The conservation management of Imperata cylindrica grassland in Nepal with fire and cutting:An experimental approach

1. Imperata cylindrica dominated grassland in the Nepal Terai supports a number of threatened species including swamp deer Cervus duvauceli, hispid hare Caprolagus hispidus and Bengal florican Eupodotis bengalensis. It is also the main source of thatch material for local communities. Current widespread cutting and burning of the grasslands is deleterious to cover-dependent vertebrates which would benefit from patches of grassland remaining unmanaged. 2. In Royal Bardia National Park, a randomized block experiment with four treatments (cutting, burning, cutting and burning, and no management) was established to examine the effects of these treatments on plant species abundance, species richness and grassland structure. The grassland was dominated by Imperata cylindrica, with Saccharum spontaneum, Vetiveria zizanioides, Desmostachya bipinnata and Schizachyrium brevifolium the other abundant species. 3. In year 3, 2 years after the first treatment, Imperata cylindrica remained the dominant grass species under all treatments. It increased in abundance in unmanaged plots and declined in abundance in managed plots. Desmostachya bipinnata showed the opposite response. Plant species richness was significantly higher in managed plots, which were structurally more heterogeneous. 4. The effects of cutting alone, burning alone, and cutting and burning combined on the structure and composition of the grassland were similar, despite additive effects on total grass cover, total forb cover and forb species richness in cut and burned plots. This allows the effects of cutting and burning to be reduced to a single treatment (cutting and burning) in future experiments to investigate the impacts of patch harvesting on community dynamics. Simpler factorial experiments can be designed than if cutting and burning had to be considered as separate treatments. 5. There was no difference in the establishment of tall grass species or woody species between managed and unmanaged plots. 6. Results suggest that patches of grassland could be left unmanaged on a 2-year rotation without significantly altering the composition of the plant community, thereby providing refugia for cover-dependent faunal species

Data from: A strong test of the Maximum Entropy Theory of Ecology

This data product include Python code to reproduce the analyses in A strong test of the Maximum Entropy Theory of Ecology (Xiao et al.) with a processed subset of datasets included in the paper

Data from: A strong test of the Maximum Entropy Theory of Ecology

The maximum entropy theory of ecology (METE) is a unified theory of biodiversity that predicts a large number of macroecological patterns using information on only species richness, total abundance, and total metabolic rate of the community. We evaluated four major predictions of METE simultaneously at an unprecedented scale using data from 60 globally distributed forest communities including more than 300,000 individuals and nearly 2,000 species. METE successfully captured 96% and 89% of the variation in the rank distribution of species abundance and individual size but performed poorly when characterizing the size-density relationship and intraspecific distribution of individual size. Specifically, METE predicted a negative correlation between size and species abundance, which is weak in natural communities. By evaluating multiple predictions with large quantities of data, our study not only identifies a mismatch between abundance and body size in METE but also demonstrates the importance of conducting strong tests of ecological theories

Phylogenetic stratigraphy in the Guerrero Negro hypersaline microbial mat

The microbial mats of Guerrero Negro (GN), Baja California Sur, Mexico historically were considered a simple environment, dominated by cyanobacteria and sulfate-reducing bacteria. Culture-independent rRNA community profiling instead revealed these microbial mats as among the most phylogenetically diverse environments known. A preliminary molecular survey of the GN mat based on only 1500 small subunit rRNA gene sequences discovered several new phylum-level groups in the bacterial phylogenetic domain and many previously undetected lower-level taxa. We determined an additional 119 000 nearly full-length sequences and 28 000 >200 nucleotide 454 reads from a 10-layer depth profile of the GN mat. With this unprecedented coverage of long sequences from one environment, we confirm the mat is phylogenetically stratified, presumably corresponding to light and geochemical gradients throughout the depth of the mat. Previous shotgun metagenomic data from the same depth profile show the same stratified pattern and suggest that metagenome properties may be predictable from rRNA gene sequences. We verify previously identified novel lineages and identify new phylogenetic diversity at lower taxonomic levels, for example, thousands of operational taxonomic units at the family-genus levels differ considerably from known sequences. The new sequences populate parts of the bacterial phylogenetic tree that previously were poorly described, but indicate that any comprehensive survey of GN diversity has only begun. Finally, we show that taxonomic conclusions are generally congruent between Sanger and 454 sequencing technologies, with the taxonomic resolution achieved dependent on the abundance of reference sequences in the relevant region of the rRNA tree of life