Abstract Detail

Floristics & Taxonomy

Neill, David A. [1], Asanza, Mercedes [1], Quizhpe, Wilson [1], Monteagudo Mendoza, Abel [2], Torres Montenegro, Luis [3], Huamantupa-Chuquimaco, Isau [4].

Forests, shrublands and páramos of the Andean tepuis in Ecuador and Peru: Phytogeographic, floristic and vegetation patterns.

The term “Andean tepuis” refers to the sedimentary formations, mainly quartz sandstone, of the sub-Andean cordilleras, east of the main Eastern Cordillera of the Andes in Ecuador and Peru, to emphasize the lithologic and edaphic similarities of these areas with the well-known tepuis of the Guiana Shield, the sandstone table mountains of southern Venezuela and adjacent countries – and also to point out the phytogeographical connections between these two regions. The Andean tepuis include, from north to south, parts of the Cordilleras Galeras and Cutucú in Ecuador, the Cordillera del Cóndor on the Ecuador-Peru border, and the Cordilleras Escalera, Azul and Yanachaga in Peru, and are mostly Cretaceous sandstone sediments that have been uplifted concurrently with the Andean orogeny to their present position, mostly above 1000 m and up to 2900 m, since the late Miocene/Pliocene. Three principal biogeographic patterns of the plant taxa that are restricted to oligotrophic sandstone or white-sand substrates include: 1) taxa with a disjunct distribution, at the generic or specific level, between the tepuis of the Guiana Shield and the Andean tepuis, mostly above 1000 m elevation; 2) taxa shared between the Andean tepuis and the lowland Amazonian white-sand areas, absent in the Guiana Shield tepuis; and 3) taxa endemic to the sandstones of the Andean tepuis, within genera that are widespread in the Andes. A large proportion of the plants in the Andean tepuis are not endemic to sandstone substrates, but also occur on volcanic or metamorphic areas of the Andes and/or in lowland Amazonia, such as Chrysophyllum sanguinolentum (Sapotaceae) and Purdiaea nutans (Clethraceae). The Guiana Shield disjuncts, in genera such as Bonnetia (Bonnetiaceae), Crepinella (Araliaceae) and Digomphia (Bignoniaceae) are often among the most abundant tree species at local scales in forest inventory plots. The vegetation of the Andean tepuis includes dense forests up to 2000 m elevation, shrublands with a canopy about 2 m tall, at about 2000-2400 m, and herbaceous páramo-like vegetation above 2400 m. Local endemics in the shrublands include species in genera such as Schradera, Ladenbergia and Palicourea (Rubiaceae), Symplocos (Symplocaceae) and Symbolanthus (Gentianaceae). The páramo vegetation includes terrestrial Bromeliaceae, Araceae and Cyclanthaceae, as well as the insectivorous Drosera, which is not found on any non-sandstone substrates in the Andes.  Botanical exploration of the Andean tepuis is still in an incipient phase, and the existing herbarium collections indicate that many more species from these areas remain to be described formally.

1 - Universidad Estatal Amazónica, Paso Lateral, km 2 1/2 vía a Napo, Puyo, Pastaza, Ecuador
2 - Universidad Nacional de San Antonio Abad del Cusco, Cusco, Cusco, Peru
3 - Herbarium Amazonense (AMAZ), Iquitos, Loreto, Peru
4 - Universidad Nacional de San Antonio Abad del Cusco, Herbario CUZ, Av. De la Cultura 733, Cusco, Cusco, Peru

none specified

Presentation Type: Oral Paper
Session: FT1, Floristics & Taxonomy I
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 10:00 AM
Number: FT1FT001
Abstract ID:204
Candidate for Awards:None

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