Research Proposal
Geomorphic and Anthropogenic Influences on Invasive Plant Distribution in the
Luckiamute Watershed: Using GIS as a Tool for Spatial Analysis
Prepared By
Ian Macnab, Earth Science Major-Geography Minor
Stephen B. Taylor, Ph.D., Advisor
Earth and Physical Sciences Department
Division of Natural Sciences and Mathematics
Western Oregon University
Monmouth, Oregon 97361
Submitted To
Urban and Regional Information Systems Association (URISA)
Oregon and Southwest Washington Chapter c/o
Keith Massie, GIS Manager
City of Medford
411 W. 8th Ave.
Medford, OR 97501
February 25, 2008
PROJECT FRAMEWORK
Invasive plant species in western Oregon are a pervasive problem that disrupt native
habitats and create annual economic losses of millions of dollars for public and private
landowners (Oregon Department of Agriculture, 2001). Nationwide, the United States
experiences annual losses of over $130,000,000 due to non-native species (Pimentel and others,
2000). Invasive plant species are problematic for both native and agricultural plant communities
as they can compete for resources and displace competitors. Local extirpation of native plant
species has obvious impacts on wildlife and natural habitats. Vegetative disturbance of natural
ecosystems by geomorphic and anthropogenic processes affect soil substrate conditions, nutrient
availability, canopy shading (solar influx), and riparian hydrology. The most abundant
concentrations of invasive species are typically associated with disturbed zones that have been
altered by human activity. As such, disturbed zones on the landscape act as primary conduits for
the dispersal of non-native species (Pabst and Spies, 1998). Understanding the controls on
spatial distribution of invasive plants in the context of disturbance regime is critical for designing
effective watershed conservation and restoration plans.
The purpose of this research is to conduct spatial analyses using GIS to delineate
associations between geomorphic and anthropogenic disturbance regimes, and patterns of
invasive plant distribution in the Luckiamute Watershed of western Oregon (Figure 1). Of 130
understory plant species identified in the riparian zone of the Luckiamute (Table 1), 55 are
considered adventive and disruptive of native habitat (Noll and others, 2007; Taylor and others
2007). The patchwork of geomorphically and anthropogenically disturbed landscapes in the
watershed are hypothesized to serve as a conduit for the dispersal of non-native species. Given
the land-use and geomorphic history of the basin, the Luckiamute is well-suited for the study of
causal factors that control spatial distribution of invasive plants in western Oregon.
METHODOLOGY AND ACTION PLAN
Data Collection and Analysis
Spatial patterns of invasive plant distribution will be examined by use of geographic
information systems (ArcGIS9.2 platform). Plant distribution will be analyzed as a function of
geomorphic and land use elements along the riparian corridor. Historic aerial photographs
(1930’s – Present) will be rasterized and riparian zones classified according to land-use and
vegetative state (e.g., woodland, cultivated, or cut timber). Channel position and floodplain
extent will be digitized and examined for geomorphic disturbance patterns over time. Statistical
techniques will be employed to identify any significant associations between invasive species
location and site disturbance history. Spatial analysis and statistical techniques will follow those
summarized by Elzinga et al. (1998), Dale (2005), Wong and Lee (2005), and Smith et al.
(2008).
Products and results of this project will include: (1) a historical set of ortho-rectified and
geo-registered aerial photos for 20 select localities along the Luckiamute river (one set per
decade, per site, 1930’s to present; refer to Figure 1 for site locations) (2) delineation of a select
set of invasive species that will serve as useful indicators for monitoring the occurrence and
spread of non-native plants in the Luckiamute Watershed, (3) identification of geomorphic and
anthropogenic disturbance regimes that are acting as principle migration corridors for invasive
plant species in western Oregon, and (4) statistical derivation of spatial associations between
invasive species and landscape-land use components. These results will form the basis of more
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extensive studies in the region and have potential use for development of larger scale predictive
models of invasive plant dispersion.
Proposed Project Timeline
The proposed research will be conducted on a part-time basis in the GIS Lab at Western Oregon
University during spring and summer terms, 2008. The anticipated project timeline is framed as
follows:
Proposal Submission:
Proposal Review / Award:
Anticipated Project Start Date:
Photo / Image Rectification:
Channel and Land-use Digitization:
Data Analysis and Synthesis:
Final Report Submission:
February 25, 2008
April 1, 2008
May 1, 2008
May-June 2008
July 2008
August-September 2008
September 15, 2008
PROJECT JUSTIFICATION
As previously stated, annual economic losses and habitat degradation by invasive plant
species in the United States are well documented (Pimentel et al., 2000). Understanding the
controls on spatial distribution of invasives in the context of disturbance regime is critical for
designing effective watershed conservation and restoration plans. To this end, the proposed
project will: (1) provide important baseline data on the dispersion of non-native invasive plant
species in western Oregon, (2) establish a strategy for discerning patterns of invasion according
to geomorphic and anthropogenic disturbance regime(s), (3) provide a methodology for assessing
susceptibility of land areas to invasion based on select comparator species, and (4) provide
valuable data and recommendations for future conservation projects by community stakeholders
in the Luckiamute Watershed.
REFERENCES CITED
Dale, P., 2005, Introduction to mathematical techniques used in GIS: CRC Press, Boca Raton,
202 p.
Elzinga, C.L., Salzer, D.W., and Willoughby, J.W., 1998, Measuring and monitoring plant
populations: Bureau of Land Management Technical Reference 1730-1, Denver, Colorado, 477
p.
Noll, K., Dutton, B., Taylor, S., and Pirot, R., 2007, Spatial distribution of invasive plant species
in the Luckiamute Watershed, central Oregon Coast Range: Vegetative response to geomorphic
processes and disturbance regime in the riparian corridor: Geological Society of America,
Abstracts with Programs, v. 39, no. 6.
Oregon Department of Agriculture, 2001, Oregon noxious weed strategic plan: ODA Plant
Division, Weed Control Program Online Resource, URL:http://www.oda.state.or.us/Plant/
weed_control/plan/contents.html, updated January, 2001.
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Pabst, R.J., and Spies, T.A., 1998, Distribution of herbs and shrubs in relation to landform and
canopy cover in riparian forests of coastal Oregon: Canadian Journal of Botany, v. 76, p. 298315.
Pimentel, D., Lach, L., Zuniga, R., and Morrison, D., 2000, Environmental and economic costs
of nonindigenous species in the United States: BioScience, v. 50, p. 53-65.
Smith, M.J., Goodchild, M.F., and Longley, P.A., 2008, Geospatial analysis: A comprehensive
guide to principles, techniques, and software tools (2nd ed.): The Winchelsea Press, Leicester,
492 p.
Taylor, S.B., Dutton, B.E., Noll, K., and Pirot, R., 2007, Riparian Plant Distribution in the
Luckiamute River Basin, Central Oregon Coast Range: Preliminary Analysis of Geomorphic and
Anthropogenic Controls on Adventive Species Propagation in an Unregulated Watershed:
Geological Society of America, Abstracts with Programs, v. 39, no. 6.
Wong, D.W., and Lee, J., 2005, Statistical analysis of geographical information with ArcView
GIS and ArcGIS: John Wiley and Sons, New Jersey, 441 p.
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