Predicting and Assessing Progress in the Restoration of Ecosystems

Abstract

Restoration of degraded landscapes has become necessary to reverse the pervasive threats from human exploitation. Restoration requires first the monitoring of progress toward any chosen goals to determine their resilience and persistence, and second to conduct in a comparable adjacent area but with less human impact the restoration of trophic structures and ecosystem processes to act as reference systems (controls) with which we compare the viability of the chosen goal. We present here the rationale and a method for predicting the trajectory of restoration and assessing its progress toward a predetermined state, the endpoint, using a restoration index. This assessment of restoration requires that we know when a predetermined endpoint has been achieved and whether the envisioned community of species and their interactions can be restored. The restoration index can use species’ presence or density, and the rate of change of ecosystem processes. The index applies to trophic levels, functional groups, successional stages, alternative states, and novel ecosystems. Also, our method allows measurement of the resilience of ecosystems to disturbance, a desired property for conservation and management. We provide global examples to illustrate these points.

Measuring rewilding progress

“…Approaches to monitor restoration progress and success rely on the quantification of indices of recovery progress [ 19 , 20 ], recovery completeness [ 21 ] or both [ 22 ], which compare degraded, restored and intact reference ecosystems. In all these cases, a key step in assessing restoration progress is finding and agreeing on a reference ecosystem, though increasingly considering environmental change.…”

Operationalizing the IUCN Red List of Ecosystems in public policy

“…Plans such as the Comprehensive Everglades Restoration Plan (USA) have proven to be effective for restoring soil conditions and carbon sequestration in the ecosystem (Osborne, Fitz, & Davis, 2017). Similarly, in Windhoek (Namibia), a series of restoration programs achieved return of groundwater levels in the aquifers (Sinclair et al, 2018).…”

“…In the United States, the National Wild Pig Task Force, established as a part of the National Feral Swine Damage Management Program, is accomplishing significant advances on control of invasive wild pigs in North American natural ecosystems (Beasley, Ditchkoff, Mayer, Smith, & Vercauteren, ). Similarly, in Mercury Islands (New Zealand), control and restoration programs eradicated introduced rats reducing predation on seabirds and thereby promoting return of nitrogen to multiple trophic levels (Sinclair et al., ). Conversely, policies to reintroduce predators have reestablished the trophic webs in the Serengeti savannas (Tanzania; Sinclair et al., ).…”

“…Similarly, in Mercury Islands (New Zealand), control and restoration programs eradicated introduced rats reducing predation on seabirds and thereby promoting return of nitrogen to multiple trophic levels (Sinclair et al., ). Conversely, policies to reintroduce predators have reestablished the trophic webs in the Serengeti savannas (Tanzania; Sinclair et al., ).…”

Challenges during the execution, results, and monitoring phases of ecological restoration: Learning from a country-wide assessment

“…After planning and executing interventions, results, progress, and effectiveness should be evaluated [ 30 ]. Monitoring enables assessing restoration outcomes compared to initial ecosystem conditions or to a reference ecosystem [ 14 ].…”