Otero Javier, Onaindia Miren
Department of Plant Biology and Ecology, University of the Basque Country, Bilbao, Spain.
Rev Biol Trop. 2009 Dec;57(4):1183-92. doi: 10.15517/rbt.v57i4.5455.
Changes in land use have generated a new landscape configuration in the Andino orobiome (mountain range) of the tropical Andes, resulting in a mosaic of cultivation and pastures interrupted by small fragments of forest and live fences. This has resulted in an ongoing decrease in the biodiversity of this biome. In the upper basin of the Cane-Iguaque River (Villa de Levya-Boyacá, Colombia), located 2,600-3,000 m above the Cordillera Oriental, over three time periods in 1960, 1984, and 2004, we characterized the structure, patterns, and evolution of the overall landscape and of the live fences (used as tools in biodiversity conservation and considered to be desirable alternatives to nonlive fences in farming production systems) within an agricultural landscape. To do this, we interpreted high-resolution satellite images using a landscape ecology approach and applied landscape map metrics. We found that the natural forests have been transformed by pastures and cultivation, and that although live fences cover only a small portion of the total landscape (4.6%), they have an important effect on landscape structure and biodiversity. There has been an increase in live fences, especially between 1960 and 1984, as well as an increase in their density. However, there has been a reduction in the average length of live fences over the periods that we studied. This could be due in part to changes in the types of agricultural products that have been cultivated in recent years, with an increase in potatoes and a decrease in other vegetables, and also by resource extraction of timber and fuel wood. In the studied area, agricultural production was sustained while biodiversity conservation was improved by the use of live fences. Therefore, live fences should be considered not only as part of an agriculturally productive area, but also as an important element of a multi-functional landscape that contributes to the maintenance of biodiversity and provides resources of economic and ecological interest, decreasing the pressure on natural forest. Improving the network of live fences constitutes an important strategy for the sustainable management of the rural landscape of the Andino orobiome of Colombia and similar areas in the tropics.
土地利用的变化在热带安第斯山脉的安第诺山地生物群落（山脉）中形成了一种新的景观格局，导致耕地和牧场镶嵌分布，中间穿插着小片森林和活篱笆。这导致该生物群落的生物多样性持续下降。在位于东科迪勒拉山脉海拔2600 - 3000米处的卡内 - 伊瓜克河上游流域（哥伦比亚博亚卡省莱维亚镇），我们在1960年、1984年和2004年的三个时间段内，对农业景观中的整体景观以及活篱笆（用作生物多样性保护工具，在农业生产系统中被视为比非活篱笆更理想的替代物）的结构、格局和演变进行了特征描述。为此，我们采用景观生态学方法解读高分辨率卫星图像并应用景观地图指标。我们发现天然森林已被牧场和耕地所取代，尽管活篱笆仅占整个景观的一小部分（4.6%），但它们对景观结构和生物多样性有着重要影响。活篱笆数量有所增加，尤其是在1960年至1984年期间，其密度也有所增加。然而，在我们研究的时间段内，活篱笆的平均长度有所减少。这部分可能是由于近年来种植的农产品类型发生了变化，土豆种植增加而其他蔬菜种植减少，同时也是由于木材和薪柴的资源开采。在研究区域，通过使用活篱笆，在维持农业生产的同时改善了生物多样性保护。因此，活篱笆不仅应被视为农业生产区域的一部分，还应被视为多功能景观的重要元素，有助于维护生物多样性并提供具有经济和生态价值的资源，减轻对天然森林的压力。改善活篱笆网络是哥伦比亚安第诺山地生物群落及热带类似地区农村景观可持续管理的重要策略。
