Ecología de los robledales de altura (bosque de Quercus) maduros y en recuperación en la Cordillera de Talamanca, Costa Rica

Abiotic and vegetation data were collected along two altitudinal transects through mature montane Quercus forests on the Pacific and Atlantic slope of Costa Rica's Chirripó Massif. Between 2000 and 3200 m asl twenty-four 0.05 ha forest plots were selected at altitudinal intervals of 100 m, and eight soil profiles were described at intervals of 200 m. A TWINSPAN classification aided in the determination of eight zonal forest communities on basis of their floristic composition. They are grouped in two sets of four: (i) the palm-rich lauraceous-fagaceous Lower Montane Mollinedia - Quercus Forests (2000 - 2600 m asl) and (ii) the bamboo-rich myrsinaceous-fagaceous Upper Montane Schefflera -Quercus Forests (2500 - 3200 m asl). Vegetation changes seem correlated with two major climatic gradients: (i) a temperature gradient (altitude), and (ii) a moisture gradient (wet Atlantic vs. moist Pacific slope). Temperature is highest and relative humidity lowest at noon during the dry season. Relative humidity values > 85 percent occur daily during both seasons. Diurnal temperature and humidity fluctuactions are greatest during the dry season in Upper Montane Forest. The predominantly denudational terrain in deeply fluvially dissected with steep to moderately steep slopes, rugged crests and a dendritic drainage pattern. Intrusive igneous rocks (granites, diorites and granodiorites) are abundant. Most soils are Andepts, and residual, colluvial or derived from volcanic material. Humus layers are thickest on the wetter Atlantic slope. A total of 431 vascular plant species consisted of 86 pteridophytes, 1 gymnosperm, 296 dicots and 48 monocots. With increasing altitude species richness, canopy height and stem diameter decrease, while the canopy surface becomes more flattened. A comparison with other studies that Chirripo's montane oak forest fit within the environmental ranges known altitudinal zonations elsewhere in the Tropics.

Bibliographic Details

Main Authors:	126028 Uffelen, J.G. van, 58011 Cleef, A.M., 82284 Kappelle, M., 20493 University of Amsterdam, Amsterdam (Países Bajos). Dept. of Palynology and Paleo, 20110 Universidad Nacional, Heredia (Costa Rica)
Format:	biblioteca
Published:	Amsterdam (Países Bajos) 1995
Subjects:	QUERCUS, CLIMA, GEOMORFOLOGIA, ALTITUD, SUELO, DISTRIBUCION NATURAL, ESTRUCTURA DEL BOSQUE, PARQUE NACIONAL CHIRRIPO, COSTA RICA,
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