30 Mary K. Clark, David S. Lee, John B. Funderburg, Jr. 



or subcanopy is closed do not seem to be frequented by any mammal 

 species, although they are certainly used for refuge by several large 

 species. 



Overall, the influence of fire is more positive than negative for 

 mammals. Plants associated with pocosins respond quickly to burning, 

 and the new growth of herbaceous species and the temporary openings 

 in shrub layers generally result in an increase in small mammals. Areas 

 we trapped in mainland Dare County one and two years after a major 

 fire in extensive Pond Pine-shrub and Pond Pine-cane pocosins pro- 

 duced higher trap yields than did adjacent unburned areas. Burned or 

 clear-cut sand rims and burned stream-head forests also had higher trap 

 yields than those that were unburned for long periods. The fire resistant 

 pines, most shrub root stocks, and moist soils would protect arboreal 

 and terrestrial species of mammals from burning. 



In many areas the plant communities are perched on hard subsoils 

 that form natural basins; these basins retain surface water in the organic 

 topsoils. Root systems of many of the bay forest trees usually do not 

 penetrate the subsoils, and the limited support offered by these shallow 

 peat soils makes larger trees extremely vulnerable to strong winds and 

 ice storms. In addition, frequency of blow downs is high because many 

 such trees are "crown heavy," a result of early competition with the 

 normally dense understory vegetation. During the spring of 1983 we 

 found extensive uprooting and limb breakage of trees (particularly Red 

 Maple, Red Bay and Atlantic White Cedar) in Carolina bays in Bladen 

 County and white cedar forests in Brunswick County. This damage was 

 caused by late March snow and ice storms. Hurricanes and tornados 

 would certainly cause even greater damage. Buell and Cain (1943) 

 observed areas where the weight of Smilax climbing into the canopies of 

 white cedar forests caused trees to uproot. Thus, natural openings in 

 advanced successional stages are commonplace. They provide numerous 

 sites for shade intolerant plants and for early successional and ecotonal 

 faunas to maintain populations during periods when pocosins are in 

 intermediate and advanced stages of development. Modest mammal 

 diversity and density is apparent in such openings. 



Degree and duration of flooding of pocosin communities is 

 extremely variable. In general, areas with organic soils have protracted 

 hydroperiods, whereas those with mineral soils have comparatively 

 short hydroperiods. Local topography, the nature of soil types of adja- 

 cent communities, and land drainage also affect the amount of standing 

 water. As expected, the soils in most communities remained saturated 

 for extended periods. However, presence or absence of small mammal 

 populations is dictated by the retention of standing surface water. The 

 following comments provide examples of the effects that flooding has 



