Doctor of Philosophy, The Ohio State University, 2017, Environmental Science

The cryosphere is shrinking as a result of climate change. Mountain glaciers, a key component of the cryosphere, serve as headwaters to glacier meltwater streams which support communities of stenothermic organisms. The Tibetan plateau is known as "the Third Pole" for its high number of glaciers, yet very few scientific papers have been published on aquatic invertebrate ecology of glacier-fed streams in the region. On the edges of the Tibetan Plateau in Southeast Tibet's Hengduan mountains, monsoonal temperate glaciers extend well below the treeline as valley glaciers, and are perhaps the most endangered cryosphere-dominated streams in the world due to their low latitudes and altitudes, which makes them sensitive to atmospheric temperature changes. The glaciated headwaters of the Mekong and Yangtze Rivers comprise a small fraction of the annual river discharge, yet at a local scale provide glacial meltwater that supports endemic and potentially rare species. Water temperature and channel stability differ between seasons due to the torrential flow from glacial meltwater during the summer melt season. The Milner & Petts (M&P) model of macroinvertebrate presence in glacier streams was based on the environmental factors of water temperature and channel stability during the summer melt season. In low temperature water close to the glacier, the macroinvertebrate communities are generally limited to Diamesinae chironomids, and further downstream more taxa are found where water temperature and channel stability increase. Therefore, temperature and channel stability are examined as potential limiting factors on the distribution of invertebrate communities, with the goal to compare the insect communities in Southeastern Tibet's glacier-fed streams with the widely-accepted M&P model of invertebrate community structure. Since discharge and hydrology may influence invertebrate distribution in glacier streams, hydraulic characteristics and invertebr (open full item for complete abstract)

Committee: Lanno Lanno Dr. (Advisor); David Denlinger Dr. (Committee Member); Richard Moore Dr. (Committee Member); Donald Dean Dr. (Committee Member) Subjects: Environmental Science

Doctor of Philosophy, Miami University, 2016, Ecology, Evolution and Environmental Biology

The Tigris and Euphrates Rivers and their tributaries form the arteries of life in the central part of the Middle East, where climate change and anthropogenic disturbance have been evident in recent decades. While the Tigris River has a long history of human use, the conservation status for the majority of its basin is poorly known. In addition, planning for conservation, given limited time, funds, and prior information, has remained a challenge. In my dissertation research, I sampled 53 randomly selected sites in the Kurdistan Region (the KR) of northern Iraq, a poorly studied region of the Upper Tigris and Euphrates freshwater ecoregion, for water quality bioindicators, mayflies (Insecta, Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) (a.k.a. EPT). I identified the mayflies to the finest possible taxonomic level and created the first Iraqi checklist and larval key to nine families, nine subfamilies, 19 genera, and 13 subgenera, and supported it with 117 state-of-the-art scientific illustrations using fresh specimens collected during my study (Chapter 1). I performed an initial species morphological identification for mayflies and stoneflies, then identified them genetically after sequencing the full-length of the mitochondrial cytochrome oxidase subunit 1 (COI) gene (658 base pairs). I introduced Genetic Similarity Blocks (GSBs), a genetic-based analysis which was used along with morphology and other genetic-based analyses to overcome the taxonomic impediment and accelerate species identification. I delineated Operational Taxonomic Units (OTUs) using genetic-based analyses, then matched OTUs to delineate Species-Like Units (SpLUs). I compared and contrasted SpLUs morphologically and found five stonefly and more than 55 mayfly taxa, the majority of them being new records for Iraq, and many of them potentially new to science (Chapter 2). I identified 76 planning units within aquatic ecosystems in the KR and prioritized a subset of them for EP (open full item for complete abstract)

Committee: David Berg (Advisor); Bruce Cochrane (Committee Member); John Morse (Committee Member); Michael Vanni (Committee Member); Thomas Crist (Committee Member); Mary Henry (Committee Member) Subjects: Animal Sciences; Aquatic Sciences; Biology; Conservation; Ecology; Environmental Studies; Wildlife Conservation; Zoology