Environmental resource management

Biogeography

Insular biogeography

Neglect

Biodiversity conservation

Species richness

Biology

Biodiversity

Nursing

Habitat

Geography

Ecology

Habitat conservation

Argument (complex analysis)

Conservation biology

Environmental science

Biochemistry

Habitat destruction

Medicine

Proceedings of the National Academy of Sciences

Island biogeography theory posits that species richness increases with island size and decreases with isolation. This logic underpins much conservation policy and regulation, with preference given to conserving large, highly connected areas, and relative ambivalence shown toward protecting small, isolated habitat patches. We undertook a global synthesis of the relationship between the conservation value of habitat patches and their size and isolation, based on 31 systematic conservation planning studies across four continents. We found that small, isolated patches are inordinately important for biodiversity conservation. Our results provide a powerful argument for redressing the neglect of small, isolated habitat patches, for urgently prioritizing their restoration, and for avoiding simplistic application of island biogeography theory in conservation decisions.

Global synthesis of conservation studies reveals the importance of small habitat patches for biodiversity