Research by scientists from Sri Lanka and Germany, published in the Proceedings of the National Academy of Sciences, has contributed to the debate on the interactions between key species and biodiversity in tropical forests. The scientists analysed how individual tree species in a tropical forest affected those nearby, whether increasing or decreasing biodiversity in their surrounding areas. They found that two thirds of species had little or no effect on the species around them, whilst the remaining third affected growth only in a small surrounding area (up to 20 metres). This supports the theory that the diversity of forests and similar complex natural ecosystems depends not on a few dominant species but on the overall interactions between organisms.

The method developed by the scientists, ‘Individual Species Area Relationship’ (ISAR) could be used in scientific conservation management of forests.