Tropical Biology Section
Cortes-Palomec, Aurea C. , Brown, Kim J. , Ballard, Harvey .
Reproductive output and leaf plasticity in the tropical violet species Viola grahamii.
The violet family (Violaceae) is a worldwide family of flowering plants consisting of 25 genera and 900 species. Within the family, the genus Viola is the largest with about 600 species. Despite the abundance of members of the genus Viola in temperate and tropical forests, often as ubiquitous understory herbs, most attention has been paid to few natural species in the temperate zone and to the ornamental pansies. To the best of our knowledge no studies have been done in any tropical Viola species regarding their ecology, reproduction and genetics. For this study Viola grahamii Bentham, a perennial plant of wide distribution in central Mexico producing both chasmogamous and cleistogamous flowers, was chosen as a study species. To study environmental factors which may influence flowering and vegetative growth, 40 semi-permanent plots were established in montane forests surrounding Lake Pátzcuaro in the state of Michoacán, Mexico, where populations of V. grahamii are abundant. Studies were conducted from June to mid-August in 2002. For each quadrat, canopy openness, and soil properties (N, K, P, Ca, Mg, pH, and moisture) were recorded. From each of the individuals of V. grahamii in the quadrat, reproductive output from each flower type was recorded and percentage of nitrogen and carbon in the leaves was used as indicator of vegetative allocation under different environmental conditions (i.e. Specific Leaf Area). Soil Nitrogen and light (canopy openness) are the two factors that seem to be primarily affecting both reproduction and vegetative allocation.
1 - Ohio University, Department of Environmental and Plant Biology, Porter Hall, Richland Avenue, Athens, Ohio, 45701-2979, USA
Specific Leaf Area.
Presentation Type: Paper
Location: Peruvian (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 9:15 AM