Skip Navigation

Invasive Plant Plots

Invasive plants are recognized as a threat to ecosystem integrity and services on the Kenai Peninsula. After an initial inventory of LTEMP (Long Term Ecological Monitoring Program) plots, systematically distributed across the Refuge, revealed that invasive plants occurred on less than 4% of the plots, a survey was designed to target human-disturbed areas of the Refuge.

Following LTEMP protocols, a set of 74 permanent invasive plant monitoring plots were established in 2006 on human-disturbed areas of the Refuge (Barnett and Simonson 2007). LTEMP plots on the Kenai Refuge integrate with the Forest Service’s FIA plots in a gridded system. In addition to complementing the LTEMP dataset, this additional set of plots provided an unbiased description of invasion across different anthropogenic disturbance types, evaluated invasive plant establishment across seismic line (used for oil and gas exploration) age, and assessed spread of invasion from disturbed landscape into adjacent undisturbed landscape.

The overall sampling design followed a stratified-random design. At least ten plots were installed in each main disturbance type, including seismic lines, campgrounds, right of ways, roads, and oil and gas roads, with distribution across fine-scale disturbance, such as developed versus undeveloped campgrounds. Circular multi-scale vegetation plot measurements included species composition, percent cover, average species height, ground cover (lichen, litter, moss, scat, rock, soil, standing duff, water, wood) in nested 1 m2 subplots. Species composition was also measured in 5.64 m radius circular plots as well as in the entire 7.32 m radius (168m2) circular plot.

Results from the largest plots in the survey (7.32m radius) included identification of a total of 184 species, of which 28 were invasive plant species. In the smaller plots (5.64 m radius, comparable to LTEMP), 26 invasive plant species were found. The most frequently found species were common non-native species including common dandelion, alsike clover, Kentucky bluegrass, disc mayweed (pineapple weed), bigleaf lupine, common plantain, quackgrass, and white clover. The greatest number of invasive plants was found in the oil and gas fields, followed by campgrounds.

Information from this survey contributed to understanding patterns and distribution of invasion on the Kenai Refuge, and enhanced risk analysis to prioritize treatment for current invaders based on habitat vulnerability to invasion. Subsequent monitoring of these plots will be useful for understanding species composition patterns and shifts both of native and invasive vegetation over time, as well as providing feedback on the efficacy of our invasive plant management program.

Barnett, D. T. and Sara E. Simonson, S. E. 2007. Report: An inventory of vegetation on disturbed areas of Kenai National Wildlife Refuge. Natural Resource Ecology Lab, Colorado State University, Fort Collins, CO. 

Morton, J. M., Bowser, M., Berg, E., Magness, D., and Eskelin, T. 2008. Long Term Ecological Monitoring Program on the Kenai National Wildlife Refuge, Alaska: An FIA Adjunct Inventory. In: McWilliams, Will; Moisen, Gretchen; Czaplewski, Ray, comps. 2008.2008 Forest Inventory and Analysis (FIA) Symposium; October 21-23, 2008; Park City, UT. Proc. RMRS-P-56CD. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.

Last Updated: Dec 19, 2012
Return to main navigation