Protected area, easement, and rental contract data reveal five communities of land protection in the United States.

Land protection efforts represent large societal investments and are critical to biodiversity conservation. Land protection involves a complex mosaic of areas managed by multiple organizations, using a variety of mechanisms to achieve different levels of protection. We develop an approach to synthesize, describe, and map this land protection diversity over large spatial scales. We use cluster analysis to find distinct "communities" of land protection based on the organizations involved, the strictness of land protection, and the protection mechanisms used. We also associate identified land protection communities with socioenvironmental variables. Applying these methods to describe land protection communities in counties across the coterminous United States, we recognize five different land protection communities. Two land protection communities occur in areas with low human population size at higher elevations and include a large amount of protected land primarily under federal management. These two community types are differentiated from one another by the particular federal agencies involved, the relative contributions of smaller actors, and the amount of protection by designations vs. conservation easements or covenants. Three remaining land protection communities have less overall protection. Land in one community is primarily protected by federally managed rental contracts and government managed easements; another is managed by a diversity of non-federal actors through fee-ownership and easements; and the third stands out for having the lowest amount of formally recorded protection overall. High elevation and poor quality soils are over-represented in U.S. protected lands. Rental contracts help fill in gaps in counties with high productivity soil while the U.S. Fish and Wildlife Service fills in gaps in low-elevation counties. Counties with large numbers of threatened species have more and stricter protection, particularly by regional entities like water management districts. The ability to synthesize and map land protection communities can help conservation planners tailor interventions to local contexts, position local agencies to approach collaborations more strategically, and suggest new hypotheses for researchers regarding interactions among different protection mechanisms.