Diversity of zonal páramo plant communities in Ecuador

• Published in: Diversity & distributions Vol. 7; no. 3; pp. 113 - 124
• Main Authors: Sklenár, Petr, Ramsay, Paul M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.05.2001; Blackwell Science; Blackwell
• Subjects: Altitude; Altitudinal gradient; Animal and plant ecology; Animal, plant and microbial ecology; Biodiversity Research; Biological and medical sciences; disturbance; Diversity indices; Ecosystems; Ecuadorian Andes; Fundamental and applied biological sciences. Psychology; Grasses; Monasteries; Plant communities; Plants; Species; Species diversity; species richness; Synecology; Terrestrial ecosystems; tropical alpine; Vegetation; zonation; South America; Ecuador; Andes; America; Species diversity; Human activity; Vegetation; Spermatophyta; Perturbation; Environmental monitoring; Species richness; Altitudinal distribution
• ISSN: 1366-9516; 1472-4642
• DOI: 10.1046/j.1472-4642.2001.00101.x

Patterns of vascular plant species diversity in high-altitude Ecuadorian ecosystems ('paramos') are examined. Data from two independent surveys were used: the first from 12 different locations and 192 samples, the other from 18 locations and 243 samples. These surveys included 348 and 284 species, respectively. The data confirmed the occurrence of two main zones in terms of vascular plant species diversity. The grass paramo and superparamo were distinguished by differences in plant cover, species richness, α-diversity and β-diversity. The transition between these two zones begins at around 4000 m. Grass paramo samples comprised more species but the strong dominance of tussock grasses resulted in low equitability compared with the superparamo, where safe sites for plant survival are limited and the environment does not permit continuous grass cover. Turnover of species across the altitudinal gradient is higher in the grass paramo than in the superparamo. This is due largely to agricultural fires at lower altitudes, which create a fine-scale mosaic of burned patches that enhances variability at this scale. Despite the loss of equitability, intermediate levels of fire disturbance appear to promote species richness within the samples. It is suggested that the complex patterns of paramo diversity in the Ecuadorian Andes are largely the outcome of three interrelated factors: altitude, disturbance and the availability of safe sites at the highest altitudes.