Freshwater Ecology
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In 1963, the Glen Canyon Dam, in Hite Utah was completed, creating the Lake Powell reservoir along the Colorado River. The water levels of Lake Powell peaked in 1983 and have declined since, releasing over-pressure on the underlying sediment. This release in over-pressure created mud volcanoes, structures along the shoreline made of cavities that allow fluid and gases to rise to the surface and escape. Green house gases including methane are released from these structures, and to better understand how development of natural wetlands can result in unintended increased levels of greenhouse gas emissions, we asked 1) how much of each gas is generated or and whether the amount of each gas is changing through time and 2) how are these gases forming in the subsurface? We first measured the amounts of carbon dioxide (CO2), methane (CH4), and air (N) in volcano gas samples collected in 2014, 2015, and 2016. We found that from 2014 through 2016, methane levels from these volcanoes fluctuated significantly. In 2016, we looked at the amounts of carbon and hydrogen isotopes in the methane, which told us the gas is generated from microorganisms feeding on organic matter and is released during water-level fluctuations. We looked at mud volcanoes only located along the Lake Powell marina delta in Hite, Utah. The data spans geological structures restricted to one marina delta.
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This is a collated plant survey data from the Fleurieu Peninsula wetlands (version.2). There is a biological and a spatial component to the dataset. [1] Biological data: This was collated from several sources, collected over the period 2000-2009 and used in the analyses for the paper <i>Diversity patterns of seasonal wetland plant communities mainly driven by rare terrestrial species</i> (Deane et al - Biodiversity and Conservation, DOI: <em>10.1007/s10531-016-1139-1</em>). Biological data were pre-processed to remove sampling bias (the method is described in the paper). Data are presence-absence of 215 native plant species (i.e., exotic species removed) from 76 seasonal wetlands (size range 0.5 - 35 ha) located on the Fleurieu Peninsula, South Australia (centred on latitude 35.5 °S). [2] Spatial data: For each of the 76 wetlands a small amount of spatial data is also provided. Area, centroids, elevation and catchment. The data could be of interest for any typical community data analysis (e.g. beta diversity, similarity, assembly), provided only native wetland plant species were of interest. Data were used to model extinction risk, species-area relationships, occupancy distributions and so on.
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The dataset comprises of a biological and a spatial component. Biological data: This was collated from several sources, collected over the period 2000-2009. Data are lists of presence-absence of 215 native plant species (i.e., exotic species removed) from 76 seasonal wetlands (size range 0.5 - 35 ha) located on the Fleurieu Peninsula, South Australia (centred on latitude 35.5 °S). After data were collated into a single dataset, sampling bias was removed to create a dataset of near-complete census wetlands. Spatial data: For each of the 76 wetlands a small amount of spatial data is also provided, i.e., area, centroids, catchment etc. The dataset could be of interest for any typical community data analysis (e.g. beta diversity, similarity, assembly)- provided only native wetland plant species are of interest. Data presented here were used to model extinction risk, species-area relationships, occupancy distributions and so on.