Long term persistence of aspen in snowdrift-dependent ecosystems
Long term persistence of aspen in snowdrift-dependent ecosystems
复制标题
白杨在依赖雪堆的生态系统中的长期存在
DOI：
10.1016/j.foreco.2020.118005
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发表时间：
2020
影响因子：
3.7
通讯作者：
E. Strand
中科院分区：
文献类型：
--
作者：
Alec M. Kretchun;R. Scheller;D. Shinneman;B. Soderquist;Kaitlin C. Maguire;T. Link;E. Strand
近几十年来，受气候变化，特别是干旱的影响，美国西部的颤杨（白杨）森林经历了严重的死亡率。在其活动范围的西部，大部分降水在冬季到来，因为降雪和夏季干燥，积雪持续到生长季节，为土壤提供水分补给，维持白杨林。白杨林是这些景观中生物多样性的重要地点。人们越来越担心，由于气候变化导致的积雪减少可能会降低这些地区白杨群落的长期持久性和生产力。在这项研究中，我们评估了气候变化和干旱对减少或消除爱达荷州西南部孤立白杨群落的潜在影响。我们使用景观模拟模型，结合从经验衍生的生物地球化学生长模型和物种更新分布模型的输入，预测未来85年气候变化、积雪减少和与针叶树物种的竞争可能如何影响白杨的占用。我们发现，模拟积雪深度的减少（以及相关的气候水分亏缺的增加）导致白杨持久性的减少；在所有高排放气候情景下，白杨占用率都有所减少。在所有未来气候条件下，道格拉斯杉木（pseudosuga menziesii）的占用率也有所下降。在所有模拟过程中，杨树再生都有所下降，在低排放和高排放的气候情景中，死亡率/建树的总比值都有所增加。在所有气候情景下，气候引起的杨树无性系死亡率都增加了，在最严重的排放情景下，导致了杨树覆盖面积的大幅下降。我们的研究表明，雪堆将成为该地区气候变化下白杨长期存续的重要决定因素。
Quaking aspen (Populus tremuloides) forests throughout the western United States have experienced significant mortality in recent decades, which has been influenced by climate variability, especially drought. In the western portion of its range, where most precipitation arrives during winter as snowfall and summers are dry, snowdrifts that persist into the growing season provide soil moisture recharge that sustain aspen groves. Aspen groves are important locations of biodiversity within these landscapes. There is growing concern that reduced snowpack due to climate change may reduce the long-term persistence and productivity of aspen communities in these regions. In this study, we evaluated the potential for climate change and drought to reduce or eliminate isolated aspen communities in southwestern Idaho. We used a landscape simulation model integrated with inputs from an empirically derived biogeochemical model of growth, and a species distribution model of regeneration to forecast how changes in climate, declining snowpack, and competition with a conifer species is likely to affect aspen occupancy over the next 85-years. We found that simulated reductions in snowpack depth (and associated increases in climatic water deficit) caused a reduction in aspen persistence; aspen occupancy was reduced under all high emissions climate scenarios. Douglas-fir (Pseudotsuga menziesii) occupancy also declined under all future climates. Aspen regeneration declined over the course of all simulations, with an ensemble ratio of mortality/establishment increasing over the course of both low and high emissions climate scenarios. Climate-induced mortality of aspen clones increased in frequency under all climate scenarios and, under the most severe emissions scenarios, contributed to a substantial decline of aspen cover. Our research suggests that snowbanks will become an important determinant of long-term persistence of aspen under changing climate in the region.