TY - JOUR T1 - Spatial scale influences the associational effects of neighbor plants on mammal herbivory. Insights from a meta-analysis JF - bioRxiv DO - 10.1101/019935 SP - 019935 AU - Emilie Champagne AU - Jean-Pierre Tremblay AU - Steeve D. Côté Y1 - 2015/01/01 UR - http://biorxiv.org/content/early/2015/07/13/019935.1.abstract N2 - There is high intra-specific variability in susceptibility of plants to herbivores with potential effects on the population dynamics of species, community composition, structure and function. This variability can be partly explained by vegetation assemblages, i.e. associational effects, but it is still unclear how the spatial scale of plant associations modulates foraging choice of herbivores; an inherently spatial process in itself. Using a meta-analysis, we investigated how spatial scale modifies associational effects of neighboring plants on the susceptibility to browsing by herbivores with movement capacities similar to deer. From 2496 articles found in main literature databases, we selected 46 studies providing a total of 168 differences of means in damage or survival with and without neighboring plants. We tested the impact of spatial scale, estimated as the distance between the focal plant and its neighbors, and the type of association effect on the effect sizes reported in these studies using a meta-analysis mixed model. The strength of associational effects slightly increases from 0 to 1 m and decreases at scales larger than 1 m. Associational defence (i.e. decrease in susceptibility with avoided neighbors) had stronger effects than any other type of associational effects, but was not more frequent. Our study is the first addressing the magnitude of change in associational effects with spatial scale. Further empirical studies should test associational effects between plants at multiple spatial scales simultaneously. The high remaining heterogeneity between the studies suggests that untested factors modulate associational effects, such as nutritional quality of focal and neighboring plants and/or timing of browsing. Associational effects are already considered in multiple restoration contexts worldwide, but a better understanding of these intratrophic relationships could improve and generalize their use in conservation and exploitation. ER -