The community and ecosystem consequences of intraspecific diversity: a meta‐analysis

Abstract

Understanding the relationships between biodiversity and ecosystem functioning has major implications. Biodiversity–ecosystem functioning relationships are generally investigated at the interspecific level, although intraspecific diversity (i.e. within‐species diversity) is increasingly perceived as an important ecological facet of biodiversity. Here, we provide a quantitative and integrative synthesis testing, across diverse plant and animal species, whether intraspecific diversity is a major driver of community dynamics and ecosystem functioning. We specifically tested (i) whether the number of genotypes/phenotypes (i.e. intraspecific richness) or the specific identity of genotypes/phenotypes (i.e. intraspecific variation) in populations modulate the structure of communities and the functioning of ecosystems, (ii) whether the ecological effects of intraspecific richness and variation are strong in magnitude, and (iii) whether these effects vary among taxonomic groups and ecological responses. We found a non‐linear relationship between intraspecific richness and community and ecosystem dynamics that follows a saturating curve shape, as observed for biodiversity–function relationships measured at the interspecific level. Importantly, intraspecific richness modulated ecological dynamics with a magnitude that was equal to that previously reported for interspecific richness. Our results further confirm, based on a database containing more than 50 species, that intraspecific variation also has substantial effects on ecological dynamics. We demonstrated that the effects of intraspecific variation are twice as high as expected by chance, and that they might have been underestimated previously. Finally, we found that the ecological effects of intraspecific variation are not homogeneous and are actually stronger when intraspecific variation is manipulated in primary producers than in consumer species, and when they are measured at the ecosystem rather than at the community level. Overall, we demonstrated that the two facets of intraspecific diversity (richness and variation) can both strongly affect community and ecosystem dynamics, which reveals the pivotal role of within‐species biodiversity for understanding ecological dynamics.

A way forward with eco evo devo: an extended theory of resource polymorphism with postglacial fishes as model systems

“…Importantly, this approach has demonstrated that ecologically driven adaptive phenotypic changes can feed back directly to ecology [e.g. population growth and ecosystem function (Thuiller et al ., ; Raffard et al ., )] – illustrating the reciprocity between ecological and evolutionary processes (Metz, Nisbet, & Geritz, ; Post & Palkovacs, ; Kinnison, Hairston, & Hendry, ). Studies of eco‐evo dynamics recognize that substantial evolutionary changes can occur at ecological time scales (i.e.…”

Independent and interactive effects of plant genotype and environment on plant traits and insect herbivore performance: A meta‐analysis with Salicaceae

“…Intraspecific variation has been shown to be comparable to, and in some cases even more important than, interspecific variation (Des Roches et al., ). In plant populations, intraspecific variation can have far‐reaching effects, from structuring associated arthropod, endophyte and secondary consumer communities (Kagiya, Yasugi, Kudoh, Nagano, & Utsumi, ; Koricheva & Hayes, ; Lamit et al., , ; Raffard, Santoul, Cucherousset, & Blanchet, ) to governing ecosystem processes, such as nutrient cycling and primary production (Crutsinger et al., ; Hughes, Inouye, Johnson, Underwood, & Vellend, ; Madritch, Greene, & Lindroth, ). These effects can have fitness consequences for interacting organisms, leading to changes in evolutionary trajectories and contributing to eco‐evolutionary dynamics (Raffard, Santoul, et al., ; Whitham et al., ).…”

Stable resource polymorphism along the benthic littoral–pelagic axis in an invasive crayfish

“…Intraspecific variability is now widely recognized as playing a crucial role in evolutionary and ecological processes (Read, Hoban, Eppinga, Schweitzer, & Bailey, 2016;Violle et al, 2012). Genetic and/or phenotypic differences among conspecific individuals can have important implications for community structure and ecosystem functioning by mediating the intensity of bottom-up or top-down processes (see review in Des Roches et al, 2017;Raffard, Santoul, Cucherousset, & Blanchet, 2018). Biological invasions provide a unique opportunity to study intraspecific variability in recently established populations.…”