Nevo Omer, Filla Caitlynn, Valenta Kim, Schupp Eugene W
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Leipzig Germany.
Institute of Biodiversity Friedrich Schiller University Jena Jena Germany.
Ecol Evol. 2023 Aug 31;13(9):e10459. doi: 10.1002/ece3.10459. eCollection 2023 Sep.
Seed dispersal is a critical phase in plant reproduction and forest regeneration. In many systems, the vast majority of woody species rely on seed dispersal by fruit-eating animals. Animals differ in their size, movement patterns, seed handling, gut physiology, and many other factors that affect the number of seeds they disperse, the quality of treatment each individual seed receives, and consequently their relative contribution to plant fitness. The seed dispersal effectiveness framework (SDE) was developed to allow systematic and standardized quantification of these processes, offering a potential for understanding the large-scale dynamics of animal-plant interactions and the ecological and evolutionary consequences of animal behavior for plant reproductive success. Yet, despite its wide acceptance, the SDE framework has primarily been employed descriptively, almost always in the context of local systems. As such, the drivers of variation in SDE across systems and the relationship between its components remain unknown. We systematically searched studies that quantified endozoochorous SDE for multiple animal species dispersing one or more plant species in a given system and offered an integrative examination of the factors driving variation in SDE. Specifically, we addressed three main questions: (a) Is there a tradeoff between high dispersal quality and quantity? (b) Does animal body mass affect SDE or its main components? and (c) What drives more variation in SDE, seed dispersal quality, or quantity? We found that: (a) the relationship between quality and quantity is mediated by body size; (b) this is the result of differential relationships between body mass and the two components, while total SDE is unaffected by body mass; (c)neither quality nor quantity explain more variance in SDE globally. Our results also highlight the need for more standardized data to assess large-scale patterns in SDE.
种子传播是植物繁殖和森林更新的关键阶段。在许多生态系统中，绝大多数木本植物物种依靠食果动物进行种子传播。动物在体型、运动模式、种子处理方式、肠道生理以及许多其他影响它们传播种子数量、每粒种子接受处理质量的因素等方面存在差异，进而影响它们对植物适合度的相对贡献。种子传播有效性框架（SDE）的提出是为了系统、标准化地量化这些过程，为理解动植物相互作用的大规模动态以及动物行为对植物繁殖成功的生态和进化后果提供了可能。然而，尽管该框架已被广泛接受，但它主要是用于描述性目的，几乎总是在局部生态系统的背景下使用。因此，跨系统SDE变化的驱动因素及其各组成部分之间的关系仍然未知。我们系统地检索了在给定系统中对多种传播一种或多种植物物种的动物进行内吞性SDE量化的研究，并对驱动SDE变化的因素进行了综合考察。具体而言，我们解决了三个主要问题：（a）在高传播质量和数量之间是否存在权衡？（b）动物体重是否会影响SDE或其主要组成部分？（c）是什么驱动SDE产生更多变化，是种子传播质量还是数量？我们发现：（a）质量和数量之间的关系由体型介导；（b）这是体重与两个组成部分之间不同关系的结果，而总SDE不受体重影响；（c）全球范围内，质量和数量都不能解释SDE中更多的方差。我们的研究结果还强调了需要更多标准化数据来评估SDE的大规模模式。
