Meeting Abstract
Biologists have increasingly used mechanistic models to predict species ranges during global change. Still, these models require assumptions about fundamental niches that severely limit their current value. First, models assume that animals avoid abiotic stress through microhabitat selection but fail to consider the costs of doing so. Second, models ignore covariances and interactions between abiotic variables such as temperature, humidity, pH, and pO2. Given these assumptions, researchers will fail to anticipate novel stresses faced by organisms in future environments. To address this problem, we present models in which organisms must balance the benefits of microhabitat selection with the energetic cost, predation risk, and missed opportunities. These models account for interactions among abiotic dimensions of the fundamental niche, which ultimately constrain fitness in real environments. In some cases, these models predict qualitatively different responses to global change than simpler models.
