Welcome to the blog of the course and textbook Facing up to global warming: What is going on and what you can do about it. This course is run by Professor Nick Gray of the Trinity Centre for the Environment at Trinity College Dublin.

Saturday, May 18, 2013

Controlling Wildfires – Sustainable for Who?

When people speak of sustainability they speak with the idea of creating a planet resourceful for all species, not just man. The human race will probably admit to being the leading cause of the disruption of sustainability so it’s fair that we also take responsibility to try repair it, not just for us but for all other organisms that inhabit earth. But what inspired me to write about this particular topic was that man is also trying to repair the disruption caused by other sources on the planet.

So what are the main disruptors of sustainability? Overpopulation, destruction of forests, burning of fossil fuels… all caused by man mainly. As a result of all these and many more, there is too much carbon being pumped into our atmosphere causing more disruption.  But we all know that and we are slowly trying to change ourselves to decrease our carbon emissions. Natural sources of carbon emissions however can’t change themselves and we’ve generously decided to also help combat their carbon emissions. But is this an entirely beneficial thing? Is this really sustainable for the entire planet or just us?

Wildfires are thought to cover 3–4 million km2 of the globe each year and are responsible for the release of 2–3 billion tonnes of carbon to the atmosphere based on estimates from previous years. I think everyone can agree that this is bad and due to global temperatures rising, forests are becoming drier and more prone to more frequent and larger fires. But do we really have the right to try stop these natural occurrences?

Despite the billions of tonnes of carbon emissions, wildfires do have their benefits, of which many species take advantage. It is said that fires cause the loss of nutrients through a variety of mechanisms however it has been shown that very high temperatures have to be reached to result in a significant loss and generally these nutrients are replaced by the organic matter left behind after the fire. Fires also remove overhead vegetation resulting in fewer leaves intercepting rain which allows more moisture to reach the soil.

It is also said that fires result in the loss of biodiversity due to the death of species caught in the fires. This has been shown incorrect in many cases. The longleaf pine savannas of the southern states of America depend on fire to prevent the invasion of deciduous forest trees whose shade eliminates both the pines and the species beneath. The diversity and abundance of these species is closely related to fire frequency. Natural fire regimes of the forests of British Columbia are important in maintaining a diverse assemblage of vertebrate species and different species have adapted to exploit the different stages of succession, regrowth and habitat change that occurs following a fire. Fires also cause the habitat to evolve differentially afterwards and influence how vertebrate species are able to use the burned areas. In most grassland ecosystems, fire is the primary mode of decomposition, making it crucial in the recycling of nutrients. There are also many plant species that depend on fires to instigate the germination of their seeds such as the Giant Sequoia.

Fire serves many important functions within fire-adapted ecosystems. Fire plays an important role in nutrient cycling, diversity maintenance and habitat structure. The suppression of fire can lead to unforeseen changes in ecosystems that often adversely affect the plants, animals and humans that depend upon that habitat. So with all that in mind, is controlling wildfires creating sustainability for all or are we just looking at the smaller picture?
  
Alice Kennedy

No comments:

Post a Comment