Bücker, A. (2010): <b>Chemical and biological water quality in tropical cloud forest streams under different land-use</b> Institute of Resources Management, University of Giessen, <i>phd thesis</i>
Resource Description
Title:
Chemical and biological water quality in tropical cloud forest streams under different land-use
Short Name:
Chemical and biological cloud forest water quality
FOR816dw ID:
880
Publication Date:
2010-05-16
License and Usage Rights:
belong to Amelie Bücker and the University of Giessen, ILR<br/>
Parts of the text has been (or will be) published
“There is, however, one natural feature of this country, the interest and grandeur of which may be fully appreciated in a single walk: it is the “virgin forest”. Here no one who has any feeling of the magnificent and the sublime can be disappointed.” Alfred Russel Wallace commented with these words on the wonders of the rain forest covering the Amazon Basin. If he had travelled further up, right to the origins of the Amazon, to the far-off places of Andean headwater streams, he would have encountered a forest ecosystem even more wondrous and unique – the montane cloud forest (Figure 1-1). The Merriam Webster dictionary defines cloud forests rather shortly as “wet tropical mountain forests at an altitude usually between 3000 and 8000 feet (1000 and 2500 meters) that are characterized by a profusion of epiphytes and the presence of clouds even in the dry season” (Merriam-Webster 2003). During the first international symposium on cloud forests in Puerto Rico in 1993, a more explicit collection of characteristics was put together (Hamilton et al. 1993). Here, the ecosystem is defined as having: - a distinctly floristic and structured form - an atmospheric environment with persistent cloud cover - reduced solar radiation - suppressed evapotranspiration - enhanced net throughfall input due to the stripping of clouds by the tree canopies - reduced canopy heights and gnarled tree trunks at higher altitudes - a large epiphyte biomass - wet and frequently waterlogged soils with a high organic content - extremely high biodiversity (a so-called biodiversity hotspot) - a high amount of endemism. Cloud forests are found all around the world (see Figure 1-2), far inland or on islands, and at altitutes ranging from as low as 500 m up to 3500 m (Hostettler 2002). Although only 2.5 % of the world’s tropical forests are cloud forests (Bubb et al. 2004) they are outstandingly important for sustaining life on our planet. A myriad of plants have evolved depending upon the constant fog and hundreds of animals have evolved to depend on these plants. Numerous plant species have been found to possess medicinal qualities and contribute to the health of a multitude of people each year. For example quinine, the cure for malaria, is extracted from the bark of the Cinchona tree, which was first discovered in the montane cloud forests of Peru (Régnier 2007). Other essential ecosystem services provided by cloud forests are the formation of soil, carbon sequestration, the cycling of nutrients and recreation among others (Costanza et al. 1997). The key function of cloud forest, though, is the provision of high amounts of good quality freshwater. Downstream populations depend on this provision of drinking and irrigation water, an important part of which is captured by the stripping of clouds by tree canopies. Even during drier periods, pristine cloud forests supply a reliable stream flow by draining the water which is abundantly stored in the forest vegetation and soil. Several large tropical capitals such as Quito, Tegucigalpa and Mexico city are dependent on this water and are thus intertwined with the fate of these watersheds (Hostettler 2002). Not without reason around 90 % of the world’s cloud forest sites are included in the WWF Global200 region list with conservation priority (Aldrich et al. 2000). Despite their importance, tropical forests all over the world are deforested at an overwhelming rate. The average annual deforestation rate for tropical forests in South America has been estimated to be 0.4 % for the year 2000. Amongst all South American countries, Ecuador has by far the highest deforestation rate with a lessening of the country’s forest cover of 1.2 % per year (FAO 2001). Reasons for deforestation are various, but are generally caused by population growth or shifts. The most widespread threat to tropical cloud forests is forest clearance for farming or pastures. In some countries hunting, forest fires and mining are also responsible for forest conversion or degradation. However, one of the most prevalent pressures on lowland rainforests, namely timber harvesting, is not such a big issue for cloud forests due to the mostly steep topography, and the reduced tree heights at these altitudes (Bubb et al. 2004). Even though the intrinsic and economic values of cloud forests are widely acknowledged, our understanding of the drivers of ecosystem functioning is still deficient. Sadly, the scarce knowledge about these fragile systems poses a hindrance for effective conservation management and future policy decisions (McClain & Naiman 2008).
Additional Infos:
PhD Thesis
Literature type specific fields:
THESIS
Degree:
phd
Degree Institution:
Institute of Resources Management, University of Giessen
