Modelo de distribución potencial de Condalia thomasiana (Rhamnaceae), especie endémica del valle del río Checua, Sabana de Bogotá, Colombia

Abstract

A distribution potential modeling was developed for Condalia thomasiana, a species endemic to the Checua valley river. These populations are in danger of extinction primarily as a consequence of habitat fragmentation in this unique geographic area where they are only found. The objective of this research was to explore a distribution potential modeling to recognize patterns and relationships between a datasets of the species presence and environmental variables of the geographic zone. The current registrations of the species correspond to 219 data of individuals identified and geo-referenced in field during 2006 and 2007 in Nemocón and Suesca municipalities.

The distribution potential modeling we created used a dataset of actual distribution of the species and 14 environmental variables: precipitation, evaporation, evapotranspiration, lithology, geological and age formation, geomorphology, landscapes, sub landscapes, basin, soils, vegetation (floristic composition), actual covertures of vegetation (structure), and potential vegetation in the past. The model was calculated based on MAXENT software, and it was tested with 25 per cent of the random data.

The model showed that Condalia thomasiana potentially is only distributed in media low Checua valley river zone in Nemocón and Suesca municipalities. The total area of predominance is 78,6 km², between 2.600 and 2.880 meters above sea level. The most important environmental variables contributing to the modeling were basin, landscape as xerophytes brush, and soils, specifically inceptisoils and alfisoils. Some conservation alternatives are suggested for this endemic species and their remaining area; it was based on the distribution potential modeling.