Nav: Home

Global levels of biodiversity could be lower than we think, new study warns

December 02, 2019

Biodiversity across the globe could be in a worse state than previously thought as current biodiversity assessments fail to take into account the long-lasting impact of abrupt land changes, a new study has warned.

The study by PhD graduate Dr Martin Jung, Senior Lecturer in Geography Dr Pedram Rowhani and Professor of Conservation Science Jörn Scharlemann, all at the University of Sussex, shows that fewer species and fewer individuals are observed at sites that have been disturbed by an abrupt land change in past decades.

The authors warn that areas subjected to deforestation or intensification of agriculture can take at least ten years to recover, with reductions in species richness and abundance.

With current biodiversity assessments failing to take into account the impacts of past land changes, the researchers believe that the natural world could be in a far worse state than currently thought.

Lead author, Dr Martin Jung said: "These findings show that recent abrupt land changes, like deforestation or intensification through agriculture, can cause even more impactful and long-lasting damage to biodiversity than previously thought.

"Our study shows that it can take at least ten or more years for areas which have undergone recent abrupt land changes to recover to levels comparable to undisturbed sites. This only strengthens the argument to limit the impacts of land change on biodiversity with immediate haste."

The study combined global data on biodiversity from the PREDICTS database, one of the largest databases of terrestrial plants, fungi and animals across the world, with quantitative estimates of abrupt land change detected using images from NASA's Landsat satellites from 1982 to 2015.

Comparing numbers of plants, fungi and animals at 5,563 disturbed sites with those at 10,102 undisturbed sites across the world from Africa to Asia, the researchers found that biodiversity remains affected by a land change event for several years after it has occurred, due to a lag effect.

Species richness and abundance were found to be 4.2% and 2% lower, respectively, at sites where an abrupt land change had occurred.

In addition, the impacts on species were found to be greater if land changes had occurred more recently, and caused greater changes in vegetation cover. At sites that had land changes in the last five years, there were around 6.6% fewer species observed.

However, at sites where a land change had taken place 10 or more years ago, species richness and abundance were indistinguishable from sites without a past land change in the same period, indicating that biodiversity can recover after such disturbances.

Dr Jung explained: "For us, the results clearly indicate that regional and global biodiversity assessments need to consider looking back at the past in order to have more accurate results in the present.

"We've shown that remotely-sensed satellite data can assist in doing this in a robust way globally. Our framework can also be applied to habitat restoration and conservation prioritization assessments."

Prof Jörn Scharlemann added: "Although the number of species and individuals appear to recover more than 10 years after a land change, we will still need to find out whether the original unique species recover or whether common widespread species, such as weeds, pigeons and rats, move into these disturbed areas."
-end-


University of Sussex

Related Biodiversity Articles:

About the distribution of biodiversity on our planet
Large open-water fish predators such as tunas or sharks hunt for prey more intensively in the temperate zone than near the equator.
Bargain-hunting for biodiversity
The best bargains for conserving some of the world's most vulnerable salamanders and other vertebrate species can be found in Central Texas and the Appalachians, according to new conservation tools developed at the National Institute for Mathematical and Biological Synthesis (NIMBioS) at the University of Tennessee, Knoxville.
Researchers solve old biodiversity mystery
The underlying cause for why some regions are home to an extremely large number of animal species may be found in the evolutionary adaptations of species, and how they limit their dispersion to specific natural habitats.
Biodiversity offsetting is contentious -- here's an alternative
A new approach to compensate for the impact of development may be an effective alternative to biodiversity offsetting -- and help nations achieve international biodiversity targets.
Biodiversity yields financial returns
Farmers could increase their revenues by increasing biodiversity on their land.
Biodiversity and wind energy
The location and operation of wind energy plants are often in direct conflict with the legal protection of endangered species.
Mapping global biodiversity change
A new study, published in Science, which focuses on mapping biodiversity change in marine and land ecosystems shows that loss of biodiversity is most prevalent in the tropic, with changes in marine ecosystems outpacing those on land.
What if we paid countries to protect biodiversity?
Researchers from Sweden, Germany, Brazil and the USA have developed a financial mechanism to support the protection of the world's natural heritage.
Grassland biodiversity is blowing in the wind
Temperate grasslands are the most endangered but least protected ecosystems on Earth.
The loss of biodiversity comes at a price
A University of Cordoba research team ran the numbers on the impact of forest fires on emblematic species using the fires in Spain's Doñana National Park and Segura mountains in 2017 as examples
More Biodiversity News and Biodiversity Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.