Rodriquez et al. 2010. Establishing IUCN Red List Criteria for Threatened Ecosystems

Question 1

How much of the world’s terrestrial ecosystems have been converted for human use?

Answer 1

Between 20 and 70 percent of the area of 11/13 terrestrial biomes has been converted

Question 2

How do the authors use the term “ecosystem”?

Answer 2

They use it to mean an assemblage of organ- isms that occur together in space and time and interact with each other and their physical environment

Question 3

How could the use of ecosystem red lists benefit the current system of species red lists?

Answer 3

Ecosystems may represent biological diversity than species, (especially given the taxonomic bias in species red list)

Ecosystems include fundamental abiotic components that are only indirectly included in species assessments.

Declines in ecosystem status may be more apparent than species extirpations/extinctions

Assessment may be easier

Ecosystem red lists may suggest areas where extinctions are likely as the loss and fragmentation precedes extinction

Question 4

What characteristics should a global system for assessing ecosystem status have?

Answer 4

It should:

• be based on objective criteria which are scientifically sound and easily quantifiable
• have thresholds that are associated with different levels of risk of elimination and loss of function
• facilitate comparisons across ecosystems
• be applicable to terrestrial and aquatic systems, at multiple spatial scales and resolutions, and to data from diverse sources

Question 5

what are the challenges that must be overcome to develop this system?

Answer 5

Classical definitions of ecosystems, which use abiotic and biotic factors, allow divisions into biomes and smaller into ecoregions, but many units of interest will occur at smaller scales than ecoregions.

In some cases, a focus on biological components may be essential for assessing the risk that ecosystems are degraded or ultimately eliminated.
For many terrestrial ecosystems, as well as some aquatic ones, landcover classification may be the most practical approach for delineating units for assessment

In some freshwater and most pelagic and deepwater marine systems , the delineation of assessment units may rely more heavily on abiotic features.

defining threat levels for ecosystems and determining the trajectory to- ward their loss may be very difficult. Are they eliminated when a key component is lost, or the last biotic element?

Aquatic systems present challenges because ecosystem conversion and loss of function may be widespread but not easily detectable

Question 6

Can approaches from species red lists be used for ecosystems?

Answer 6

In terrestrial systems, temporal trends in the distribution of land cover have been proposed and applied as criteria for assessing the status of some types of ecosystems - the Cape Flats Sand Fynbos, in South Africa, is listed as critically endangered because the expansion of Cape Town has resulted in a reduction of over 84% of the original extent of the ecosystem.

However, abundance and trend-based criteria used presently for species assessments may lose meaning in the context of ecosystems (which do not simply consist of “individuals”) because in ecosystems changes in spatial extent represent the endpoint of processes such as structural conversion and functional decline.

Question 7

What criteria do the authors tentatively propose?

Answer 7

A: short term decline in distribution or function
B: Historical decline
C: small range and decline
D: V. small range and plausible threats

Within these thresholds are suggested for CR, EN, VU
Species-area relations, for example, may inform the definition of thresholds for criteria on the basis of changes in geographical distribution,

Question 8

Provide some indicators of functional loss

Answer 8

1) measures of threat (e.g., increases in the proportion of invasive species or pollutant levels),
2) measures of structure (e.g., changes in species richness, trophic configuration, or guild diversity or status of particular keystone species, such as seed dispersers or pollinators), or
3) measures of function (e.g., changes in nutrient cycling, trophic complexity, energy flows, biomass accumulation, or patterns of water flow

e.g. in New South Wales, Artesian Mound Springs is listed as an endangered ecolog- ical community because its artesian aquifers have been largely depleted, not because its geographical extent has been changed