Despite the widespread use of conservation easements, their conservation outcomes are relatively unknown. (1) Evaluating conservation easement effectiveness requires interdisciplinary research that reaches beyond legal analysis to examine how easements influence human behaviors, which subsequently influence environmental conditions. (2) Doing so involves social- science research on the formal and informal ways that conservation easements influence the behavior of landowners and other community members. It also involves natural-science research to examine the resulting pattern of species, habitat, and ecosystem protection and restoration. Conservation organizations commonly claim that all the conservation easements they acquire "save" land. (3) Only those acquisitions that result in changes to the trajectory of land use represent real conservation gains. It is impossible to observe the alternative scenario in which conservation easements were not acquired. However, comparative approaches allow for examination of likely alternatives and help to demonstrate conservation effectiveness.
Conservation easement effectiveness is not a fixed target, but is influenced over time by social and ecological landscape change. The promise of perpetuity is central to the appeal of conservation easements within the conservation movement. (4) Yet the value of perpetual conservation easements is widely debated. Conservation easement purposes, rights, and restrictions are individually negotiated for particular social and ecological landscapes, but the balance they strike between landowner rights and conservation restrictions may not be well tailored for future conditions. For instance, ecosystem dynamics, climate change, and socioeconomic change might alter the desired purposes of conservation easements, or the restrictions appropriate to meet those purposes. Issues of adaptive land management pose particular challenges for the conservation easement tool. (5) This article examines the effectiveness and adaptation of conservation easements and provides recommendations for improving the practice and science of conservation through analysis of the conservation literature and multidisciplinary research on conservation easements in a case-study landscape.
Conservation easements are partial-property-rights agreements that bind future landowners, often in perpetuity. (6) In exchange for restricting future land uses such as building, grazing, or timber harvesting, landowners often receive a tax reduction, cash payment, or permit. Nonprofit land trusts and government agencies rely increasingly on conservation easements to protect ecological and cultural resources on private lands, and occasionally on other organizations' lands. (7)
Part II of this article applies the outputs--outcomes--impacts logic model framework--an established approach to the evaluation of environmental policies--to conservation easements. (8) Outputs of the policy-making process refer to laws, agreements, and conservation easements themselves. In this article, outcomes refer to changes in human behavior as a result of environmental policies. In the context of conservation easements, outcomes refer to changes in land use and land management. Finally, impacts refer to changes in environmental conditions that result from these behavioral changes. In order to have positive environmental impacts, conservation easements must result in environmental benefits in addition to what would have occurred without the conservation easement in place.
Part III explores connections between the outputs--outcomes--impacts framework and ongoing debates over conservation easement permanence and adaptation. Ecosystems are dynamic, and ecological sciences increasingly recognize nonequilibrium processes rather than linear, cyclical, or climax models of change." In order to continue influencing human behavior and affecting environmental conditions, conservation easements must have mechanisms that allow conservation-oriented adaptation over time. …