Applying cumulative effects to strategically advance large‐scale ecosystem restoration

Abstract

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

Understanding the combined effects of multiple stressors: A new perspective on a longstanding challenge

“…More details are given in the text and Appendix F. solutions to reduce the current risk to populations. Management goals could guide the selection of which stressors within the available mixture can effectively be manipulated to ensure that the risk of adverse impacts on populations remains below acceptable thresholds (Groffman et al, 2006;Huggett, 2005;Kelly et al, 2015), i.e., the stressors that are relevant in practice (Diefenderfer et al, 2021;National Academies, 2017).…”

Ten years of Gulf Coast ecosystem restoration projects since the Deepwater Horizon oil spill

“…Such organization falls into categories of lines of evidence (table 3.3 of ref. 2 ) that large-scale restoration programs on all continental US coasts have used, along with causal criteria for synthesis and evaluation ( 24 , 25 ).…”

“…Using multiple lines of evidence helps to compensate for the inability to use traditional experimental designs, lack of reference conditions, lack of replication, difficulties in establishing causality, and often the shortage of appropriate data ( 25 ). Adoption of comparative cross-system analysis methods ( 26 ) for the 34 US GoM estuaries could provide an initial step bridging spatial gaps between existing estuary-scale assessments of cumulative effects and future GoM-wide assessments.…”

Using ecosystem risk assessment science in ecosystem restoration: a guide to applying the Red List of Ecosystems to ecosystem restoration

“…Undertaking a landscape-or seascapescale assessment of restoration priorities, as described in Chapter 3, is critical prior to planning restoration at the local scale because ecosystems are affected by and have effects on the larger context in which they are embedded. 25 Therefore, their management cannot occur in isolation, but rather requires explicit consideration of the types and proportions of ecosystems within the landscape or seascape, the spatial organisation of the units, and linkages among composition, structure and function (see Figure 2). For example, because threats from the larger landscape or seascape cause degradation at the local level, local restoration activities may fail if they have not been identified and mitigated.…”