The Effect of Willow Short Rotation Coppice Cultivation on the Biodiversity Quality of Ground-Layer Invertebrates

Michael Alan Williams,Alan Feest

doi:10.4236/as.2022.133026

Abstract

The biodiversity quality of ground-layer invertebrates within the cropped area of a plantation of the biomass crop willow short-rotation coppice (SRC) grown within a floodplain was compared to the biodiversity quality of the neighbouring plots of floodplain grassland and a mixed deciduous woodland plantation. Pitfall traps were used to collect ground beetles (Carabidae) and arachnids (Araneae and Opiliones) in the plots over a period of two years. A range of biodiversity indices was used to assess the biodiversity quality of each of the three plots, and the willow SRC was compared to each of the controls using Mann-Whitney tests. The willow SRC transitioned from almost bare ground to young woodland during the two years of the study, which affected comparisons with alternative land uses as the habitat during the second year was very different from the habitat at the start of the study. Compared to plantation woodland, in the first year, the effect was mostly positive, but this declined in the second year. Compared to grassland there was a largely negative effect in both years. However, when in combination with other habitats, willow SRC cultivation on floodplain land may have an overall positive effect on invertebrate biodiversity quality.

Highlights

With the utilisation of biomass as an energy source considered to be among the measures necessary to tackle climate change [1], it becomes important to understand the impact that biomass crops might have on biodiversity
The biodiversity quality of ground-layer invertebrates within the cropped area of a plantation of the biomass crop willow short-rotation coppice (SRC) grown within a floodplain was compared to the biodiversity quality of the neighbouring plots of floodplain grassland and a mixed deciduous woodland plantation
Neither ground beetle nor arachnid assemblages were significantly similar between the willow SRC and plantation woodland, but ground beetles in both years and arachnids in year 1 were significantly similar to the grassland plot (P < 0.001)

Summary

Introduction

With the utilisation of biomass as an energy source considered to be among the measures necessary to tackle climate change [1], it becomes important to understand the impact that biomass crops might have on biodiversity. There have only been limited studies on the effect on biodiversity of willow SRC cultivation, and fewer that compared willow SRC to the conventional land-uses it would in many cases be replacing. Species-richness and abundance of butterflies (Lepidoptera) have been found to be increased in willow SRC compared to arable controls with the difference significant (P < 0.05) [4], this study was confined to the margins and headlands, which were wider in the willow SRC plots, and did not account for the cropped habitat. Significant (P < 0.05) increases of winged Hymenoptera and large Hemiptera in willow SRC, when compared to arable crops, have been recorded [5]. Work by Haughton et al [9] suggests that willow SRC supports greater invertebrate and “weed” biodiversity than arable crops, habitats such as grassland and woodland were not included in their study

Objectives

Methods

Results

Discussion

Conclusion