PARENT SESSION
Contributed Oral Session 141: Restoration and Adaptive Management: Soils and Nutrients
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal
Can the plant life history characteristics of Desmodium nudiflorum be used as indicators of the effects of ecological restoration treatments?
Huang, Jianjun*,1, Boerner, Ralph1, Rebbeck, Joanne2, 1 Ohio State University, Columbus, OH2 USDA Forest Service, Delaware, OH
ABSTRACT- Ecological restoration treatments such as dormant season fire and overstory thinning often change light and soil resource availability. Consequently, perennial plants that persist might be expected to acclimate to the altered environment by changing their life history characteristics. We evaluated how naked-flowered tick trefoil (Desmodium nudiflorum), a common and widespread herbaceous perennial, responded to dormant season fire alone (B) or in combination with thinning (B+T) in southeastern Ohio mixed oak forests. We also assessed the relative importance of various plant characteristics as response indicators of these restoration treatments. During the fourth growing season following treatments, plants were studied in situ and harvested within 49 plots of the Ohio Hills Fire and Fire Surrogate Network study site. Plants from B+T plots had significantly greater root and leaf [N], root N:P ratio, and stomata conductance and significantly lower root mass ratio than plants from untreated control (C) and B plots. Stem N:P ratio was highest in B plots. Plants from C plots tended to have lowest biomass, specific leaf area (SLA), leaf area ratio, and highest light-saturated photosynthetic rate. Leaf mass ratio, specific root length (SRL), [N], [P] in leaf and stem, root N:P ratio, transpiration rate and water use efficiency were unaffected by the treatments. Discriminant function analysis (DFA) correctly classified 87.8% of the 49 plots. Total leaf area, leaf number, SLA and total biomass were the variables most responsive to the different treatments. Overall, the results provided support for the hypothesis that nutrient content, biomass allocation, photosynthesis, and other ecological characteristics of perennial plants can change in response to the resource changes caused by fire and thinning. This study goes beyond previous work in the breadth of plant responses studied, the range of restoration treatments considered, and the identification of plant life history parameters that maybe particularly sensitive as ecological indicators.
Key words: fire, thinning, life history