1  Unit of assessment

Ecosystem name: Tropical glacier ecosystem of the Cordillera de Mérida

Ecosystem id: T6.1-SA-01-VE-01 (preliminary ID)

Assessment authors: José R. Ferrer-Paris, Luis D. Llambí, Alejandra Melfo

Other contributors: David Keith

Peer Review: 2 anonymous reviewers

1.1 Scope of the assessment

This is a global and national assessment for this ecosystem unit. The assessment unit is defined in a global context but its whole distribution is contained in one country (Venezuela). Thus, the assessment outcomes will inform both global and national RLE initiatives.

1.2 Ecosystem description

Tropical glacier ecosystems are cryogenic ecosystems in tropical environments where the main substrate is formed by ice accumulated over several years and provides different habitats to microbiological communities and other meso- and macro-biota. Tropical glaciers share key features with other glaciers, such as the icy substrate; atmospheric deposition of nutrients; a biota dominated by micro-organisms with cold-adaptation traits that inhabits several habitat compartments on (supra-), in (endo-) or below (subglacial) the icy substrate; truncated trophic networks; and very low productivity and diversity (Anesio & Laybourn-Parry, 2012; Hotaling et al., 2017; Keith et al., 2020).

Tropical glacier ecosystems are originally formed by processes of snow and ice accumulation and ablation over geological time frames. However the characteristic microbiota can persist in the ice substrate even if processes of ice accumulation have ceased or the overall mass balance of ice is negative.

The Tropical glacier ecosystem of the Cordillera de Mérida is described here as a distinct ecosystem type that formerly occupied several peaks above 4600 m in the Sierra Nevada National Park in the state of Mérida, Venezuela. It is geographically isolated from the nearest occurrences of Tropical glacier ecosystems in Colombia and has distinct bioclimatic characteristics.

1.3 Classification

We use the IUCN Global Ecosystem Typology (Keith et al., 2020) as a reference ecosystem classification system and identify (tentatively) Tropical glacier ecosystems as a subgroup within the ecosystem functional group T6.1 Ice sheets, glaciers and perennial snowfields:

IUCN Global Ecosystem Typology

• Level 1: Terrestrial Realm
  • Level 2: T6 Polar/Alpine (cryogenic) functional biome
    • Level 3: T6.1 Ice sheets, glaciers and perennial snowfields
      • Subgroup: Tropical glacier ecosystems
      • Level 4: T6.1-SA-01-VE-01 Tropical glacier ecosystem of the Cordillera de Mérida

Other classification schemata

The IUCN Habitat Classification Scheme does not have a category for glacier ecosystem or other cryogenic ecosystems.

Sagredo & Lowell (2012) proposes a climatic classification of Andean glaciers and includes de Cordillera de Merida in Group 1: inner tropics and Tierra del Fuego and specifically in Group 1.1 Inner tropics.

Anesio, A.M. & Laybourn-Parry, J. (2012) Glaciers and ice sheets as a biome. Trends in ecology & evolution, 27, 219–225.

Hotaling, S., Hood, E. & Hamilton, T.L. (2017) Microbial ecology of mountain glacier ecosystems: Biodiversity, ecological connections and implications of a warming climate. Environmental Microbiology, 19, 2935–2948.

Keith, D.A., Ferrer-Paris, J.R., Nicholson, E. & Kingsford, R.T. (eds) (2020) IUCN global ecosystem typology 2.0: Descriptive profiles for biomes and ecosystem functional groups. In. IUCN, International Union for Conservation of Nature.

Sagredo, E.A. & Lowell, T.V. (2012) Climatology of andean glaciers: A framework to understand glacier response to climate change. Global and Planetary Change, 86-87, 101–109.