ABSTRACT. Although few successful examples of large-scale adaptive management applications are available to ecosystem restoration scientists and managers, examining where and how the components of an adaptive management program have been successfully implemented yields insight into what approaches have and have not worked. We document five key lessons learned during the decadelong development and implementation of the Comprehensive Everglades Restoration Plan (CERP) Collaborative Adaptive Management Program that might be useful to other adaptive management practitioners. First, legislative and regulatory authorities that require the development of an adaptive management program are necessary to maintain funding and support to set up and implement adaptive management. Second, integration of adaptive management activities into existing institutional processes, and development of technical guidance, helps to ensure that adaptive management activities are understood and roles and responsibilities are clearly articulated so that adaptive management activities are implemented successfully. Third, a strong applied science framework is critical for establishing a prerestoration ecosystem reference condition and understanding of how the system works, as well as for providing a conduit for incorporating new scientific information into the decision-making process. Fourth, clear identification of uncertainties that pose risks to meeting restoration goals helps with the development of hypothesis-driven strategies to inform restoration planning and implementation. Tools such as management options matrices can provide a coherent way to link hypotheses to specific monitoring efforts and options to adjust implementation if performance goals are not achieved. Fifth, independent external peer review of an adaptive management program provides important feedback critical to maintaining and improving adaptive management implementation for ecosystem restoration. These lessons learned have helped shape the CERP Adaptive Management Program and are applicable to other natural resource management and restoration efforts; they can be used to help guide development and implementation of adaptive management programs facing similar challenges.

A lthough the common foundations of site-scale ecosystem restoration are well understood, the spatial scale and duration of restoration are rapidly expanding, raising theoretical questions and practical concerns. For instance, the primary goal of the Bonn Challenge, issued jointly in 2011 by the International Union for Conservation of Nature and the Government of Germany, is to restore 350 million ha of degraded land by 2030, while the UN General Assembly recently proclaimed 2021-2030 to be the Decade on Ecosystem Restoration. Such coordinated restoration across large spatial and temporal scales is a response to widespread environmental degradation, human welfare needs, and increased understanding of how species are sustained by distributed habitats and ecosystems (Lotze et al. 2006; Hall et al. 2018). In view of these trends, the Society for Ecological Restoration (SER) recently formed a Large-Scale Ecosystem Restoration section (Daoust et al. 2014). What does ecological restoration science offer to those working toward such ambitious goals? Restoration ecology provides information about the study of individual sites, ecosystems, and vulnerable species developed over the past half century (Roman and Burdick 2012; Clewell and Aronson 2013), yet for the most part it has not addressed large-scale restoration that includes multiple ecosystems and restoration projects across landscapes. Large-scale restoration is usually more cost-effective than local site-specific planning (Neeson et al. 2015); however, little formal research on achieving successful program-level outcomes has been reported. Useful principles to support the enormous projected expansion of restoration and ensure that large investments produce planned ecosystem functions are urgently needed. In practice, large-scale restoration is typically overseen by multidisciplinary teams and based on an ecosystem approach developed at the site scale, as can be seen in the programs we reviewed (Figure 1). Geomorphic conditions and hydrological

Implementation guidance for Sections 2036 and 2039 of WRDA 2007 and Section 1161 of WRDA 2016 requires that ecosystem restoration projects either include appropriately scoped monitoring and adaptive management plans or provide sound justifications for why adaptive management is not warranted. Under adaptive management, decisions are based on the best available (yet often incomplete and imperfect) scientific data, information, and understanding, recognizing uncertainties that introduce risks to the achievement of goals and objectives. Revision to management actions based upon information derived from ongoing monitoring and evaluation is possible. This guide provides an overview of adaptive management practice, emphasizing underpinning principles. An approach to determine the need for and development of adaptive management plans is presented, and the implementation of ecosystem restoration projects under adaptive management is presented. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.