Data from: Dispersal syndromes can impact ecosystem functioning in spatially structured freshwater populations

Dispersal can strongly influence ecological and evolutionary dynamics.
Besides the direct contribution of dispersal to population dynamics,
dispersers often differ in their phenotypic attributes from
non-dispersers, which leads to dispersal syndromes. The consequences of
such dispersal syndromes have been widely explored at the population and
community level, however, to date, ecosystem-level effects remain unclear.
Here, we examine whether dispersing and resident individuals of two
different aquatic keystone invertebrate species have different
contributions to detrital processing, a key function in freshwater
ecosystems. Using experimental two-patch systems, we found no difference
in leaf consumption rates with dispersal status of the common native
species Gammarus fossarum. In Dikerogammarus villosus, however, a
Ponto-Caspian species now expanding throughout Europe, dispersers consumed
leaf litter at roughly three times the rate of non-dispersers.
Furthermore, this put the contribution of dispersing D. villosus to leaf
litter processing on par with native G. fossarum, after adjusting for
differences in organismal size. Given that leaf litter decomposition is a
key function in aquatic ecosystems, and the rapid species turnover in
freshwater habitats with range expansions of non-native species, this
finding suggests that dispersal syndromes may have important consequences
for ecosystem functioning.

扩散（dispersal）可对生态与进化动态产生显著影响。除扩散对种群动态的直接贡献外，扩散个体与非扩散个体的表型特征往往存在差异，由此形成扩散综合征（dispersal syndromes）。此类扩散综合征的相关后果已在种群与群落层面得到广泛探究，但截至目前，其对生态系统层面的影响仍不明晰。本研究针对两种不同的水生关键无脊椎动物物种，旨在探究其扩散个体与定居个体对碎屑加工——淡水生态系统的核心功能之一——的贡献是否存在差异。借助双斑块实验系统，我们发现普通本土物种钩虾（Gammarus fossarum）的叶片取食速率与其扩散状态并无显著差异。然而对于庞蒂-里海起源且目前正扩散至全欧洲的河角钩虾（Dikerogammarus villosus）而言，其扩散个体的叶片碎屑取食速率约为非扩散个体的三倍。此外，在校正个体大小差异后，扩散的河角钩虾对叶片碎屑加工的贡献可与本土钩虾（Gammarus fossarum）持平。鉴于叶片碎屑分解是水生生态系统的关键功能，且淡水生境随外来物种范围扩张正经历快速的物种更替，本研究结果表明，扩散综合征可能对生态系统功能产生重要影响。