Wang Rui-Wu, Dunn Derek W, Luo Jun, He Jun-Zhou, Shi Lei
Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.
Kunming Institute of Zoology, Chinese Academy of Science, Kunming, Yunnan, 650223, China.
Sci Rep. 2015 Oct 5;5:14826. doi: 10.1038/srep14826.
Understanding the factors that enable mutualisms to evolve and to subsequently remain stable over time, is essential to fully understand patterns of global biodiversity and for evidence based conservation policy. Theoretically, spatial heterogeneity of mutualists, through increased likelihood of fidelity between cooperative partners in structured populations, and 'self-restraint' of symbionts, due to selection against high levels of virulence leading to short-term host overexploitation, will result in either a positive correlation between the reproductive success of both mutualists prior to the total exploitation of any host resource or no correlation after any host resource has been fully exploited. A quantitative review by meta-analysis on the results of 96 studies from 35 papers, showed no evidence of a significant fitness correlation between mutualists across a range of systems that captured much taxonomic diversity. However, when the data were split according to four categories of host: 1) cnidarian corals, 2) woody plants, 3) herbaceous plants, and 4) insects, a significantly positive effect in corals was revealed. The trends for the remaining three categories did not significantly differ to zero. Our results suggest that stability in mutualisms requires alternative processes, or mechanisms in addition to, spatial heterogeneity of hosts and/or 'self-restraint' of symbionts.
了解促使互利共生关系得以进化并随时间推移保持稳定的因素，对于全面理解全球生物多样性模式以及制定基于证据的保护政策至关重要。从理论上讲，互利共生者的空间异质性，通过结构化种群中合作伙伴之间忠诚度增加的可能性，以及共生体的“自我约束”（这是由于对导致宿主短期过度开发的高毒力水平进行选择），将导致在任何宿主资源被完全开发之前，两种互利共生者的繁殖成功率之间呈正相关，或者在任何宿主资源被充分开发之后不相关。一项对来自35篇论文的96项研究结果进行的荟萃分析定量综述表明，在涵盖多种分类多样性的一系列系统中，没有证据表明互利共生者之间存在显著的适合度相关性。然而，当数据根据宿主的四类进行划分时：1）刺胞珊瑚，2）木本植物，3）草本植物，以及4）昆虫，在珊瑚中发现了显著的正向效应。其余三类的趋势与零没有显著差异。我们的结果表明，互利共生关系的稳定性需要除宿主的空间异质性和/或共生体的“自我约束”之外的其他过程或机制。
