Steps to operationalize a rewilding decision: Focus on functional types

Abstract

If transparent and inclusive stakeholder discussion delivers a consensus for active rewilding, then five steps are recommended for operationalizing that decision, focused initially on the large herbivore assemblage. Consideration of large predators could follow, contingent upon the establishment of prey populations. First, determine the potential biomass density (kg/km2) of large mammalian herbivores in the target landscape. Regression models based on rainfall or primary productivity are helpful if applicable, otherwise comparative studies are needed. Second, use empirical data from reference ecosystems to apportion biomass density among functional types, crudely defined by body size and feeding type (grazer, browser, mixed feeder). Third, identify specific functional traits (coarse grazing, endozoochory, etc.) of particular local importance. Fourth, identify species within each functional type that are already present, estimate their potential biomass densities, and thus identify the shortfall within each cell of the body size x feeding type matrix. A candidate set of native and non-native (surrogate) species is then identified to make up the shortfalls. This is followed by an iterative process of estimating equilibrium population sizes, stakeholder acceptance, and viability of each potential population. Fifth, stakeholders must be inclusively re-engaged to visualize the potential assemblage, its expected functional interactions, the ecosystem services to be delivered, and the long-term costs (including opportunity costs) and benefits. When a plan is supported, local stakeholders should be integrated as active participants in the implementation, monitoring, and championing of their rewilding project.

Navigating ecological novelty towards planetary stewardship: challenges and opportunities in biodiversity dynamics in a transforming biosphere

“…To address these challenges, we must embrace innovative approaches to ecosystem stewardship—such as the novel ecosystem perspective [ 9 ], rewilding approaches [ 48 , 87 ], assisted migration [ 88 ], as well as diverse cultural practises [ 75 , 76 ]—adapting to change and promoting biodiversity outcomes, all while aligning with societal values, ethics and feasibility concerns. Key characteristics of adequate approaches are that they can be upscaled to be effective at the large scales needed for effective contributions to planetary stewardship, effective under rapidly changing, novel environmental conditions and societally sustainable.…”

Rewilding as a Multifaceted Concept and Emerging Approach: The Romanian Experience

“…Policy and advocacy are complementary to rewilding measures taken at local scales to allow rewilding to scale up across entire landscapes [56], while the aims of rewilding can be achieved through careful site-specific interpretations [15]. To operationalize the rewilding concept for an ecologically degraded landscape, stakeholders' full engagement and consensus are vital [59]. Focusing on large herbivore assemblage, du Toit [59] recommends five steps for operationalizing active rewilding: estimation of total potential biomass density, allocation of biomass to functional types, prioritizing ecosystem services and requisite functional traits, prioritizing native species, and taking into account surrogates and re-engagement of stakeholders.…”

“…To operationalize the rewilding concept for an ecologically degraded landscape, stakeholders' full engagement and consensus are vital [59]. Focusing on large herbivore assemblage, du Toit [59] recommends five steps for operationalizing active rewilding: estimation of total potential biomass density, allocation of biomass to functional types, prioritizing ecosystem services and requisite functional traits, prioritizing native species, and taking into account surrogates and re-engagement of stakeholders. Developing typologies of functional types of animals within bioregions of trait space would help operationalize the rewilding concept on a global scale [59].…”

“…Focusing on large herbivore assemblage, du Toit [59] recommends five steps for operationalizing active rewilding: estimation of total potential biomass density, allocation of biomass to functional types, prioritizing ecosystem services and requisite functional traits, prioritizing native species, and taking into account surrogates and re-engagement of stakeholders. Developing typologies of functional types of animals within bioregions of trait space would help operationalize the rewilding concept on a global scale [59]. Implementing comprehensive long-term plans to manage herbivore populations will maximize biodiversity gains, mitigating welfare concerns and reputational risks [52].…”