“Pygmy Forests are unique forests of miniature trees and shrubs.
The growth of these trees has been inhibited by the poor soil fertility and wetness of the soil that restricts the growth of vegetation and induces a dwarf condition. These trees may be 100 or more year old and are able to survive in this soil but they do not prosper here.
Pine trees here are rarely more than 3 to 4 feet high giving them a natural bonsai effect. Many of the tree trunks are only an inch thick and yet contain 80 or more growth rings. A couple of feet away with younger soils, the same species of trees grow dozens of feet high.
Analysis of pygmy forest soils show low levels of macro and micro nutrients and high levels of exchangeable aluminium, which limits the ability of plants to grow. Highly acidic soils with low pH support formation of an iron hardpan thereby preventing the trees from setting deep roots and blocking internal drainage of soil water.
The unusual geology results in trees growing about 1/5 or 1/10 of their normal size. In some, the forest soil layer is only 18 inches deep and lies on an impermeable layer of rock.”