Space resource utilization of dominant species integrates abundance- and functional-based processes for better predictions of plant diversity dynamics

Sustainable ecosystem management relies on our ability to predict changes in plant diversity and to understand the underlying mechanisms. Empirical evidence demonstrates that abundance- and functional-based processes simultaneously explain the loss of plant diversity in response to human activities. Recently, a novel indicator based on percent cover (CoverD) and maximum height (HeightD) of the dominant plant species – Space Resource Utilization (SRUD) – has proven to give robust and better predictions of plant diversity dynamics than community biomass. Whether the superior predictive ability of SRUD is due to its capacity to simultaneously capture abundance- and functional-based processes remains unknown. Here, we tested this hypothesis by quantifying mechanistic links between changes in SRUD and biodiversity in response to nutrients and herbivores. Furthermore, we assessed the relative contribution of dominant, intermediate, and rare species to reduced density of individuals by combining null model analysis with field experiments. We found that SRUD successfully captured changes in ground-level light availability and changes in the number of individuals to predict plant diversity dynamics, and each of CoverD and HeightD partly and independently contributed to both processes. Comparative results from null model analysis and field experiments confirmed that individual losses of dominant, intermediate, and rare species followed non-random processes. Specifically, compared with random loss process, rare species lost proportionally more individuals and thus disproportionately contributed to species loss, while dominant and intermediate species lost less. Our results demonstrate that SRUD captures both abundance- and functional-based processes thus explaining why SRUD provides more accurate predictions of changes in species diversity. Given that rare species can play an important role in shaping community structure, resisting against invasion, impacting higher trophic levels, and providing multiple ecosystem functions, reducing the SRU of dominant species could alleviate the risk of exclusion of rare species by mitigating abundance- and functional-based competition processes.可持续生态系统管理（Sustainable ecosystem management）有赖于我们精准预测植物多样性变化、解析其内在作用机制的能力。现有实证研究表明，基于物种丰度与功能性状的作用过程可同时解释人类活动干扰下的植物多样性丧失。近期，一项基于优势植物物种盖度百分比（CoverD）与最大株高（HeightD）构建的全新指标——空间资源利用指数（Space Resource Utilization，SRUD）——已被证实相较群落生物量，能够更稳健、精准地预测植物多样性动态。然而，SRUD优异的预测能力是否源于其可同时捕获基于丰度与功能性状的作用过程，目前仍不明确。本研究通过量化养分与草食动物干扰下SRUD变化与生物多样性（biodiversity）间的机制性关联，对该假说进行了验证。此外，我们结合零模型分析（null model analysis）与野外实验，评估了优势种、中间种与稀有种对个体密度降低的相对贡献度。研究结果显示，SRUD可有效捕获地表光照可利用性与个体数量变化，以此实现对植物多样性动态的预测；且CoverD与HeightD均可分别独立地对这两类过程产生部分贡献。零模型分析与野外实验的对比结果证实，优势种、中间种与稀有种的个体丧失均遵循非随机过程。具体而言，相较于随机丧失过程，稀有种的个体丧失比例更高，因此在物种丧失过程中承担了不成比例的贡献；而优势种与中间种的个体丧失则相对更少。本研究结果证实，SRUD可同时捕获基于丰度与功能性状的作用过程，这也解释了为何SRUD能够更精准地预测物种多样性变化。鉴于稀有种在塑造群落结构、抵御生物入侵、影响更高营养级以及提供多种生态系统功能方面发挥着重要作用，降低优势物种的空间资源利用（SRU）水平可通过缓解基于丰度与功能性状的竞争过程，减轻稀有种被排除的风险。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于植物多样性动态预测，通过引入空间资源利用（SRUD）这一新指标，结合优势物种的覆盖度和高度数据，同时捕捉丰度和功能过程，以提升预测准确性。数据来源于野外调查的群落测量，包括物种高度、覆盖度、生物量和丰度等信息，适用于生态学和生物多样性研究。数据集支持了关于优势物种如何影响稀有物种竞争机制的研究，并得到国家自然科学基金资助。