Temperature effects on the temporal dynamics of a subarctic invertebrate community.

Sinikka I Robinson,Otso Ovaskainen,Eoin J O'Gorman,Juha Mikola

doi:10.1111/1365-2656.13448

Abstract

Climate warming is predicted to have major impacts on the structure of terrestrial communities, particularly in high latitude ecosystems where growing seasons are short. Higher temperatures may dampen seasonal dynamics in community composition as a consequence of earlier snowmelt, with potentially cascading effects across all levels of biological organisation. Here, we examined changes in community assembly and structure along a natural soil temperature gradient in the Hengill geothermal valley, Iceland, during the summer of 2015. Sample collection over several time points within a season allowed us to assess whether temperature alters temporal variance in terrestrial communities and compositional turnover. We found that seasonal fluctuations in species richness, diversity and evenness were dampened as soil temperature increased, whereas invertebrate biomass varied more. Body mass was found to be a good predictor of species occurrence, with smaller species found at higher soil temperatures and emerging earlier in the season. Our results provide more in-depth understanding of the temporal nature of community and population-level responses to temperature, and indicate that climate warming will likely dampen the seasonal turnover of community structure that is characteristic of high latitude invertebrate communities.

Highlights

Temperature plays a pivotal role in structuring terrestrial communities, especially in high latitude ecosystems with strong seasonal weather dynamics and short growing seasons
Our results provide more in-depth understanding of the temporal nature of community and population-level responses to temperature, and indicate that climate warming will likely dampen the seasonal turnover of community structure that is characteristic of high latitude invertebrate communities
These results suggest that climate warming may decrease the seasonal turnover of arthropod communities and amplify seasonal fluctuations in their biomass, with variable species-level responses explained by their body size

Summary

Introduction

Temperature plays a pivotal role in structuring terrestrial communities, especially in high latitude ecosystems with strong seasonal weather dynamics and short growing seasons. Higher temperatures in early spring may lead to more rapid development of communities following winter diapause, through earlier emergence, faster growth rates and/or increased activity levels (Forrest, 2016; Høye & Forchhammer, 2008; Koltz et al, 2018; Leingärtner et al, 2014). This may result in communities moving past the transient assembly phase much earlier in the season and exhibiting more stable diversity and biomass throughout the summer.

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Conclusion