Giorgio Castellaro G.1 ,Cristián Gajardo A., Víctor H. Parraguez G., Roberto Rojas C. y Luis Raggi S.
Seasonal variation ofqualitative and quantitative productive characteristics of"bofedales" (dwarf herbaceous forbs and cushion plants growing in areas of moderate to high water content) was studied in an area of Parinacota province (18°10' L.S. 69°20' L.W. elevation 4400 m over sea level). A floristic inventory and vegetation mapping was made, identifying different vegetational types. Pastures corresponding to "bofedales" type and in suitable condition to be used by animals were selected. From these, it was determined herbage botanical composition and dry matter availability, metabolizable energy and crude protein content, pastoral and forage value. Evaluations were carried out during winter-dry season (August and July) and summer - rainy-season (November and February). Vegetacional dynamic of "bofedales" showed important differences between rainy-season and dry season. The most important species ofpasture botanical composition were Oxichloe andina, Festuca nardifolia, Carex incurva and Distichia muscoides. Herbage dry matier availability varied from 1.382 kg DM ha-1 in the dry-season to 3.089 kg DM ha-1 in the rainy-season. The herbage metabolizable energy content was 7,7 Mj kg-1, in the dry season and 7,1 Mj kg-1 in the rainy-season. The protein content varied from 6,8% in the dry season and 11,5% in the rainy season. According to these data values, the main restriction to animal production is the herbage metabolizable energy content, being crude protein only limitative during winter-dry season and earIy rainy-season. In function to pastoral value data of "bofedales", it was estimated a theoric grazing capacity varying between 0,31 and 0,36 AU ha-1 year-1.
Key words: camelids, bofedales, botanic composition, nutritive value, North of Chile.
1 Actividad Privada, Apolo – 6 1843, Vitacura, Santiago, Chile.