Abstract:Conservation Biology 41In an attempt to provide a state of the art of the effect of forest management on biodiversity, 42we performed a MA comparing the species richness of managed and unmanaged forests in 47Our MA provides basic ecological knowledge needed for conservation and ecologically 48 sustainable forestry. In this paper, we showed that forest management has a negative effect 49 on the biodiversity of forest dwelling species. Because we were aware of the limitations of 50 our MA, we used caution when discussing the results considering that: (i) the effect is 51 strongly heterogeneous between different taxa; (ii) there is a trend for recovery of biodiversity 52 once management has been abandoned; (iii) no strong conclusion on the effect of different 53 management types could be drawn from our data due to low replication number. The obvious 54 main conclusion of this paper was that research on the subject in Europe was scarce and 55 that more controlled studies may help answer the questions raised. 113always provided negative slopes, except for bryophytes and birds (see Table 3, p. 107). 114Finally, even if the effect of TSA was significant only for carabids, saproxylic beetles and 115 fungi, most of the negative slopes for taxa have much higher value than the slope for all 160(2002): this paper compares old growth with 15 years-old stands, which were not considered 161 as "young regeneration phases" nor "clearfelling stands" in our protocol. We assume that our 162 selection protocol was restrictive enough regarding the number of studies finally included in 163 our MA; if we had been more restrictive in our inclusion criteria (i.e. excluding young stands), 164we would have rejected this paper. 166 Conclusions 167The paper we published does not aim at influencing European forest and conservation 168 policies in any way, but to provide decision-making tools based on scientific facts. Both 169 managed and unmanaged forests are needed to preserve European forest biodiversity, but 170 since there are many managed forests and very few old-growth ones, a special effort should 171 be allocated to create protected reserves, as suggested by Paillet et al. (2010).

Climate warming is causing a shift in biological communities in favor of warm-affinity species (i.e., thermophilization). Species responses often lag behind climate warming, but the reasons for such lags remain largely unknown. Here, we analyzed multidecadal understory microclimate dynamics in European forests and show that thermophilization and the climatic lag in forest plant communities are primarily controlled by microclimate. Increasing tree canopy cover reduces warming rates inside forests, but loss of canopy cover leads to increased local heat that exacerbates the disequilibrium between community responses and climate change. Reciprocal effects between plants and microclimates are key to understanding the response of forest biodiversity and functioning to climate and land-use changes.

No abstract

Global biodiversity is affected by numerous environmental drivers. Yet, the extent to which global environmental changes contribute to changes in local diversity is poorly understood. We investigated biodiversity changes in a meta-analysis of 39 resurvey studies in European temperate forests (3988 vegetation records in total, 17-75 years between the two surveys) by assessing the importance of (i) coarse-resolution (i.e., among sites) vs. fine-resolution (i.e., within sites) environmental differences and (ii) changing environmental conditions between surveys. Our results clarify the mechanisms underlying the direction and magnitude of local-scale biodiversity changes. While not detecting any net local diversity loss, we observed considerable among-site variation, partly explained by temporal changes in light availability (a local driver) and density of large herbivores (a regional driver). Furthermore, strong evidence was found that presurvey levels of nitrogen deposition determined subsequent diversity changes. We conclude that models forecasting future biodiversity changes should consider coarse-resolution environmental changes, account for differences in baseline environmental conditions and for local changes in fine-resolution environmental conditions.

In European beech forests windstorms often create canopy gaps and change the level of incident light, soil moisture and nutrient availability on the forest floor. Understanding the interrelations between gap size and environmental change, and the effects these have on regeneration processes is a prerequisite for developing techniques of nature-based forestry. The aims of this study were to investigate the effects of gap size on the resulting spatial distributions of key abiotic environmental variables (light and soil moisture) in gaps, and to study how light and soil moisture affect the abundance and distribution of herb layer species. To do this we used eight artificially created gaps -three large (diameter: 35 -40 m) and five small (diameter: 10 -15 m) -in a mesotrophic submontane beech forest. Data on species' importance and substrate types were collected in systematically distributed 1 mÂ1 m quadrats before gap creation and on four occasions during the next two growing seasons. Hemispherical photographs were taken and analysed to estimate relative light intensity. Soil moisture was measured by frequency domain and capacitance probes. It was found that gap size had a profound effect on the environmental variables measured. While relative light intensity values in small gaps did not reach those in large gaps, soil moisture levels did reach similar maximum values in gap centres regardless of gap size. Richness, composition and total cover of herbaceous vegetation were different in small versus large gaps. Much of this difference was attributed to the presence of specific relative light intensities and also to the increased amount of available soil moisture in gaps. Species were differently affected by the combined effects of light and soil moisture, as well as by differences in available substrates. All this resulted in species-specific distribution patterns within gaps.