Native species of North America are often defined as those species that were present in North America before Europeans arrived in the early 1600s. When Europeans arrived, they found extensive forests dominated by the American chestnut tree. These chestnut trees were extensively cultivated and planted by the North American natives for food and other wood products. In the early 1900s the chestnut blight (a fungus) virtually exterminated all of the American chestnut trees from North America. (a) Is the American chestnut considered a native species despite its intensive cultivation? Explain why.

(b) Is the chestnut blight considered a native or invasive species? Explain why.

(c) Discuss why invasive species tend to proliferate at very high rates.

(d) Many people are trying to grow hybrid chestnut trees that will be immune to the chestnut blight so that forests can be restored to those found by the Europeans in the 1600s. Do you agree or disagree that this should be done? Justify your answer

a) Yes! the American chestnut tree is a native species. The American chestnut tree was present before the Europeans arrived in North America in the 1600s. Since a native species has been defined as any species that was present in North America before the arrival of the Europeans, then it is a fact that the North American chestnut tree is a native species.

b) The chestnut blight is an invasive species that is native to east East Asia, and was accidentally introduced into North America around the early 1900s, when the Japanese chestnut was commercially cultivated in the United States.

c) Invasive species tend to proliferate at a very high rate because they lack some natural constraints in the new environment such as natural predators, competition, and as in the case of this chestnut blight; the host has no natural defense mechanism against them. These conditions allow them thrive more than they would in their natural environment, unchecked

d) Yes, I agree with this idea, albeit to some extent. The development of hybrid chestnut resistant to the chestnut blight will possibly return the forests back to how it was before the Europeans arrived in the 1600s, but the genetic conservation will be altered, since these new trees will be an hybrid of the old trees, and the forest won't truly be as it was before the 1600s