Biophysical Constraints to Development Dream and Reality

Abstract

An intricate pattern of physical and cultural features is characteristic of the Northern Andes which, as a region, is unique among the world's mountain ecosystems. As the highest and most extensive area of mountainous terrain in the equatorial zone, it exhibits the utmost development of altitudinal belts of climate and vegetation. Chimborazo, at latitude 1°30' South in Ecuador, is the loftiest of the equatorial peaks (6,310 m), surpassing by more than 300 m the summit of Kilimanjaro. Eight mountains in the Northern Andes are high and wet enough to support active glaciers. This segment of the longest mountain chain in the world enjoys adequate to abundant rainfall over nearly all of its area. Combined with the extreme altitudinal range this affords a maximum diversity of ecological niches. In comparison with the other equatorial mountain regions of East Africa and New Guinea, the Northern Andes is the most populous, most industrialized, and most developed. The land area of the Northern Andes ranks it after the much more extensive Central Andes, but ahead of the Southern Andes, as defined by Gomez Molina and Little (1981). Ecuador, Colombia, and Venezuela have a combined population (1981) of over 51 million, or some 20 percent of the South American total. According to common socioeconomic indices, the three countries rank at or above the average for the continent. Literacy rates in the mid-1970s were reportedly 75 percent for Ecuador, 78 percent for Colombia, and 82 percent for Venezuela. Per capita incomes in the late 1970s were U.S. $830 for Colombia, $1,099 for Ecuador, and $2,590 for Venezuela, the highest in South America. Petroleum exploitation tends to inflate the averages for the latter two. The northern Andean republics are growing rapidly in population. Ecuador and Venezuela have rates of annual natural increase above 3 percent, while in Colombia rates have in recent years dropped down to just over 2 percent. As measured by the new physical quality of life index (PQLI)a composite of infant mortality, life expectancy at age one, and literacy, e ch with equal weight-Ecuador receives 69, Colombia 72, nd Venezuela 79; these values are about average for the continent but above those of the Central Andes. The distinctive physical and cultural character of the region, and the interaction between the human populations and the ec zones they inhabit, complicate the offering of suggested courses of action. Because of adequate rainfall and position astride the equator, the successful adaptive strategies of the Central and Southern Andes have only limited applicability to the Northern Andes. Thus both analyses and recommendations must be region specific. The purpose of this concluding paper is to restate the reasons underlying the subject matter in this special Unesco MAB collection of papers on the Northern Andes, to comment on selected issues raised by the individual contributions, to provide some additional bibliographic references of general utility, and to summarize the ecologically-related research needs. In Volume One of this series, Glaser and Celecia (1981) stated the general objectives of man-biosphere research in the Andes, and those topics of particular relevance to the Northern Andes. For the latter, population pressure and migration are identified as paramount concerns. Ever-increasing population pressure has led to deforestation, acc lerated erosion, soil impoverishment, stream flooding and silting, and further expansion of the agricultural frontier into areas of primary forests at lower elevations. A major problem is low agricultural productivity. Human migration is related to and results from these conditions and creates an additional set of social problems. The authors point out th need to consider catchment areas as the natural units for ecosystem analysis and for land-use studies. Shifting cultivation is also identified as a key research area. To the extent possible, aspects of these issues are addressed by means of a blend of systematic essays and case studies. For purposes of discussion, these can be grouped under three headings: land-use practices, environmental repercussions, and socio-economic repercussions and remedies.