Amazonian Bacterial Communities after Ecosystem Conversion

by Caroline Vurlumis

The Amazon rainforest is the most extensive tropical forest worldwide containing the largest amount of plant and animal diversity. For years there has been deforestation to create agriculture and cattle pasture which greatly harms biodiversity and causes homogenization in bacterial communities. Rodrigues et al. (2013) tested the impacts of soil microbial biodiversity when land is converted from forest to agriculture. Using transects from forest and pasture, the authors took soil samples of each to test local (alpha) diversity and differentiation (beta) diversity by concentrations of taxonomy and phylogeny. The results showed an increase in alpha diversity and decrease in beta diversity indicating a significant difference in bacterial communities when conversion occurs. There was significant loss in endemic species diversity and an increase of homogenization in the soil which poses a higher risk for net loss of biodiversity in the future. As a result of this study the authors argue that microbial biodiversity loss should be strongly considered when engaging in land conversion due to its important role in tropical ecosystems. Continue reading

Plastic Pollution and Associated Microorganisms in the North Pacific Gyre

by Chloe Mayne

Anthropogenic plastic pollution in the ocean has become extremely harmful to marine organisms and their environment. These problems include ingestion, entanglement, leaching of chemicals and adsorption of organic pollutants. The most common marine debris are small plastic fragments, which often are larger items that have been degraded. Microorganisms likely interfere with the degradation process as a result of biofilm formation on plastic surfaces. They may block plastic from UV radiation and photo-catalysis, which would increase plastic longevity. Inversely, microorganisms may accelerate degradation. Fouling microorganisms are extremely important to understanding the problems with plastic pollution, yet they have not been adequately studied. In this experiment, Carson et al. (2013) examine the abundance and diversity of microorganisms on plastics in the North Pacific Gyre. Continue reading