Can multifunctional forest landscapes sustain a high diversity of saproxylic beetles?

Abstract

Abstract Intensive forestry practices have led to fragmentation of habitats that have high conservation value and has reduced the availability of deadwood in forests. This has in turn, led to a decline in species associated with deadwood (e.g. saproxylic beetles). Conservation measures have been developed in order to halt the negative trend in forest biodiversity, both at local and landscape scales. Ecoparks are large forest landscapes, with at least 50% of the forestland being managed with enhanced conservation concern including legal and voluntary protection or restoration of forests. Ecoparks aim to combine production, nature conservation and recreation (e.g. berry picking, hiking, hunting, fishing) and thereby represent multifunctional forest landscapes. The purpose of this study was to evaluate whether ecoparks can sustain greater diversity of saproxylic beetles than conventionally managed production landscapes, and whether the local habitat amount and diversity can have an additional effect on species assemblages. Two ecoparks and two representative conventional production landscapes, which implement a rotation forestry with general nature consideration, were selected for the study. Beetles were collected during three years in sun-exposed plots, where local (20\xa0m radius) forest structures were measured. We found that both ecoparks sustained greater abundance and richness of nationally red-listed beetles (IUCN classes NT, VU, EN) and contained different beetle assemblages in comparison with conventional landscapes. Local deadwood volume had a positive relationship with the richness and abundance of saproxylic and red-listed beetles in the southern study area (long history of land-use), but not in the north (short history of land-use), partially supporting habitat amount hypothesis (HAH) at the local scale. Instead, the responses of beetles to deadwood diversity showed inconclusive results, varying between years and study areas. Our results highlight the potential of multifunctional forests in conserving biodiversity of saproxylic beetle species, especially red-listed species, as well as the importance of local deadwood availability.