Mesures de gestion favorisant les coléoptères du bois dans une réserve forestière

Abstract

Measures favouring saproxylic beetles in a forest reserve The goal of this study is to propose conservation measures aiming at favouring saproxylic beetle populations, considering the general management of a forest reserve. The study site is a periurban forest above the city of Neuchâtel in the Swiss Jura. The studied habitats are oak and beech forests alternating with dry meadow patches and black pine (Pinus nigra) plantations. The general management goal of this forest reserve is to conserve rare plant associations and to preserve characteristical fauna and flora. In order to achieve these goals, the following management actions were undertaken: preserve open habitats, reduce black pine occurrence, restore and enhance oak forest and preserve islands of old growth. An inventory of four beetle families (Cerambycidae, Buprestidae, Lucanidae and Cetoniidae) was made by means of direct collection. Between 2004 and 2009, twenty-five collecting tours lasting for an average of 1 hour 45 minutes were performed from the beginning of May to the beginning of July. Fifty-two beetle species were caught and grouped in six categories based on their larval ecology. For each of them, enhancing actions were proposed, potential conflicts between saproxylic beetle conservation and general management actions were discussed. In order to find a balance between sometimes contradictory actions, the best solution to promote an optimal biodiversity is a patchwork of forest and open biotopes. As far as saproxylic beetles are concerned, tree diversity should be enhanced and old trees preserved. In the open areas, old bushes growing in the edges should not be removed.