IUCN Red List of Ecosystems

Piloting the Red List of Ecosystems in the Americas

About This Project

Accelerating landscape change threatens biological diversity worldwide. Therefore, knowledge of trends in the extent and condition of ecosystems provides a key foundation for conservation action. Risk assessment of ecosystem types provides a complement the IUCN Red List of Species and NatureServe Conservation Status ranks. Assessment of ecosystem types addresses ecological processes for many species that share similar habitat requirements, and for many other species for which little is known.

We are helping to initiate the IUCN Red List of Ecosystems of the Americas. The scientific aim of this effort is to document the conservation status of terrestrial ecosystems (uplands and wetlands) of the Americas by developing a series of baselines across the continental distribution of each type, assessing land cover change against these baselines, quantifying the drivers of change, and applying the Red List criteria to each ecosystem type.

NatureServe terrestrial ecological systems and IVC vegetation macrogroups are primary units of assessment.

The red listing process involves:

  • Classification and description of ecosystem types
  • Description of natural environmental setting, key ecological processes and interactions, major threats and stressors, and indicators of ecological collapse.
  • Maps of potential/historical as well as current distribution
  • Maps depicting stressor and condition indicators
  • Tabular summaries of applied IUCN assessment criteria
  • Maps depicting location of ecosystem types scored as Vulnerable, Endangered, and Critically Endangered.

After an initial focus on upland and wetland ecosystem types, we aim to expand assessments to other realms (freshwater aquatic, marine, subterranean).

Goal

Through this process, we document which upland and wetland ecosystem types should be considered “Vulnerable (VU)” “Endangered (EN)” or “Critically Endangered (CR)” using newly developed criteria by IUCN. Othe catergories include "Near Threatened (NT)" "Least Concern (LC)" and "Data Deficient (DD)" and "Not Evaluated (NE)."  With several hundred described and mapped types as assessment units, we are documenting which forest, savanna, shrub-scrub, grassland, desert, wetland, and riparian types are of most urgent conservation need.

As compared with individual species, ecosystems represent recurring patterns of species assemblages that reflect biogeography, patterns in the physical environment, and dynamic ecological processes. Outright conversion (e.g., for intensive agriculture), or change in either the physical environment or dynamic processes may result in a departure from expected species composition. Therefore, ecosystem risk assessment aims to detect trends in the magnitude of change to species composition. Threats to ecosystems result in a departure from expected species composition to varying degrees. For ecosystems, the analog to species extinction (i.e., population collapse) is the transformation of species composition and ecological processes to an alternate condition from that which was previously supported. Therefore, the “collapse” of a given example of an ecosystem type occurs where ecological conditions have transformed beyond recognition.

Preliminary Findings for Red List Status in the USA

Initial application of IUCN Red List of Ecosystems criteria in the USA provides a demonstration of an approach to rapidly assess the majority of types and “paint the picture” of ecosystem status. Following from this analysis, investments to fill key information gaps may be targeted to maximize their impact and complete the picture.

From this preliminary analysis, 108 terrestrial ecosystem types may be confidently scored as either CR, EN, or VU using assessment criteria for long-term trends in extent (A3), restricted distributions (B1 and B2), Long-term trends in environmental degradation (C3), and long-term trends in biotic process disruption (D3). Types scored as CR, EN, and VU represent 17% of all described types from the NatureServe terrestrial ecological systems classification.  Historically, these ecosystems occurred across about 37% of the continental study area, and today account for just 12%.  Here we have focused on ecosystem types that have been described and mapped. It may be safe to presume that, in a continent has heavy transformed as temperate North America, there may well be ecosystem types that were never documented prior to their elimination. 

RLE Status

# Types

% types

Total Potential Extent (km2)

% historic land area

Sum of Current Land Area (km2)

% total land area

CR

11

2%

499,033

4.70%

30,534

0.3%

CR (EN-CR)

17

3%

570,067

5.37%

107,508

1.0%

EN

16

2%

689,094

6.49%

183,207

1.7%

CR (VU-CR)

5

1%

14,633

0.14%

4,754

0.0%

EN (VU-EN)

32

5%

956,494

9.01%

301,574

2.8%

VU (VU-EN)

11

2%

340,765

3.21%

191,898

1.8%

VU

16

2%

889,758

8.38%

440,648

4.2%

EN (LC-EN)

38

6%

776,932

7.32%

541,565

5.1%

VU (LC-EN)

12

2%

623,465

5.87%

488,555

4.6%

VU (LC-VU)

95

14%

2,358,296

22.22%

2,066,108

19.5%

NT (NT-EN)

2

0%

295,495

2.78%

191,676

1.8%

NT (LC-VU)

2

0%

19,068

0.18%

9,670

0.1%

NT (LC-NT)

10

1%

214,646

2.02%

201,791

1.9%

LC (LC-EN)

2

0%

29,524

0.28%

7,381

0.1%

LC (LC-VU)

15

2%

447,610

4.22%

332,408

3.1%

LC (LC-NT)

2

0%

63,690

0.60%

38,746

0.4%

LC

64

10%

930,983

8.77%

787,344

7.4%

DD

181

27%

241,927

2.28%

292,834

2.8%

NE

139

21%

651,615

6.14%

638,497

6.0%

Grand Total

670

100%

10,613,096

100.00%

6,856,697

64.6%

Given the continental scale of this analysis, and reliance on spatial data sets, we have utilized the option to score types within a plausible range. This provides a practical indication of our confidence in overall scores and points to types that could use additional investments in data and analysis to increase our confidence and specify their scores.

Those types that we could confidently score as CR to VU tended to be concentrated among forests and grasslands that have been subjected to extensive landscape fragmentation for over 200 years. These ecosystem types included many forests types of the eastern interior, Atlantic and Gulf Coastal Plain, central Appalachians, prairies of the Great Plains, and shrublands of the intermountain West.

Significance

Ecosystem types, such as forests, grasslands, and wetlands form the life support system for humanity, providing the foundation for all ecosystem services. As a companion to the Red List of Species, the IUCN Red List of Ecosystems provides a mechanism for integrating data and knowledge to document trends in the extent and condition of ecosystems. Findings from these assessments feed directly into efforts to prioritize conservation action, including raising citizen awareness, informing policymakers, and directing public and private investments towards sustainable ecosystem protection. By applying Red List criteria to an established classification of ecosystem types, we provide one focus for governments and researchers to further develop robust data sets that are critical to natural resource conservation assessment, planning, management, and monitoring.

For More information visit on the IUCN project visit: IUCN Red List of Ecosystems.