By Lic. Carlos Portillo and Dr. Miguel Pietrangeli
The local deforestation figures provided by MARN indicate that the Zulia region has been the most deforested, with more than 90% of its forests having disappeared from 1982 to 2003.
Only a small portion (0.3%) of the water available on the planet corresponds to fresh water or water that can be consumed by humans. Most of this resource is found in glaciers, while rivers, lakes and the atmosphere only have a tiny fraction of the planet's fresh water. An important part, however, is contained in aquifers or groundwater as well as in soil moisture.
In recent decades, research has highlighted the importance of maintaining tropical forests, their plant and animal species, as part of the water resource. It has been found that a forest community maintains the porosity of the soil, prevents its compaction, erosion and desiccation.
In addition, the water vapor released from the treetops (a process called evapotranspiration) rises by convection, cooling until it reaches the "dew point" where masses of water vapor condense to form clouds and precipitate as rain. . On the other hand, deforestation not only causes the instability of the rain regime but also a more intense flow of water at the surface level (runoff) in rainy seasons, causing floods, and the total desiccation of rivers in dry seasons.
The maintenance of the rain regime at the local level is conditioned by the state of the forests in the region. Fortunately, the mountainous formations of the Maracaibo Lake System favor precipitation to the south of the lake, ensuring a water supply for the State. However, both the effects of global climate change and deforestation at the local level could change the rainfall patterns for the region, affecting not only the stability of the Lake Maracaibo basin, but also the quality and regularity of the water resource for the towns. region of.
Local deforestation figures provided by MARN indicate that the Zulia region has been the most deforested, with more than 90% of its forests having disappeared from 1982 to 2003. The effects of intense surface runoff, due to deforestation, in recent times Rainy have been part of the cause of the appearance of the Lemna sp. species, promoting the carry-over of high concentrations of pollutants from the headwaters of the rivers and changes in the proportion of fresh water in Lake Maracaibo.
To measure the intensity of the conversion of the ecosystems of tropical dry forests to the north-west of the Zulia State, a case study was evaluated in the lower basin of the Socuy, Guasare and Cachirí rivers. In this area, the changes produced on the Tropical Dry Forest from 1986 to 2001 were quantified, where it was achieved that between 7 thousand and 12 thousand hectares of these ecosystems have disappeared, with a deforestation rate of 505 to 854 ha per year, projecting an original forest vegetation cover of less than 40% in 30 years. These data, when contrasted by the category system created by the Threatened Environments Project (Provita, IVIC, Fundación Polar, 2004) classifies these ecosystems as threatened with extinction (Vulnerable Categories in an optimistic scenario and Critically Endangered in a pessimistic scenario) .
The results are alarming taking into account the region studied where the main sources of drinking water are concentrated for the state of Zulia, and when taking regional deforestation data, calculated by MARN, we observe that more than 3 million hectares have disappeared in the last 21 years, leaving only 8% of what there was in 1982.
The situation now forces us to recover degraded areas and protect the remnants of unprotected forests. The recovery of forests through reforestation applying knowledge in plant succession (process of formation of forest communities similar to the original ones) is a local need that must be carried out by MARN, ICLAM, and regional government as soon as possible. The knowledge exists, the people exist, and unfortunately the need exists, but the conceptual and economic initiative is lacking from the decision makers in these institutions.
The same case occurred from 1940 to 1980 in Costa Rica, where almost all of the country's forests were deforested for agricultural use. The government and government institutions undertook economic studies to establish reforestation strategies. Since 1980, economic incentives have been given to landowners to conserve their remaining forest fragments or to reforest their lands. The type of forest management as well as the number of hectares involved have earned these owners a certain amount of money paid annually. This strategy has not only served to ensure the maintenance of biodiversity and water resources for Costa Rican towns, but also for the economic development of rural areas.
The funds to finance economic incentives come from taxes (called environmental taxes) on fuel consumption, tourism activity, alliances between companies and the government, and funds from international institutions such as the World Bank, the World Fund for the environment. environment and international conventions (once the Kyoto Protocol has been ratified). The success of this strategy is such that today the main economic activity in Costa Rica is tourism.
In the Edo. Zulia is experiencing another reality, of course, and it would be illusory to want to study the implementation of a development model based on tourism, but to think of similar alternatives is necessary. Possibly a regional plan of this type could be applied at the level of the municipalities present in the foothills of the Sierra de Perijá and at the headwaters of the most important rivers in the State.
In any case, the proposal of alternatives at this time, when the consequences of poor management of the lake basin has significantly affected the health and economic activity of the region, should be part of the work of ecologists, sociologists , economists and others concerned about the impending disappearance of the forest ecosystems of the lake system.
* Laboratory of Plant Ecology and Systematics of Vascular Plants. Biology Department, University of Zulia, Maracaibo, Venezuela.