Structure and diversity of Condalia thomasiana Fdez-A. low forest and shrub and endemic species in the dry valley of the Checua river (Nemocón-Cundinamarca-Colombia)

Abstract

This paper deals with the structure and diversity of Condalia thomasiana Fdez-A low forest and shrub vegetation. The research project «Integral study for the conservation of the endemic species Condalia thomasiana in the dry valley of the Checua river (municipality of Nemocón)». This vegetation is distributed in altitudes between 2650 and 2800 m, growing on structural geoforms, which are in direct contact with bad lands. The annual range of precipitation is 600- 800 mm, which characterizes the vegetation as subxerophyitic. This type of vegetation has three to four strata that can vary according to the successional stage. The low stratum presents cover values between 40 and 100 per cent, the herbaceous between 5 and 40 per cent; the shrubby vegetation is dominant and presents between 60 and 100 per cent cover. In some cases emergent tree are present in and cover between 8 and 43 per cent. The flora recorded in this study is composed by 46 families, 96 genera and 119 species and determines regional and local endemisms. In spite of being in both atmospherically dry areas and on dry soils, these shrubs and low forests maintain high levels of internal humidity particularly in their low strata and exhibit epiphytic vegetation. This is very important for the water economy, especially during the annual-long periods of drought.