Consistency of landscape compositional effects on microclimate, arthropods and plant performance across different years and regions

Context

Reinforcement of agrobiodiversity in peri-urban areas requires a landscape lens. Relationships between land use composition and indicators of ecosystem services can depend on weather conditions and differ between regions.

Objectives

In this study we present new empirical data on relationships between landscape composition and indicators of regulating and provisioning agroecosystem services. Furthermore, we check if these data are consistent between two different ecoregions and different years.

Methods

We apply an innovative methodology in a research landscape in the province of Antwerp (Flanders, Belgium) in 2021 with 1 m²-garden as phytometers along a landscape compositional gradient. Landscape composition at different scales is used as explanatory variable for microclimate variation, arthropod activity, leaf herbivory and crop yield in the 1 m²-gardens. Results are compared to an identical experiment in another ecoregion in East Flanders in 2018, 2019.

Results

We found that the proportion of built-up areas is negatively related to local agroecosystem functioning. High-value herbaceous vegetation (e.g. extensive grasslands) promotes the activity of predators and high green vegetation buffers soil moisture and temperature variation, during dry and warm periods. Comparison between cases indicates that there is more consistency in the response of predatory invertebrates to the landscape composition than in the response of pollinators. The buffering effect of high green vegetation in the landscape increases when temperature and drought extremes occur.

Conclusions

The extent of high green vegetation can be enhanced at landscape level to maximise their ability to buffer extreme weather conditions. In peri-urban areas we should avoid further urban sprawl into the rural matrix and promote high-value herbaceous vegetation.