Influence of grazing on populations of the specialist grasshopper Mioscirtus wagneri inhabiting hypersaline habitats in La Mancha Region, Central Spain

Grazing is an influential land use that has introduced profound changes in worldwide landscapes, ecosystems and their species. In this paper, we analysed the influence of grazing on the presence and abundance of the endangered Mioscirtus wagneri, a monophagous grasshopper inhabiting inland hypersaline ecosystems in Spain and showing a marked spatial and genetic fragmentation. Using count transects, we analyzed the presence and abundance of this grasshopper in relation to specific vegetation cover and the abundance of goat and sheep droppings, considering this variable as a surrogate of livestock activity and grazing impact. We found that both the presence and abundance of M. wagneri were positively related to the cover of its host plant Suaeda vera and negatively associated with the abundance of droppings. We conclude that dropping abundance is a useful parameter to assess livestock impact and evaluate habitat quality and the conservation status of M. wagneri and many other singular species of macroinvertebrates inhabiting inland hypersaline ecosystems. We highly recommend the use of electric shepherd fencing around all sensitive and protected areas where inland hypersaline ecosystems are present in order to deter livestock. We also suggest intensive educational campaigns for farmers and shepherds, revealing the ecological importance of these singular and unique habitats for rare and exclusive species like M. wagneri and many other coexisting plants and invertebrates.

This work received financial support from grants: POII09-0198-8057, PCI08-0130-3954 and POII10-0197-0167 (Junta de Comunidades de Castilla-La Mancha and European Social Fund), CGL2011-25053 and CGL2016-8742-R (Spanish Dirección General de Investigación y Gestión del Plan Nacional I+D+i and European Social Fund). JO was supported by a Ramón y Cajal (RYC-2013-12501) research fellowship.

Peer Reviewed