Ecological simulations and ecological complexity studies Application: Understanding the nutritional mechanisms controlling brown bear populations
Friday seminar by Claudia V. López-Alfaro
My research goals have been focussed to understand wildlife-habitat relationships and predict how environmental changes affects individual fitness and thus population trends. To reach this goal I use different simulation models techniques to explore the mechanism underlying ecological processes. These models provide understanding of the ecological systems and its complexity through the identification of key parameters and trade-offs among variables.
In this seminar I will present the development of a “system dynamic simulation model”, which we used to understand the mechanisms influencing body mass gain on brown bears.
Dynamics in wildlife populations emerge from the interactions between individuals and their environment. A fundamental interaction is the necessary transfer of energy and matter from the environment to the individual in order to support life. Constraints between individual physiology, ecology and food availability are therefore fundamental to understanding how species adapt to environmental variability and to identify nutritional mechanisms that control population trends.
Using a system dynamic simulation techniques I have integrated existing knowledge of the physiology, nutrition and ecology of brown bears to explore how the interactions among these variables together with the nutritional characteristic of their habitats influence reproductive success of female bears. The model simulates the transfer of energy and protein from the environment to the individual, accounting for allocation in maintenance, growth and reproduction. The model evaluates the dynamic on body mass gain (lean and fat mass) of individual bears under different diets and environmental conditions.
Model analysis illustrates how trade-offs among the nutritional quality of bear diets and bear physiology limits reproductive success. Lactation and body mass gain are highly affected by the interactions between the digestive tract capacity and the food resource quality. Results also reveal that lean tissue and high protein foods, especially in spring and summer, play a fundamental role in reproductive success of female bears.
Observed differences in life history traits among bear populations (e.g. individual body size) might be consequence of different nutritional constraints and thus correlation analysis might be insufficient to detect the nutritional mechanism underlying the differences in population trends.
Claudia V. López-Alfaro
Agricultural Engineer, MSc, PhD Wildlife Ecology and Management