Comparison of survey methods for fungi using metabarcoding and fruit body inventories in an altitudinal gradient.

Metabarcoding of environmental samples is nowadays an established method in biodiversity research. When it comes to studying fungal populations in various ecotypes, fruit body inventories are the traditional method to assess the diversity of fungal communities. In this study, both methods-metabarcoding of soil samples and a traditional fruit body inventory-were conducted on 144 sample plots in an altitudinal gradient in the Bavarian Forest (Germany) and the results were compared. Metabarcoding detected significantly more species than the traditional fruit body inventory. The majority of taxa recorded in the fruit body inventory belonged to the Basidiomycota, whereas in the metabarcoding data, the distribution of species between Basidiomycota and Ascomycota was approximately balanced. Species of several orders forming inconspicuous or hypogeous fruit bodies were detected only by metabarcoding, while several wood decomposers were recorded only in the fruit body inventory. The proportion of detected wood-colonising species with melanized spores was considerably higher with metabarcoding than with the fruit body inventory, where more than 70% of recorded wood-colonisers had hyaline spores. Based on the metabarcoding data, a decline of species richness with increasing altitude was evident, but this was not visible in the fruit body inventory data. Detrended correspondence analyses yielded similar results for relative species community similarities with both survey methods.

Interactive influence of rainfall manipulation and livestock grazing on species diversity of the herbaceous layer community in a humid savannah in Kenya.

Changes in rainfall regime and grazing pressure affect vegetation composition and diversity with ecological implications for savannahs. The savannah in East Africa has experienced increased livestock grazing and rainfall variability but the impacts associated with those changes on the herbaceous layer have rarely been documented. We investigated the effect of livestock grazing, rainfall manipulation and their interaction on the composition and diversity of the herbaceous community in the savannah for two years in Lambwe, Kenya. Rainfall manipulation plots were set up for vegetation sampling; these plots received either 50% more or 50% less rainfall than control plots. Simpson's diversity and Berger-Parker indices were used to determine diversity changes and dominance respectively. The frequency of species was used to compute their abundance and their life forms as determined from the literature. Grazing significantly increased species diversity through suppression of dominant species. Rainfall manipulation had no significant impact on plant diversity in fenced plots, but rainfall reduction significantly reduced diversity in grazed plots. In contrast, rainfall manipulation had no impact on dominance in either fenced or grazed plots. The interaction of grazing and rainfall manipulation is complex and will require additional survey campaigns to create a complete picture of the implications for savannah structure and composition.