Scientific Foundations for an IUCN Red List of Ecosystems

Abstract

An understanding of risks to biodiversity is needed for planning action to slow current rates of decline and secure ecosystem services for future human use. Although the IUCN Red List criteria provide an effective assessment protocol for species, a standard global assessment of risks to higher levels of biodiversity is currently limited. In 2008, IUCN initiated development of risk assessment criteria to support a global Red List of ecosystems. We present a new conceptual model for ecosystem risk assessment founded on a synthesis of relevant ecological theories. To support the model, we review key elements of ecosystem definition and introduce the concept of ecosystem collapse, an analogue of species extinction. The model identifies four distributional and functional symptoms of ecosystem risk as a basis for assessment criteria: A) rates of decline in ecosystem distribution; B) restricted distributions with continuing declines or threats; C) rates of environmental (abiotic) degradation; and D) rates of disruption to biotic processes. A fifth criterion, E) quantitative estimates of the risk of ecosystem collapse, enables integrated assessment of multiple processes and provides a conceptual anchor for the other criteria. We present the theoretical rationale for the construction and interpretation of each criterion. The assessment protocol and threat categories mirror those of the IUCN Red List of species. A trial of the protocol on terrestrial, subterranean, freshwater and marine ecosystems from around the world shows that its concepts are workable and its outcomes are robust, that required data are available, and that results are consistent with assessments carried out by local experts and authorities. The new protocol provides a consistent, practical and theoretically grounded framework for establishing a systematic Red List of the world’s ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity

Habitats on the grid: The spatial dimension does matter for red-listing

“…We used a grid with 10 × 10 km 2 cell size, as recommended by Keith et al (2013), but similar results would be obtained with other theoretical habitats and grids with larger or smaller cells. Although sharing the same total distribution surface, the AOO of the 3 theoretical Habitats drastically varied.…”

“…CITES, 1973;European Commission, 2011;United Nations, 1976, 1992. The most challenging aspect stems from the complexity of biodiversity, that in itself comprises both multiple levels of organisation Despite the cutting edge importance of species Red Lists, the realisation that an approach focused exclusively on the species level is unfit to conserve all components of biodiversity led the scientific community, conservation professionals and institutions to be increasingly concerned with biodiversity assessments, addressing higher levels of biological organisation (Izco, 2015;Keith, 2009;Keith et al, 2013Keith et al, , 2015Kontula & Raunio, 2009;IUCN, 2015a;Nicholson, Keith, & Wilcove, 2009;Rodríguez et al, 2011Rodríguez et al, , 2012Rodríguez et al, , 2015. Ecological communities may more efficiently represent the biological diversity as a whole, compared to the species-level approach, which often lacks direct information about fundamental abiotic components, thus missing both the targets of protecting ecological patterns and processes, and ensuring the persistence of ecosystem functions and structure (Balmford et al, 2002;Cowling et al, 2004;Millennium Ecosystem Assessment, 2005;Noss, 1996; Secretariat of the Convention on Biological Diversity, 2010).…”

“…Nevertheless, differently from species, as yet there is no acknowledged international methodology on which to base the habitat red-listing. In Europe, Rodwell, Janssen, Gubbay, and Schaminée (2013) recently started a project aimed at developing a Red List of the European habitat types, while the IUCN council (CEM-IUCN & Provita, 2012) formally endorsed the protocol proposed by Keith et al (2013).…”

“…Besides a common origin from the protocol developed for species (IUCN, 2013;Mace et al, 2008), the various methodologies adopted for plant communities/habitats/ecosystems red-listing share several characteristics: (a) although some protocols define assessment units of large dimensions, such as 'ecosystems' (Keith et al, 2013) or 'Land Environments' (Walker et al, 2006), most of them refer to 'plant species assemblages' or 'vegetation types', used as proxies for ecosystems or habitats; (b) as a rule, the assessment is based on quantitative criteria and only few protocols rely on qualitative ones, i.e. on the best expertise supported by specific paradigms (e.g.…”

National and subnational Red Lists in European and Mediterranean countries: current state and use for conservation

“…The combination of multi-scale RLTSs (including available assessments from the global, regional, national and subnational RLTSs) can also provide valuable information during prioritization processes (Barneix & Gigot 2013). The combination of RLTSs with other knowledge products such as the Red List of Ecosystems (Keith et al 2013) and Key Biodiversity Areas (Foster et al 2012) also provides great potential for enhanced conservation planning.…”