Michael Pollak wrote:
> In a couple of different contexts, I've run into the idea that soil
> reclaimed from rain forests is bad for farming. Jeffrey Sachs makes the
> idea prominent in some of his recent arguments for why African economic
> history developed differently over the longue duree. And recently it
> showed up in an article on Colombia, about how farmers in the recently
> sprayed Putamayo district would likely be planting coca there again, even
> if the government made good on its offer to provide $2000 worth of
> fertilizer to each peasant that joined the voluntary eradication program
> (originally it was supposed to $5000, in cash), because the fragile jungle
> soils that had no tree cover couldn't support intensive agriculture.
In tropical rainforests the nutrient cycles are far different from those in some temperate ecosystems. In tropical rainforest soils typically there is no reservoir of organic nutrients in the soil. There is no long dormant season, like winter, when dead plant material falls to the forest floor and decays slowly building up the organic material (duff) in the soil. In the tropics organic nutrients are reused relatively rapidly by living organisms. Thus when the living elements of the tropical forest are destroyed, there is little left. When temperate forests are removed, there remains a reservoir of organic material in the soil.
M. Ferro