Reduced Biodiversity/Increased Monoculture

‘Preservation of biodiversity’ often implies preservation of native species, although this isn’t strictly necessary.  Non-natives that don’t dominate or that stay in disturbed areas are of less concern to land managers.  The critical factor is preventing the spread of eco-system changers:  species that take over and change ecosystems.  Invasive non-natives have the potential to create ‘monocultures,’ or ecosystems where they are the only plant species left.

Typically, these species are extra-adaptable and lack natural enemies here in the Pacific Northwest.  They outcompete natives for nutrients, sunlight, and water, causing native populations and biodiversity to decline and disappear.  The resulting monocultures offer little for local wildlife, whose populations suffer as well.  This is why invasive plants are the second leading cause of species extinction worldwide.