Abstract
Tree growth is important because through photosynthesis trees capture CO2 from the atmosphere and store it as biomass for long periods of time, acting as carbon sinks and helping us to regulate climate change effects. However, trees are being affected by global change, and one of the ways trees respond to changing climate is through changes in their growth rates. Dendrochronology has played a critical role in characterizing tree growth patterns in northern-temperate systems. In the tropics and subtropics, however, tree rings have been studied less creating a knowledge gap spanning three continents. Using dendrochronology, I studied tree growth at an annual resolution, identified drivers of growth such as climate and human disturbances, and studied changes in growth through time and across geographical space. In chapter two, I assessed how tree growth changes through space and time according to the “fitness-suitability” hypothesis. In chapters three and four, I addressed the subtropical dendrochronology knowledge gap by analyzing tree rings and growth rates of Bursera simaruba, Swietenia mahagoni, Pinus elliottii, Taxodium ascendens, and T. distichum in South Florida’s natural forest and urban ecosystems. In chapter three, I studied the pine rocklands species P. elliottii and the hardwood hammocks species Bursera simaruba, Swietenia mahagoni. I characterized long-term growth patterns in three dominant native tree species from these ecosystems growing in natural vs urban parks and I analyzed responses to climate and anthropogenic disturbances like urbanization. In chapter four, I studied the three most dominant tree species of Big Cypress National Preserve: Taxodium ascendens, T. distichum, and Pinus elliottii, and how tree growth rates are affected by climate and hydrology across time and space.