The role of phylogenetic diversity on community assembly and ecosystem functioning: experimental tests using laboratory microcosms

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

The past several decades have seen escalating human activities that have substantially transformed our biosphere, resulting in widespread loss of biodiversity in many of Earth's ecosystems. Does this erosion of biodiversity affect the way that ecological communities assemble from individual species? Will it have any impact on the functioning of natural and managed ecosystems, including products and services (e.g., food, medicine, water quality, nutrient retention) that they provide for humanity? Ecologists have used a multitude of approaches, including mathematical models, field and laboratory experiments, and observations, to answer these important questions. While the large body of research conducted so far has revealed that biodiversity change can carry significant ecological consequences, our knowledge is rather incomplete. In particular, our current understanding of biodiversity effects is largely based on species richness (that is, the number of species in a given area) or diversity indices associated with species richness. It is largely unknown how phylogenetic diversity, an important element of biodiversity that accounts for species' evolutionary histories, affects community and ecosystem properties. In this project, the research team aims to fill this void by conducting a series of laboratory experiments using bacteria as model organisms. The project will start by examining the relationship between species' evolutionary relationships and the strength of competition between species, an issue first addressed by Darwin 150 years ago and yet still unresolved. With this basic information in hand, several hypotheses will be tested on how evolutionary relationships among species affect a number of community and ecosystem processes and functions. The research will be conducted in small artificial ecosystems called microcosms. Besides scientific contributions, this project will also contribute to educational outreach by training graduate and undergraduate students, particularly those from underrepresented minority groups. Minority students will be recruited from the Summer Undergraduate Research Program in Engineering/Science at Georgia Institute of Technology and from Agnes Scott College (a small liberal arts women's college in metro Atlanta).