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

TL;DR

This study found that simulated warming had little effect on arthropod diversity or grass productivity in Azorean pastures, but diversity increased slightly over a year.

Contribution

The study provides new insights into temperature effects on arthropod communities in island ecosystems using a one-year field experiment.

Findings

Simulated warming did not significantly alter grass biomass or arthropod diversity.

Arthropod community composition was influenced by both warming treatment and altitude.

Diversity indices increased slightly over the course of the experiment.

Abstract

This study examined the effects of simulated warming on arthropod diversity and grass productivity in intensively managed pastures on Terceira Island, Azores. Simulating an increase in temperature via Open Top Chambers (OTCs), we found that warming did not significantly alter grass biomass or arthropod diversity, although diversity slightly increased over the year. Community composition was influenced by both treatment and altitude, but other factors like vegetation structure or microclimate may also play a role and need to be investigated. These findings highlight the need for long-term, multifactorial studies to understand warming effects on island ecosystems.

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.

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