Characteristics, significance, and human dimension of global invasive weeds - Invasive Plants: Ecological and Agricultural Aspects - page 237

i) “Stakeholders” means, but is not limited to, State, tribal, and local govern-
ment agencies, academic institutions, the scientific community, nongovern-
mental entities including environmental, agricultural, and conservation
organizations, trade groups, commercial interests, and private landowners.
j) “United States” means the 50 States, the District of Columbia, Puerto Rico,
Guam, and all possessions, territories of the United States.
Future policies
Legal impacts
It is recognized that isolated and unilateral action by individual States can
never be enough to manage the full range of activities and processes that gen-
erate invasions. Effective management requires not only national legal frame-
works but also concerted bilateral, regional, or global action based on common
objectives and joint international agreements. Regulations are necessary to
implement policy, set principles, rules and procedures, and provide a founda-
tion for global, regional and national efforts.
Currently, there are more than 50 global and regional soft law instruments
dealing in one way or another with alien species [22]. They cover terrestrial,
marine, freshwater, wetlands and coastal ecosystems as well as processes and
pathways that generate introductions [29]. International instruments are often,
though not always, fairly general in character. National legislation and regula-
tions are necessary to operationalize these instruments in national legal sys-
tems. National policy makers should seek to develop a structural legal frame-
work to address all the issues concerning alien species. Such legal frame work
has been included under the Executive Order in the United States in 1999. In
general, National frameworks should be established, streamlined or strength-
ened to: i) harmonize objectives, 2) standardize terminology, 3) implement
measures to prevent unwanted introductions, iv) support mechanisms for early
warning systems, v) provide management measures, including the restoration
of native biodiversity, and vi) promote compliance and accountability.
Prediction of species invasiveness
Question may be asked: Which traits enable a species to invade a new habitat?
How can we predict the invasiveness of a plant species? The leading theory for
the exceptional success of invasive plants is their escape from the natural ene-
mies that hold them in check, freeing them to utilize their full potential for
resource competition [30]. Invasiveness of many terrestrial plant species is
explained by allelopathic suppression of neighboring plants [31, 32]. This has
been proposed as an alternative theory for the success of some invasive plants
(see Chapter 2, this volume).