物种优先效应对植物群落构建的影响及其生态恢复意义

植物群落构建是退化生态系统恢复中的关键生态学过程，但如何定向培育植物群落以加快生态系统过程与功能的恢复仍是当前亟待解决的关键问题。优先效应是指在植物群落重塑中，早期到达物种对随后到达物种的建植、生长及繁殖等产生促进、抑制或无影响的现象，其对群落结构调整、功能维持及演替动态等过程起到重要的调控作用，在植物群落的人为构建中具有不可忽视的作用。当前此类研究主要集中于北美和欧洲国家，用于解决外来物种入侵、多样性保护、植被建设与管理等问题，而在我国的研究尚十分少见。本研究通过文献检索分析，综述了物种优先效应的研究现状，归纳了其主要驱动因素、响应机制及量化方法等内容。结果表明：优先效应的大小和方向受物种特性、组装顺序、环境条件及相互作用等多种因素影响；两个主要的驱动机制为生态位抢占和生态位修饰；存在研究区域较为局限，试验观测时间短，生物与非生物因素的交互研究少及理论支持缺乏等问题。本研究结合我国退化植被恢复的迫切需求，提出了未来的研究方向，以期为今后相关研究提供借鉴，为我国生态恢复工作提供新思路。

Priority effects on plant community assembly and ecological restoration significance

Plant community assembly is a key ecological process in the restoration of degraded ecosystems. However， how to reconstruct the plant community， so as to accelerate the restoration of ecosystem processes and functions， remains a key problem that is in urgent need of a solution. The ‘priority effect’ is defined by whether species that arrive early have positive， negative or neutral effect on establishment， growth， or reproduction of species that arrive later in plant community assembly. The priority effect plays an important role in regulating the process of community structure improvement， the functional maintenance and the community succession dynamics. To the present time， studies on the priority effect have been mainly focused on North America and some European countries to better understand the impact of alien species invasion and answer questions relating to grassland diversity conservation， artificial grassland construction and management， among others. However， such research has not been conducted in China. Based on a systematic literature review， this paper summarized the current status of research on priority effects in plant community assembly， identifying the driving factors， response mechanisms and quantitative methods used. It was found that the strength and direction of priority effects were influenced by species identity， community assembly order， environmental factors and interactions between community members. Niche preemption and niche modification have been proved to be the two major driving mechanisms for priority effects. Currently there are some knowledge gaps in this research field， such as the impact of choice of study area， the limitations of shorter experiment duration， and the effects of interactions between biotic and abiotic factors. We conclude by proposing future research directions in this area， taking account of the urgent needs for vegetation restoration in China. Thus， our study provides some new insights for future researchers and new ideas for ecological restoration practice.