A study released in ScienceDaily, in March — How trees coexist: Understanding biodiversity found trees grow better in areas that are rich in diversity.
The international project is based on a 50 hectare planted forest in subtropical China, and is one of the largest studies of its kind ever done. The researchers said, “It is generally assumed that tree-tree interactions are dominated by competition for resources such as light, water or nutrients. This view is generally not wrong, but our understanding of how trees interact is still limited.”
They found, “The local environment of a tree strongly determines its productivity, meaning that tree individuals growing in a species-rich neighbourhood produce more wood than those surrounded by neighbours of the same species. Particularly impressive is the finding that the interrelations of a tree with its immediate neighbours induce higher productivity of the entire tree community, and that such local neighbourhood interactions explain more than 50 per cent of the total forest stand productivity."
“The importance of local neighbourhood interactions in regulating forest stand productivity increases as forest stands were richer in tree species. These findings show that the coexistence of neighbouring trees and their small-scale interactions are substantial in explaining the productivity of species-rich mixed forests.”
One practical measure the researchers report, “Afforestation programs in countries that have experienced dramatic deforestation in the past, may benefit from planting multiple native tree species, instead of planting monocultures or mixing monospecific patches at larger spatial scales. Furthermore, the study emphasizes the importance of long-term measures preserving global biodiversity.”