PS 16-105 - Hummock-scale analyses of Pterocarpus officinalis stem structure over time

Tuesday, August 9, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center

ABSTRACT WITHDRAWN

Diamonique D. Clark, Stevenson University; Tamara Heartsill Scalley, United States Forest Service

Background/Question/Methods

Wetland forests have global importance as carbon sinks and habitat for wildlife. One such type of wetland forest found in the Caribbean are those dominated by the tree Pterocarpus officinalis. Pterocarpus trees have distinct buttress roots that accumulate organic matter and form structures called hummocks. Hummocks are elevated structures that increase the survivorship of seedlings and saplings from frequent wetland flooding. This study was conducted in two stands of Pterocarpus forests in Sabana Seca, Toa Baja, Puerto Rico. The goals of this study were to compare size class distribution among the two stands, analyze how size class distribution of these two stands have changed over time, determine if soil characteristics affect size class distribution, and analyze the success of a previous Pterocarpus restoration project.  The abundance of seedlings, saplings, and adults stems were compared among both stands and from data of previous years. Soil samples from each stand were analyzed for total carbon, nitrogen, soil conductance, and pH. 

Results/Conclusions

Generally, it was found that there were a similar number of adult stems among the two stands, however, one stand had a higher abundance of seedlings and saplings. Recruitment declined in one stand and increased in the other. Soil characteristics between the stands showed similar results. Having survived natural and anthropogenic disturbance, the restoration project is likely to continue to grow. Overall, the most likely cause for the difference in size class distribution, although not directly measured is light levels. Future research and restoration projects should focus on microtopography and microclimate of the study species. Restoration projects conducted in close proximity to communities should make the effort to integrate the community so the value of the restoration effort is shared.