Seminars

The series hosts a seminar every other week on current research topics. The seminar often features an invited guest speaker and occasionally local faculty members, students or others affiliated with the department. The usual time of the seminar is 3:30-4:30 pm on Fridays. Professors  Tatiyana V Apanasovich (apanasovich@gwu.edu), Qing Pan (qpan@gwu.edu) and Emre Barut (barut@gwu.edu ) are the Seminar Series Coordinators.

Department Seminars in Fall 2014


Upcoming Seminar

Date: Friday, April 24th, 3:30-4:30pm

Location: Duques Hall, Room 251

Title: Mixture of Inhomogeneous Matrix Models for Species-Rich Ecosystems

Speaker: Dr. Frédéric Mortier CIRAD, UPR Bsef, Montpellier, France

Abstract: Understanding how climate change could impact population dynamics is of primary importance for species conservation. Matrix population models are widely used to predict population dynamics. However, in species-rich ecosystems with many rare species, the small population sizes hinder a good fit of species-specific models. In addition, classical matrix models do not take into account environmental variability. We propose a mixture of regression models with variable selection allowing the simultaneous clustering of species into groups according to vital rate information (recruitment, growth, and mortality) and the identification of group-specific explicative environmental variables. We develop an inference method. We first highlight the effectiveness of the method on simulated datasets. Next, we apply it to data from a tropical rain forest in the Central African Republic. We demonstrate the accuracy of the inhomogeneous mixture matrix model in successfully reproducing stand dynamics and classifying tree species into well-differentiated groups with clear ecological interpretations.