Biology

Lin Jiang, Assistant Professor

Ph.D. Rutgers University, New Brunswick, Ecology and Evolution. 2003.
Phone: (404) 385-2514
Fax: (404) 894-0519
Email:
Office: Cherry Emerson, C120

Research Interests

Community ecology. My research focuses on fundamental problems in community ecology, including (but not limited to) causes and consequences of biodiversity, community assembly, food web dynamics, ecological consequences of environmental noises, and adaptive evolution of plankton. My lab uses multiple approaches, including experiments, theoretical models, and meta-analysis to tackle these problems. A large part of our research involves using highly tractable aquatic microbial microcosms as experimental model systems.

Current Interests

Competitive coexistence and species diversity
Classic equilibrium-based competition theory predicts that competition should limit species diversity. Natural communities, however, are often characterized by high species diversity. Ecologists have proposed various hypotheses to explain this discrepancy between theory and data, but many of these hypotheses remain empirically untested. In this NSF-funded project, we focus on competition for self-reproducing biotic resources and experimentally evaluate important hypotheses of competitive coexistence under non-equilibrium conditions.

The relationship between biodiversity and ecosystem functioning (BEF)
An emerging BEF pattern is that ecosystem functioning tends to increase with biodiversity. This pattern, however, is largely based on studies with aggregated community biomass as the focal ecosystem variable. The positive biodiversity-biomass relationship occurs due frequently to positive selection effects that arise from positive correlations between species competitive ability and biomass production (i.e., competitively dominant species are most productive). An interesting hypothesis is that neutral and negative BEF relations may be common for other functions for which species competitive abilities are poor indicators of their functional impacts, where negative selection effects may dominate (Jiang et al. 2008, Oikos). Our recent work with bacteria-mediated organic matter decomposition (Jiang 2007, Ecology) provided support for this hypothesis. We are conducting meta-analyses of BEF relations for some non-biomass ecosystem variables to further evaluate this idea. We are also conducting experiments to explore how biodiversity affects population and ecosystem stability in systems of varying trophic diversity.

Community assembly
Natural communities do not come to existence all of a sudden, but are typically assembled through sequential species colonization events. Using microbial microcosms, we have investigated the influences of species dispersal within meta-communities and disturbance regimes on the structuring role of the history of community assembly. We are in the process of exploring the significance of community assembly for ecosystem functioning and other aspects of the context dependency of community assembly.

Selected Publications

Jiang, L., J. Tan, and Z. Pu. An experimental test of Darwin's naturalization hypothesis. American Naturalist (in press).

Jiang, L. and Z. Pu. 2009. Different effects of species diversity on temporal stability in single-trophic and multi-trophic communities. American Naturalist, 174: 651-659

Wang, H., L. Jiang and J. S. Weitz. 2009. Bacterivorous grazers facilitate organic matter decomposition: a stoichiometric modeling approach. FEMS Microbiology Ecology, 69: 170-179.

Violle, C. and L. Jiang. 2009. Towards a trait-based quantification of species niche. Journal of Plant Ecology, 2: 87-93.

Jiang, L., S. Wan and L. Li. 2009. Species diversity and productivity: why do results of diversity-manipulation experiments differ from natural patterns? Journal of Ecology, 97: 603-608.

Jiang, L. 2009. Biodiversity and ecosystem functioning: beyond complementarity and positive selection effects. Pages 38-57 in Wu, J. and J. Yang (eds), Lectures in Modern Ecology (IV): Theory and Applications. Higher Education Press, Beijing.

Jiang, L., H. Joshi and S. N. Patel. 2009. Predation alters relationships between biodiversity and temporal stability. American Naturalist, 173: 389-399.

Jiang, L. and S. N. Patel. 2008. Community assembly in the presence of disturbance: a microcosm experiment. Ecology, 89: 1931-1940.

Jiang, L., Z. Pu, and D. R. Nemergut. 2008. On the importance of the negative selection effect for the relationship between biodiversity and ecosystem functioning. Oikos, 117: 488-493.

Jiang, L. and P. J. Morin. 2007. Temperature fluctuation facilitates coexistence of competing species in experimental microbial communities. Journal of Animal Ecology, 76: 660-668.

Jiang, L.  2007. Negative selection effects suppress relationships between bacterial diversity and ecosystem functioning in experimental bacterial communities. Ecology, 88: 1075-1085.

Jiang, L. 2007. Density compensation can cause no effect of biodiversity on ecosystem functioning. Oikos, 126: 324-334.

Jiang, L. and J. A. Krumins 2006. Consumer versus environmental productivity control of bacterial diversity and bacteria-mediated organic matter decomposition. Oikos 114: 441-450.

Jiang, L. and J. A. Krumins 2006. Emergent multiple predator effects in an experimental microbial community. Ecological Research 21: 723-731.

Jiang, L., O. Schofield, and P. G. Falkowski 2005. Adaptive evolution of phytoplankton cell size. American Naturalist 166: 496-505.

Shi, T., T. S. Bibby, L. Jiang, A. J. Irwin and P. G. Falkowski 2005. Co-evolution of photosynthetic genes in cyanobacteria. Molecular Biology Evolution 22: 2179-2189.

Jiang, L. and P. J. Morin. 2005. Predator diet breadth influences the relative importance of bottom-up and top-down control of prey biomass and diversity. American Naturalist 165: 350-363.

Jiang, L. and P. J. Morin. 2004. Productivity gradients cause positive diversity-invasibility relationships in microbial communities. Ecology Letters 7: 1047-1057.

Jiang, L. and N. Shao. 2004. Red environmental noise and the appearance of delayed density dependence in age-structured populations. Proceedings of the Royal Society of London, series B, 271: 1059-1064.

Jiang, L. and P. J. Morin. 2004. Temperature-dependent interaction explains unexpected responses to environmental warming in communities of competitors. Journal of Animal Ecology, 73: 569-576.

Jiang, L. and A. Kulczycki. 2004. Competition, predation, and responses to environmental change. Oikos, 106: 217-224.

Jiang, L. and N. Shao. 2003. Autocorrelated exogenous factors and the detection of delayed density dependence. Ecology, 84: 2208-2213.

Petchey, O. L., T. M. Casey, L. Jiang, P. T. McPhearson, and J. Price. 2002. Species richness, environmental fluctuations, and temporal change in total community biomass. Oikos 99: 231-240.

Current Lab Members

Wade Ryberg (postdoc)
Zhichao Pu (third-year graduate student, Ph. D. candidate)
Jiaqi Tan (second-year graduate student)
Yeonjin Jung (undergraduate researcher)
Bora Kim (undergraduate researcher)
Janet Lee (undergraduate researcher)
Harsh Patel (undergraduate researcher)
Carrie Stallings (undergraduate researcher)

Graduate Student Openings  

I am always looking for motivated graduate students to join my lab. I expect my students’ work to not completely overlap with, but to complement my own research. So don’t be discouraged from applying if you feel that your research interests do not coincide with mine. It is always a good idea to let me know your intention to apply before you actually file the application form (for further information, go to http://www.biology.gatech.edu/graduate-programs/apply/). Graduate students in our department are supported by fellowships, teaching assistantships, and research assistantships.