The Importance of Spatiotemporal Heterogeneity for Biodiversity in Forest—Heathland Mosaics and Implications for Heathland Conservation

In biodiversity management, spatio-temporal heterogeneity is important to consider conserving high levels of habitat diversity and ecosystems. In this study, we investigated the relationship between landscape spatio-temporal heterogeneity and biodiversity in a mosaic-landscape, located in the Fontainebleau forest (France). The diversity of successional stages along a gradient from heathland to forest as well as the persistence of Calluna vulgaris (L.) Hull in different forest stands was examined in order to find how the numerous patches of European Heathland habitat embedded in this area should be maintained. The results indicated that in the areas of high spatio-temporal heterogeneity, a general increase is observed in species richness, in particular for vascular plants, bryophytes and carabids. C. vulgaris persisted in coniferous stands and young mixed stand but decreased under deciduous trees and old mixed stands. The Ellenberg’s values for light, nutrients and acidity, show the persistence of favorable enviromental conditions for heathland vegetation under coniferous stands and young mixed stands. These results enable us to offer recommendations to better manage mosaic-landscape biodiversity, and in particular, the heathland semi-natural habitats in the Fontainebleau forest and elsewhere in Europe.

Soil Macrofaunal Communities are Heterogeneous in Heathlands with Different Grazing Intensity

Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heathlands. Our study was performed to test the impact of grazing intensity on soil macroinvertebrate communities in heterogeneous landscapes in a private property eligible to the Natura 2000 European Network of Special Protection Areas within the Brenne Natural Regional Park(Indre, France). We sampled macroinvertebrates along a broken line crossing 5 different land-use types, from pasture to pine forest, passing through a besom heath(Erica scoparia) heathland at 3 levels of cattle pressure. We hypothesized that: i) litter-dwelling(mostly arthropods and mollusks)and soil-dwelling macroinvertebrates(mostly earthworms) would respond in an opposite manner to various grazing intensities, and ii) intermediate cattle pressure(pastured heath) would increase soil and community heterogeneity. The results supported the first hypothesis, which was explained by land-use impacts mediated by soil properties. However, our results supported only partly the second hypothesis since maximum dissimilarity(whether in the composition of soil macroinvertebrate communities or in soil features)was observed in only one out of the two pastured heaths where cattle pressure was intermediate.