Protected areas are working. That’s the conclusion of a new analysis of over 80 different studies on the efficacy of parks and nature reserves in safeguarding wildlife. Published in the open access journal, PLOS ONE, the new study finds that in general protected areas house higher abundances of wildlife as well as greater biodiversity than adjacent areas.
“This positive conservation outcome provides some hard data to show that investing in protected areas for biodiversity conservation is worthwhile,” lead author Bernard Coetzee with Monash University in Australia told mongabay.com.
The research found that on average both the abundance and number of species were higher for mammals, reptiles, amphibians, birds, and arthropods inside protected areas rather than beyond their borders. Findings for plants proved more variable with the researchers reporting a “non-significant” difference between plants inside protected areas and out.
“‘Non-significant’ means that we do not have enough data, or the data is too variable, to say with certainty if there is more, or less, biodiversity conserved inside to outside reserves,” said Coetzee. “It does not mean protected areas are ineffective at conservation—it more likely means that some work better than others.”
Regionally, Coetzee and his team also found that protected areas were largely effective across the board. The only exception was South America, where the team also found a ‘non-significant’ difference.
“This pattern is not straightforward to interpret,” said Coetzee. “One explanation may be hunting pressure. Some studies included in our analysis found higher rates of poaching inside protected areas, which diminishes large mammal populations inside reserves. While primary forest is irreplaceable for conservation, other studies, particularly those done in South America, have shown that land use areas under low extraction, or regenerating forests, can contribute to some degree to conservation—which means that overall the effect of protected areas designation will not be as statistically marked in South America as in other regions.”
However, Coetzee stresses that the findings in South America may also be due to a lower sample size on that continent.
“Other studies with higher sample sizes, across primary forest and not just protected areas like our study, found a much more positive signal for South America. Combined, our results suggest that not transforming primary habitat is the best strategy to conserve biodiversity, and much of that is achieved by designating protected areas.”
Interestingly, the study further found that the protected area location and size appeared to have little to do with its ability to safeguard biodiversity. In addition, socio-economic conditions by country also revealed little impact in the study.
“There is no doubt that in general, larger protected areas benefit biodiversity more than small ones, and also that socio-economic and political factors will ultimately help shape the fate of biodiversity,” said Coetzee, but he added that their results also prove “that biodiversity benefits by protected area establishment itself, as protected areas offset at least some of the pressures to biodiversity.”
Currently protected areas cover nearly 12 percent of the world’s land surface (but less than 3 percent of the oceans). In fact terrestrial protected areas are often viewed as one of the biggest conservation successes on the planet over the last century. Yet many protected areas remain threatened by underfunding and poor management, as well as illegal logging, poaching, mining, the fossil fuel industry, climate change and other impacts.
Worse still, conservationists have recently noted that a number of governments have taken steps to shrink, downgrade, or even abolish entirely some protected areas at the behest of powerful industries.
“We now have hard data that in general protected areas work at biodiversity conservation, but the next step is more action to ensure increased coverage and better safeguards for their long-term maintenance,” said Coetzee.
Citation: Coetzee BWT, Gaston KJ, Chown SL (2014) Local Scale Comparisons of Biodiversity as a Test for Global Protected Area Ecological Performance: A Meta-Analysis. PLoS ONE 9(8): e105824. doi:10.1371/journal.pone.0105824