Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA.
Purdue Climate Change Research Center, Purdue University, West Lafayette, IN 47907, USA.
Sci Adv. 2017 May 17;3(5):e1603055. doi: 10.1126/sciadv.1603055. eCollection 2017 May.
Climate change can have profound impacts on biodiversity and the sustainability of many ecosystems. Various studies have investigated the impacts of climate change, but large-scale, trait-specific impacts are less understood. We analyze abundance data over time for 86 tree species/groups across the eastern United States spanning the last three decades. We show that more tree species have experienced a westward shift (73%) than a poleward shift (62%) in their abundance, a trend that is stronger for saplings than adult trees. The observed shifts are primarily due to the changes of subpopulation abundances in the leading edges and are significantly associated with changes in moisture availability and successional processes. These spatial shifts are associated with species that have similar traits (drought tolerance, wood density, and seed weight) and evolutionary histories (most angiosperms shifted westward and most gymnosperms shifted poleward). Our results indicate that changes in moisture availability have stronger near-term impacts on vegetation dynamics than changes in temperature. The divergent responses to climate change by trait- and phylogenetic-specific groups could lead to changes in composition of forest ecosystems, putting the resilience and sustainability of various forest ecosystems in question.
气候变化会对生物多样性和许多生态系统的可持续性产生深远影响。各种研究已经调查了气候变化的影响，但对大规模、特定特征的影响了解较少。我们分析了过去三十年来美国东部 86 个树种/组的时间序列丰度数据。我们发现，与向北迁移相比，更多的树种（73%）的丰度向西迁移，这种趋势在幼树中比在成年树中更为明显。观察到的迁移主要是由于前缘亚种群丰度的变化，并且与水分可用性和演替过程的变化密切相关。这些空间迁移与具有相似特征（耐旱性、木材密度和种子重量）和进化历史（大多数被子植物向西迁移，大多数裸子植物向北迁移）的物种有关。我们的研究结果表明，水分可用性的变化对植被动态的短期影响大于温度变化。特征和系统发育特定群体对气候变化的不同响应可能导致森林生态系统组成发生变化，从而影响各种森林生态系统的恢复力和可持续性。
