Assessing Temperature-Induced Changes in Arthropod Communities over One Year: A Comparative Analysis

Understanding how rising temperatures driven by climate change affect biodiversity and ecosystem functioning is particularly relevant in fragile island environments. Terceira Island, part of the Azorean Archipelago (Portugal) in the mid-Atlantic Ocean, was selected for an in situ experiment to assess the effects of simulated warming on arthropod diversity and grass productivity in intensively managed pastures. Over one year, we examined the influence of a simulated increase in temperature via Open Top Chambers (OTCs) on ground-dwelling arthropod assemblages and plant biomass. We used several statistical methods to analyze both individual variables and overall community patterns to explore the relationships between treatments, grass biomass, and arthropod community structure. Although the OTC treatment did not result in any significant changes to the analyzed variables, an increase in diversity indices was observed over the course of the experiment. Distance-based redundancy analysis revealed significant effects of both OTC treatment and altitude on arthropod community composition. Models showed that the analyzed variables only partially explained the observed changes. Nevertheless, additional factors, such as vegetation structure and microclimatic variation, may also contribute to the observed patterns and warrant further investigation. These results underscore the importance of long-term, multifactorial approaches to understanding interactions between warming, plant productivity, and arthropod diversity.