Plant Diversity and Composition Changes along an Altitudinal Gradient in the Isolated Volcano Sumaco in the Ecuadorian Amazon

The paramo is a unique and severely threatened ecosystem scattered in the high northern Andes of South America. However, several further, extra-Andean paramos exist, of which a particular case is situated on the active volcano Sumaco, in the northwestern Amazon Basin of Ecuador. We have set an eleva...

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Bibliographic Details
Published in:Diversity
Main Authors: Pablo Lozano, Omar Cabrera, Gwendolyn Peyre, Antoine Cleef, Theofilos Toulkeridis
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2020
Subjects:
Online Access:https://doi.org/10.3390/d12060229
https://doaj.org/article/98bd35e3f80842edb0338e2030d8f53c
Description
Summary:The paramo is a unique and severely threatened ecosystem scattered in the high northern Andes of South America. However, several further, extra-Andean paramos exist, of which a particular case is situated on the active volcano Sumaco, in the northwestern Amazon Basin of Ecuador. We have set an elevational gradient of 600 m (3200–3800 m a.s.l.) and sampled a total of 21 vegetation plots, using the phytosociological method. All vascular plants encountered were typified by their taxonomy, life form and phytogeographic origin. In order to determine if plots may be ensembled into vegetation units and understand what the main environmental factors shaping this pattern are, a non-metric multidimensional scaling (NMDS) analysis was performed. In addition, species turnover was quantified in order to appreciate the quantity and sort of species which are responsible for the similarity or dissimilarity between vegetation units. Therefore, a SIMPER similarity percentage analysis was conducted. We encountered 68 plant species belonging to 54 genera and 31 families, of which three are Ecuadorian endemics. The most frequent life forms were erect herbs, rosette and tussocks, whereas the least were cushions. At genus level, 44% of the Sumaco paramo flora was of tropical origin, followed by temperate (33%) and finally cosmopolitan (22%). The neotropical montane element was the most represented with 15 species, followed by the Austral-Antarctic with ten, wide temperate with another ten and cosmopolitan with seven. Regarding vegetation, four floristically distinct groups were segregated being lower gradient (3250–3500 m a.s.l.) and high altitude (3500–3800 m a.s.l.)