EAGER: Metapopulation and metacommunity dynamics in a changing spatial and environmental mosaic - The importance of dispersal and gene flow

Portland State University, Portland OR

Investigators

Abstract

Water development projects have transformed aquatic landscapes by changing vegetation, altering seasonality of wetlands, and increasing connectivity via canals. The ecological and evolutionary effects of these changes on aquatic plants and animals are poorly understood, but will likely become more common in the coming decades. This project will make use of 70-year records of the largest water development project in U.S. history to determine how changes in water flow and amount have altered the ecology and evolution of small aquatic animals. An exciting part of the study involves resurrecting these animals from eggs buried in mud for up to 70 years. Their genes will be compared to modern-day individuals to understand what changes have taken place and why those changes have occurred. Graduate and undergraduate students will be mentored, learning cutting-edge genetic techniques, experimental design, statistical analyses, and scientific writing. Results will be communicated to the public through outreach to public schools, collaboration with volunteer citizen scientists, a blog and a website. Understanding the structure of spatial processes is a critical need in ecology. Dispersal is one such process and a primary mechanism by which species respond to a rapidly changing environment; it is also important in determining the structure of communities and functioning of ecosystems. However, understanding dispersal's role can be confounded by rapid adaptation of species, which is affected by the spatial structure of the environment and priority effects. The goal of this study is to measure ecological and evolutionary responses of invertebrate populations across a period of change in a complex environmental mosaic, using a new approach: landscape paleogenetics. Hypotheses will be tested using the Columbia Basin Project as an extraordinarily large experimental system. The study will exploit a unique feature of some invertebrates, prolonged dormancy, to trace population-level shifts over decades of changes in water distribution. A combination of landscape surveys, historical ecological data going back 70 years, DNA analysis, and landscape genetics will be employed.