Short-term effects of clearing restoration on the relationship of plant and moth communities

Abstract

Insects and plants share a close relationship; plants provide feeding opportunities, ecological niches, and shelters for insects, while insects, in turn, facilitate pollination for plants. Management actions might positively or negatively affect insect species richness and/or abundance, in particular, forest practices can significantly influence insect communities. In this study, we investigated the effects on plant and moth communities following the realization of an ecological corridor (composed of 10 clearings) in forest in NW of Italy. Specifically, through plant surveys and moth light traps, we investigated plant and moth communities and their relationship in newly shaped clearings and their surrounding forest. We found that plants responded quickly to clearing formation, presenting differentiated plant communities between xero-thermophile clearings, mesophile clearings and forest. These differences reflected on moth communities as well, allowing to find indicator species for each ecosystem. Structural variables (i.e. openness) and topography (i.e. elevation) were key factors affecting the differentiation of moth communities. On the other hand, plants explained most of the variance in moth communities, so, through plants, we differentiated moth communities into those typical of xero-thermophile clearings, mesophile clearings and forest. In conclusion, forest management significantly affects plant and moth communities. Newly shaped clearings support higher species richness (including specialist species) and abundance than closed canopy forest. To increase species richness and abundance for both plants and moths, we suggest conservation measures that include creating open habitats within forests at medium elevation (650–950 m a.s.l.).