Here we report details of the European research initiative “Soil Crust International” (SCIN) focusing on the biodiversity of biological soil crusts (BSC, composed of bacteria, algae, lichens, and bryophytes) and on functional aspects in their specific environment. Known as the so-called “colored soil lichen community” (Bunte Erdflechtengesellschaft), these BSCs occur all over Europe, extending into subtropical and arid regions. Our goal is to study the uniqueness of these BSCs on the regional scale and investigate how this community can cope with large macroclimatic differences. One of the major aims of this project is to develop biodiversity conservation and sustainable management strategies for European BSCs. To achieve this, we established a latitudinal transect from the Great Alvar of Öland, Sweden in the north over Gössenheim, Central Germany and Hochtor in the Hohe Tauern National Park, Austria down to the badlands of Tabernas, Spain in the south. The transect stretches over 20° latitude and 2,300 m in altitude, including natural (Hochtor, Tabernas) and semi-natural sites that require maintenance such as by grazing activities (Öland, Gössenheim). At all four sites BSC coverage exceeded 30 % of the referring landscape, with the alpine site (Hochtor) reaching the highest cyanobacterial cover and the two semi-natural sites (Öland, Gössenheim) the highest bryophyte cover. Although BSCs of the four European sites share a common set of bacteria, algae (including cyanobacteria) lichens and bryophytes, first results indicate not only climate specific additions of species, but also genetic/phenotypic uniqueness of species between the four sites. While macroclimatic conditions are rather different, microclimatic conditions and partly soil properties seem fairly homogeneous between the four sites, with the exception of water availability. Continuous activity monitoring of photosystem II revealed the BSCs of the Spanish site as the least active in terms of photosynthetic active periods.Electronic supplementary materialThe online version of this article (doi:10.1007/s10531-014-0645-2) contains supplementary material, which is available to authorized users.

The main function of the epidermis is to protect us against a multitude of hostile attacks from the environment. Its main cell type, the keratinocytes have a sophisticated system of different proteins and lipids available to form the cornified envelope, which is responsible for the barrier function of the skin. During ageing, dramatic changes are taking place. Some proteins of the SPRR-, S100- and LCE3-family are massively up-regulated, whereas others like loricrin, filaggrin and the LCE1&2 protein families are significantly down-regulated. The latter ones are known to be under control of calcium and/or 'calcium response elements'. We were able to show that the calcium peak specific for the stratum granulosum, which is the site where loricrin and the LCE1&2 families are synthesized, is reduced during ageing. The resulting cornified envelope in old skin has an extensively changed composition on the molecular level compared to young skin. This knowledge is of critical importance to understand chronic wound formation and ulcers in old age.

Overyielding in mixed‐species forests has been demonstrated in a vast body of literature, and the focus of functional biodiversity research is now shifting towards a mechanistic understanding of these observations. We explored diversity–productivity relationships at two sites of a large‐scale tree diversity experiment, with harsh (Ged) and benign (Zed) environmental conditions for plantation establishment. Additive partitioning methodologies were adopted to detect phenomenological patterns in the productivity data, and the trait structure of mixed communities was used to advance insights into compositional effects. After 6 years of plantation development, biomass productivity was significantly higher in mixtures compared to the monocultures of component species. We observed that processes operated through direct tree–tree interactions, as the diversity signal disappeared where trees in mixed stands were surrounded by conspecific neighbours only. This result is particularly relevant for mixed‐species plantation systems, as trees are commonly planted in monospecific patches to simplify management.Partitioning unveiled strong selection effects at both plantation sites. However, at the harsh Ged‐site this was caused by competitive dominance of species with fast young growth, whereas at the benign Zed‐site, species with slow young growth improved their performances but not at the expense of others (i.e. trait‐dependent complementarity). Species tolerance to shading is an influential trait for predicting biodiversity effects, with community‐weighted means in shade tolerance mediating dominance effects (Ged) and functional diversity in shade tolerance mediating (trait‐dependent) complementarity effects (Zed). Synthesis. This study highlights that biodiversity effects in young tree plantations could be explained by the functional composition of mixed communities, with a key role for species levels of shade tolerance. As contrasting results between plantation sites were observed, future research should target the context‐dependency of diversity–productivity relationships.

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Industrial wastes generated from tanneries located in the southwestern part of Dhaka, pose serious threat to the environment. Surface accumulation of trivalent chromium reaching as high as 28,000 mg/kg have been encountered at 1 km distance from the waste lagoon. In contrast, maximum concentration of hexavalent chromium is about 1 mg/ kg, and is very irregularly distributed all over the area. Although soil pH is alkaline in general, a sharp drop of pH down to 3.4 has been observed at some locations. Furthermore, high chloride (Cl) and lead (Pb) concentrations pose risk for city's groundwater quality, of which Pb is vulnerable for any chelateassisted phytoremediation as it can enhance its mobility. Scanning electron microscope study showed chromium within the structure of clay minerals, mainly illite-smectite, and also as chlorite-chromian. Presence of lepidocrocite indicates a rather reactive phase which can undergo reductive dissolution and release Cr in the environment.

1. Biodiversity can insure ecosystems against declines in their functioning by increasing the mean level of ecosystem processes and decreasing the spatial or temporal variance of these processes. On this basis, mixing tree species is expected to be an effective management strategy to reduce the risk of planting failure in young plantations. 2. We examined the effects of biodiversity insurance on sapling survival in three tree diversity experiments across Belgium. Based on the survival scoring of 89 254 saplings, planted in 126 plots with up to four-species mixtures, we tested two hypotheses: (i) variability in plot-level survival is lower for mixtures compared to monocultures due to compensation among the species (i.e. buffering effect) and (ii) mean survival is higher due to facilitation (i.e. performanceenhancing effect). 3. Variation in plot-level survival decreased strongly with diversity, indicating a buffering effect. The risk of severe planting failure was reduced in mixtures because species exhibit different survival rates; therefore, mixing ensures that not all trees in the plantation are equally susceptible to environmental stressors. In contrast, the mean plot-level survival did not increase with diversity, and thus, an overall performance-enhancing effect was lacking. However, species-level analyses did show performance-enhancing effects, where some species profited from mixing while others did not. 4. Synthesis and applications. We conclude that biodiversity through mixing tree species insures young experimental plantations against planting failure and is therefore highly recommended as a planting management strategy. The risk of large mortality gaps is reduced if tree plantation saplings are mixed at the scale of individual trees or small cells of trees.

Biological soil crusts are ecologically important communities in areas where vascular plant coverage is low, and their presence is often vital in prevention of soil erosion. Despite recurrent threats to biological soil crusts across different environments, their recovery after disturbance has been little studied. We therefore established experiments across a latitudinal gradient in Europe, from Öland, Sweden in the north, to Gössenheim, Germany and Hochtor, Austria, to Almeria, Spain in the south, spanning over 20 ∘ latitude and 2,300 m in altitude, and including natural and semi-natural sites. At each site 10 (1 × 1m)paired plots were constructed where the biological soil crusts were either completely removed, or left intact. Over a 2-year period (2012–2014) the plots were regularly sampled to assess functional group recovery (cyanobacteria, algae, lichens, bryophytes, vascular plants), soil stability, and chlorophyll, carbon, and nutrient contents. Cyanobacterial assemblages were examined by denaturing gradient gel electrophoresis, a technique used to detect DNA in environmental samples. The results indicated that recovery was site dependent, suggesting that physical and climatic parameters play a major role in biological soil crust recovery. This conclusion is supported by the results of the soil properties, which were found to differ between sites, although they did not show meaningful recovery over the study period. Although 2 years was insufcient for pronounced biological soil crust recovery, this study documents changes over the initial recovery period, suggests management practices for future projects, and recommends proxies for measuring recovery over time