Rainforest regeneration

3 May 2010

Will Gosling of the Open University (talk at Aylesbury Museum) says recent research into past climate change in the Amazon basin via ancient pollen preserved in lake sediments, has shown that climate differed in the Ice Ages - and the rainforest was not as extensive as it is now. Pollen analysis also showed the extent of human impact on the rainforest in the 1000 years preceding Columbus - and it was considerable. There are distinct layers of charcoal in lake sediments which appear to denote human activity - as well as evidence humans worked soils (agriculture). The process of modern deforestation has revealed numerous human earthworks which suggests large sections of the rainforest have only gone wild within the last 400 years. However, human impact at that time was disjointed, large areas of clearing but surrounded by remaining rainforest - which simply closed in and hid the human traces when people died from introduced diseases and the Amazon basin population shrank. Regeneration was fairly rapid but that does not mean modern human clearing over much larger areas of territory is capable of doing the same thing today.

Although trees are one element behind rainforest clearing - and tropical wood fetches lots of money, I was surprised when he said one of the main crops being grown in cleared areas was soya.This is a bit of a paradox as soya is used to make a milk substitute in vegan diets. It is also a substitute for milk for people allergic to lactose - presumably because of the way milk is processed and treated in order to give a longer supermarket shelf life. Soya is also an important source of protein in meat free diets which is a bit of an own goal for the AGW activists - who are fond of criticising meat eaters for creating all that methane from the intestines of cattle. A direct parallel can be made with the biofuel plantations in places such as Borneo where the local fauna is being decimated to satisfy the anti-oil brigade. This includes the rapidly approaching extinction of the sidekick of Clint Eastwood, namely the orang utan. Obviously, ranching also plays a major role after clearance of the forest, especially in the eastern section of the rainforest - so steaks on plates is also implicated in a major way.

Will Gosling is saying that the ecological dream scenario of a pristine rain forest that has survived for millennia is quite untrue - and wicked humans in modern times are not the only people to have exploited the region. In addition, the rainforest as it developed in the Holocene did not exist in the Pleistocene.