The role of a mound-building ecosystem engineer for a grassland butterfly

Abstract

Both land use intensification and abandonment within grasslands lead to a homogenisation of vegetation structure. Therefore, specially structured microsites such as vegetation gaps with bare ground play an important role for species conservation within grasslands. Vegetation gaps are crucial for the establishment of low-competitive plant species and offer special microclimatic conditions essential for the development of the immature stages of many invertebrate species. The influence of small-scale soil disturbance in the form of mounds created by ecosystem engineers such as ants or moles on biodiversity is therefore of special scientific concern. The effects of mound-building species on plant species diversity have been extensively studied. However, knowledge on the significance of these species for the conservation of other animals is rare. In this study we analyse the importance of mounds created by the European mole (Talpa europaea) as an oviposition habitat for the small copper (Lycaena phlaeas) within Central European mesotrophic grasslands. Our study showed that host plants occurring at molehills were preferred for oviposition. Oviposition sites were characterised by an open vegetation structure with a high proportion of bare ground (with a mean coverage of about 50 %), a low cover of herbs and low-growing vegetation (mean height: 4.5 cm). Our study clearly illustrates the importance of small-scale soil disturbance for immature stages of L. phlaeas and the conservation of this species within mesotrophic grasslands. Mound-building ecosystem engineers, such as T. europaea, act as important substitutes for missing dynamics within mesotrophic grasslands by diversifying vegetation structure and creating small patches of bare soil.

Beauty and the beast: multiple effects of wild boar rooting on butterfly microhabitat

“…Similarly positive effects of soil perturbation by ecosystem engineers were also reported with regard to the oviposition patterns of other butterfly species, i.e. the case of mound-building mammals (Streitberger and Fartmann 2013;Streitberger et al 2014) and arthropods (Streitberger and Fartmann 2016). Besides the possible indirect effects on host plant occurrence and abundance, direct effects of rooting can be explained in terms of increase of accessibility and/or visibility of oviposition sites.…”

“…Recent studies reported effects on butterfly oviposition and larval requirements due to soil disturbances by ecosystem engineers, e.g., European mole (Streitberger and Fartmann 2013;Streitberger et al 2014) and meadow ant (Streitberger and Fartmann 2016). However, only few researches were performed on the significance of wild boar rooting effects on butterfly habitat requirements (de Schaetzen et al 2018).…”

Abandonment of traditional land use and climate change threaten the survival of an endangered relict butterfly species

“…Moreover, occupied microhabitats were characterised by sparser swards with more bare ground than unoccupied ones. Consequently, they provided conditions that generally favour a warm microclimate through daytime (Stoutjesdijk & Barkman, 1992; Krämer et al ., 2012a; Streitberger et al ., 2014). Moreover, a higher litter cover may act as a microclimatic buffer during winter by reducing temperature fluctuations, which could be detrimental for the survival of hibernating pupae (cf.…”

A Review of the Engineering Role of Burrowing Animals: Implication of Chinese Pangolin as an Ecosystem Engineer

“…The low grass cover increased occupancy of the favoured host plant Pyrgus malvae indirectly supports effective microhabitat selection by females during oviposition, which strongly determines larval survival. In addition, the importance of mounds created by the European mole (Talpa europaea) as an oviposition habitat for the small copper (Lycaena phlaeas) within Central European mesotrophic grasslands was reported [80] . The author found that even though L. phlaeas is considered a generalist species inhabiting a wide range of open habitats, a high proportion of eggs was found on molehills where the vegetation structure clearly differed from the surrounding vegetation.…”