Environmental Engineering Reference
In-Depth Information
Table 9.1
A list of approaches and some examples of techniques used in the
management of weeds and invasive plants.
Approach
Techniques
Prevention
Using weed-free feed for stock animals; adhering to weed laws
and quarantines; conducting risk assessment; screening plants
for suitability for introduction; conducting surveys and mon-
itoring; using clean machinery; using clean soil and gravel;
inspecting nursery stock for weed seeds; avoiding planting
invasive species or cultivars.
Eradication
Complete removal by any means.
Control:
Physical
Hand pulling; using manual implements; using fi re; using
machines to remove plants; mowing; chaining; using mulches;
solarizing the soil in defi ned areas.
Cultural
Prevention (see above); manipulating competition by native or
other desirable species.
Biological
Introduction of natural enemies; augmentation of natural
enemies; habitat management to enhance predators and
parasitoids; using grazing.
Chemical
Using herbicides.
Integrated weed
management
Using a combination of methods from techniques listed above.
impact to an economically acceptable level in agroecosystems or an ecologically
acceptable level in wildland ecosystems (Fig. 9.4) (Radosevich
et al
. 2007).
Similar to control, containment is often a goal of management of invasive
plants, where the infestation is held to a defi ned geographic area and not
allowed to spread (Wittenberg and Cock 2005). Weed control, therefore, is
a matter of degree that depends upon the goals of the people involved, eff ect-
iveness of the tool or tactic used, and the abundance and competitiveness of
the species present. Just as in agroecosystems where weed control occurs in the
context of crop production, control of invasive plants requires careful consid-
eration of the native plant community in which the invaders occur. In many
cases, eff ective management will also require restoration of desired species con-
current with control eff orts.
h ere are four general methods of controlling unwanted plants: physical, cul-
tural, biological, and chemical, which are described below and summarized in
Table 9.1 (Ross and Lembi 1999). In view of the complexity and diversity of most
wildland ecosystems, the best approach in many cases is an integrated one that uses
a combination of the most appropriate methods and tools in the context of the
system in question.
