4.3 Wetland Natural Communities
T ABLE 4.20 Comparison of climate change with other threats to freshwater tidal wetlands
Rank Order Comments
Threat
Climate Change
1 Tis ecosystem group is likely to experience drastic changes in extent and sig- nifcant movement and composition of communities. Sea level rise, drought, increased storm activity, and saltwater intrusion are threats to freshwater tidal wetlands. 2 Common Reed, Chinese Tallow Tree, Alligator Weed, and Nutria are primary con- cerns. Te disruptions created by shifting communities and catastrophic events may increase the spread of Common Reed. Giant Salvinia could become a prob- lem. Early control of species that have proven more invasive farther south will be less costly and less ecologically disruptive than allowing populations to become large. 2 Erosion control measures may help protect these communities, but measures that alter the shoreline, whether sea walls, “soft” structures, or planting of-site species, are potentially destructive to these communities. Shoreline armoring and harden- ing to protect infrastructure will prevent ecosystems such as tidal marshes from migrating inland (DeWan et al. 2010) . 3 Logging is a threat to some tidal cypress-gum swamps, while others are in pro- tected status or are too wet for logging equipment. Drying may create opportuni- ties for logging these wet areas. 3 Many herbaceous plants of tidal freshwater marshes appear to need fre to main- tain their populations. Lack of fre allows unnatural vegetation succession, espe- cially invasion by woody species, in some freshwater marshes. 4 Alteration of food regimes in rivers may afect these systems. Some areas are fresh largely, or at least partly, because of the dilution of sea water by river input. Increased water withdrawal or interbasin transfer may increase this problem in the future. Te efects are local, afecting primarily the mouth of the altered rivers, but could be important cumulatively. Existing drainage ditches and canals bring- ing saltwater into wetlands is a serious threat. Tide gates or blocking ditches are needed. 5 As development continues inland, water demands in the Piedmont will afect freshwater fows from the major rivers that feed this system through water removals.
Invasive Species
Shoreline Hardening
Logging/ Exploitation
Fire
Flooding Regime Alteration
Freshwater Withdrawal
susceptible to extirpation from the state if they or their specialized habitats cannot keep pace with the efects of sea level rise and saltwater intrusion.
Nutria are considered a serious pest species in the United States because they eat a variety of wetland and agricultural plants and their burrowing damages streambanks, impound- ments, and drainage systems. Nutria may also be a vector for diseases (tuberculosis and septicemia) or parasites ( Giardia, Fasciola , Liver Flukes, and nematodes), with fecal con- tamination in water the likely pathway. As warming trends increase, the range of Nutria is likely to expand and populations currently limited by intolerance to cold winters will quickly expand ( Carr 2010 ).
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2015 NC Wildlife Action Plan
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