The tropical mountain ecosystem of one of the "hottest" hotspots of biodiversity in the world was investigated by almost 30 groups of researchers from various disciplines. They performed ecosystem analyses following two gradients: an altitudinal gradient and a gradient of land use intensity and ecosystem regeneration following human use. Based on these analyses, this volume discusses findings in macro and microclimate; physics, chemistry, and biology of soils; water relations; matter turnover and nutrient availability; biomass allocation; plant growth; floral composition; vegetation structure and dynamics; plant life forms; organismic interactions; population diversity of birds, moths, and microarthropods; ethnobotanical and sociological aspects; forest management; and reforestation with indigenous species. Several new hypotheses regarding biodiversity, ecosystem functioning, and the sustainable management of a biodiversity hotspot are presented.