4.4 Terrestrial Communities
to pastures or Christmas tree plantations are much greater concerns than impacts from climate change.
4.4.6.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help defne short- and long-term conservation actions and recommendations. Te efect of climate change on the species of balds is particularly uncertain. Some species are at their southern range limits and some are northern disjuncts, and these may be directly harmed by warmer temperatures. Some are dependent on seeps or wet areas, and may be harmed by more frequent or more intense drought. Habitat specialists and species with restricted ranges will likely be some of the greatest afected by the combined efects of habitat loss and climate change. Such populations are more vulnerable to extinction by rare events and susceptible to additional stressors such as climate change (DeWan et al. 2010) . Table 4.31 summarizes the comparison of climate change with other existing threats.
T ABLE 4.31 Comparison of climate change with other threats to grass and heath balds
Rank Order
Threat
Comments
Woody Succession
1 Trees and shrubs have been invading grassy balds in recent years. Te eco- logical processes that kept them open in the past are not well known, and appear to no longer operate. 2 Conversion to pasture land has historically degraded some grassy balds and continues to be a threat even at otherwise protected sites. Agriculture activities that threaten these areas include Christmas tree production. 3 Development (primarily housing) has had an impact upon both the habitat and the species utilizing it. 4 Te invasion of native shrubs and trees is a greater concern than exotic species in grassy balds. Problems with exotic species invasion in grassy balds may increase with warmer temperatures and increased fre, but this is not certain. Pasture grasses, Coltsfoot, and Angelica are the most common exotic species likely to invade grassy balds. In addition to these, the Roan Mountain area has been invaded by thistle, Spotted Knapweed, and Garlic Mustard. Some of these are currently restricted to the roadsides, but others (thistle in particular) have been found on the balds. Seeds are brought in on vehicles (trucks and tractors) and boots, and spread from roadsides and trails. Invasive exotics may be more of a problem than cur- rently acknowledged. 4 Heath balds are probably less likely to be strongly afected by climate change than grassy balds. Communities and species associated with this ecosystem are likely to be afected by changes in temperature and mild winters associated with climate change. 5 It is unclear if fre is likely to be harmful or benefcial. If wildfres increase, it could ofset the problem of tree and shrub invasion and could allow balds to expand.
Conversion to Agriculture/ Silviculture Development
Invasive Species
Climate Change
Fire
415
2015 NC Wildlife Action Plan
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