Ertsgaard Erik W, Gjording Nicholas L, Bakker Jonathan D, Kleinkopf Joseph A, Giblin David E
University of Washington Herbarium (WTU), Burke Museum, Seattle, Washington, United States of America.
School of Environmental and Forest Sciences, University of Washington, Seattle, Washington, United States of America.
PLoS One. 2025 Jan 7;20(1):e0317140. doi: 10.1371/journal.pone.0317140. eCollection 2025.
Alpine areas are host to diverse plant communities that support ecosystems through structural and floral resources and persist through specialized adaptations to harsh high-elevation conditions. An ongoing question in these plant communities is whether composition is shaped by stochastic processes (e.g., dispersal limitations) or by deterministic processes (e.g., climate, geology), and if those processes select for common phylogenetic clades across space. This study evaluates the drivers of dissimilarity in alpine vascular plant communities across 32 peaks in the Cascade Mountain Range of Washington State and examines the effects of incorporating phylogenetic relatedness to these conclusions. We documented an average of 54 species per peak and used our overall inventory of 307 taxa to construct a phylogenetic tree for the entire mountain range plant community sampled. We used multivariate techniques to quantify the phylogenetic and taxonomic differences between alpine plant communities and to relate those differences to each peak's climate, geology, and topography. Our models indicate that the age of each peak's parent material formation, precipitation, latitude, and temperature had the largest role in shaping alpine plant communities relative to the baseline effects of distance between peaks and time of sampling. A unique result was a distinct plant community in peaks with ultramafic geologic parent material formed in the Paleozoic Era, which has an extreme geochemistry that we found to form evolutionarily distinct lineages compared to all other peaks. With changing climate conditions and disturbance regimes, understanding facets of alpine plant communities like species turnover, geologic endemism, and responses to precipitation changes are vital to conserving these ecosystems.
高山地区拥有多样的植物群落，这些群落通过结构和花卉资源来支持生态系统，并通过对恶劣高海拔条件的特殊适应而得以存续。这些植物群落中一个一直存在的问题是，其组成是由随机过程（如扩散限制）还是由确定性过程（如气候、地质）塑造的，以及这些过程是否会在空间上选择共同的系统发育分支。本研究评估了华盛顿州喀斯喀特山脉32座山峰上高山维管植物群落差异的驱动因素，并研究了纳入系统发育相关性对这些结论的影响。我们记录到每座山峰平均有54种植物，并利用我们对307个分类单元的总体清单为整个山脉采样的植物群落构建了一棵系统发育树。我们使用多变量技术来量化高山植物群落之间的系统发育和分类学差异，并将这些差异与每座山峰的气候、地质和地形联系起来。我们的模型表明，相对于山峰之间的距离和采样时间的基线影响，每座山峰母质形成的年龄、降水量、纬度和温度在塑造高山植物群落方面发挥了最大作用。一个独特的结果是，在古生代形成的具有超镁铁质地质母质的山峰中存在一个独特的植物群落，其具有极端的地球化学特征，我们发现与所有其他山峰相比，它形成了进化上不同的谱系。随着气候条件和干扰状况的变化，了解高山植物群落的各个方面，如物种更替、地质特有性以及对降水变化的反应，对于保护这些生态系统至关重要。
