Chapter 4 Habitats
Specifically, vegetation of clay-based depressions has been altered by fire suppression or exclusion in adjacent uplands, ditching of wetlands, or by intentional fire exclusion by maintaining fire lines around wetland habitats. Even where fire has been re-introduced into the longleaf pine ecosystem in theSoutheast, most managers use winter or spring burning instead of hot, summer fires that would have naturally occurred in the past. Winter or spring fires usually do not burn through wetlands because water is often present in the pond basin at that time of year. Indeed, fire suppression or exclusion has been linked to the encroachment of trees into historically treeless ponds in the Southeast (Kushlan 1990; Kirkman et al . 1990; De Steven and Toner 2004) . Hydrologic Changes . The reduction of open-canopy, ephemeral ponds is a major reason for the loss of populations of some southeastern amphibian species (e.g., Gopher Frog) that depend on them exclusively for breeding (LaClaire 2001) . Additionally, the encroachment of trees into temporary wetlands can have multiple adverse effects on the larvae of many amphibian species (Schiesari 2006;Thurgate and Pechmann 2007; Werner and Glennemeier 1999) . The most obvious effect is increased evapotranspiration in the pond resulting in a shorter hydroperiod (Sun et al. 2001) . Shorter hydroperiods may not allow larval amphibians enough time to reach metamorphosis (Skelly 2004) . Vegetation Changes . Shading of ponds can also lower the pond’s water temperature, slowing the growth and development of larval amphibians (Blaustein et al . 1999; Skelly et al. 2002) . Ponds with significant canopy cover may also suffer from lowered oxygen availability (Skelly et al. 2002) and reduced algal communities (Skelly and Golon 2003) , both of which have detrimental effects on larval amphibian growth and survival. Further, increases in leaf litter associated with the establishment of overstory trees can substantially lower the pH in these degraded wetlands. Evidence exists that breeding habitats can indeed become too acidic for the successful hatching and rearing of some southeastern amphibian larvae (Braswell 1993 and references therein) . 4.3.11.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help define short- and long-term conservation actions and recommendations. In this comparison, the greatest threat to depression communities is likely to be habitat conversion. Habitat conversion occurs for various reasons, including suppression of natural fire regimes, development, and land use changes. Drier basins are destroyed by development or conversion to pine plantations, while wetter ones are degraded by these activities on the surrounding uplands. In protected examples, alteration of hydrology and effects of fire suppression are usually the most serious threats. Climate change is likely to exacerbate existing effects, increasing the number and severity of droughts and increasing the amount of evaporation even in years of normal rainfall. If increased drought and severe weather reduce the ability to conduct prescribed burning, this may reduce fire even in the few examples that are getting burned. With respect to climate change, however, upland pools and their associated species are likely to respond differently from the
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2025 NC Wildlife Action Plan
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