biomass in 2030 would be 15468 Tg,with an increase of 1100 Tg as compared to the situation in 2005.In the planned scenario,the planted forest area would be larger while the forest age would be younger,resulting in a much lower vegetation biomass density in 2030 than that in the historical scenario,and thus,the China’s vegetation in the planned scenario would have a higher potential to act as a carbon sink.