Andean Forests and farming systems in part of the Eastern Cordillera (Colombia)

Andean ecosystems are among the most diverse and threatened ecosystems in t he world. Only very general data on the extent and impacts of the transform ation processes that have affected ecosystems in Colombia are available to date. This study analyzes the transformation of forests in part of the East ern Colombian Andes, using the landscape ecological approach, with remote s ensing, fieldwork, and GIS. There are two levels of analysis: a region al l evel (1:500,000) covering 4.1 million ha and a subregional level (1:50,000) covering 225,000 ha. The former covers the central portion of the East-And ean Cordillera, where the remaining forest and paramo areas were quantified and their spatial distribution analyzed. The subregional analysis level is located in the Middle Chicamocha Watershed. The effects of human activitie s on the ecosystems were analyzed, taking current farming systems into cons ideration. The historical human impact in the region has been intense, espe cially in the drier parts of the study area. At the regional level, only 22 % of the original forests remain, of which 28.7% are located in the nationa l parks. In the subregional study area, only 7.6% remain, mainly at altitud es of more than 3000 m. Of five identified forest types, the two with consi derable covered areas were the High-Andean Polylepis Forests (33.6%) and th e High-Andean mixed forests (35.1%). The original land cover of the sub-And ean dry forests has been almost totally replaced by seminatural shrublands, pastures, crops, and severely degraded areas. The largest fragments are An dean mixed forests and the Andean oak forests, with sizes up to 866 and 118 2 ha. Of 19 identified farming systems at the subregional level, only 5 inc lude substantial proportions of their original forest covers.