Changing climate and endangered high mountain ecosystems in Colombia

• Published in: The Science of the total environment Vol. 398; no. 1; pp. 122 - 132
• Main Authors: Ruiz, Daniel, Moreno, Hernán Alonso, Gutiérrez, María Elena, Zapata, Paula Andrea
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 15.07.2008; [Amsterdam; New York]: Elsevier Science; Elsevier Science
• Subjects: Altitude; Animal and plant ecology; Animal, plant and microbial ecology; Basins; Biodiversity; Biological and medical sciences; Climate; climate change; Climatology. Bioclimatology. Climate change; Clouds; Colombia; Earth sciences; Earth, ocean, space; Ecosystem; Ecosystems; Exact sciences and technology; External geophysics; Fundamental and applied biological sciences. Psychology; Glaciers; Global change; Greenhouse Effect; Ground truth; Headwaters; High mountain ecosystems; Humidity; Hydrology. Hydrogeology; Low level; Meteorology; Mountains; Paramos; Páramos; Rain; Rainfall; Reduction; Relative humidity; Rivers; Sunlight; Synecology; Temperature; Terrestrial ecosystems; Time series; Tropical environments; Water resources; Water supplies; Weather stations; Colombia; South America; Andes; Brazil, Claro R; Páramos; Glaciers; High mountain ecosystems; Global change; time series analysis; mountains; trend-surface analysis; Climatic data; Regional scope; tropical zone; Atmosphere cryosphere interaction; species diversity; environment impact; water resources; global change; ecosystems; Glacier retreat; Observation data; Forest fire; climate change
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2008.02.038

High mountain ecosystems are among the most sensitive environments to changes in climatic conditions occurring on global, regional and local scales. The article describes the changing conditions observed over recent years in the high mountain basin of the Claro River, on the west flank of the Colombian Andean Central mountain range. Local ground truth data gathered at 4150m, regional data available at nearby weather stations, and satellite info were used to analyze changes in the mean and the variance, and significant trends in climatic time series. Records included minimum, mean and maximum temperatures, relative humidity, rainfall, sunshine, and cloud characteristics. In high levels, minimum and maximum temperatures during the coldest days increased at a rate of about 0.6°C/decade, whereas maximum temperatures during the warmest days increased at a rate of about 1.3°C/decade. Rates of increase in maximum, mean and minimum diurnal temperature range reached 0.6, 0.7, and 0.5°C/decade. Maximum, mean and minimum relative humidity records showed reductions of about 1.8, 3.9 and 6.6%/decade. The total number of sunny days per month increased in almost 2.1 days. The headwaters exhibited no changes in rainfall totals, but evidenced an increased occurrence of unusually heavy rainfall events. Reductions in the amount of all cloud types over the area reached 1.9%/decade. In low levels changes in mean monthly temperatures and monthly rainfall totals exceeded + 0.2°C and − 4% per decade, respectively. These striking changes might have contributed to the retreat of glacier icecaps and to the disappearance of high altitude water bodies, as well as to the occurrence and rapid spread of natural and man-induced forest fires. Significant reductions in water supply, important disruptions of the integrity of high mountain ecosystems, and dramatic losses of biodiversity are now a steady menu of the severe climatic conditions experienced by these fragile tropical environments.