PARENT SESSION
Poster Session # 17: Aquatic Systems.
Thursday, August 7 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Models of salamander population dynamics and response to human-mediated disturbance.
Jalics Rauschert, Emily*,1, Rubbo, Michael1, 1 The Pennsylvania State University, University Park, PA
ABSTRACT- Amphibian populations have suffered widespread declines and extinctions in recent decades. Some declines are hypothesized to be the result of mortality caused by factors such as chemical pollutants, direct human habitat disturbance (i.e. logging), and climate change. However, the population-level consequences of mortality have not been examined explicitly, and may be complicated by density dependence in intervening life-history stages. We examine the population dynamics of 4 salamander species: Ambystoma maculatum, Plethodon cinereus, Desmognathus fuscus and Notophthalmus viridescens under various types of human disturbance. Although they are not currently declining, these species are ideal model organisms because they are well-studied and likely to be increasingly impacted by human urbanization at different life-history stages. We develop demographic models to examine how various forms of human disturbance affect the relationship among stage-specific survival rates and long-term population dynamics of the salamanders. Using stage-structured matrix models with parameters estimated from the literature, we analytically solve deterministic models. Simulations then allow us to incorporate the influence of environmental variability, including human disturbances and stochastic pond drying. Our results highlight the need to a priori identify critical life stages if we are to assess accurately how stressors are likely to affect amphibian populations of conservation concern.
Key words: matrix model, population dynamics, salamander, human-mediated disturbance