Does closure of traditionally managed open woodlands threaten epigeic invertebrates? Effects of coppicing and high deer densities

Abstract

The demise of traditional woodland management techniques, such as coppicing or woodland pasture, is causing a gradual closure of formerly sparse lowland woods across Central Europe. It is established that these processes threaten such organisms as butterflies and higher plants. Effects on other groups, such as epigeic invertebrates, are little known, hindering rational conservation decisions. We investigated the effects of stand openness on three epigeic groups, carabids (Carabidae), arachnids (Araneae+Opiliones) and myriapods-isopods (Chilopoda+Diplopoda+Oniscidea), in a lowland deciduous wood in the Czech Republic. Situating some of the traps in an intensive deer park allowed a simultaneous assessment of effects of high vs. low ungulate densities. Carabids reached the highest species richness in either sparse stands with low game or dense stands, high game. More arachnids occurred under low game and in sparse stands than under high game density and in dense stands. The highest richness of myriapods-isopods was in sparse stands with low game. Ordinations revealed that species of conservation concern (‘relic species’ according to C. European authors) tended to be associated with sparse stands and low game. A considerable proportion of epigeic woodland invertebrates, including many species of conservation concern, depends on preserving highly heterogeneous sparse canopy conditions. Restoring such conditions in selected areas will benefit these sensitive open woodland specialists while causing minimum harm to specialists of dense stands, that likely prosper in commercially managed high forests.