Vertical structural complexity of plant communities represents the combined effects of resource acquisition and environmental stress on the Tibetan Plateau

Knowledge of vertical structural complexity (VSC) is important, because the resulting spatial partitioning is closely linked to resource utilization and environmental adaptation. However, the spatial pattern of VSC on large scales and its underlying mechanisms are poorly understood. Here, we systematically investigated 2,013 plant communities through grid sampling on the Tibetan Plateau (TP). VSC was quantified as the maximum plant height within a plot (Height-max), coefficient of variation of plant height (Height-var), and Shannon evenness of plant height (Height-even). Precipitation dominated the spatial variation in VSC in forests and shrublands, supporting the classic physiological tolerance hypothesis (PTH). In contrast, for alpine meadows, steppes, and desert grasslands in extreme environments, non-resource limiting factors (e.g., wide diurnal temperature ranges and strong winds) dominate VSC variation. Generally, with the shifting of climate from favorable to extreme, the effect ..., Field sampling was conducted during the high-growth period from mid-July to late August in 2018, 2019, and 2020. According to the latitude and longitude, we divided the entire Tibetan Plateau (TP) into 1,000 grids of equal area (0.5° × 0.5°). For alpine grasslands (i.e., alpine meadows, alpine steppes, and alpine desert grasslands), we selected the dominant plant communities via visual observation in each grid and randomly set up three 1 m × 1 m plots for the field investigation. There were 1,527 plots for grassland communities, and the height of the tallest plant in each plot was measured. For each species within the plots, we recorded their coverage and then randomly selected three plants of each species to measure their height (all measurements for less than three individuals); in total, 19,320 plants were measured.
For forests (456 plots) and shrublands (30 plots), three 20 m× 20 m plots were randomly established in each grid, for a total of 486 plots. For forests, we recorded all v..., , # Vertical structural complexity of plant communities represents the combined effects of resource acquisition and environmental stress on the Tibetan Plateau

We systematically investigate 2,013 plant communities through grid sampling on the Tibetan Plateau. Vertical structural complexity is quantified as the maximum plant height within a plot (Height-max), coefficient of variation of plant height (Height-var), and Shannon evenness of plant height (Height-even). Field sampling was conducted during the high growth period of mid-July to late August in 2018, 2019, and 2020. We divided the entire TP according to the latitude and longitude into 1,000 grids with equal area (0.5° × 0.5°).

**Abbreviation list**
TP, Tibetan Plateau
Height-max, the maximum plant height within a plot
Height-var, coefficient of variation of plant height
Height-even, Shannon evenness of plant height

For more details and citations, see our paper published in Communications Biology (Changjin Cheng, 2024).

植被垂直结构复杂性（Vertical Structural Complexity, VSC）的相关认知至关重要，因其介导的空间分区格局与资源利用及环境适应过程紧密关联。然而，大尺度下VSC的空间分布模式及其潜在驱动机制仍未得到充分阐释。本研究依托青藏高原（Tibetan Plateau, TP）开展网格采样，系统性调研了2013个植物群落。

本研究将VSC量化为样地内最高植株高度（Height-max）、植株高度变异系数（Height-var）以及植株高度的香农均匀度（Height-even）。降水主导了森林与灌丛的VSC空间变异，这一结果支持经典的生理耐受假说（Physiological Tolerance Hypothesis, PTH）。与之相对，极端环境下的高寒草甸、草原与荒漠草原，其VSC变异则由非资源限制因子（如昼夜温差悬殊、强风等）主导。总体而言，随着气候由适宜向极端方向转变，其调控效应……

野外采样于2018、2019及2020年的7月中旬至8月下旬的植物旺盛生长期开展。研究团队依据经纬度将整个青藏高原划分为1000个等面积（0.5°×0.5°）的网格单元。对于高寒草地类群（即高寒草甸、高寒草原与高寒荒漠草原），通过目视踏勘在每个网格内选取优势植物群落，并随机设置3个1m×1m的样方开展野外调查。草地群落共设1527个样方，测定每个样方内最高植株的高度；针对样方内的每个物种，记录其盖度，并随机选取3株该物种个体测定株高（若个体数不足3株则全数测量），共计测定19320株植物。

对于森林（456个样方）与灌丛（30个样方），每个网格内随机设置3个20m×20m的样方，总计486个样方。针对森林群落，我们记录了所有……，

# 植物群落垂直结构复杂性代表了青藏高原上资源获取与环境胁迫的综合作用效应

本研究系统性调研了青藏高原上的2013个植物群落，采用网格采样方法开展研究。垂直结构复杂性被量化为样地内最高植株高度（Height-max）、植株高度变异系数（Height-var）以及植株高度的香农均匀度（Height-even）。野外采样于2018、2019及2020年的7月中旬至8月下旬的植物旺盛生长期开展。研究团队依据经纬度将整个青藏高原划分为1000个等面积（0.5°×0.5°）的网格单元。

**术语缩写列表**
TP：青藏高原（Tibetan Plateau）
Height-max：样地内最高植株高度
Height-var：植株高度变异系数
Height-even：植株高度的香农均匀度

更多细节与参考文献可参阅我们发表于《Communications Biology》的论文（Changjin Cheng, 2024）。