Saturday, November 13, 2010

Invasive Plants

What are invasive plants?
Alien or "exotic" plant species are those which have been introduced by some non-natural process (primarily human transportation and/or planting) into an environment in which they did not naturally evolve or spread. Some exotic species are able to thrive outside their normal zones, and those termed "invasive" are capable of aggressively competing with native species to the point of displacing them. To accomplish this, invasives tend to exhibit very strong vegetative growth, abundant long-lived seed production, a high degree of germination, and rapid maturation to seed-producing capability. While there can be overlap, the term "invasive plants" generally refers to natural areas management, and is distinct from the more legal designation "noxious weeds" applicable to economic impact in agricultural systems and regulated by the U.S. Department of Agriculture.

Why should we worry about invasive plants?
Invasive plants can have a tremendous negative influence on balanced ecosystems of soil, water, plants and animals. They can crowd out primary or even sole source species of food or hosts for a variety of insects, birds, mammals, and other organisms, and can restrict wildlife movements and natural migration patterns. The long term effect can often be a significant reduction in the diversity of species occupying a local or even regional ecosystem, in some extreme cases leading to native species extinction. Such a reduction in diversity can place both terrestrial and aquatic habitats and their occupying animal populations under great stress. Government agencies and local park districts charged with enhancing and preserving natural habitats face rising costs in their efforts to remove invasive plants and reduce their spread.

What can we do about them?
At Habitat Home, we follow a few simple rules.  First, we try not to introduce exotic plants of any kind, using only native plants in both our natural areas and in the landscaping around the house.  By the way, we consider the house landscaping to be just another case of the natural areas management we are doing in the prairie, savanna, and riparian corridor areas of the property.  Second, we actively remove invasive species as we find them.  And find them we do!  It is a never ending process.  The biggest problem species at Habitat Home are bush honeysuckle (Lonicera spp.), autumn olive (Elaeagnus umbellata), and yellow sweet clover (Melilotus officinalis).  Mowing helps, especially for the olives, but we cut the clover and honeysuckle and spray the honeysuckle stumps with a small amount of glyphosate (for example, Roundup).

1 comment:

  1. "Noxious" weeds also include plant species that have a negative physical effect. The definition is supposed to cover plants like Giant Hogweed and Wild Parsnip, both of whose sap causes severe chemical burns.