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Identifying amphibian habitats within a landscape provides a tool for managing their populations. I identified if and how amphibians used small ephemeral wetlands (≤ 0.1ha) and streams within the mixedwood forest area managed by Daishowa Marubeni International Ltd. near Peace River, north-western Alberta. Twenty-seven wetlands and their riparian zones were sampled for all life stages of amphibians in 2008 using timed visual encounter surveys. The riparian zones of 11 small streams were sampled with pitfall traps within 120 m of their beds from 2006 to 2008. Habitat features were also measured. Lithobates sylvaticus, Anaxyrus boreas and Pseudacris maculata used small ephemeral wetlands and the riparian zones of ephemeral, intermittent and permanent streams at different life stages. Water temperature and canopy cover influenced amphibian presence and abundance in wetlands. Coniferous and deciduous tree density were associated with L. sylvaticus abundance at the stream sites. I conclude that small waterbodies are amphibian habitats in the mixedwood forest of boreal Alberta. / Ecology

In the southeastern United States, ephemeral wetlands in pine flatwoods provide important habitat for amphibians and aquatic invertebrates, but extensive deforestation has destroyed or isolated many wetlands and fire suppression has altered vegetation in others. My goals were to identify how wetland hydroperiods have changed through time and to examine the effects of long-term fire suppression on aquatic communities, including Reticulated Flatwoods Salamanders (Ambystoma bishopi) and Ornate Chorus Frogs (Pseudacris ornata). Chapter 1 used a modeling approach to relate wetland hydroperiods to current climate conditions and to hindcast historic conditions. Over the past 118 years, hydroperiods were often unfavorable for A. bishopi reproduction, and in recent years hydroperiods were shortened by persistent drought. Chapters 2 and 3 focused on identifying the effects of shifting from an open, grass dominated wetland to a wetland with high canopy cover and little herbaceous vegetation. In Chapter 2, I quantified amphibian and invertebrate communities in several wetlands. A. bishopi and P. ornata tended to occupy wetlands with lower canopy cover and higher herbaceous vegetation cover. Aquatic invertebrate abundance was generally higher in wetlands with lower shrub density and lower canopy cover. In Chapter 3, I examined how a reduction in herbaceous vegetation affected tadpoles when a predatory crayfish was present using two experiments. Crayfish were effective predators of both species across all vegetation treatments and often caused nonlethal tail injury. My results suggest that managers should focus on ensuring that wetland basins regularly burn, and wetlands with longer hydroperiods should be a management priority. / Master of Science