In a first global assessment of the world’s flora, scientists have estimated that there are 390,900 plants known to science.
The new tally is part of a report carried out by the Royal Botanic Gardens, Kew.
Prof Kathy Willis, director of science at RBG Kew, said,
“It’s really important to know how many plant species there are, where they are and the relationship between the groups, because plants are absolutely fundamental to our well-being.
“They provide us with our food, our fuel, our medicines – even controlling our climate.”
The study also noted that 2,034 new plant species were discovered last year. Last year’s discoveries include a tree called Gilbertiodendron maximum, found in the forests of Gabon in West Africa.
The scientists estimated that with the exclusion of algae, mosses, liverworts and hornworts, there are 390,900 plants, of which around 369,400 are flowering.
“This is just scratching the surface. There are thousands out there that we don’t know about,” said Prof Willis.
Risk Of Extinction For 21% Plants
The report has also warned that 21% of plants were at a risk of extinction. The threats to these endangered plant species include climate change, habitat loss, disease and invasive species.
The researchers said habitat changes and the loss of mangroves and forests have a detrimental effect on many species.
The scientists also studied movement of plant species around the world.
“Invasive species are really one the biggest challenges for native biodiversity,” said Dr Colin Clubbe, head of conservation science at Kew.
“They are a real driver of species loss.”
The report said that the global cost of invasive species is estimated at nearly 5% of the world’s economy. The conservationists have recorded a number of 4,979 invasive species around the world.
“Now that we’ve got this list and this number, it’s certainly a bit like know your enemy,” said Dr Clubbe.
“We know what we are dealing with, we can then look at them, and see what’s similar, what makes a good invasive, and then see how we can use that information to have better management practices in place or recommendations for how you deal with them.”
The report also found that more than 10% of the parts of the Earth covered with vegetation are highly sensitive to climate change. Prof Wallis said,
“There are some areas where the increase in atmospheric carbon dioxide is good for some plants, so we have the greening of the Arctic, some areas of savannah are also getting shrubbier and some trees are getting bigger.
“However, we are also seeing big changes in terms of distribution patterns and flowering of plants. And also the indirect impact of climate change – for example, changes in terms of pollinators – which could have a really serious effect on plants.”
Global Assessment Of Plants
Kew’s global assessment will now be carried out every year, which will allow scientists to monitor how plants are changing over time.
To compute the total, the researchers searched through existing databases.
During the study, the researchers found a lot of overlapping, with some plants being given different names by different botanists at different times.
Botanists from China, Australia and Brazil are most likely to find and name new plants.