Abstract
My dissertation investigates the dynamics of invasive water hyacinth (Pontederia crassipes) using a combination of modeling and empirical approaches, with support from the Greater Everglades Priority Ecosystem Science program. My dissertation has seven chapters, each addressing a critical aspect of the research, from theoretical modeling to experimental validation, and offering insights into the broader applications for invasive species control.
In Chapter 1, we develop a non-spatial model to study the interaction between herbicide, invasive floating species (water hyacinth), and biocontrol. Building upon the non-spatial model from Chapter 1, Chapter 2 extends this model to spatial scales. A spatially explicit model is developed to simulate the competition between invasive floating aquatic plants (FAV) and submerged aquatic vegetation (SAV), based on the classic competition model by Scheffer et al. (2003). In Chapter 3, we introduce biological control into the spatial model that is developed in Chapter 2. The chapter introduces across the modeled landscape the concepts of traveling waves, rock-paper-scissors dynamics, and long transient patterns, which drive the exploration in the following chapters. In Chapter 4, we focus on understanding the transition between long transient spatial patterns. In Chapter 5, we investigate the mechanisms behind the transition between long transient spatial patterns in more depth. In Chapter 6, the spatial competition model is expanded to include seasonal and temperature variation, examining how these factors affect the competition between Pontederia crassipes and submerged vegetation. In Chapter 7, we shift to testing the theoretical predictions made in earlier chapters. This chapter bridges the gap between theoretical modeling and field experimentation, providing empirical support for the predictions made in earlier chapters.
In the future, I plan to apply the modeling approaches developed in this dissertation to other ecosystems.