|Previous studies reported that our planet is currently suffering the worst spate of species die-offs since the extinction of the dinosaurs about 65 million years ago / Photo by: hurricanehank via Shutterstock|
Earth is now in the midst of its sixth mass extinction of plants and animals, whether we like it or not. Previous studies reported that our planet is currently suffering the worst spate of species die-offs since the extinction of the dinosaurs about 65 million years ago. Experts have estimated that we are losing species at up to 1,000 times the “background” rate of about one to five species every year.
One of the most affected is the plant species. A recent study published in the journal Nature Ecology and Evolution revealed that since 1750, over 571 plant species have been wiped out. This figure is almost four times compared to the previously known estimate of around 150 plant species officially recognized as extinct in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. The researchers also found out that the number is more than twice the combined number of birds, mammals, and amphibians that have gone extinct.
“It is way more than we knew and way more than [what] should have gone extinct. It is frightening not just because of the 571 number but because I think that is a gross underestimate,” Dr. Maria Vorontsova, a Russian pediatric endocrinologist, said.
According to The Guardian, a British daily newspaper, the study also discovered that there are thousands of “living dead” plant species across the world. These species have no chance of reproducing for several reasons. For instance, the big animals needed to spread their seeds are already extinct or only one sex remains. Aside from that, botanists found some plant species that may have gone extinct before ever being discovered. They usually find about 2,000 new species every year.
The researchers reported that most instances of extinction of plant species are recorded in Hawaii (79), followed by the Cape provinces of South Africa (37), with Australia, Brazil, India, and Madagascar also among the top regions. Alan Gray, a researcher from the UK’s Center for Ecology and Hydrology, stated that the numbers presented in the study are large underestimates only because scientists haven’t yet studied the vast majority of the world’s plants in any detail.
Rare Plant Species Are Vulnerable to Climate Change
The destruction of natural habitats by human activities is the main cause of plant species extinction. These include converting the land into fields for farming and cutting down forests. While there has been an increasing awareness for our plant species, Vorontsova believed that we are suffering from plant blindness. “Animals are cute, important, and diverse, but I am absolutely shocked by how a similar level of awareness and interest is missing for plants. We take them for granted and I don’t think we should,” she said.
A recent study conducted by researchers from the University of Arizona revealed that nearly 40% of global land plant species are categorized as “exceedingly rare,” and these species are most at risk of extinction due to climate crisis. According to Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, 35 researchers from different institutions across the world have worked for a decade to compile 20 million observational records of the world’s land plants. The largest dataset on botanical biodiversity ever created is the result of this, which aims to help reduce the loss of global biodiversity.
Out of 435 unique land plant species on Earth 36.5% have only been observed and recorded less than five times ever, the researchers found. "According to ecological and evolutionary theory, we'd expect many species to be rare, but the actual observed number we found was actually pretty startling. There are many more rare species than we expected,” lead author Brian Enquist, University of Arizona professor of ecology and evolutionary biology, said.
Also, these rare species are found in regions that have remained climatologically stable as the world emerged from the last ice age. This allowed them to persist. These regions include the Northern Andes in South America, Costa Rica, South Africa, Madagascar, and Southeast Asia. However, this doesn’t mean that they are safe from the climate crisis. The researchers discovered that these very rare-species hotspots are predicted to suffer a disproportionately high rate of future climatic changes and human disruption.
"We learned that in many of these regions, there's increasing human activity such as agriculture, cities and towns, land use, and clearing. So that's not exactly the best of news. If nothing is done, this all indicates that there will be a significant reduction in diversity—mainly in rare species—because their low numbers make them more prone to extinction," Enquist said.
Disrupting Local Plant Diversity
While reports show that the total number of plant species on Earth may be in decline, researchers discovered that the average number of plant species found locally seems stable. Some are even increasing.
A recent study conducted by researchers from the University of York revealed that the “disruption” of these local plant communities may be allowing new species to grow as well as increasing local diversity. Dr. Andrew Suggitt, the lead author from the University of York's Department of Biology, stated that they tested the influence of climate change alongside other well-known drivers of diversity change using a large dataset of more than 200 studies of plant species.
The models discovered that there’s a 5% increase of local species per decade in cooler regions of the world. However, this doesn’t disregard the fact that many more plant species are endangered or extinct. "… it also highlighted the sore need for greater clarity over how climate change is shuffling the deck of plant species found in particular locations—especially in under-sampled areas such as the tropics, Africa, and Asia,” Suggitt said.
We should be worried about the alarming extinction rates of plant and animal species. If this trend continues, there’s a great possibility that humans will feel the full force of this ecological disruption.
|While reports show that the total number of plant species on Earth may be in decline, researchers discovered that the average number of plant species found locally seems stable. Some are even increasing / Photo by: Fotografiecor.nl via Shutterstock|