Dataset for A systematic review and conceptual framework for the mechanistic pathways of nurse plants

Aim To conceptualize the mechanistic pathways of the nurse-plant syndrome by life-form and to identify the implications of positive plant–plant interactions for landscape and evolutionary ecology.

Location Global.

Methods We conducted a quantitative review examining 298 articles to catego- rize the literature on nurse-plant interactions based on geographic region, mecha- nism of facilitation, ecological hypothesis and nurse life-form.

Results A total of nine different nurse mechanisms were identified and two were classified as meta-mechanisms. We found that shrubs were the dominant nurse life-form (46% of total studies) and that studies of positive plant interactions were most frequent in areas of high abiotic stress. Nurse-plant studies were also distrib- uted unevenly around the globe with nearly a quarter in the South American Andes and Spain. Studies testing the direct nurse–protégé interactions were the most frequently performed, including the ecophysiological responses of protégé species (32.2%). Research gaps identified in the nurse-plant literature included indirect interactions and seed trapping as well as the large-scale implications for landscape ecology and evolution.

Main conclusions Nurse plants are often considered keystone species because they commonly structure plant communities. This is an important confirmatory finding in many respects, but it is also novel in that it challenges traditional plant ecology theory and has important implications for landscape-level dynamics over time. The categorization of mechanisms proposed provides a conceptual frame- work useful for organizing the research to date and can accelerate linkages with theory and application by identifying important connections. It is becoming increasingly apparent that future studies of the nurse-plant syndrome must decouple and consider multiple mechanisms of interaction to explain the processes that influence community structure, particularly in high-stress conditions, given a changing climate and potential shifts in biodiversity.

研究目的：本研究旨在基于生活型系统阐明护植综合征（nurse-plant syndrome）的作用机制通路，并厘清植物正相互作用对景观生态学与进化生态学的潜在影响。
研究范围：全球尺度。
研究方法：本研究开展定量综述，共梳理298篇相关文献，依据地理区域、促进作用机制、生态学假说以及护植植物生活型，对护植相互作用的相关研究进行分类。
研究结果：本研究共识别出9种不同的护植作用机制，其中2种被归类为元机制。研究发现，灌木是占比最高的护植植物生活型（占总研究量的46%）；植物正相互作用相关研究在非生物胁迫较高的区域最为集中。全球范围内护植植物相关研究的分布并不均衡，近四分之一的研究集中于南美安第斯山脉与西班牙地区。其中，针对护植植物与被护植物（protégé）直接相互作用的研究最为常见，包括被护植物物种的生理生态响应研究（占比32.2%）。本研究识别出的护植植物研究领域现存研究缺口包括：间接相互作用、种子捕获效应，以及景观生态学与进化层面的大尺度影响。
主要结论：护植植物通常被视为关键种，因其可显著塑造植物群落结构。这一结论在诸多层面均具备重要的验证价值，同时亦具创新性：它挑战了传统植物生态学理论，且对长期景观尺度动态具有重要的实践指导意义。本研究提出的作用机制分类体系，可为现有相关研究提供系统化的概念框架，通过明确关键关联加速理论与应用研究的衔接。现有研究愈发清晰地表明，在气候变化与生物多样性潜在变迁的背景下，未来针对护植综合征的研究需拆解并综合考量多种相互作用机制，以阐明调控群落结构的核心过程，在高胁迫环境中尤为如此。