The effects of grazing and mowing on large marsh grasshopper, Stethophyma grossum (Orthoptera: Acrididae), populations in Western Europe: a review

Tim Gardiner,Jacqui Miller

doi:10.3897/jor.27.23835

Abstract

The large marsh grasshopper,StethophymagrossumL. (Orthoptera: Acrididae), has undergone a significant range contraction in the UK and is now restricted to the bogs and mires of the New Forest and Dorset Heaths. In other parts of Western Europe, the species makes use of a wider range of wetland habitat types. Traditionally, many of these habitats would be managed through low intensity grazing, mowing, or both, and these measures are now often employed in the conservation management of wet grassland habitats. This paper reviews the effects of mowing and grazing onS.grossumpopulations, through looking at the potential impacts (both positive and negative) on different life stages of the grasshopper. Both techniques are valuable in the maintenance of an open and varied vegetation structure which is known to benefitS.grossumin all its life stages. However, grazing on very wet sites or at high intensity can result in trampling of vegetation andS.grossumeggs, and mowing which is too frequent may negatively affect populations through repeated losses of nymphs. Recommendations are given regarding the suitability of mowing and grazing for different habitats and intensity of management to generate the required vegetation structure. Measures are also outlined, such as the provision of unmown or ungrazed refuge areas, which can help reduce negative effects.

Highlights

Grazing and mowing exert important influences on vegetation structure and are key factors affecting grasshopper populations (Clarke 1948, Gardiner et al 2002, Humbert et al 2009, Kenyeres and Szentirmai 2017)
The following recommendations for mowing and grazing as part of the management of wet grassland habitats occupied by S. grossum can be derived from this review:
– Grazing and/or mowing are valuable management techniques for the maintenance of the open and varied vegetation structure required by S. grossum

Summary

Introduction

Grazing and mowing exert important influences on vegetation structure and are key factors affecting grasshopper populations (Clarke 1948, Gardiner et al 2002, Humbert et al 2009, Kenyeres and Szentirmai 2017). A wide variety of wet habitats are used, some of which will provide the required vegetation structure through management by mowing and/or grazing. Sensitive management by mowing and/or grazing is considered beneficial overall to S. grossum.

Results

Conclusion