Plant Extinctions Grossly Underestimated

“Extinction of seed plants is occurring at a faster rate than the normal turnover of species.” This is one of the salient points raised by a study published in June of this year in the Nature, Ecology & Evolution journal called ‘Global dataset show geography and life form predict modern plant extinction and rediscovery’.

This study is a first of its kind and presents a comprehensive global analysis of modern extinction in seed plants. The term plants includes wooded plants (trees). The study concludes that 571 species have become extinct since 1750 at rates that are 500 times higher than the pre-industrial revolution rate. These extinct plant species come from a quarter of seed plant families.

Although about the same number have been rediscovered after having been declared extinct, 89% of these rediscovered species are at a high extinction risk with several of them already functionally extinct as the surviving populations are not viable and are doomed to extinction. Extinction reports coming from islands, such as Mediterranean islands, from the tropics or of shrubs, trees or species with narrow ranges are not likely to be rediscovered once declared extinct.

“Plants underpin all life on Earth,” said Dr Eimear Nic Lughadha of the Royal botanic Gardens, Kew, England, further emphasising that “They provide the oxygen we breathe and the food we eat, as well as making up the backbone of the world’s ecosystems – so plant extinction is bad news for all species.” The number of extinct plant species in this report is four times more than the number of extinct plant species listed in the International Union for Conservation of Nature’s red list (IUCN).

Dr Maria Vorontova, one of the authors of the report, said “It is way more than we knew and way more than should have gone extinct. It is frightening not just because of the 571 number but because I think that it is a gross underestimate.” She explains that she is of this opinion as there are thousands of plant species where the last survivors have no means of reproducing as there is only one sex left alive or the big animals needed to spread their seeds are extinct. The main cause for extinction is the destruction of forests and clearing of land for agriculture. The conclusions in this study is the result of years of researching scientific journals and fieldwork worldwide.

This study was peer reviewed. Ecologist Bjorn Robroek from the Southampton University said “The finding that extinction rates are highest in biodiversity hotspots that are at risk due to land-use change is alarming”. Alan Gray, of the UK’s Centre for Ecology and Hydrology said “Scientists have not studied the vast majority of the world’s plants in any detail, so the authors are right to think that the numbers they have produced are large underestimates. To address this extinction crisis, humanity will need to devise solutions that target funding towards conservation research and action. It is time to ask not what biodiversity can do for us but what we can do for biodiversity.”

The report makes the point that any proper understanding of the current extinction crisis involving all species must include plants. Species on Earth exist in a symbiotic relationship. Extinction causes go across biological kingdoms. Plant extinctions cause insect extinctions that in turn cause amphibian and bird extinctions. The latter then also feed into the extinction rates of mammals.

The report concludes that geography and life form best predict current extinction of plants. In layman’s terms what this means is that firstly plants are at a much greater risk of extinction in areas where humans have substantially destroyed or disturbed their natural habitats. Secondly the biological make-up of plants and their relationship with their environment will dictate their resilience and survival in the face of the onslaught from humanity.

There are numerous people of around the globe endeavouring to stop the acceleration of plant and tree extinctions. The most obvious actions are stopping deforestation and rewilding large tracts of land into new forests.

The New York Declaration of Forests (NYDF) is one of these initiatives. The NYDF is a partnership of more than 190 entities including governments, multinational companies and civil society and indigenous peoples who strive to half deforestation by 2020 and to end it by 2030. The NYDF outlines ten ambitious global targets related to protecting and restoring forests, which, if realised, have the potential to reduce annual carbon emissions by 4.5 to 8.8 billion tonnes of CO2 – equivalent to the annual emissions of the United States.

The Bonn Challenge is a global effort to bring 150 million hectares of the world’s deforested and degraded land into restoration by 2020, and 350 million hectares by 2030. It was launched in 2011 by the Government of Germany and International Union for the Conservation of Nature (IUCN), and later endorsed and extended by the New York Declaration on Forests at the 2014 UN Climate Summit. The Bonn Challenge is not a new global commitment but rather a practical means of implementing many existing international commitments.

The African Forest Landscape Restoration Initiative (AFR100) is a country-led effort to bring 100 million hectares of land in Africa into restoration by 2030. It aims to accelerate restoration to enhance food security, increase climate change resilience and mitigation, and combat rural poverty. AFR100 is a partnership of more than 20 African governments.

Ultimately the questions are: Will governments deliver on their promises? Are multinationals just green washing? The 350 million hectares target is anyway still only a third of the 1 billion hectares that the UN International Panel on Climate Changes has gone on record to state is necessary to be reforested globally in order to seriously mitigate the effects of global warming.

We have a long way to go as the majority of the world population and the vast majority of politicians globally are still not taking this climate and extinction crisis seriously. We need to react to what scientists are telling us and act now. Stopping all deforestation and rewilding the available land into forests is achievable and is a long term solution that will not only mitigate the effect of climate change for us and all future generations, but also go a long way to stunt the progress of the sixth mass extinction of species.

The danger that we are all facing cannot be overstated as we sleepwalk towards the end of life on earth as we know it. It is unprecedented in the entire 450 million years of life on Earth that one species (people) is systematically annihilating all other species, be they plants or animals. Humanity is singlehandedly causing a mass extinction of life – humans will also die in unprecedented numbers. The last time this happened was 66 million years ago and was caused by a meteor hitting the planet. That time 76% of all life on Earth died – the chances that modern humans are biologically equipped to survive a mass extinction event are very low indeed. You also should ask yourself whether you would actually want to survive to live in a post mass extinction world. Think about it.

Main Source: Nature, Ecology & Evolution journal July 2019 – ‘Global dataset show geography and life form predict modern plant extinction and rediscovery’. Authors: Aelys M. Humphreys, Rafael Govaerts, Sarah Z. Ficinski, Eimear Nic Lughadha and Maria S. Vorontsova.