Establishing IUCN Red List criteria for threatened ecosystems.
The potential for conservation of individual species has been greatly advanced by the International Union for Conservation of Nature's (IUCN) development of objective, repeatable, and transparent criteria for assessing extinction risk that explicitly separate risk assessment from priority setting. At the IV World Conservation Congress in 2008, the process began to develop and implement comparable global standards for ecosystems. A working group established by the IUCN has begun formulating a system of quantitative categories and criteria, analogous to those used for species, for assigning levels of threat to ecosystems at local, regional, and global levels. A final system will require definitions of ecosystems; quantification of ecosystem status; identification of the stages of degradation and loss of ecosystems; proxy measures of risk (criteria); classification thresholds for these criteria; and standardized methods for performing assessments. The system will need to reflect the degree and rate of change in an ecosystem's extent, composition, structure, and function, and have its conceptual roots in ecological theory and empirical research. On the basis of these requirements and the hypothesis that ecosystem risk is a function of the risk of its component species, we propose a set of four criteria: recent declines in distribution or ecological function, historical total loss in distribution or ecological function, small distribution combined with decline, or very small distribution. Most work has focused on terrestrial ecosystems, but comparable thresholds and criteria for freshwater and marine ecosystems are also needed. These are the first steps in an international consultation process that will lead to a unified proposal to be presented at the next World Conservation Congress in 2012.
Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela. jonpaul@ivic.gob.ve
Jon Paul
JP
Rodríguez
Kathryn M
KM
Rodríguez-Clark
Jonathan E M
JE
Baillie
Neville
N
Ash
John
J
Benson
Timothy
T
Boucher
Claire
C
Brown
Neil D
ND
Burgess
Ben
B
Collen
Michael
M
Jennings
David A
DA
Keith
Emily
E
Nicholson
Carmen
C
Revenga
Belinda
B
Reyers
Mathieu
M
Rouget
Tammy
T
Smith
Mark
M
Spalding
Andrew
A
Taber
Matt
M
Walpole
Irene
I
Zager
Tara
T
Zamin
D044822:Biodiversity; D003226:Congresses as Topic; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D056727:Endangered Species; D053476:Extinction, Biological; D018570:Risk Assessment / Q000379:methods