摘要
基于生态系统碳平衡方程以及净第一性生产力(NPP) 和气候资料反演了1km分辨率的中国土壤异养呼吸系数(aij),结果表明:aij总体上是东南和东北地区高,西北地区低;和NPP相比,东南沿海和华南的大部分地区的aij值并不大,而在东北北部和东部有大面积的aij高值区。这表明当气候适宜时,这些地区的土壤异养呼吸将具有较大的增长潜力。在假定气温平均升高1.5 oC,降水平均增加5%的情景下,对中国净生态系统生产力(NEP) 的研究表明:生态系统与大气的碳通量都有所增加,其中NPP平均增加了6.2%,土壤异养呼吸平均增加了5.5%,不同生态系统的NEP存在很大的差异,其中最稳定最有潜力的自然生态系统的碳汇是北方落叶针叶林;对人工植被而言,最多最稳定的碳汇是一年一熟作物;而双季稻连作喜温作物和单(双) 季稻连作喜凉作物生态系统起着较稳定的碳源作用。
Many factors can impact RH, but up to now most of the researches only consider the climatic factors such as temperature and soil moisture or precipitation. The impacts of soil properties on RH have been ignored, so the models' effect is not as good in large area where soil properties vary greatly as in small area where soil properties vary less. The coefficient of soil heterotrophic respiration reflected the influence of soil properties on RH. Based on carbon balance equations of ecosystems, the 1-km resolution's soil heterotrophic respiration coefficient (aij) in China has been calculated by using net primary production (NPP) of ecosystems and observed climate data. The results show that the value of aij as a whole, is larger in Southeast and Northeast China than that in Northwest China. Compared with the NPP's distribution throughout the country, the value of aij in most parts of Southeast China is not large, but it is large in vast area of Northeast and East China, which indicates that the soil heterotrophic respiration has great increase potential in these regions if climate becomes favorable. And then, the authors simulate the carbon flux change between terrestrial ecosystem and atmosphere on the hypothesis of climate change, the average temperature is 1.5oC higher and average precipitation is 5% more. The results show that both fluxes from atmosphere to terrestrial and from terrestrial to atmosphere increase. The rate of average increase of NPP and soil heterotrophic respiration is about 6.2% and 5.5% respectively. The most powerful natural ecosystem which could accumulate carbon is needle-leaved deciduous forest, and the most powerful agricultural ecosystem which could accumulate carbon is one crop per year. On the contrary, the double cropping rice followed by a cool-loving crop per year and the double cropping rice followed by a thermophilous crop per year are potential carbon sources.
出处
《地理学报》
EI
CSCD
北大核心
2004年第3期357-365,共9页
Acta Geographica Sinica
基金
国家自然科学基金主任基金项目(40352004)
自然科学基金面上项目(40371001)~~
