Plant extinction - a worrying fact

Scientists say that worldwide plant extinction is occurring far faster than would be expected naturally. With almost 600 plant species lost from the wild in the last 250 years, the number is twice that of all bird, mammal and amphibian extinctions combined. That's at a rate of nearly 3 species a year since 1900.
In May, a UN report estimated that one million animal and plant species were threatened with extinction. "Whereas most people can name a mammal or bird that has become extinct in recent centuries, only a few could name an extinct plant," said Dr Aelys Humphreys of Stockholm University.  "This study is the first time we have an overview of what plants have already become extinct, where they have disappeared from and how quickly this is happening."
Data collated at the Royal Botanic Gardens, Kew and Stockholm University suggests plant extinction is happening as much as 500 times faster than would be expected normally, due to the impact of human life. As botanist Dr Jurriaan de Vos, a phylogeneticist at the University of Basel, says about plant hunting, “You're looking for a rainforest species, but you’re standing in a city. Then you realize just how massive the scale of destruction or land-use change has been over the past 50 or 80 or 100 years.”
The researchers believe even these numbers underestimate the true levels of ongoing plant extinction. The lost plants include the Chile sandalwood, which was exploited for essential oils; the banded trinity plant, which spent much of its life underground; and the pink-flowered St Helena olive tree. The biggest losses are on islands and in the tropics, which are home to highly valued timber trees and tend to be particularly rich in plant diversity. However, there is evidence that some plants once thought extinct have been rediscovered, such as the Chilean crocus.
Why does plant extinction matter?
Plant extinctions can lead to a whole cascade of extinctions in other organisms that rely on them, for instance insects that use plants for food and for laying their eggs. All life on Earth depends on plants: they provide the oxygen we breathe,the food we eat, plus fabric and construction materials.  They are an integral part of our ecosystem functionality - such as carbon fixation and oxygen creation.  They even underpin human mental health, through enjoying green spaces.
The research is published in the journal, Nature Ecology and Evolution.
Photo credit: Rebecca Cairns-Wicks, Kew Temperate House
Tuesday, 11 June 2019