PARENT SESSION
Symposium 8: Old-Growth Savannas as Models for Management of Upland Coastal Systems: The Role of Disturbance in a Time of Global Change
Organized by: F Gilliam and W Platt
Tuesday, August 5. 1:30 PM to 5:00 PM, SITCC Chatham Ballroom B.

Trees and herbaceous plants: genetic implications for the conservation of old-growth communities.

Hamrick, James^*,1, ¹ University of Georgia, Athens, Georgia, U.S.A.

ABSTRACT- One of the goals of any conservation effort is to maintain native levels of genetic diversity. To accomplish this goal, detailed information is usually needed concerning the distribution of genetic diversity within and among populations of the target species. But strategies for the conservation of genetic diversity may differ among species within a plant community with different life history traits (i.e. breeding systems, seed dispersal mechanisms, etc.) and spatial distributions. For example, most dominant forest tree species maintain the majority of their genetic diversity within their populations while many herbaceous species growing beneath their canopy may have a much higher proportion of their genetic diversity among their populations. These divergent patterns of genetic diversity are magnified if the tree species has a continuous distribution while the herbaceous species have disjunct distributions. How then can efficient strategies of genetic conservation be developed for the community? A further complication is that both theory and empirical data demonstrate that plant species with higher levels of genetic differentiation among populations also have more population-to-population variation in the amount of diversity contained within their populations, increasing the difficulty to design effective conservation plans. Case studies of southeastern plant species will be presented to illustrate these points. Suggestions regarding the decision-making process and the information needed to develop efficient and effective conservation strategies will be discussed.

Key words: genetic diversity, herbaceous species, conservation, trees