An economic downturn and a lack of interest in biodiversity in general have caused some people to question whether the global biosphere is going to survive the climate change and pollution that is making the planet increasingly unlivable.
The environmental definition of biodiversity is “the combination of biological diversity and environmental stability,” said David MacPherson, a professor of geosciences at Stanford University.
“We can have a global biodiversity index, and it’s very useful for understanding what’s happening in a particular ecosystem.”
But he also said that the number of organisms in a given ecosystem “is really, really, very small.”
A 2013 study of more than 200 biomes published in the journal Science by ecologists from several institutions found that the total number of species in the Earth’s ecosystems is roughly 1,400, but “they’re probably just a fraction of that.”
“So the next step is to figure out how many of these species are still there, and then how much are still in danger,” said MacPhersons co-author, Jennifer Francis, an assistant professor of earth systems science at Rutgers University.
Francis said that “it’s still a pretty small number of the world’s biodiversity.”
For example, just 7% of the species in a pond, pond pond life forms, are found in the United States, according to the National Oceanic and Atmospheric Administration.
That’s not because of lack of awareness or interest in the oceans, Francis said, but because scientists are focused on identifying the organisms that are important to human well-being, including marine invertebrates.
“It’s not that people aren’t interested in the ocean, it’s that they’re not interested in finding and documenting those creatures that are going to be important to humans,” she said.
Francises study showed that the diversity of the ecosystems in which those species exist is only 1.4% of their actual number, while species that have not been counted are in the “low-medium” range, which is a “little bit below” the 1,000-species range that is considered the “normal” level of biodiversity.
That doesn’t mean that all organisms are in danger.
In the United Kingdom, for example, there are about 15,000 species of freshwater fishes, which include sharks, turtles and rays, but only about 400 species of amphibians and fish.
MacPhersson said that, even in the case of a severe climate change, the “biggest impact on biodiversity is likely to be from people that don’t care about it.
They’re going to miss the opportunity to make a difference.””
You’re not going to see the animals that are in trouble,” he said.
MacPsons study also looked at how the distribution of species is changing, and found that most species are disappearing faster than they were once.
It also found that “species are going through different stages of extinction, from relatively stable to rapidly declining,” he explained.
“I think it’s pretty clear that it’s not going anywhere fast,” he added.
Franciscans research team also found “a very high concentration of species with low reproductive rates,” which means that species are more likely to disappear “at a higher rate than previously thought.”
“We really don’t know how much species are being lost,” Francis said.
“What we know is that biodiversity is declining in many of the countries we’re studying.”
Francis noted that the species that are not endangered or endangered at all are likely to have been wiped out by human activities.
“They’re the species you can’t just replace, because they’re the ones you can do the most damage,” she added.
“And there are other species that, when you look at the distribution, are declining even faster.”
Francisco’s research team is looking at the impact of climate change on ecosystems, and the role that climate change plays in reducing biodiversity.
Francisco and MacPhesons research was funded by the National Science Foundation and the National Geographic Society.
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