Graduate Program
Biological Sciences
Degree Name
Master of Science (MS)
Semester of Degree Completion
2009
Thesis Director
Scott Meiners
Thesis Committee Member
Barbara Carlsward
Thesis Committee Member
Andrew Methven
Abstract
Although they are important components of forest communities, the general ecology of temperate lianas, especially during forest regeneration, is largely unknown. The dependence of lianas on other plants for physical support makes them a potentially important driver of community dynamics. I examined current and past vegetation data from an old-field succession study in the Piedmont region of New Jersey, USA to determine the dynamics of liana expansion and their role in forest regeneration. Fifty years of vegetation data were utilized to determine community controls and population dynamics oflianas during expansion. Five lianas, Celastrus orbiculatus, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp., occurred throughout the forest and were the focus of this research. To understand potential impacts of lianas on the current forest community, the intensity of liana burdens on host trees was evaluated by examining host preference of lianas on established trees. I also used these trees to examine how lianas impacted the growth of established canopy trees within the young forests that resulted from 50 years of old-field succession.
Based on long term data, liana cover peaked during mid succession (20-30 years post-abandonment) when community composition was mostly herbaceous with scattered trees and shrubs. Liana cover began to decrease as trees became dominant and the canopy closed. In contrast to cover, frequency of lianas increased throughout succession, indicating that liana populations persisted despite dramatic declines in cover. Two lianas, C orbiculatus and Vitis spp., appeared to be late successional and may persist at higher covers. Differences in host tree preference were found among liana species. Most liana species had higher colonization probabilities and greater canopy cover on early successional trees, particularly Juniperus virginiana. When liana burdens were related to growth over a nine year period, trees with greater amounts of lianas along their trunks grew the most, presumably where conditions were favorable for both trees and lianas. In contrast, lianas slightly decreased growth of trees with high liana canopy cover, suggestive of canopy competition between liana and trees. Most of the variation in tree growth was related to the successional stage of the tree species with late successional trees growing 60% more than early successional trees. This difference in growth was probably a result of the timing of my measurements during the transition in dominance from early successional to late successional trees. The minor effects oflianas on tree growth may not be greatly detrimental to tree and overall temperate forest health in a young, closed-canopy forest. However, the slight growth reducing impacts of lianas combined with their preference for early successional trees may make lianas a contributing factor to the acceleration of succession within this eastern deciduous forest. The spatio-temporal dynamics of lianas indicate that successional processes may ultimately lead to the decline in abundance of most lianas. However, the persistence of lianas as high numbers of suppressed individuals suggests that they may rebound quickly following canopy disturbance.
Recommended Citation
Ladwig, Laura Marie, "Ecology And Impacts Of Lianas In Regenerating Forests" (2009). Masters Theses. 57.
https://thekeep.eiu.edu/theses/57
