Mountain pine beetle and forest carbon feedback to climate change
Mountain pine beetle and forest carbon feedback to climate change
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DOI：
10.1038/nature06777
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发表时间：
2008-04-24
期刊：
影响因子：
64.8
通讯作者：
Safranyik, L.
中科院分区：
文献类型：
--
作者：
Kurz, W. A.;Dymond, C. C.;Safranyik, L.
山松甲虫(Dendroctonus ponderosae Hopkins，鞘翅目：卷尾虫科，Scolytinae)是北美西部松林中的一种土生昆虫，其种群周期性地爆发成大规模暴发(1-3次)。在暴发期间，由此导致的广泛的树木死亡减少了森林的碳吸收，并增加了未来因死亡树木的腐烂而产生的排放量。然而，在大规模的模拟分析中，昆虫对森林碳动态的影响通常被忽视。加拿大不列颠哥伦比亚省目前的疫情在面积和严重程度上比以往所有有记录的疫情都大一个数量级(4)。在这里，我们估计2000-2020年受影响地区甲虫暴发的累积影响将是270兆吨(Mt)碳(或平均36g碳m(-2)年(-1)超过374,000平方公里的森林)。这种影响在暴发期间和暴发后立即将森林从一个小的净碳汇转变为一个大的净碳源。在最糟糕的一年，不列颠哥伦比亚省甲虫暴发造成的影响相当于1959-1999年加拿大所有地区年平均直接森林火灾排放量的75%。由此造成的净初级生产量的减少与1980年代和1990年代由于全球变化而出现的增长幅度相似(5)。气候变化导致此次疫情达到前所未有的程度和严重程度(6)。像这样的昆虫暴发是气候变化可能破坏北方森林吸收和储存大气碳的能力的一个重要机制，这种影响应该在大规模模拟分析中考虑在内。
The mountain pine beetle ( Dendroctonus ponderosae Hopkins, Coleoptera: Curculionidae, Scolytinae) is a native insect of the pine forests of western North America, and its populations periodically erupt into large- scale outbreaks(1-3). During outbreaks, the resulting widespread tree mortality reduces forest carbon uptake and increases future emissions from the decay of killed trees. The impacts of insects on forest carbon dynamics, however, are generally ignored in large- scale modelling analyses. The current outbreak in British Columbia, Canada, is an order of magnitude larger in area and severity than all previous recorded outbreaks(4). Here we estimate that the cumulative impact of the beetle outbreak in the affected region during 2000 - 2020 will be 270 megatonnes ( Mt) carbon ( or 36 g carbon m(-2) yr(-1) on average over 374,000 km 2 of forest). This impact converted the forest from a small net carbon sink to a large net carbon source both during and immediately after the outbreak. In the worst year, the impacts resulting from the beetle outbreak in British Columbia were equivalent to similar to 75% of the average annual direct forest fire emissions from all of Canada during 1959 - 1999. The resulting reduction in net primary production was of similar magnitude to increases observed during the 1980s and 1990s as a result of global change(5). Climate change has contributed to the unprecedented extent and severity of this outbreak(6). Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large- scale modelling analyses.