Microorganisms play a crucial role in the biological decomposition of plant litter in terrestrial ecosystems. Due to the permanently changing litter quality during decomposition, studies of both fungi and bacteria at a fine taxonomic resolution are required during the whole process. Here we investigated microbial community succession in decomposing leaf litter of temperate beech forest using pyrotag sequencing of the bacterial 16S and the fungal internal transcribed spacer (ITS) rRNA genes. Our results reveal that both communities underwent rapid changes. Proteobacteria, Actinobacteria and Bacteroidetes dominated over the entire study period, but their taxonomic composition and abundances changed markedly among sampling dates. The fungal community also changed dynamically as decomposition progressed, with ascomycete fungi being increasingly replaced by basidiomycetes. We found a consistent and highly significant correlation between bacterial richness and fungal richness (R = 0.76, P< 0.001) and community structure (RM antel  = 0.85, P < 0.001), providing evidence of coupled dynamics in the fungal and bacterial communities. A network analysis highlighted nonrandom co-occurrences among bacterial and fungal taxa as well as a shift in the cross-kingdom co-occurrence pattern of their communities from the early to the later stages of decomposition. During this process, macronutrients, micronutrients, C:N ratio and pH were significantly correlated with the fungal and bacterial communities, while bacterial richness positively correlated with three hydrolytic enzymes important for C, N and P acquisition. Overall, we provide evidence that the complex litter decay is the result of a dynamic cross-kingdom functional succession.

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model or whether there are other mechanisms for producing such echoes. Possible mechanisms are wind-driven atmospheric waves excited by topographic features and various types of wavelike structures in the ionosphere driven by interactions with the solar wind.Conclusion. The MARSIS ionospheric soundings have shown that the ionosphere of Mars is in good agreement with the expectations of Chapman's 1931 photoequilibrium theory for the origin of planetary ionospheres. The soundings have also revealed a number of unexpected features. These include echoes that reoccur at the electron cyclotron period, large variations in the absorption apparently caused by energetic solar events, oblique echoes caused by ionospheric structures associated with the crustal magnetic fields of Mars, diffuse echoes apparently caused by scattering from ionospheric irregularities, and ionospheric holes. Because the subsurface soundings must occur at frequencies well above the maximum electron plasma frequency in the ionosphere and under conditions of low ionospheric absorption, these measurements have already proved to be quite useful for planning subsurface sounding operations. The electron cyclotron echoes also provide a new method of measuring the local magnetic field strength, which is useful because Mars Express does not have a magnetometer. Animal Evolution and the Molecular Signature of Radiations Compressed in TimeAntonis Rokas,* Dirk Krüger,. Sean B. Carroll-The phylogenetic relationships among most metazoan phyla remain uncertain.We obtained large numbers of gene sequences from metazoans, including key understudied taxa. Despite the amount of data and breadth of taxa analyzed, relationships among most metazoan phyla remained unresolved. In contrast, the same genes robustly resolved phylogenetic relationships within a major clade of Fungi of approximately the same age as the Metazoa. The differences in resolution within the two kingdoms suggest that the early history of metazoans was a radiation compressed in time, a finding that is in agreement with paleontological inferences. Furthermore, simulation analyses as well as studies of other radiations in deep time indicate that, given adequate sequence data, the lack of resolution in phylogenetic trees is a signature of closely spaced series of cladogenetic events.Detailed knowledge of the phylogenetic relationships among Metazoa and their eukaryotic relatives is critical for understanding the history of life and the evolution of molecules, phenotypes, and developmental mechanisms.Currently, with the exception of the well-resolved phylogenetic history of the deuterostomes (1), the relationships between and within protostome and diploblastic metazoan phyla remain unresolved (2-5). The uncertainty surrounding metazoan relationships may result from analytical and biological factors such as insufficient amounts of available sequence data, mutational saturation, the occurrence of unequal rates of evolution between lineages, or the rapidity with which metazoan phyla diversified (3-7). Recen...

Fungi play vital roles in the decomposition of deadwood due to their secretion of various enzymes that break down plant cell-wall complexes. The compositions of woodinhabiting fungal (WIF) communities change over the course of the decomposition process as the remaining mass of wood decreases and both abiotic and biotic conditions of the wood significantly change. It is currently not resolved which substrate-related factors govern these changes in WIF communities and whether such changes influence the deadwood decomposition rate. Here we report a study on fungal richness and community structure in deadwood of Norway spruce and European beech in temperate forest ecosystems using 454 pyrosequencing. Our aims were to disentangle the factors that correspond to WIF community composition and to investigate the links between fungal richness, taxonomically-resolved fungal identity, and microbial-mediated ecosystem functions and processes by analyzing physico-chemical wood properties, lignin-modifying enzyme activities and wood decomposition rates. Unlike fungal richness, we found significant differences in community structure between deadwood of different tree species. The composition of WIF communities was related to the physico-chemical properties of the deadwood substrates. Decomposition rates and the activities of ligninmodifying enzymes were controlled by the succession of the fungal communities and competition scenarios rather than fungal OTU richness. Our results provide further insights into links between fungal community structure and microbialmediated ecosystem functions and processes.