When we "upside down" our natural systems, removing those creatures and plants that we deem "in our way economically ",,,,,,,,,,,,,,,,,,,,,THE RESULT IS INVASIONS OF TRULY HARMFUL LIVING MATERIAL THAT BOTH IN THE SHORT RUN AND LONG RUN BRING US MORE ECONOMIC AND HEALTH CONCERNS THAN THE NATIVES THAT WE PREVIOIUSLY BANISHED!

http://www.sciencedaily.com/releases/2014/06/140620103207.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fplants_animals%2Fecology+%28Ecology+Research+News+--+ScienceDaily%29#.U6WOK_Gqse8.email


http://www.sciencedaily.com/releases/2014/03/140324104512.htm#.U6WOf00g9zo.email


The killing off of our native carnivores(Wolves/Pumas/Wolverines/Grizzlies/martens/fishers), the destruction of our own "rain forests(Decidouos woodlands from the Atlantic to the Mississippi/Conifer woodlands of the Pacific Northwest et al.) has led to invasions of non-natives,,,,,,,,,,,,,encouraging new illness and ecosystem malfunctions that cost us tremendously both economically and health-wise---example is the 
invasion of the tics that spread debilitating Lyme Disease