Why local people don't like deforestation

If you live someplace warm, deforestation may make you decidedly hot under the collar.

Yeah, but it's a dry heat...  (photo by William Laurance)

Yeah, but it's a dry heat...  (photo by William Laurance)

Compared to rainforests, deforested lands often suffer more flooding, soil erosion, and mosquitoes--which can carry deadly diseases like malaria.  Water quality also frequently declines.

But what do local residents dislike most about deforestation?  The fact that it gets hotter--a lot hotter.

According to a recent study in Climatic Change, for instance, oil palm plantations were on average 4.7 degrees Celsius (8.5 degrees F) hotter than nearby rainforests.  One would imagine that open croplands and cattle pastures are even worse.

In Borneo, Erik Meijaard and colleagues surveyed nearly 8000 local residents in 800 villages.  When asked how deforestation affected them, by far the most common response from the villagers was that it made their climate uncomfortably "hotter".

The hotter conditions reduced crop yields, increased mosquitoes and disease, and made people more tired, according to the villagers.  Overall, quality of life was perceived to diminish substantially.

These findings align well with an intriguing study by Paul West and colleagues, who found tropical rainforests and boreal forests both have a big influence on their local climates. 

Rainforests keep things cool both by preventing most sunlight from reaching the ground surface and by promoting evaporative cooling.

The bottom line: deforestation doesn't just harm biodiversity and native ecosystems.  It can make people very hot and bothered as well.

Agriculture will massively impact the tropics

In a review article that has just appeared in the leading journal Trends in Ecology & Evolution, I teamed up with Jeff Sayer and Ken Cassman to assess the impacts of agriculture this century on tropical ecosystems and biodiversity.  It's quite a sweeping review with many important conclusions.

Oil palm: highly profitable and often deadly for tropical forests (photo by Niels Anten).

Oil palm: highly profitable and often deadly for tropical forests (photo by Niels Anten).

Among the biggest concerns are:

- Prospects for dramatic expansion of agriculture in Sub-Saharan Africa and South America

- Great uncertainty in the amount of land that will be converted to agriculture, in order to meet growing global food demands

-The prospects that biofuel production could also impact greatly on native ecosystems and also compete with agriculture

- The likelihood of massive environmental impacts on freshwater ecosystems and water supplies

- Profound challenges ahead in producing enough food to feed the world

Those who wish to have a PDF of the paper can email me directly (bill.laurance@jcu.edu.au).

-Bill Laurance