Protecting many small patches will maximize biodiversity conservation
for most taxa: the SS > SL principle
Abstract
The principle that a single large patch has higher value for
biodiversity than several small patches of the same total area (SL
> SS) is widely applied in conservation. We show this
principle is incorrect, and that biodiversity conservation requires
placing more emphasis on protection of large numbers of small patches
(SS > SL). Analyzing 76 metacommunities (4401 species, 1190
patches) we demonstrate that, at equal habitat area, species richness
accumulates more rapidly in large numbers of small patches twice as
often as in few large patches (45.2% vs 19.9% of cases). This pattern
is clear for plants, birds, mammals, and invertebrates, but reversed for
herptiles. We therefore propose a new principle: for a given area,
protecting the largest possible number of patches will maximize
biodiversity for most taxa. Our findings indicate large untapped
potential for biodiversity conservation worldwide, highlighting the need
for a paradigm shift in conservation policy.