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Deadwood provides important ecological and biogeochemical functions in forest ecosystems. These functions rely on tree species-specific decay dynamics, but only few studies investigated how exogenous parameters affected the decay of deadwood at the regional scale. Here, we explore the influence of climate, soil traits and forest structure on decay dynamics and mass loss of logs of 13 tree species in 29 plots across three regions in Germany. This long-term experiment (BELongDead) comprises 1,066 logs of 9 angiosperms and 4 gymnosperms and covers a decay time of almost 10 years. Mass loss of logs was relatively high for the temperate climate with partly different half-lives ranging from 6 to 13 years (mean 8.9 ± 2.2 years). Diffuse-porous angiosperms lost 70 ± 13 % of their initial mass, followed by gymnosperms (49 ± 16 %) and ring-porous angiosperms (46 ± 12 %) within the study period. We applied three different mathematical models to fit mass loss in time and found that a linear model is most appropriate for 10 tree species. A sigmoidal model best described the mass loss of Fraxinus, Quercus and Pinus logs. A multivariate analysis revealed a significant effect of soil, temperature and precipitation on mass loss at the plot level. Mass loss increased with decreasing soil nutrient content, possibly as a result of enhanced bidirectional element translocations between nutrient-poor soils and logs by fungal hyphae. Temperature had a positive effect on mass loss, whereas increasing precipitation and soil moisture were negatively related to mass loss. The region with warmer, moderately humid climate and unfavourable soil properties led to overall higher mass loss (66 ± 4 %) whereas the other two regions were indifferent (both 57 ± 3 %). Forest structure, including canopy cover, share of coniferous trees and the stock of deadwood in the vici

During a foray to the mountain rainforests of the Democratic Republic of the Congo, a peculiar species of Xylariaceae was found, which could not be accommodated in any of the existing genera. It is recognised as representative of a new genus, named Ruwenzoria, owing to the presence of a new combination of teleomorphic and anamorphic characters that are regarded as significant for generic segregation within the Xylariaceae. Studies on its secondary metabolites in stromata and cultures by high performance liquid chromatography, coupled with diode array and mass spectrometric detection (HPLC-DAD/MS), and on its phylogenetic affinities based on 5.8S/ITS rDNA sequence data, respectively, revealed a close relationship of the new taxon to the genera Daldinia and Entonaema, from which it differs by having neither a hollow, gelatinous nor a conspicuously zonate stromatal interior, and an anamorph featuring enteroblastic rather than holoblastic conidiogenesis. A specimen from the same geographic region, previously identified as Daldinia bakeri by R.W.G. Dennis was found to constitute a mixture of stromata of Ruwenzoria and an additional, undescribed Daldinia species. The latter fungus is not formally described due to the scantiness of the material, but its morphological characteristics are illustrated, During a foray to the mountain rainforests of the Democratic Republic of the Congo, a peculiar species of Xylariaceae was found, which could not be accommodated in any of the existing genera. It is recognised as representative of a new genus, named Ruwenzoria, owing to the presence of a new combination of teleomorphic and anamorphic characters that are regarded as significant for generic segregation within the Xylariaceae. Studies on its secondary metabolites in stromata and cultures by high performance liquid chromatography, coupled with diode array and mass spectrometric detection (HPLC-DAD/MS), and on its phylogenetic affinities based on 5.8S/ITS rDNA sequence data, respectively, revealed a close relationship of the new taxon to the genera Daldinia and Entonaema, from which it differs by having neither a hollow, gelatinous nor a conspicuously zonate stromatal interior, and an anamorph featuring enteroblastic rather than holoblastic conidiogenesis. A specimen from the same geographic region, previously identified as Daldinia bakeri by R.W.G. Dennis was found to constitute a mixture of stromata of Ruwenzoria and an additional, undescribed Daldinia species. The latter fungus is not formally described due to the scantiness of the material, but its morphological characteristics are illustrated.

The tropical genus Thamnomyces is characterized by having wiry, black, brittle stromata and early deliquescent asci, lacking an amyloid apical apparatus. Thamnomyces is regarded as a member of the Xylariaceae because the morphology of its ascospores and the anamorphic structures are typical for this family. However, its relationship to other xylariaceous genera remained to be clarified. Cultures of three Thamnomyces species were obtained and studied for morphological characters, and their secondary metabolite profiles as inferred from high performance liquid chromatography coupled with mass spectrometric and diode array detection (HPLC-MS/DAD) were also compared. Cultures of Thamnomyces closely resembled those of the genera Daldinia and Phylacia and even produced several secondary metabolite families that are known to be chemotaxonomic markers for the aforementioned genera. These findings were corroborated by a comparison of their 5.8S/ITS nrDNA sequences. We conclude that Thamnomyces, Daldinia, and Phylacia are derived from the same evolutionary lineage, despite these genera differing drastically in their stromatal morphology and anatomy. Along with Entonaema and Rhopalostoma, these fungi comprise an evolutionarily derived lineage of the hypoxyloid Xylariaceae. A new species of Thamnomyces is erected, and preliminary descriptions of three further, potentially new taxa are also provided