Resumen

BACH, Kerstin et al. Vegetation, soil and climate in different altitudinal belts in montane cloud forests of the Yungas, Bolivia: first results . Ecología en Bolivia [online]. 2003, vol.38, n.1, pp. 3-14. ISSN 1605-2528.

Since June 2000 an interdisciplinary research project is carried out in the Cotapata National Park (Yungas, Bolivia), which investigates climate, soils and vegetation covering an elevational gradient of 1.700 to 3.400 metres. The main objective is to determine correlations and interactions between biotic and abiotic factors along the elevational gradient. Four elevational vegetation types have been recognized: the montane forest (up to ca. 2.100 m), the high montane forest I and II (ca. 2.100-3.150 m) and the tropical subalpine forest (up to 3.400 m). Annual air temperature decrease from 17°-20°C to 12°-17°C with increasing elevation and 0.63°C per each 100 m elevation range. The soil examinations show the following hypsometrical soil differentiation: in the montane forest Humic Dystrudepts (according to Soil Survey Staff 1998) are dominant. From the high montane forest the following soil types appear in relation to slope inclination, micro relief and soil age: Typic Placaquod, Spodic Dystrudept, Typic Durorthod and Histic Humaquept. Reduction of evapotranspiration with increasing elevation is a decisive factor for soil development. At 3.000 m the ground water almost permanently attains field capacity. It is proposed, that ground water balance is a keyfactor affecting the distribution of terrestrial plant species and the vegetation classification along the gradient.

Palabras llave : Bolivia; tropical montane cloud forests; climate; soil; vegetation types.