Boreal forests and tundra
Boreal forests and tundra
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北方森林和苔原
DOI：
10.1007/978-94-011-1982-5_3
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
T. Vinson
中科院分区：
文献类型：
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作者：
M. Apps;W. Kurz;R. Luxmoore;L. Nilsson;R. Sedjo;R. Schmidt;L. G. Simpson;T. Vinson
环极地北方生物群落覆盖。北半球 2 109 公顷，包含生物量、碎屑、土壤和泥炭碳池中含有 800 Pg C。目前的估计表明，生物群落目前的净碳汇量为 0.54 Pg C yr−1。森林生态系统的生物量、碎屑和土壤（包括约 419 Pg 泥炭）含有约 419 Pg 的碳。 709 Pg C 并封存估计 0.7 Pg C yr−1。苔原和极地地区储存了 60-100 Pg C yr−1，最近可能已成为 0.17 Pg C yr−1 的净来源。林产品碳库，包括来自森林生物质的垃圾填埋场碳，储存量少于 3 Pg C，但增加了 0.06 Pg C yr−1。目前北方森林净汇的机制被认为是对过去环境变化的持续反应，特别是小冰期的恢复、森林扰动制度的变化，以及在某些地区，空气污染造成的养分输入。即使在没有气候变化的情况下，碳汇强度也可能会降低，生物群落可能会转向碳源。尽管未来植被复合体中陆地碳储存的长期（平衡）变化仍不确定，但下个世纪陆地碳储存对气候变化的瞬时响应可能会伴随着与大气的大量碳交换。这种瞬态响应是由许多（通常是非线性）过程的相互作用造成的，这些过程对未来碳循环的影响仍然很难量化。只有一小部分北方生物群落直接受到森林管理的影响，因此减轻气候变化对碳储存影响的选择有限，但加速大气碳释放的潜力很大。
The circumpolar boreal biomes coverca. 2 109 ha of the northern hemisphere and containca. 800 Pg C in biomass, detritus, soil, and peat C pools. Current estimates indicate that the biomes are presently a net C sink of 0.54 Pg C yr−1. Biomass, detritus and soil of forest ecosystems (includingca. 419 Pg peat) containca. 709 Pg C and sequester an estimated 0.7 Pg C yr−1. Tundra and polar regions store 60–100 Pg C and may recently have become a net source of 0.17 Pg C yr−1. Forest product C pools, including landfill C derived from forest biomass, store less than 3 Pg C but increase by 0.06 Pg C yr−1. The mechanisms responsible for the present boreal forest net sink are believed to be continuing responses to past changes in the environment, notably recovery from the little ice-age, changes in forest disturbance regimes, and in some regions, nutrient inputs from air pollution. Even in the absence of climate change, the C sink strength will likely be reduced and the biome could switch to a C source. The transient response of terrestrial C storage to climate change over the next century will likely be accompanied by large C exchanges with the atmosphere, although the long-term (equilibrium) changes in terrestrial C storage in future vegetation complexes remains uncertain. This transient response results from the interaction of many (often non-linear) processes whose impacts on future C cycles remain poorly quantified. Only a small part of the boreal biome is directly affected by forest management and options for mitigating climate change impacts on C storage are therefore limited but the potential for accelerating the atmospheric C release are high.