Defining a regional approach for invasive plant research and management - Invasive Plants: Ecological and Agricultural Aspects - page 120

Defining a regional approach for invasive plant
research and management
Steven R. Radosevich 1 , Bryan A. Endress 1 and Catherine G. Parks 2
1 Department of Forest Science, Oregon State University, Corvallis, OR 97331, USA
2 USDA Forest Service, Pacific Northwest Research Station, La Grande, OR 97850, USA
Introduction
Invasive plants are now recognized as a serious threat to most extensive man-
agement systems, such as forests, meadows, deserts, and riparian areas [1-3].
Vitousek et al. [3] described exotic plant invasion as a significant element of
global environmental change because exotic plants can alter primary produc-
tivity, decomposition, hydrology, nutrient cycling, and natural disturbance
regimes. Non-native plants also impact landscapes by changing the structure,
composition, and successional pathways of native communities [3-8].
In North America, preventing, reducing or eliminating undesirable impacts
of non-native invasive plants is a difficult challenge facing public and private
land managers. Non-native plants account for about 65% (over 1,350 species)
of the total number of invasive species in the United States and impacts to the
US economy are believed to exceed $13 billion per year [9]. In the Pacific
Northwest Region (PNW, Fig. 1), non-native plant invasions began in the mid-
1800 s with the arrival of European settlers. Non-native invasive plants initial-
ly spread through contaminated crop seeds, a rapidly developing railroad sys-
tem, and often-intense livestock grazing [10]. More recently, road building,
road use, logging, grazing, forage seeding, certain erosion control practices,
fire rehabilitation measures, and irrigation ditching facilitate the spread of non-
native invasive plants [11-13]. Harrod [8] reviewed the effects of invasive
plants on land management in eastern Oregon and Washington, and found that
65 plant species in the Blue Mountains (Fig. 1) were listed as “noxious weeds”
by federal and state agencies. The Invaders Database [14] lists 53 non-native
plant species characterized as noxious that are found in eastern Oregon. An
additional 16 non-native species to those found in eastern Oregon were char-
acterized as noxious in Idaho and Washington (Tab. 1).
Because of the serious invasive plant problem in the PNW, there is a need
to develop research programs than span biological and spatial scales while at
the same time facilitate relationships between scientists and land managers.
This is not easily accomplished and requires considerable coordination and
communication. In this paper, we present a framework for research that can be