Kathryn Amatangelo

Ecosystem Ecology, Invasion Biology, Plant Community Ecology
Postdoctoral Research Associate

Department of Botany
University of Wisconsin, Madison
(608) 262-86441
kamatang at gmail.com

Education
Current Research
Doctoral Research
Publications

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Education

• Ph.D. Department of Biology, Stanford University, Stanford, CA. 2008.
• B.S. Resource Ecology and Management, University of Michigan, School of Natural Resources and the Environment, Ann Arbor, MI. 2001.

Current Research

My core research interest is understanding how human disturbance affects plant communities, particularly plant trait diversity, and how this change affects ecosystem function. Recently I have become interested in focusing on the spread and impact of invasive species in forest systems. Studying the cause of invasibility and invasion speed - whether it is characteristics of the environment, community, or unique qualities of the invader – is of primary interest to me. More specifically, I am interested in linking ecological and evolutionary traits of invasive species to their predicted spread (at a population level) and impact (at a community and ecosystem level).

The Waller lab has access to a large vegetation composition dataset collected around 1950 by John Curtis and his students, consisting of data at upland and lowland forest sites sampled throughout Wisconsin. Many of these sites have been or will be re-sampled using similar techniques, allowing us to detect changes in forest communities over the past fifty years. I am using this valuable dataset, in concert with additional collections on plant species traits, to answer invasion-related questions. In particular I am investigating how invaders with particular traits interact with plant communities and environmental/landscape variables to result in invasion success.

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Doctoral Research

Plants replace each other in space and time as dominant species in communities in part due to traits that affect their access to limiting resources. Decomposition is a critical link in nutrient cycling, determining the availability of nutrients for subsequent plant growth. Plant biochemistry interacts with site resources and climate to control microbial decomposer activity. I performed experiments designed to test the effects of litter biomass and biochemistry on plant community and litter decomposition dynamics. Manipulating litter levels resulted in litter-induced shading that changed plant communities in ways correlated with plant traits including seed size and functional grouping. Using ferns in Hawai’i, I focused on foliar biochemistry and resultant impacts on decomposition. Two groups of ferns, recently diversified monophyletic “polypod” ferns and all other “non-polypod” ferns, had nutrient profiles distinct from each other and co-occurring angiosperms. Biochemical differences among these groups were preserved in litter and constrained decomposition rates; fern and angiosperm litter had distinct biochemical correlates of decomposition. Additionally, six common species were decomposed in a controlled low-nutrient environment. Analyses of microbial biomass, microbial community composition, and enzyme production demonstrated that initial litter lignin concentration controlled microbial colonization and litter decomposition. Litter carbon biochemistry did not change significantly until more than 50% of litter had disappeared. These results suggest that plant leaf characteristics that vary between functional and phylogenetic groups directly affect decomposition through changes in microbial dynamics, and litter production and decomposability are important structures of plant communities.

Publications

Amatangelo, K.L. and P.M. Vitousek. Contrasting predictors of fern versus angiosperm decomposition in a common garden. Biotropica, in press.

Cornwell, W.K., J.H. Cornelissen, K.L. Amatangelo, +25 others. The leaf economic trait spectrum drives litter decomposition rates in regional floras worldwide. Ecology Letters, in press.

Amatangelo, K.L. and P.M. Vitousek. Stoichiometry of ferns in Hawaii:  Implications for nutrient cycling. Oecologia, in press.

Amatangelo, K.L., Dukes, J.S., and C.B. Field.2008. Responses of a California annual grassland to litter manipulation. Journal of Vegetation Science 19(5): 605-612.

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