According to a recent research comprising more than 100 experts from across the world and the world’s biggest forest database, there are around 73,000 tree species on Earth, with roughly 9,200 species still to be identified.
The worldwide estimate is around 14% larger than the number of tree species currently recognized. According to the research, the majority of the unknown species are expected to be uncommon, with small populations and restricted geographic range.
According to the research authors, this renders the unknown species particularly sensitive to human-caused disturbances like as deforestation and climate change, and the new discoveries will assist prioritize forest conservation efforts.
“These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes, particularly land use and climate, because rare taxa are disproportionately threatened by these pressures,” said Peter Reich, a forest ecologist at the University of Michigan and one of two senior authors of a paper set to be published in Proceedings of the National Academy of Sciences on Jan. 31.
“By establishing a quantitative benchmark, this study could contribute to tree and forest conservation efforts as well as the future discovery of new trees and associated species in certain parts of the world,” Reich, director of U-School M’s for Environment and Sustainability’s Institute for Global Change Biology, said.
The researchers integrated tree abundance and occurrence data from two worldwide databases that employ ground-sourced forest-plot data, one from the Global Forest Biodiversity Initiative and the other from TREECHANGE. A total of 64,100 recorded tree species were detected in the combined databases, which is close to a previous research that revealed roughly 60,000 tree species on the globe.
“We integrated separate datasets into one enormous worldwide collection of tree-level data,” Jingjing Liang of Purdue University, the study’s other senior author and coordinator of the Global Forest Biodiversity Initiative, stated.
“Each set is the result of someone visiting a forest stand and measuring every single tree, gathering data on the species, sizes, and other features of the trees. Counting the number of tree species throughout the planet is like putting together a jigsaw with parts all over the place.”
The researchers employed innovative statistical approaches to estimate the total number of distinct tree species at biome, continental, and global sizes after integrating the information, including species that have yet to be identified and documented by experts. A biome, such as a tropical rainforest, a boreal forest, or a savanna, is a significant biological community type.
According to the researchers, their conservative estimate of the total number of tree species on Earth is 73,274, implying that about 9,200 tree species have yet to be discovered. Their new study uses a much larger dataset and more advanced statistical methods than previous attempts to estimate the planet’s tree diversity. According to Reich, the researchers employed current versions of methods used by mathematician Alan Turing during WWII to decipher Nazi coding.
South America, which is noted many times in the report as having unique relevance for world tree diversity, is anticipated to include over 40% of the unknown tree species, more than any other continent.
South America also has the largest estimated number of uncommon tree species (about 8,200) and the highest estimated proportion (49%) of continentally endemic tree species (species that are only found on that continent).
The Amazon basin’s tropical and subtropical wet forests, as well as Andean forests at altitudes between 1,000 meters and 3,500 meters, are possible hotspots for unknown South American tree species (about 11,480 feet).
“There might be another 4,000 tree species still to be found in South America, in addition to the 27,000 known tree species. The majority of them might be unique to the Amazon basin and the Andes-Amazon interface, and they’d be found in biodiversity hotspots “Reich, who was recruited by U-Biosciences M’s Initiative and joined the faculty last fall after a dual appointment at the University of Minnesota, said.
“With the present tropical forest problem caused by human influences such as deforestation, fires, and climate change, forest conservation becomes a top concern in South America,” he stated.
Tropical and subtropical wet forests, which are both species-rich and little investigated by scientists, are home to around half to two-thirds of all known tree species worldwide. Undiscovered tree species are expected to be abundant in tropical and subtropical dry forests.
“A thorough understanding of tree richness and diversity is critical for maintaining ecosystem stability and function,” said research lead author Roberto Cazzolla Gatti of the University of Bologna in Italy.
Many “ecosystem services” are provided to humans for free by forests. Forests clean the air, filter the water, and assist manage erosion and floods, in addition to providing timber, fuelwood, fiber, and other items. They assist to protect biodiversity, store climate-warming carbon, and support soil formation and nutrient cycling while also providing recreational possibilities like hiking, camping, fishing, and hunting.