The páramo
The páramo is a neotropical alpine wetland ecosystem covering the upper region of the northern Andes. It consists of accidented, mostly glacier formed valleys and plains with a large variety of lakes, peat bogs and wet grasslands intermingled with shrublands and low-statured forest patches. It covers the upper parts of the northern Andes, roughly between 11° north and 8° south latitude. They form a discontinuous belt between the Cordillera de Merida in Venezuela to the Huancabamba depression in the north of Peru. Two separate complexes exist in, one in Costa Rica and another in the Sierra Nevada de Santa Marta, Colombia. Similar biomes are found in other continents. Tropical alpine grasslands similar to the páramo are abundantly present in the afroalpine belt, stretching from Ethiopia and Uganda to Kenya, Tanzania and South Africa. To a smaller extent, they occur in New Guinea and Indonesia. While most of the analysis is also valid for these regions, this website concentrates on the south American páramo. The total area covered by páramo is estimated between 35000 and 77000 km². This discrepancy is primarily due to uncertainties in the lower limit of the páramo. The natural forest line is severely altered by human activity (logging, intensive grazing), which makes the difference between natural and artificial grasslands difficult to distinguish.
The isolated and fragmented occurrence of the páramo over the Andean highlands promotes high speciation and an exceptionally high endemism. The ecosystem hosts about 5000 different plant species. About 60% of these species is endemic, adapted to the specific physio-chemical and climatic conditions, such as the low atmospheric pressure, intense ultra-violet radiation, and the drying effects of wind. The vegetation consists mainly of tussock grasses, ground rosettes, dwarf shrubs cushion plants and conspicuous giant rosettas like Espeletia and Puya. In some areas, a clear altitudinal vegetation gradient is present. In the subpáramo, 3000-3500 m altitude, mosaics with shrubs and small trees alternate with grasslands. Extensive cloud forests may develop at certain places, consisting of small, twisted and gnarled trees with small and thick, notophyllous leaves and many epiphytes. In the proper páramo (3500 - 4100 m), grasslands dominate and patches of woody species such as Polylepis and Gynoxys occur only in sheltered locations and along water streams. The superpáramo is a narrow zone with scarce vegetation between the grass páramo and the snow line. In all vegetation belts, azonal vegetation types (cushion bogs, mires, aquatic vegetation) occur in flat, perhumid areas.