Importance of tree- and species-level interactions with wildfire, climate, and soils in interior Alaska: Implications for forest change under a warming climate
Importance of tree- and species-level interactions with wildfire, climate, and soils in interior Alaska: Implications for forest change under a warming climate
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DOI：
10.1016/j.ecolmodel.2019.108765
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发表时间：
2019-10-01
影响因子：
3.1
通讯作者：
Ranson, K. Jon
中科院分区：
文献类型：
--
作者：
Foster, Adrianna C.;Armstrong, Amanda H.;Ranson, K. Jon
阿拉斯加的北方地带主要是由干扰，植被和土壤之间的相互作用。这些相互作用可能会在未来发生变化，包括永久冻土融化增加，野火更加频繁和激烈，以及干旱和竞争导致的植被变化。我们利用一个单独的树木为基础的植被模型，弗吉尼亚大学的森林模型增强（UVAFME），估计当前和未来的森林条件在阿拉斯加内陆的网站。我们更新了UVAFME在阿拉斯加内陆的应用，包括改进模拟永冻层动态，凋落物腐烂，营养动态，火灾死亡率，火灾后再生。在这些更新之后，UVAFME输出的物种特定的生物量和树干密度是在阿拉斯加内陆的各种森林类型的库存测量相媲美。然后，我们模拟森林对气候变化的反应，在特定的库存位置和整个塔纳纳山谷河流域的2 × 2公里（2）网格。我们从RCP 4.5和8.5情景下CMIP 5档案中的五个模型平均值中得出了预计的温度和降水。结果表明，气候变化以及随之而来的野火和永久冻土动态的影响将导致生物量的总体减少（特别是云杉（云杉属））。在塔纳纳山谷的内部，尽管增加了震颤白杨（杨树tremuloides）的生物量，并由此转向更高的落叶部分。模拟结果还预测，在温和（RCP 4.5）和极端（RCP 8.5）气候变化情景下，寒冷、潮湿和高海拔地区的生物量会增加，而干燥地区的生物量会减少。这些模拟表明，一个非常详细的，物种相互作用的模型可以在阿拉斯加的一个大区域内使用，以调查植被，气候，野火和永久冻土之间的相互作用。这里预测的植被变化有能力反馈到更大规模的气候-森林相互作用在北美北方森林，一个地区，这对全球碳和能源预算作出了重大贡献。
The boreal zone of Alaska is dominated by interactions between disturbances, vegetation, and soils. These interactions are likely to change in the future through increasing permafrost thaw, more frequent and intense wildfires, and vegetation change from drought and competition. We utilize an individual tree-based vegetation model, the University of Virginia Forest Model Enhanced (UVAFME), to estimate current and future forest conditions across sites within interior Alaska. We updated UVAFME for application within interior Alaska, including improved simulation of permafrost dynamics, litter decay, nutrient dynamics, fire mortality, and post-fire regrowth. Following these updates, UVAFME output on species-specific biomass and stem density was comparable to inventory measurements at various forest types within interior Alaska. We then simulated forest response to climate change at specific inventory locations and across the Tanana Valley River Basin on a 2 x 2 km(2) grid. We derived projected temperature and precipitation from a five-model average taken from the CMIP5 archive under the RCP 4.5 and 8.5 scenarios. Results suggest that climate change and the concomitant impacts on wildfire and permafrost dynamics will result in overall decreases in biomass (particularly for spruce (Picea spp.)) within the interior Tanana Valley, despite increases in quaking aspen (Populus tremuloides) biomass, and a resulting shift towards higher deciduous fraction. Simulation results also predict increases in biomass at cold, wet locations and at high elevations, and decreases in biomass in dry locations, under both moderate (RCP 4.5) and extreme (RCP 8.5) climate change scenarios. These simulations demonstrate that a highly detailed, species interactive model can be used across a large region within Alaska to investigate interactions between vegetation, climate, wildfire, and permafrost. The vegetation changes predicted here have the capacity to feed back to broader scale climate-forest interactions in the North American boreal forest, a region which contributes significantly to the global carbon and energy budgets.