Matthew L. Kirwan

Research Geologist, U.S. Geological Survey, Patuxent Wildlife Research Center

Visiting Scientist, University of Virginia, Dept. of Environmental Sciences

B.S. 2002, The College of William and Mary (Geology and Mathematics)

Ph.D. 2007, Duke University, Earth and Ocean Sciences

< click for CV >

In many environments exhibiting rapid geomorphic change, landscapes evolve by a combination of physical, biological, and anthropogenic forces. In my research, I aim to better understand how these coupled processes influence the formation and survival of large scale landscapes, and how they respond to climate change. The couplings are particularly strong in tidal marshes, where I concentrate most of my research. Physical factors such as the amount of tidal inundation influence the growth of vegetation. Vegetation, in turn, slows the flow of water, resists erosion, traps mineral sediment, and provides a source of organic matter for bed accretion- thereby influencing the physical factors themselves by building bed elevations relative to sea level. Humans impact both the physical components (sea level, sediment delivery rates) and biological components (vegetation growth under climate change) of the system. Of course, these ecomorphodynamic couplings apply to landscapes beyond marshes. Weathering rates, soil development, and sediment transport on the densely vegetated hillslopes of the Southern Appalachians, for example, may be dominated by biotic processes, at least during interglacial periods. While at the University of Virginia, I am working towards using biologically based forest-gap models to model sediment transport by tree throw.

Publications (click for PDFs):

Kirwan, ML and Temmerman, S., 2009. Coastal marsh response to historical and future sea-level acceleration. Quaternary Science Reviews, v. 28, p. 1801-1808, doi:10.1016/j.quascirev.2009.02.022.

Kirwan, ML, Guntenspergen, GR, and Morris, JT., 2009. Latitudinal trends in Spartina alterniflora productivity and the response of coastal marshes to global change. Global Change Biology, v. 15, p. 1982-1989, doi:10.1111/j.1365-2486.2008.01834.x

Kirwan, ML and Guntenspergen, GR., 2009. Accelerated sea-level rise – a response to Craft et al. Frontiers in Ecology and the Environment. v. 7, p. 126-127. doi: 10.1890/09.WB.005 (Peer-reviewed letter)

Kirwan, ML and Murray, AB. 2008. Tidal marshes as disequilibrium landscapes? Lags between morphology and Holocene sea level. Geophysical Research Letters. v. 35, L24401,doi:10.1029/2008GL036050.

Murray, AB, Knaapen, MAF, Tal, M, and Kirwan, ML. 2008. Biomorphodynamics: Physical-biological feedbacks that shape landscapes. Water Resources Research, v. 44, W11301, doi:10.1029/2007WR006410.

Kirwan, ML, Murray, AB, and Boyd, WS., 2008. Temporary vegetation disturbance as an explanation for permanent loss of tidal wetlands. Geophysical Research Letters, v. 35, L05403, doi:10.1029/2007GL032681.

Kirwan, ML and Murray, AB., 2008. Ecological and morphological response of brackish tidal marshland to the next century of sea level rise: Westham Island, British Columbia. Global and Planetary Change, v. 60, p. 471-486.

Kirwan, ML and Murray, AB., 2007. A coupled geomorphic and ecological model of tidal marsh evolution. Proceedings of the National Academy of Science, v. 104, p. 6118-6122 doi:10.1073/pnas.0700958104.

Hancock, GS and Kirwan, ML. 2007. Summit erosion rates deduced from ¹⁰Be: Implications for relief production in the Central Appalachians. Geology, v.35, p. 89-92.

Kirwan, ML, Kirwan JL, and Copenheaver CA. 2007. Dynamics of an estuarine forest and its response to rising sea level. Journal of Coastal Research, v.23, p. 457-463.

Manuscripts in review (email me for pdf):

Contact:

Department of Environmental Science
University of Virginia
PO Box 400123

Charlottesville, VA 22904
mlk4n@virginia.edu

434-924-3186

Website last updated June 2009