Department of Biological Sciences, Florida International University, Miami, Florida, United States of America.
USDA Forest Service, Rocky Mountain Research Station, Fort Collins, Colorado, United States of America.
PLoS One. 2018 Mar 19;13(3):e0193481. doi: 10.1371/journal.pone.0193481. eCollection 2018.
Like many other high elevation alpine tree species, Rocky Mountain bristlecone pine (Pinus aristata Engelm.) may be particularly vulnerable to climate change. To evaluate its potential vulnerability to shifts in climate, we defined the suitable climate space for each of four genetic lineages of bristlecone pine and for other subalpine tree species in close proximity to bristlecone pine forests. Measuring changes in the suitable climate space for lineage groups is an important step beyond models that assume species are genetically homogenous. The suitable climate space for bristlecone pine in the year 2090 is projected to decline by 74% and the proportional distribution of suitable climate space for genetic lineages shifts toward those associated with warmer and wetter conditions. The 2090 climate space for bristlecone pine exhibits a bimodal distribution along an elevation gradient, presumably due to the persistence of the climate space in the Southern Rocky Mountains and exclusion at mid-elevations by conditions that favor the climate space of other species. These shifts have implications for changes in fire regimes, vulnerability to pest and pathogens, and altered carbon dynamics across the southern Rockies, which may reduce the likelihood of bristlecone pine trees achieving exceptional longevity in the future. The persistence and expansion of climate space for southern bristlecone pine genetic lineage groups in 2090 suggests that these sources may be the least vulnerable in the future. While these lineages may be more likely to persist and therefore present opportunities for proactive management (e.g., assisted migration) to maintain subalpine forest ecosystem services in a warmer world, our findings also imply heighted conservation concern for vulnerable northern lineages facing range contractions.
像许多其他高海拔高山树种一样，落矶山狐尾松（Pinus aristata Engelm.）可能特别容易受到气候变化的影响。为了评估其对气候变化的潜在脆弱性，我们定义了每个狐尾松的四个遗传谱系以及与其相邻的其他亚高山树种的适宜气候空间。测量遗传谱系组的适宜气候空间的变化是超越假设物种在遗传上同质的模型的重要一步。到 2090 年，狐尾松的适宜气候空间预计将减少 74%，遗传谱系的适宜气候空间的比例分布将向那些与温暖和潮湿条件相关的谱系转移。2090 年狐尾松的气候空间在海拔梯度上呈现双峰分布，可能是由于南落矶山脉的气候空间持续存在，以及中海拔条件排斥有利于其他物种气候空间的原因。这些变化对火灾发生频率、对害虫和病原体的脆弱性以及整个南落矶山脉的碳动态的改变都有影响，这可能会降低未来狐尾松树达到非凡长寿的可能性。在 2090 年，南狐尾松遗传谱系组的气候空间的持续存在和扩展表明，这些来源在未来可能是最不容易受到影响的。虽然这些谱系可能更有可能存活下来，因此为在更温暖的世界中维持亚高山森林生态系统服务提供了积极管理（例如，辅助迁移）的机会，但我们的研究结果也意味着，面对范围收缩，脆弱的北方谱系需要更高的保护关注。
