Invasives are the second leading cause of species extinction worldwide.  This is mainly a result of monocultures and the poor environment they provide for wildlife, inevitably resulting in populations decreasing.

Invasives often outcompete native plants for water, sunlight and nutrients leading to a reduction of diversity and causing monocultures to arise. Monocultures occur when a single invasive species takes over an entire area. Monocultures can cause forest failures, where tree seedlings cannot survive, and eventually entire canopies are lost. As well as decrease root infiltration causing a decrease in soil moisture retainability. 

Invasive species can increase erosion along riverbanks and result in a decrease of shade coverage over waterways. The Klamath community has been increasingly concerned over the years about water temperatures rising, leading to algae blooms throughout the area. A decrease in shade cover directly correlates with an increase in water temperature, decrease in oxygen for the fish populations and an increase in algae growth.