PARENT SESSION
Poster Session #41: Plant Demography.
Thursday, August 9, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall
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Rapid recovery of witch hazel (Hamamelis virginiana) by sprouting, following release from deer browsing.
Townsend, Daniel1, Meyer, Andrew2, 1 2
ABSTRACT- We studied the response of witch hazel (Hamamelis virginiana) seedlings and basal sprouts to release from white-tailed deer (Odocoileus virginianus) browsing in a hemlock-hardwoods forest in northeastern Pennsylvania. We measured seedlings and sprouts inside and outside of a 0.7 ha deer exclosure during the second growing season after its construction. There were no significant differences in seedling density, frequency or growth variables inside versus outside. Except for the number of basal sprouts per witch hazel, all basal sprout variables were significantly different inside the exclosure versus outside. Basal sprouts inside were four times longer and had four times as many leaves as those outside. Inside sprouts had a mean leaf dry mass 13.6 times, and a mean stem dry mass 5.7 times, those of outside sprouts. Over half of the witch hazels that we sampled, both inside and outside, had dead main stems and were producing sprouts from persistent crowns. Those with dead main stems exhibited somewhat shorter sprouts bearing more branches, and more leaves, per sprout than those with living main stems. Witch hazel, therefore, is capable of rapid recovery from severe browsing via basal sprouting. Even shrubs that suffer main stem death can survive for years and will produce growth equivalent to plants with living main stems, once browsing ceases. These characteristics may confer a competitive advantage on witch hazel in forest understories experiencing intense browsing.
KEY WORDS: recovery from browsing, Hamamelis virginiana, basal sprouting, seedling