The fruit of the tree, chestnuts, nourished the locals and their livestock. They also provided for their economic means. As a source of trade with the big cities, it helped the locals to prosper. The trees provided adequate fruit to feed local species such as bears, deer, squirrels, and turkeys. Today you will not see an American chestnut tree. The fungus swept across the northeastern United States to such an extent that you will only see an occasional sprout. This sprout will die when its bark is old enough to fissure. The economic damage that was done to these settlers can not be estimated nor can the effects of major food loss on the local species be measured. .
The desert grasslands of North America were affected by the introduction of Lehman love grass from southern Africa. This has caused the natural black grama grass to be overtaken. The introduction was intentional to reduce soil erosion within the desert. However, the invasion of the non-native species has increased the speed at which the grasslands have become shrub lands. The short-lived grasses produce large quantities of small seeds that are easily mobile, causing the spread of non-native grasses to increase. .
Asian longhorn beetles, originally from China, Japan, North and South Korea, have become a major pest in North America. These insects cause damage to orchards, woodlots, and other commercially harvested regions. Their larva infests hardwood trees and bore large holes, making the wood useless for commercial production and weakening the trees" resistance to other diseases. .
This beetle was introduced into the United States during international shipping. This species was once contained within warehouses but has managed to escape. Control efforts have relied on removal of all trees in the affected areas. .
An example of infectious marine life has occurred with the introduction of the zebra mussel. During international shipping of goods from continent to continent, the ships travel across the ocean.
