Biology Reference
In-Depth Information
In addition, plant pathogens of forests cause a loss of about 9%, or about $7 bil-
lion of forest products each year (Hall and Moody 1994; USCB 2007). The propor-
tion of introduced plant pathogens in forests is similar to that of introduced insects
or about 30%. Thus, about $2.1 billion in forest products are lost each year to exotic
plant pathogens in the United States. Again, damages from exotic pests appear to
be more severe than those from native pests.
1.3 Conclusions
With more than 50,000 introduced species of plants, animals, and microbes in the
United States, only a portion of these cause significant damage to agriculture, for-
estry, and natural ecosystems, and require costly control measures. Plants and
plant pathogens are one group of invasive species that cause significant ecological
damage. More research is needed for the prevention of these invasions and to
improve management of pest species using environmentally safe methods.
References
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