Last updated April 23, 2020 at 11:15 am
To preserve biodiversity, a new report suggests conservation efforts should focus on both large wild habitats and human-dominated ones.
Why This Matters: We’ve got the instructions, now we need to use them.
With the planet’s biodiversity crisis putting hundreds of thousands of species at risk of extinction, conservationists aren’t sure whether to focus efforts and resources on protecting large wild habitats, or those that are fragmented and degraded.
An analysis published in the journal Proceedings of the National Academy of Sciences now reveals that both are important, identifying valuable habitats in untouched and human-dominated environments. And rather than focussing on one strategy, we should be recognising the value of both.
“The world is facing a biodiversity crisis, with up to half a million species under imminent threat of extinction over coming decades,” says James Watson from the University of Queensland, who oversaw the analysis.
“Rather than trying to extol the virtues of either strategy, we’re getting down to business and finding exactly which parts we need to protect now.”
Without habitats, species go extinct
Habitats are key to saving species, says Karel Mokany from CSIRO, who led the work.
“Averting this extinction crisis requires us to retain and protect high-value habitats for biodiversity,” he explains. “Habitat is where species live – without habitat, species go extinct.”
Humans have left a hefty footprint on the planet, dominating more than half the world’s land area with cities, intensive agriculture, population density, roads and other means of transport, along with hunting and invasive species introduction.
“One strategy suggests proactively retaining large contiguous areas with the least human impact – such as wilderness areas like the vast savannahs of northern Australia and the Brazilian Amazon,” says Watson.
“The other strategy argues we should focus on areas of remnant habitat in highly modified regions where farms and mines dominate, like the last remaining unique woodland remnants in the Australian wheatbelt.”
Why not both?
To identify high-value biodiversity habitats around the globe, Mokany’s team collaborated with the Wildlife Conservation Society to harness recent advances in large data streams, computing, biodiversity modelling and assessment.
This includes a newly developed global biodiversity assessment system called BILBI.
“We combined global datasets on habitat condition and spatial biodiversity patterns to identify the value of habitat for retaining biodiversity,” Mokany says, “for every location on the land surface of the Earth.”
They define high-value habitats as “locations which are in better condition than more than half of the areas expected to have supported a similar assemblage of species, and, hence, they cover approximately half the land surface of the planet”.
This essentially means habitats that are in the best condition to sustain the greatest diversity of species, which naturally live in different environments.
The uniquely broad analysis included data for more than 400,000 species of plants, vertebrates and arthropods.
It confirmed that large untouched areas are important for biodiversity conservation, while partly damaged, fragmented environments are also critical for sustaining species that have lost large chunks of their homes.
“While not obvious at the global scale,” the authors write, “most heavily impacted regions contain very small areas of high-value habitat that is important for biodiversity conservation.”
“Some places in good condition support suites of species that have suffered habitat loss/degradation across most of their range,” Mokany explains.
An example is tropical forests of southeast Asia, which have endured considerable degradation but still retain unique biodiversity that can be preserved.
Targets need to take the best of both habitat approaches
Having identified the most valuable habitats, the team found that only 18.6% are protected globally. Channelling efforts to the regions identified would help meet international biodiversity goals.
The finding is timely as the world’s nations gear up to adopt a new post-2020 biodiversity framework under the Convention on Biological Diversity, with the goal of “Living in harmony with nature” by 2050.
“It’s really important that these targets are well formulated and informed by the best available science,” says Mokany, to provide guidance “on which areas are critical to retain and protect if we are to avert the current species extinction crisis”.