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Beetles Global Warming Essay

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Sophie Worrell
November 25th 2015
The Effects of Global Warming: The Mountain Pine Beetle and Northwestern American Pine Forests

Across Northwestern America the climate has protected pine forests from parasitic mountain pine beetles for millennia, but due to recent global climate warming these delicate ecosystems are experiencing an extreme shift. Normally the beetle population explodes every 25 years or so when there is a spell of warm winters and hot dry summers. In this natural cycle the beetles kill most of the older pines. The dead trees lose their needles over the next few years and open the canopy letting light in. This frees space and nutrients allowing new tree growth. Historically, the climate system kept the beetle population
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These rice-sized beetles (see Figure 2) attack the tree’s thick bark and penetrate it resulting in resin flows that can kill beetles. Pine beetles, not engulfed by resin, convert the resin chemicals into aggregation pheromones that signal other beetles to a mass attack on the tree. In this manner, the tree’s defenses are penetrated and death can occur within a day. Cold winters would control the beetle population to limit the impacts to pine forests, and the resulting forest thinning would benefit the forest by allowing new tree growth to establish and flourish. Climate change effects have upset this natural…show more content…
Increased temperatures cause warmer winters and hotter, dryer summers, allowing the beetle population to expand and put the forests in jeopardy. There are multiple negative effects associated with the beetle’s deforestation. Such deforestation causes a positive climate feedback loop, economic loss for the lumber and tourism industries, and hydrological impacts, which include alteration of storm water run off levels, water turbidity, and water quality effects. The impacts of global warming on the mountain pine beetle population have resulted in unprecedented effects on the Northwestern American pine
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