ANTHROPOGENIC CHANGE IN THE LANDSCAPES OF HIGHLAND ECUADOR*

ABSTRACT. The anthropogenic nature of Andean ecosystems is discussed in the framework of tree‐line dynamics in selected sites in Ecuador. Indicators of human impact are evidence of the need for a scientific understanding of neotropical mountains that is better in tune with the special conditions of tropical Andean environments. Tropandean systems are neither tropical ecosystems nor midlatitude regions, and lessons from ecologically damaging activities in those ecosystems cannot be transferred readily to Tropandean systems. Better research from the ethnobiological and ecological fronts is needed if we are to comprehend the intricate functions of neotropical mountains, particularly the cloud‐forest belt, which is regarded as the most threatened ecosystem when considering sustainability scenarios.     

高压摆喷灌浆技术在西藏病险水库大坝防渗中的设计与施工

在西藏高原地区第四系冰碛和湖积松散堆积层防渗加固中,针对高原特殊的气候条件、工程地质与水文地质条件,通过改进高压摆喷设备与工艺,优化设计参数,取得了较好的防渗加固效果。工程实例表明,在高寒冻融地区,采用高压摆喷灌浆防渗加固技术,对砂砾石土坝进行加固处理,技术可靠,经济合理,效果明显,是一种有效的防渗处理方法,值得在高原地区进一步推广使用。