4.3 Wetland Natural Communities
that prevent the colonization of trees and shrubs (e.g., limestone sinks with a groundwater connection).
However, many upland, isolated wetlands would have historically been maintained as open, “grassy” ponds through a combination of hydroperiod and fre regime processes (DeSteven and Toner 2004) . In these situations, summer fres would occasionally burn through the dry basins, limiting the establishment and growth of fre-intolerant woody species and controlling the buildup of excessive amounts of peat (Florida Natural Areas Inventory 1990) . Specifcally, vegetation of clay-based depressions has been altered by fre suppression or exclusion in adjacent uplands, ditching of wetlands, or by intentional fre exclusion by maintaining fre lines around wetland habitats. Even where fre has been reintroduced into the Longleaf Pine ecosystem in the Southeast, most managers use winter or spring burn- ing instead of hot, summer fres that would have naturally occurred in the past. Winter or spring fres usually do not burn through wetlands because water is often present in the pond basin at that time of year. Indeed, fre suppression or exclusion has been linked to the encroachment of trees into historically treeless ponds in the Southeast (Kushlan 1990; Kirkman et al . 1999; De Steven and Toner 2004) . Te reduction of open-canopy, ephemeral ponds is a major reason for the loss of popula- tions of some southeastern amphibian species (e.g., Gopher Frog) that depend on them exclusively for breeding (LaClaire 2001) . Additionally, the encroachment of trees into tempo- rary wetlands can have multiple adverse efects on the larvae of many amphibian species (Schiesari 2006; Turgate and Pechmann 2007; Werner and Glennemeier 1999) . Te most obvious efect 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 metamorpho- sis (Skelly 2004) . 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 signifcant canopy cover may also sufer from lowered oxygen availability (Skelly et al. 2002) and reduced algal communities (Skelly and Golon 2003) , both of which have detrimental efects on larval amphibian growth and survival. Further, increases in leaf litter associated with the estab- lishment 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) .
4.3.9.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help defne short- and long-term conservation actions and recommendations. In this comparison, the greatest threat to
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2015 NC Wildlife Action Plan
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