Discipline: Ecology Environmental and Earth Sciences
Emily Silva - California State University, Los Angeles
Co-Author(s): Natalie Colin-Santana, California State University Monterey Bay, Seaside CA.
Samples of ferns were collected from two sites differing in canopy cover along a forest trail in the Children’s Eternal Rainforest in Costa Rica in order to evaluate allocation of growth to below-ground and above-ground tissue. Length and biomass were measured for shoots, roots, and the whole plant. The soil volume potentially accessed by the roots of each plant was estimated from the length of the longest lateral root and the depth of the longest vertical root. Percent water content of soil was similar at the two sites, with around 43% moisture by weight. Soil penetrability did not differ between the two sites. Total biomass per plant was greater in the open site. Shoot length did not differ. Rooting depth and root biomass were greater in the open, while lateral extension of the roots was greater in the shade. In the shade, vertical roots were more consistent in length than horizontal roots, indicating that nutrients and water are taken up from a restricted range of soil depth. Based on data from both sites, root length accounts for around 34% of the total length of the ferns, while root biomass makes up around 62% of the total biomass of the ferns. There was no difference between the two sites in the ratio of root length to total length or in the ratio of root biomass to total biomass. Further research questions would include determining the changes in soil moisture throughout the year and how this may affect the growth rates of the fern. It would also be interesting to compare these results with other sites.
Funder Acknowledgement(s): We thank the Chancellor's Office of California State University and the CSU-LSAMP program for funding this research, through NSF grant number HRD-0802628
Faculty Advisor: Dr. Diana Lieberman, email@example.com
Role: To begin, I asked the question of how does the growth of the ferns found in the nearby portion of the Children's Eternal Rainforest differ by sunlight exposure. I collected and measured samples from the two sites. Afterwards, I analyzed the raw data to draw conclusions. This project introduced me to various statistical methods of analyzing data.