They are tall, often green at many times of the year, and there are an estimated 73,000 different species (or my precisely, the latest assessment puts the number of trees at 73,274). Not all of these 73,000-plus tree have been characterised.
This means that despite the ubiquity of trees across our planet there remain many more species to find. Scientists have made a stab at estimating how many species of tree have yet to be discovered and documented. This number of undiscovered trees is set at around 9,200. By ‘undiscovered’ this means trees that have not bene typed and catalogued, for such trees may be inhospitable regions or they may be within areas where people live, it’s just that those residing in close proximity may not know their trees have not been documented by the scientific community.
This estimate come from the University of Michigan and it is drawn from research based on more than 100 scientists from across the globe. The efforts have created the largest forest database yet assembled.
The research shows that previous estimates of tree yet-to-be-discovered was an underestimation, of around 14 percent. This means there are 64,100 documented tree species, with the remainder still to be tracked down.
As to how scientists know there are more trees to find, this is based on observations (often photographic from space) and the use of statistical methods. These can be combined to estimate the total number of unique tree species at biome (a major ecological community type), continental and global scales.
The statistical methods were based on the code-breaking techniques developed by the ‘father of computing’ Alan Turing during World War II.
As to where these trees are located, the research suggests that South America is the continent with the highest estimated number of rare tree species (it also happens to be where the greatest diversity of trees are). The areas that researchers have targeted looking for new species of trees include the Amazon basin, as well as Andean forests.
Understanding more about trees is important for preserving the Earth’s ecosystem. The information also helps to preserve biodiversity, store climate-warming carbon, and promote soil formation and nutrient cycling. Trees hold carbon both while they grow and long after they are harvested; hence, both living and felled trees are an efficient carbon-capture mechanism (provided that a tree is not burned).
The research appears in the journal Proceedings of the National Academy of Sciences, titled “The number of tree species on Earth.”
