title: The importance of spatial heterogeneity and self-restraint on mutualism stability - a quantitative review.
abstract: 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.
authors.affiliation: 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.
authors.forename: Rui-Wu
authors.initials: RW
authors.lastname: Wang
authors.affiliation: Kunming Institute of Zoology, Chinese Academy of Science, Kunming, Yunnan, 650223, China.
authors.forename: Derek W
authors.initials: DW
authors.lastname: Dunn
authors.affiliation: Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: Kunming Institute of Zoology, Chinese Academy of Science, Kunming, Yunnan, 650223, China.|Statistics and Mathematics College, Yunnan University of Finance and Economics, Kunming, Yunnan, 650221, China.
authors.forename: Jun-Zhou
authors.initials: JZ
authors.lastname: He
authors.affiliation: Statistics and Mathematics College, Yunnan University of Finance and Economics, Kunming, Yunnan, 650221, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000502:physiology; D004141:Dinoflagellida / Q000502:physiology; D007313:Insecta / Q000502:physiology; D018521:Plant Physiological Phenomena; D010944:Plants; D013559:Symbiosis