Agri-environment schemes are associated with greater terrestrial invertebrate abundance and richness in upland grasslands

Amy Arnott,Mark Emmerson,Gillian Riddell,Neil Reid

doi:10.1007/s13593-021-00738-4

Amy Arnott, Mark Emmerson + Show 2 more

Open Access

https://doi.org/10.1007/s13593-021-00738-4

Copy DOI

Abstract

Agri-environment schemes are a key mechanism by which agricultural sustainability is encouraged by subsidising farmers to adopt environmentally friendly management (e.g. reduction of inputs) to maintain and enhance the delivery of biodiversity-associated ecosystem services. Studies testing the efficacy of agri-environment schemes have yielded varying results, and few have focused on upland (marginal or Less Favoured Area) grassland (> 150 m above sea level) where productivity is poor. This study used a factorial field experiment to examine patterns in plant communities and terrestrial invertebrates between agri-environment scheme and conventionally managed semi-improved and improved upland grasslands, using 90 spatially paired fields. Total plant species richness and rare plant species richness (those with < 10% occurrence) were unaffected by agri-environment scheme management, but were significantly higher on semi-improved than improved grasslands. Total and rare invertebrate abundance and family-level richness were unrelated to grassland type (semi-improved or improved). Total and rare invertebrate abundances were 4% and 218% higher, and total and rare invertebrate family-level richness were 17% and 14% higher in agri-environment scheme than conventionally managed fields, respectively. Here, we show that agri-environment scheme management of marginal or Less Favoured Area upland grassland was associated with higher multi-taxa invertebrate abundance and richness associated with swards indicative of wetter conditions with lower dominance of perennial ryegrass (Lolium perenne) and greater coverage of other native grass species compared to conventional management. This suggests that agri-environment schemes may maintain, enhance or offset declines in terrestrial invertebrates and their associated ecosystem service delivery by maintaining more diverse swards, and suggests that they make a positive contribution to biodiversity conservation.

Highlights

Agricultural production has been predicted to double by 2050 (Tilman 1999; Butler et al 2007), raising the extinction risk of species that dwell in farmland habitat
The study was conducted in County Antrim, Northern Ireland, whose landscape is characterised by marginal upland grassland and where < 2% of agricultural land is managed under agri-environment scheme (AES) (DAERA 2019)
The first dbRDA axis had the lowest cover of perennial ryegrass and the highest cover of, for example, Sphagnum spp. mosses, crested dogstail Cynosurus cristatus and Yorkshire fog Holcus lanatus (= less intensively managed grassland), whilst the second axis had the lowest cover of Sphagnum spp. mosses and the highest cover of ryegrass, Yorkshire fog and broad-leaved dock Rumex obtusifolius (= more intensively managed)

Summary

Introduction

Agricultural production has been predicted to double by 2050 (Tilman 1999; Butler et al 2007), raising the extinction risk of species that dwell in farmland habitat. Fragmentation and degradation of semiimproved and natural habitat remain the principal drivers of species extinction in developed nations (Thomas et al 2004), and the continued intensification of agriculture is a major contributor to the current global biodiversity crisis (Chapin III et al 2000; Barnosky et al 2011; Ceballos et al 2017). Invertebrates comprise around 80% of all described species (Cardoso et al 2011), yet in some regions, for example Germany, there has been a 75% decline in aerial insect biomass over the last 30 years (Hallmann et al 2017). It has been reported that invertebrates have undergone large declines not just in biomass, and in habitats occupancy, in contrast

Objectives

Methods

Results

Conclusion