Limited directional change in mountaintop plant communities over 19 years in western North America

Plant communities on mountain summits are commonly long-lived, cold-adapted perennials with low dispersal ability. These characteristics in tandem with limited area to track suitable conditions make these mountain communities potentially highly vulnerable to climate change, and indicators of climate change impacts. We investigated temporal changes in plant communities on 29 arid mountain summits across eight study regions in California and Nevada, USA over 19 years. We analyzed community dynamics in terms of species richness, turnover, gain and loss of functional groups, and relative abundance of functional groups. First, across all summits and regions, we found no change in species richness over time. Second, there was relatively high species turnover (21.7%) between the five-year survey intervals, but turnover was not significantly different from random expectation. Within functional groups, forbs had the greatest proportion of gains and cushions had the greatest proportion of losses...., , , # Limited directional change in mountaintop plant communities over 19 years in western North America Repository for code, data, and figures related to Goff et al. manuscript: \"Limited directional change in mountaintop plant communities over 19 years in western North America\" ## File Manifest: ### code: 04_richness_model_figure1d.R - Performs species richness analysis, including statistical analysis and creating manuscript Figure 1d. 05_turnover_binomial_model_figureS2_figureS4_tableS2.R - Performs turnover analysis, using a modified function \"turnover\" in the package code to compute turnover between pairs of sequential surveys on the same peak, and feeding this data into statistical analysis. These results are used to create supplemental Figure S2 and S4, as well as table S2 05A_modify_codyn_turnover.R - makes one small modification to the source code of codyn (Hallet et al. 2013), so that gains and losses are not proportional to the total species richness of a given replicate. Al...山地峰顶的植物群落通常为长寿、冷适应型多年生植物，且扩散能力较弱。这类特性加上可用于追踪适宜生境的区域有限，使得这类山地群落极易受到气候变化的影响，同时也可作为气候变化影响的指示物。我们针对美国加利福尼亚州与内华达州境内8个研究区域内的29座干旱山地峰顶的植物群落展开了历时19年的时序变化调查。我们从物种丰富度（species richness）、物种更替（species turnover）、功能群（functional groups）的获得与丧失以及功能群相对多度这几个维度分析了群落动态。其一，在所有峰顶与研究区域中，我们未观测到物种丰富度随时间发生变化。其二，在每五年一次的调查间隔间，物种更替率相对较高（21.7%），但该更替率与随机预期值并无显著差异。在功能群层面，非禾本科草本植物（forbs）的获得比例最高，而垫状植物（cushions）的丧失比例最大…… # 北美西部19年间山地峰顶植物群落的有限方向性变化 本仓库存储了与Goff等人的论文"Limited directional change in mountaintop plant communities over 19 years in western North America"相关的代码、数据与图表。 ### 代码文件清单： 04_richness_model_figure1d.R：用于开展物种丰富度分析，包含统计分析与论文图1d的绘制。 05_turnover_binomial_model_figureS2_figureS4_tableS2.R：用于开展物种更替分析，通过程序包代码中修改后的"turnover"函数计算同一峰顶连续两次调查间的物种更替率，并将该数据导入统计分析流程。所得结果用于绘制补充图S2、S4以及附表S2。 05A_modify_codyn_turnover.R：对codyn（Hallet et al. 2013）的源代码进行一处小幅修改，使功能群的获得与丧失比例不再与给定重复样本的总物种丰富度成正比。Al...