non native species definition
Non-native species can be added to a community either by natural range extensions or because they are introduced as a result of human activity. Most non-native species have harmful ecological effects; these are referred to as invasive species.Virtually all ecosystems are at risk from the harmful effects of introduced invasive species (also see exotic species, marine invasive species, and aquatic invasive species).nvasive species are a major threat to our environment because they (1) can change habitats and alter ecosystem function and ecosystem services, (2) crowd out or replace native species, and (3) damage human activities, costing the economy millions of dollars.