Page 174 - Mapping the Nation: Taking Climate Action

Applying Science and Mapping to Safeguard Species: Half-Earth Project Maybe you've dreamed of catching a glimpse of the ivory- billed woodpecker in a southern swamp. Now the best you can do is watch a video, because in September 2021 scientists at the US Fish and Wildlife Service declared this and 22 more species extinct. The cause of habitat degradation and destruction has raised fresh cries to set aside more land and ocean for nature. Decades ago, Robert MacArthur and E. O. Wilson pioneered a theory to assess how larger conserved land areas support the survival of more species. Their original theory, developed in the 1960s, was born of research on island biogeography with the observation that larger islands contain more species, but it has since been applied more broadly to species preservation. "The theory addresses biogeographical dynamics," said Walter Jetz, professor and director of the Yale Center for Biodiversity and Global Change. "Larger habitat fragments and those closest to other undisturbed forest habitats hold more species, and as humans encroach and create smaller patches that are less connected, you rapidly lose species diversity." Wilson articulated the theory in his 2016 book Half-Earth, Our Planet's Fight for Life, in which he proposed, "Only by committing half of the planet's surface to nature can we 173