Jatropha is invasive species in many parts of the world including in
India. Instead of managing this weed we are promoting its cultivation
as biodiesel crop. We are already having long list of invasives like
Ipomoea, Parthenium, Lantana, Water hyacinth etc. Now we are
spreading one more invasive. I am forwarding information on Economic
damage caused by invasive species in USA. Such studies are required
in India in order to aware the planners about the impact of foreign
plant on our ecosystem.

How do invasive species affect me?

Invasive species have severe environmental and economical impacts.

Why you should be concerned

Estimates indicate that invasive plants are spreading at about 4,600
acres per day on Federal lands alone in the western United States.

Weeds have invaded approximately 17 million acres of public
rangelands in the West-more than quadrupling their range from 1985-
1995.

Ecological damage caused by invasive species

The largest threat to native wildlife is loss of habitat. The two
most common (and destructive) types of habitat loss are due to
development and invasive species.

Weeds are destroying wildlife habitat and forage. Wildlife needs a
variety of forage to thrive. Because of aggressive growing habits,
invasive weeds often out compete native plants, replacing plant
diversity with monocultures.

Weeds are damaging endangered species and native plants. Two-thirds
of all Federally-listed species, and many native plants, are
threatened by weeds.

Aquatic weeds can cover the surface of bodies of water, removing
sunlight and oxygen that aquatic organisms need to survive.

Invasive animal species like burros feed on native tree species such
as mesquite and paloverde. These trees host numerous insects that
serve as a prey base for native birds and bats. As the burros strip
these trees of foliage, insect numbers and diversity declines, as
well as the species that feed off the insects. Burros also directly
compete with the native Desert bighorn sheep for water and food
resources.

Economic damage caused by invasive species

Land values may drop to as little as 10% of their original value when
lands become heavily infested with invasive plants.

Economic impacts of leafy spurge on grazing and wildlands in Montana,
North and South Dakota, and Wyoming are approximately $129 million.

http://www.fws.gov/southwest/refuges/arizona/havasu/invaffect.html


Pankaj Oudhia