ALERT welcomes to its ranks Jeremy Hance, an accomplished environmental journalist. ALERT is growing rapidly -- now reaching around 100,000 people worldwide each week -- and Jeremy will be making periodic contributions to help us cover highly topical conservation news and research findings. Here, Jeremy tells us about an important new study that highlights the vital role of protected areas for conserving biodiversity.
In a world of rising human population and increasing demand for natural resources, it’s challenging to make the case for designating more protected areas or for supporting more rigorous protection of such areas if we can’t prove that parks are actually working to protect wildlife and other species.
This is why a recent study in Nature Communications, led by Claudia Gray from the University of Sussex, UK, is so important. It gives conservationists a new weapon in their arsenal -- by finding that nature really is doing better inside parks than outside.
Gray and her colleagues found that sites inside protected areas had 11 percent more species than did unprotected sites. Moreover, parks had 15 percent more individuals than did areas outside the parks.
Parks Protect Life
At first blush, the findings don't seem all that surprising. Conservationists have long believed that parks are important for harboring biodiversity, and a few earlier studies have come to similar conclusions.
But the research of Gray and her colleagues stands apart for its remarkably breadth and rigor.
Using a database called PREDICTS, Gray and her team were able to look at surveys of 13,699 species of vertebrates (amphibians, reptiles, birds, and mammals) as well as invertebrates (insects, spiders, and the like) and plant species.
The scope of their study was massive: they examined species trends across 1,939 sites inside 359 different protected areas. They compared these findings with species data from a staggering 4,592 sites outside of protected areas.
The study by Gray and colleagues is utilizing big data at its best.
PREDICTS -- which stands for Projecting Responses of Ecological Diversity In Changing Terrestrial Systems -- collects data from published research as well as scientists working on the ground, to assess how biodiversity is changing at local levels.
The Gray study also controlled for various factors that might influence local biodiversity, such as the elevation, slope, and agriculture suitability of each site.
Digging deeper, Gray and her team found that there was little difference between protected and unprotected areas in little-impacted primary or secondary forests -- meaning that so long as an area remains left alone by humans it retains much of its biodiversity.
But protected areas set aside in agricultural or plantation regions had significantly higher biodiversity than did the surrounding countryside, especially in the tropics.
However, Gray and her team found that protected areas don’t do everything.
For example, parks didn’t show increased ecological niches for biodiversity. Rather, their greater biodiversity simply arose because they maintain larger populations of species.
Parks also did not harbor many more endemic species than did unprotected areas -- something that surprised the researchers.
But overall, parks still did a lot better than human-dominated lands when it comes to protecting nature.
More Parks or Better Parks?
Currently, around 15 percent of Earth's land area is set aside as protected areas. But the Convention on Biological Diversity has pledged to raise this figure to 17 percent by 2020.
However, Gray and her colleagues argue that simply increasing the number and extent of parks may not be the best way forward.
Instead, they suggest, it may be better to increase protection of already-established parks -- though they hasten to add that more data are needed before confident recommendations can be made.
Whatever the way forward, the study by Gray and her colleagues means it will be just a little bit easier to justify protected areas than it was before.
They're not perfect, but by and large, parks are working much better than unprotected areas to conserve Earth's imperiled biodiversity.