Often when we think of habitat destruction the first image that pops into our minds is the loss of rainforests in South and Central America due to the vast amount of deforestation that occurs every day. And it’s no surprise that that’s the case, between 2004-2012 estimates suggest that 17.7 million hectares of the Amazon rainforest was lost. For perspective, that’s an area almost twice the size of Portugal.
It’s not only the Amazon either. Deforestation is a phenomenon that’s happening all around the world. Whether due to logging activities, wildfires, or other causes, it’s something that’s been going on for a while. However, logging is often only the first step in humans changing the environment and attempting to use its resources. While the wood from logging is indeed useful, often it’s the opportunities for agricultural land that people are after when deforestation is taking place.
Sometimes looking back can offer insight into the way forward, and there’s an interesting article from 1997 (my year of birth!) that looks at the effects of logging and agriculture on habitat fragmentation and birds. Habitat fragmentation was known to decrease reproductive success and survival in birds from a variety of studies prior to this, however these studies focused mostly on logging and did not consider the area surrounding the remaining fragments of habitat. Bayne and Hobson were interested in studying whether utilizing the land between fragments for agriculture would affect survivorship and population levels of birds.
What was found was that for areas where only logging took place predator populations and their interactions with prey didn’t change much and was very similar to areas where natural disasters shaped the landscape, as well as quite similar to continuous forest habitats. Contrary to this, when the surrounding lands were being used for agriculture there was a much greater predatory pressure on the birds.
While there have been many studies done since, a take away point from looking at this study at-a-glance is that, while logging often steals the show with regards to habitat destruction, agriculture is in fact a more powerful agent of change for the remaining patches of forest. The vast amount of deforestation occurring across the world is indeed something to be worried about, but rather than just focusing on the loss of trees we should focus on what is being done with the remaining land, and finding ways to mitigate and reduce the ecological damage that these changes impart.
Sources:
https://conbio-onlinelibrary-wiley-com.ezproxy.library.yorku.ca/doi/pdf/10.1046/j.1523-1739.1997.96135.x (paywall – will be updated with open access link)
https://wwf.panda.org/our_work/forests/deforestation_fronts2/deforestation_in_the_amazon/
Applied Plant Ecology Winter 2020 