Setting the scene: Land cover in South America

 Hello and welcome to my blog!

Remotely sensed data, photography and population statistics all point to the interesting changes the South American continent is undergoing. Rapid urbanization, rising prosperty and growing agribusinesses drive the anthropogenically induced land cover changes and the global changes in climate exacerbate local climate variability to top things up.

South America was the world region with the highest net forest loss 1990-2005.

My blog for the next few weeks will focus on the land cover changes of the recent past, present and predicted future under climate change scienarios. What I am most interested in, is how these differently caused changes affect an even wider set of phenomena. These can range from the global climate system to populations' livelihoods, local biodiveristy and anexed biomes.

To introduce the topic, a detailed land-cover map of South America shows the current spread of 10 identified ecological groups in Eva et.al. (2004).

Natural climate variability (e.g. intensified, more frequent ENSO events) affect the continent's vegetation cover over time. However, the observed unprecedented rate of land cover change calls for a close examination of the influence of human activities.

Land use change = change in the use or management of land by humans, which may (or may not!) lead to a change in land cover.

This diagram below by Foley et. al. (2005) shows (very generalised) how a transitions in land use may affect land cover of a developing area.

Some of these changes have been observed in South America. The advancement of the agricultural 'frontier' into the humid tropical forest domain both from the west along the Andes and from the southeast has led to continuously high rates of forest clearance, and resulted in higher proportion of agricultural/pasture land cover. However, Amazonia has experienced the appearance of "deforestation hotspots" and the high rates of urbanisation in major cities have often meant a jump from natural land use to fully urban build-up environments. These examples highlight the diversity of rates and types of change observable on the continent.

With this introductory post, I hoped to highlight the varied land cover of South America, and give an overview of drivers and rates of change. My blog will explore these issues together with an examination of the wider environmental, climatic and societal consequences.