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6. Conversion and conservation of cloud forests

In the humid tropics the main causes of deforestation and forest conversion are generally the following:

1. forest exploitation without planning or silvicultural management, causing degradation and erosion;
2. the advancement of the "agricultural frontier" which converts natural forests into farm areas - a more and more frequent occurrence in areas unsuitable for cultivation or grazing;
3. new roads that cross forested And frequently mountainous areas provoking spontaneous and uncontrolled human colonization the length of their trajectories.

In many tropical mountain areas it is possible to observe the agricultural frontier moving rapidly towards increasingly steeper areas with high rainfall, including large areas of cloud forest. The deforestation of cloud forests in mountainous areas endangers their protective role in hydrological terms and soil conservation. The consequences of erosion provoked by the destruction of cloud forests can be indeed disastrous, as shown by Daugherty (1973).

Cloud forests are frequently destroyed with the aim of establishing grazing land for extensive cattle farming, resulting in soil compaction thus reducing its infiltration capacity and provoking a considerable increase in surface runoff. This change in the hydrological regime, combined with the erosion processes in the upper watersheds, presents a great flood danger for lower watersheds where there are frequently large concentrations of people on river banks.

Although it is not possible to give figures on the loss of cloud forests through the different deforestation and degradation processes, Zadroga (1981) thinks that cloud forests are currently being converted into one of the most rapidly disappearing forest ecosystems under pressure from man.

It is therefore important to support and promote all attempts and activities to protect cloud forests against a change in land use, not only because they are fragile ecosystems (I,a Bastille and Pool, 1978), but also because of their important hydrological properties (Budowski, 1976; Hamilton and King, 1983). Other arguments in favour of the total protection of cloud forests include the danger of erosion, and the protection of endemic species, unique landscapes and genetic resources, mentioned in the previous chapter.

For the Central American and Caribbean region, La Bastille and Pool (1978) described the currently protected cloud forests (generally in the form of national parks) and proposed various additional areas for future protection. They also emphasized the necessity of creating a system or network of cloud forests in the region, with the aim of improving and strengthening their protection and the exchange of scientific information between the different institutions charged with managing and administering the parks.

La Bastille and Pool's (1978) proposal concentrated primarily on cloud forests that, from the biogeographical point of view, exhibit outstanding ecological characteristics, such as special biotopes or endemic species, and are generally restricted to limited areas. Beyond this extremely valid approach, the necessity of ensuring the protection of relatively extensive areas of cloud forest should also be emphasized here, where particular ecological characteristics are of secondary importance to their hydrological role. In the case of Central America, for example, it can be seen that a wide belt in the mountains, particularly on the Atlantic slope, serves this function. According to Holdridge (1982) tropical cloud forests predominate as a wet atmospheric association in the life zones from Moist Forest to Rain Forest of the Premontane and Lower Montane belts. The exposure to prevailing winds must be considered a factor of great importance; in the case of Central America, for example, this implies that the majority of cloud forest zones are situated in the Premontane and Lower Montane belts of the Atlantic slope.

The neotropical region currently has 67 protected areas which include cloud forests (IUCN, 1982). The principal categories of these areas are: National Parks, Biological Reserves, National Reserves, Ecological Reserves, Biosphere Reserves and National Monuments See table 5).

Table 5.Protected areas, including cloud forests in the humid tropics of the Neotropical Realm according to IUCN (1982)

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