Adena R. Rissman and Adina M. Merenlender. University of California, Berkeley
The conservation easement has recently become one of the most commonly used tools to conserve biodiversity on private land, yet little is known about what is actually being protected at the site or landscape scale. We analyzed a spatial database of conservation easement properties in California that includes dozens of government and land trust easement holders. To understand site-level land use, we asked what types of restrictions are contained in conservation easements to protect and restore biodiversity and ecosystem processes in California oak woodlands and grasslands. At the landscape scale, we analyzed conservation easement size, habitat type, regional connectivity, and the level of surrounding development pressure. We found that the specificity of easement restrictions increased over time and that there was significant variability in easement terms related to land use restrictions and mechanisms for management and restoration. Surrounding development threat, regional sociopolitical differences, and institutions (e.g. land trusts) also affected the location and level of development on easement properties. The majority of conservation easements are established on relatively small properties; but these sites do often serve as buffers for other protected areas and are found on more productive land at lower elevations as compared to public lands. Understanding the promise as well as the limits of conservation easements is critical for assessing and refining their ability to maintain and restore natural systems.