Research Interests

Dr. Marcarelli is an ecosystem ecologist who studies biogeochemical cycles and linkages between physical, chemical and biological structure and function in streams, rivers and lakes.  Linking biogeochemical patterns and controlling factors often requires understanding the underlying structure of microbial, algal, and animal communities. Therefore, her research occurs at the interface of ecosystem and community ecology.  She is particularly interested in research questions that have both fundamental and applied implications, such as how land use change and ecosystem disturbances alter nutrient processing, uptake and export from watersheds and energy flow through food webs.

Dr. Marcarelli is currently focused on the role of nutrient and organic matter subsidies on stream ecosystem and food web function.  She is a member of an interdisciplinary project examining the effects of marine-derived nutrients via salmon carcasses on carbon and nutrient flow through stream-riparian ecosystems and food webs in the Snake River basin, western Idaho, where salmon migrations have been blocked by dam construction. She is interested in expanding this work to include streams with healthy salmon runs in the Pacific Northwest and Alaska, and streams with introduced salmon runs in the Upper Peninsula.  In a second project, she is working to synthesize understanding of the relative importance carbon subsidies for carbon flow among periphyton, macroinvertebrate, and fish communities.  She is currently constructing a flow food web for a forested stream in Hokkaido, Japan, supported by a fellowship from the Japan Society for the Promotion of Science.  Finally, she is interested in the role of nitrogen fixation as a novel N source to aquatic ecosystems, and how nitrogen fixation might affect food web dynamics by altering periphyton nutrient content and food quality for invertebrate and fish consumers.

Recent publications:

Mineau MM, Baxter CV & Marcarelli AM. In press. A non-native riparian
tree (Elaeagnus angustifolia) changes nutrient dynamics in streams.
Ecosystems.

Hopkins JM, Marcarelli AM & Bechtold HA. 2011. Ecosystem structure
and function are complementary measures of water quality in a polluted,
spring-influence river. Water Air and Soil Pollution 214: 409-421.

Marcarelli AM, Van Kirk RW & Baxter CV. 2010. Predicting effects of
hydrologic alteration and climate change on ecosystem metabolism in a
western U.S. river. Ecological Applications 20: 2081-2088.

Marcarelli AM, Bechtold HA, Rugenski AT & Inouye RS. 2009. Nutrient
limitation of biofilm biomass and metabolism in the Upper Snake River
basin, southeast Idaho, USA. Hydrobiologia 620: 63-76.

Marcarelli AM & Wurtsbaugh WA. 2009. Habitat and seasonal variations
in nitrogen fixation in linked lake-stream ecosystems. Biogeochemistry
94: 95-110.

Marcarelli AM, Baker MA & Wurtsbaugh WA. 2008. Is in-stream N_2
fixation an important N source for benthic communities and stream
ecosystems? Journal of the North American Benthological Society 27:
186-211.

Rugenski AT, Marcarelli AM, Bechtold HA & Inouye RS. 2008. Effects of
temperature and concentration on nutrient release rates from nutrient
diffusing substrates.  Journal of the North American Benthological
Society 27:52-57.