CARACTERIZACIÓN DE LA VEGETACIÓN A LO LARGO DE UNA GRADIENTE ALTITUDINAL EN LA COMUNIDAD DE COCHAHUAYCO, CUENCA MEDIA DEL RÍO LURÍN, LIMA.

There are many studies on vegetation and ecosystem characterization in the occidental slope of the Central Andes of Peru. However the knowledge of the vegetation of the highlands of Lima is limited. Therefore, we conducted a study of the vegetation in the middle basin of the Lurin river, department of Lima. The aim was to characterize the upland vegetation of the Cochahuayco community according to an altitudinal gradient, ranging from 1720 to 2957 masl, based on samples and field observations. We established eight sampling units along the gradient, following a systematic sampling model with random start. The sampling units were evaluated on a quarterly basis from july-2009 to july-2010. Five vegetation units were differentiated, based on the composition, abundance and coverage of species of the shrub layer. These units were: Cacti Zone (between 1720 and 2000 masl), where Haageocereus acranthus and Espostoa melanostele were the dominant cacti; Bastardia Zone (from 2000 to 2230 masl), where Bastardia bivalvis was dominant; Tall shrubs Zone (from 2230 to 2500 masl), where Euphorbia cf. laurifolia and Perymenium jelskii were dominant; Sub-thorny shrubs Zone (from 2500 to 2850 masl), where Verbesina saubinetioides was dominant; and Thorny Shrubs Zone (from 2850 to 2957 masl), where Proustia cuneifolia was dominant. The first two units fell within the Subtropical desert scrub life zone, and the other three in the Lower montane thorn steppe life zone; all these belonged to the shrub thicket coverage type. [ABSTRACT FROM AUTHOR]