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Shannon Claeson

Shannon Claeson

Pacific Northwest Research Station
Wenatchee Forestry Sciences Lab

Contact via email
Phone: (509)664-1741
Fax: (509)665-8362

Statement of Research:

My research focuses on the interactions between riparian and aquatic systems, specializing on the role of aquatic invertebrates in stream and lake systems.
I am interested in community ecology, disturbance ecology, food-webs, and the ecological impact of invasive organisms.

Projects & Activities:


Knotweed Restoration and Litter Decomposition
Japanese, giant, and Bohemian knotweeds (Polygonum
, P. sachalinense, P. x bohemicum) are invasive
plants that spread aggressively along rivers and displace
native plants. Leaf litter inputs from riparian plants are an
important source of nutrients and organic matter for aquatic
organisms in small streams. When the riparian vegetation
changes from diverse native plants to a monoculture of
knotweed, the quantity, quality, and timing of these inputs is
altered and may negatively affect aquatic insects and fish.
We measured the resulting diversity and composition of
plant species in riparian areas formerly treated with
chemicals to eradicate knotweed in the Chehalis River
basin of Washington. In addition, we measured the nutrient
and decomposition properties of knotweed leaf litter as
compared to native species, along with the aquatic fungi and
macroinvertebrates using the leaf litter.

Collaborators: The Nature Conservancy, Chehalis Basin Knotweed Project
U.S. Fish and Wildlife Service, Western Washington Fish and Wildlife Office
Dr. Carri LeRoy, The Evergreen State College

stream restoration on the Entiat River, WA
Entiat River Restoration
In-stream habitat structures, such as large wood, play a vital role in river
ecosystems by helping to restore channel morphology and providing cover,
shelter, and invertebrate prey for fish. The addition of in-stream habitat
structures by land owners and resource agencies is a common effort to
protect and recover salmonid populations across the Pacific Northwest,
especially in rivers with a history of habitat degradation. However, it can be
challenging to determine the success of restoration efforts. We are
monitoring and evaluating the effectiveness of in-stream structures added to
the Entiat River, a major sub-basin of the Upper Columbia River in eastern
Washington. Habitat occupancy and growth of juvenile Chinook salmon
(Oncorhynchus tschawytscha) and steelhead trout (Oncorhynchus mykiss)
are measured at restored and natural pools, before and after restoration
For more information, see publications and website by Karl Polivka, research
fish biologist with the USDA Forest Service, PNW Research Station.

Collaborators: Cascadia Conservation District, Wenatchee WA
Link: http://cascadiacd.org/intensively-monitored-watershed_334.html

Debris Flows and Stream Biota Recovery

Debris Flows and Stream Biota Recovery
Climate change models for the Pacific Northwest predict more
extreme climatic events. Therefore, our understanding of natural
biotic recovery from major disturbances is important. In December
2007, a rain-on-snow event triggered large-scale debris flows
down two adjacent streams in Capitol State Forest, WA, removing
all riparian vegetation. We are monitoring stream temperatures,
fish and amphibian abundances, fish movement, aquatic insect
assemblages, and riparian vegetation succession before and
after the debris flows.

Collaborators: Washington Department of Fish & Wildlife Habitat Program

Macroinvertebrates and Dam Removal

Macroinvertebrates and Dam Removal
Hemlock Dam, on the Gifford Pinchot National Forest, was removed
from Trout Creek during the summer of 2009 in order to improve habitat,
productivity, and passage for fish. The intent of this study is to monitor
the impacts of dam removal and stream channel restoration on benthic
macroinvertebrate assemblages of Trout Creek upstream and downstream
of the removed dam. Certain macroinvertebrates are sensitive to
environmental stress and thus are representative of stream health.

Link: Gifford Pinchot National Forest

Selected Publications:

Vizcarra, N. 2015. Knocking out knotweed: research pins down a rogue invasive. Based on science by Shannon Claeson. Science Findings #169. http://www.fs.fed.us/pnw/sciencef/scifi169.pdf

Claeson, S.M., C.J. LeRoy, J.R. Barry, and K.A. Kuehn. 2013. Impacts of invasive riparian knotweed on litter decomposition, aquatic fungi, and macroinvertebrates. Biological Invasions. DOI 10.1007/s10530-013-0589-6

Claeson, S.M., and P.A. Bisson. 2013. Passive reestablishment of riparian vegetation following removal of invasive knotweed (Polygonum). Invasive Plant Science and Management 6: 208–218

Bisson, P.A., S.M. Claeson, S.M. Wondzell, A.D. Foster, A. Steel. 2013. Evaluating headwater stream buffers: lessons learned from watershed-scale experiments in southwest Washington. In Anderson, P. D. and K. L. Ronnenberg (eds). Density management for the 21st Century: west side story. Gen. Tech. Rep. PNW-GTR-880. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 169-188 Link to the full GTR at http://www.fs.fed.us/pnw/pubs/pnw_gtr880.pdf or at http://www.treesearch.fs.fed.us/pubs/44785

Foster, A.D., and S.M. Claeson. 2011. Habitats and seasonality of riparian-associated millipedes in southwest Washington, USA. Terrestrial Arthropod Reviews 4(3): 1-18. http://www.treesearch.fs.fed.us/pubs/40836

Claeson, S.M., J.L. Li, J.E. Compton, and P.A. Bisson. 2006. Response of nutrients, biofilm, and benthic insects to salmon carcass addition. Canadian Journal of Fisheries and Aquatic Sciences 63(6):1230-1241. http://naldc.nal.usda.gov/download/27914/PDF

Galvan, S.K., M.J. Adams, P.J. Happe, and S.M. Claeson. 2003. Final Report - Olympic National Park amphibian and reptile inventory, with emphasis upon terrestrial herpetofauna (1999-2001). USGS Forest and Rangeland Ecosystem Science Center, p. 94. http://fresc.usgs.gov/products/ProductDetails.aspx?ProductNumber=1254

Jung, R.E., S.M. Claeson, J.E. Wallace, and W.C. Welbourn, Jr. 2001. Eleutherodactylus guttilatus (Spotted Chirping Frog), Bufo punctatus (Red-spotted Toad), Hyla arenicolor (Canyon Tree Frog), and Rana berlandieri (Rio Grande Leopard Frog). Mite infestation. Herpetological Review 32 (1):33-34

Adams, M.J., and S.M. Claeson. 1998. Field response of tadpoles to conspecific and heterospecific alarm. Ethology 104: 955-961 http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.1998.tb00044.x/pdf