Influences of Tree Diversity on Soil Nutrient Properties and Foliar Chemistry
Plants can both influence and respond to the light and soil nutrient availability in the ecosystems where they grow. As human activities continue to change Earth’s biodiversity and climate, understanding these relationships is increasingly essential. Soil nutrients and light availability influence a tree’s ability to grow. Too much light can lead to photooxidative stress, and low soil nutrient availability can inhibit plant physiological processes. Thus, the availability of soil nutrients and light play major roles in a tree’s fitness in an environment. This research project investigated how tree diversity influences light and soil nutrient availability. We hypothesized that increased tree diversity will increase soil nitrogen and carbon availability, and decrease the amount of light stress the leaves experience due to niche segregation. For this research we collected leaf and soil samples from a forest diversity experiment at the Cedar Creek Ecosystem Science Reserve designed to study the consequences of functional and phylogenetic diversity of trees. To assess the response to light availability of different tree species in forest plots of varying tree diversity, we examined leaf pigment concentrations using High Performance Liquid Chromatography (HPLC). Additionally, nitrogen and carbon concentrations were measured from the soil using C:N analysis to determine nutrient availability in plots with different levels of tree diversity. Increased tree diversity was linked to a decrease in the production of light-sensitive pigments and decreased soil carbon and nitrogen concentrations. Overall, this project shows how changes in tree diversity impact the ability of individual trees and forest communities to grow by decreasing conditions of light stress and soil nutrient availability.