Giraldo Lina Paola, Chará Julián, Zúñiga Maria del Carmen, Chará-Serna Ana Marcela, Pedraza Gloria
Rev Biol Trop. 2014 Apr;62 Suppl 2:203-19.
The expansion of the agricultural frontier in Colombia has exerted significant pressure on its aquatic ecosystems during the last few decades. In order to determine the impacts of different agricultural land uses on the biotic and abiotic characteristics of first and second order streams of La Vieja river watershed, we evaluated 21 streams located between 1,060 and 1,534 m asl in the municipalities of Alcalá, Ulloa, and Cartago (Valle del Cauca, Colombia). Seven streams were protected by native vegetation buffers, eight had influence of coffee and plantain crops, and six were influenced by cattle ranching. Habitat conditions, channel dimensions, water quality, and aquatic macroinvertebrates were studied in each stream. Streams draining cattle ranching areas had significantly higher dissolved solids, higher phosphorus, higher alkalinity, higher conductivity, and lower dissolved oxygen than those covered by cropland and forests. Coarse substrates and diversity of flow regimes were significantly higher in cropland and protected streams when compared to streams affected by cattle ranching, whereas the percent of silt and slow currents was significantly higher in the latter. A total of 26,777 macroinvertebrates belonging to 17 orders, 72 families and 95 genera were collected. The most abundant groups were Diptera 62.8%, (Chironomidae 49.6%, Ceratopogonidae 6.7%), Mollusca 18.8% (Hydrobiidae 7.2%, Sphaeriidae 9.6%) and Trichoptera 5.7% (Hydropsychidae 3.7%). The Ephemeroptera, Trichoptera, and Plecoptera orders, known for their low tolerance to habitat perturbation, had high abundance in cropland and forested streams, whereas Diptera and Mollusca were more abundant in those impacted by cattle ranching. Results indicate that streams draining forests and croplands have better physical and biological conditions than those draining pastures, and highlight the need to implement protective measures to restore the latter.
在过去几十年里，哥伦比亚农业前沿的扩张对其水生生态系统施加了巨大压力。为了确定不同农业土地利用方式对拉维耶哈河流域一级和二级溪流的生物和非生物特征的影响，我们评估了位于阿尔卡拉、乌略亚和卡尔塔戈市（哥伦比亚考卡山谷省）海拔1060至1534米之间的21条溪流。其中7条溪流受到原生植被缓冲带的保护，8条受到咖啡和大蕉作物的影响，6条受到养牛业的影响。我们对每条溪流的栖息地条件、河道尺寸、水质和水生大型无脊椎动物进行了研究。与农田和森林覆盖的溪流相比，流经养牛区的溪流的溶解固体、磷、碱度、电导率显著更高，溶解氧更低。与受养牛业影响的溪流相比，农田和受保护溪流中的粗基质和水流形态多样性显著更高，而后者的淤泥和缓流百分比显著更高。共采集到26777只大型无脊椎动物，分属于17目、72科和95属。数量最多的类群是双翅目62.8%（摇蚊科49.6%，蠓科6.7%）、软体动物18.8%（溪螺科7.2%，球蚬科9.6%）和毛翅目5.7%（纹石蛾科3.7%）。蜉蝣目、毛翅目和襀翅目对栖息地扰动耐受性低，但在农田和森林溪流中数量较多，而双翅目和软体动物在受养牛业影响的溪流中更为丰富。结果表明，流经森林和农田的溪流比流经牧场的溪流具有更好的物理和生物条件，并强调需要采取保护措施来恢复后者。
