A paper currently undergoing peer review aims to cut through current debates on how best to do area-based biodiversity conservation in light of the increased global attention on national biodiversity targets and investments and the emergence of nature-based credit markets.
Academics from Vrije Universiteit Amsterdam, Michigan State University, Carleton University, and Imperial College London have proposed three principles they see as “unequivocal” on how best to protect and restore biodiversity.
The three principles proposed are:
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- Protect habitats in every biome and ecoregion
- Protect as much habitat as possible, including smaller and larger patches
- Protect habitat to facilitate connectivity
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“Despite the different schools of thought in this field, there is no debate about the need to conserve habitat, the effects for biodiversity of increasing native habitat area are overwhelmingly positive,” the paper said.
“Ongoing debates should not distract from the areas of consensus reached after decades of research in biodiversity conservation.”
The paper’s authors contended that the outlined principles represent the scientific consensus. Current academic debates are not necessarily helpful to policymakers and land managers who are looking for clarity as the world looks to implement its 30×30 targets as part of the Kunming Montreal Global Biodiversity Framework.
One such debate within the scientific community is the SLOSS question: should conservation prioritise “a single large or several small” habitat patches? This debate has evolved over recent years from the assumption that the fragmentation of habitats is bad for species diversity to more recent literature that questions whether may have a positive effect on species, according to the authors.
These issues inevitably vary by historical and biogeographical context, and small losses in habitat can have a cumulative effect, even if obvious large-scale market forces are not driving habitat loss.
The authors referenced the case of Southern Ontario, Canada, where only 15% of native habitat remains and nearly all the wetland habitat loss has occurred in areas less than 2 hectares in size, the threshold for environmental regulation under local rules. This contrasts with the large-scale persistent case of vast areas of land that have been deforested in the Amazon, which could reach an ecological tipping point if one-fifth of its area is lost.
“Biodiversity conservation is destined to fail unless the rights and needs of people enter the equation,” said the paper, outlining another topical debate.
“While the necessity to protect native habitat is undeniable, the provision of food, water, shelter, and energy to humans often implies the sacrifice of large areas of native habitat.”
Agricultural production often appears at odds with large-scale area-based conservation but the authors explained that natural habitats have played a key role in sustaining crucial agricultural services, such as nutrient retention in the Midwestern US. Similarly, small tropical forest plots in oil plantations need not compromise productive yield.
The authors concluded that to achieve the 30×30 targets, policymakers can work with the principles first and look to address the specific debates second. While large wilderness areas require protection, restoring and protecting small habitat areas where human activities dominate may represent the greatest potential net gains in achieving national targets.
By Tom Woolnough – tom@carbon-pulse.com
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