Fewer Trees, More Disease: The Link Between Deforestation and Epidemics
Astonishing in their quantity and variety, microbes can be found in almost every habitat: jungles and jungle gyms, snowflakes and tears. Most microbes are neutral or beneficial to humans, but a small percentage are pathogens--organisms that cause disease. The coexistence between microbes and other species has evolved over millennia, but human activity on a global scale is now altering many of these interactions. This has resulted in a dramatic increase in the incidence of infectious diseases.
The Earth Has Lost More Than Half Its Forest
“One of the clearest examples of how ecosystem disruption affects disease behavior can be seen in the interaction between deforestation and the infectious, and particularly vector-borne, diseases that are common through tropics and subtropics,” writes Francesca Grifo, director of the Center for Biodiversity and Conservation at the American Museum of Natural History. (A vector is an organism that transmits a disease from place to place.) Humans have removed almost 50 percent of the Earth’s original forest cover. The rate of deforestation has increased considerably over the last few decades, largely in response to human population growth and a corresponding rise in demand for natural resources.