Effects: Wildfires

Trees and terrestrial vegetation have been understood as a widely influential natural aspect.  They serve as a habitat for certain animals, a driver of ecosystem precesses and a major global carbon sink; immensely important for the current struggle to combat global warming.  Our great ally has been yet another subject to destruction by the wide-reaching effects of trophic downgrading.

A recent study in the Serengeti ecosystem in East Africa, showed that when the historic control over wildebeest (Connochaetes taurinus) and buffalo (Syncerus caffer) populations was eradicated, ecosystem revitalization ensued (Holdo, 2009).  Rinderpest, a viral disease of ungulates, was introduced to Africa through human expansion and cattle trade in the 19th and 20th centuries.  This extremely infectious disease regulated wildebeest and buffalo populations within Serengeti National Park up until its eradication in the 1960's.  From 1960 to 2003, data collection and state-space models have linked the removal of the disease with the subsequent irruption of the ungulate populations.  With the increase in wildebeest and buffalo, both herbivores,  decreases in grass and small plant cover resulted from the increase in grazing .  The decrease in fuel loads (plant biomass) was finally correlated to the decreased average rate of wildfires and decreased average area of burnt biomass and soil per fire occurrence (Holdo 2009).  The land was slowly converted from a grasslands to a more tree-dense plain, which have been long known to be less susceptible to intense fires during dry seasons.

 The study utilized information gathered from prior research and reconstructed data showing the relatively lower  rate and effect of wildfires during the 1940's and 1950's to serve as comparison.  The study produced empirical evidence that for over a hundred years, the increased death rate of wildebeest and buffalo was directly correlated to high average wildfire rates and increased extent of fires.  Now that wildebeest and buffalo populations have returned, fire intensities have decreased to a manageable and even healthy level.

 This proves yet another example of how a anthropogenic introduction of population control (the rinderpest virus) in the 1800's lead to adverse effects for the ecosystem.  Human expansion has obviously lead to the globalization of our world and the mixing of cultures and ideas, however it has had terrible collateral effects on human health and biodiversity.  Wildfires burn roughly 500 million hectares globally every year resulting in billions of dollars in fire suppression efforts and direct property loss (Levine 1999). This releases an estimated 4000 Tg (tera=1E12) of carbon into the atmosphere, contributing to global warming and all the direct effects of that and the increased need for research money.