The Timing and Extent of Water Limitation Structures Trophic Interactions in a Terrestrial Plant-insect System

In many terrestrial systems, water is an important resource that impacts plant growth, survival and responses to herbivory. These impacts often cascade to affect herbivores and their predators, altering trophic interactions. Working with milkweed plants and aphid herbivores, I investigated: 1) The interactive effects of water availability and temperature on plant-herbivore-predator dynamics and 2) The effect of drought timing on plant-herbivore interactions. I show that water is important in shaping trophic dynamics. While I did not find evidence for interactions between temperature and water availability impacting trophic dynamics, my first study demonstrates the influence of water and temperature on herbivore populations differed over time, and my second study showed both plants and herbivores to be highly sensitive to changes in the timing of short-term drought. This research illustrates the significance of considering temporal scale when examining environmental change and trophic dynamics.M.Sc