Predicting the net effect of climate change on communities requires understanding how increasing temperatures alter interactions between predators, herbivores, and plants. Over the last several decades, warming experiments have provided important information about how species and their interactions will respond to increasing temperatures. These studies typically examine climate warming by experimentally increasing temperature at a constant level (24 hours) or asynchronously during the daytime, relative to unwarmed control treatments. However, advances in climate models now project that increases in mean global temperatures have been disproportionately driven by increasing nighttime (minimum) temperatures rather than daytime (maximum) temperatures. The timing of warming could have important ecological implications. For example, while night warming could benefit an organism by increasing temperatures towards a more thermally-optimal environment, day warming could raise temperatures beyond a thermal optimum and induce heat-stress. Consequently, mismatching the timing of warming in experiments relative to actual temperature changes could generate misleading predictions about the effects of climate warming. My dissertation has evaluated climate-warming experiments by characterizing past methods, demonstrating present methods, and providing a foundation for future studies. I conducted a meta-analysis on past terrestrial predator-prey climate warming studies that revealed experimental temperatures rarely match model projections, and the magnitude of this mismatch correlated with increased changes in measured effects. Two experiments, one focused on predator functional traits and the other trophic cascades, showed that different types of warming treatments result in different effects of climate change. The context dependency of warming effects necessitates careful consideration of experimental treatments if studies are to accurately predict the effects of climate warming. Region specific climate data are now readily available. Moving forward, ecologists can use these models to inform their warming treatments and perform experiments with the highest level of realism.

An ecological study was conducted at Cascade Springs, Wasatch county, Utah from August 1965, to June 1967. The algae and aquatic moss species were determined and ecological information about these organisms was obtained. Physical data were also collected: bicarbonates, carbonates, free carbon dioxide, hydroxides, oxygen, pH, and temperature. The physical environment of the water was found to be very constant. Tests taken at the different study sites were consistently similar, not only during each day, but all year around. No great variation of any kind was found in the water. In contrast to the water environment, the topography of the spring varied greatly. Variations were noted in bottom composition, sunlight, water depth, velocity, and volume. But although Cascade Springs appears to have a variety of ecological niches, the number of species of algae and mosses were low. Twelve genera and fourteen species of algae, and ten genera and thirteen species of mosses were collected. The terrace region, both edges and pools, were occupied by all algae species. All but Vaucheria were found in the terrace pools, and all but Chara were found on the terrace edge, and none were found in the terrace pools. The only species of algae found in the spring basin were Chara and Spirogyra, and all moss species but one were found in the spring basin. The algae species were most abundant in the spring and summer months, and least abundant in the winter, although the water temperatures remained constant. The mosses were found to be perennials, and they were constant in both abundance and location. One species of algae was found unique to the spring: Plectonema tomasinianum. This was an abundant species that had not been collected elsewhere in Utah. The other species, both algae and mosses, were common in Utah.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.