Impacting Ecosystems

Once Upon a time… www.indianarttulsa.com …before the invaders came, North America was a pristine, natural, and unspoiled wilderness with ancient forests covering the landscapes. This idyllic land was tenanted by millions of Natives who were at one with nature, living as extensions of ecosphere. Their world was void of perceptible human disturbance. This peaceful, mythic, magical ideal, often referred to as tabula rasa (blank slate), is frequently represented in the modern environmental movement. However, these impressions of a benevolent people living as one with the environment is wrong.

Human Impact Native Americans burned through the forests clearing farmland, as a hunting tactic. Over 99% of the tall grass prairie of North America has been cleared, resulting in extreme habitat fragmentation. Habitat fragmentation is the emergence of division in an organism's preferred environment, causing population fragmentation. Habitat fragmentation can be caused by geological processes that slowly alter the layout of the physical environment, and one of the causes of speciation. However, human activity can alter the environment much faster and causes extinctions of many species and increasing Edge Effects, which occur at the boundary of two habitats with increased biodiversity. Keeping large areas of forest and mountains free of undergrowth and small trees was just one of many reasons for using fire in ecosystems. en.wikipedia.org maps.thefullwiki.org

 Native Americans were responsible for the conversion of America’s forest to grassland, savanna, scrub, open woodland, and forest with grassy openings. Forest ecosystems are dynamic and complex. A disturbance to any part of the network can alter the balance of relationships and affect the entire ecosystem either positively or negatively. Fire is unique in that it can be either a beneficial natural process or a devastating catastrophe. For species like lodgepole pine (Pinus Contorta), fire is necessary to help reduce competition and help the species release its seeds. However, climate change, drought and other conditions have caused occurrences of intense wildfire to increase, which can damage forests so badly that it takes years for them to naturally recover. Wildfire is necessary for forests, but also a threat to them. sagehen.ucnrs.org www.answers.com www.wnps.org

U.S. Flora Map www.adventure-journal.com

Vegetation Biomes of the Earth visual.merriam-webster.com www.nature.com Vegetation By Region