BUENOS AIRES - The howling monkeys (Alouatta palliata) that inhabit the northeastern subtropical forest of Argentina play an important role in the regeneration of the jungle as they move back and forth across the Paraná River, says a new study by the University of Buenos Aires school of natural science.

The population of this species remains homogeneous without being isolated. Because these monkeys feed on seeds, their excrement contributes to the maintenance of plant populations on both sides of the Paraná.

Unlike the Amazon river, which constitutes a barrier between species on each bank, the Paraná "acts as a canal of species maintenance" and aids in the reproduction of jungle plant varieties, says professor Marta Mudry.

BOGOTA - Colombian authorities are holding regional forums through mid-March to inform the public about the structure, functioning and responsibilities of the new Ministry of Environment, Housing and Territorial Development.

"The objective of these meetings is to open spaces for citizen participation, so that people take responsibility for promoting action on the environmental problems in their regions," says Minister Cecilia Rodríguez.

The new ministry is the result of the fusion, under the Alvaro Uribe administration, of the environment and development ministries, the latter of which was in charge of housing and public services.

LIMA - The Constitutional Tribunal of Peru is to issue a ruling in late March on the case involving the municipal government of Cajamarca and the Yanacocha mining company about a city regulation that bans the exploitation of the gold and copper ore of Quillish hill.

The conflict began in October 2000 when the municipality of Cajamarca, in the northern sierra, declared Quillish hill a protected reserve, saying the area is the source of the subterranean waters that supply the city and would be contaminated by mining operations.

In a public hearing before the Tribunal, Yanacocha avoided giving an in-depth response to the matter, but challenged the authority of the municipal council to create protected areas, saying that power belongs to the national government.

MEXICO CITY - Scientists at the Autonomous Metropolitan University of Mexico are developing an innovative technique to treat wastewater from the local petro-chemical industry, which includes the use of carbon dioxide and an anaerobic reactor.

Contaminated water is neutralized with carbon dioxide and then passed through a special oxygen-free reactor, where anaerobic microorganisms act to clean the water, say the scientists.

The system proved 90-percent effective in experiments, but it has yet to be tested using massive volumes of water. Mexico's state-run oil company, PEMEX, produces nearly 15,000 cubic meters of highly contaminated water each day.

The PEMEX refinery Miguel Hidalgo, in the southern state of Hidalgo, will try out the new technique later this year.

MANAGUA - The Nicaraguan Territorial Studies Institute (INETER) is drawing up the country's first map of subterranean waters in order to evaluate the state of its aquifers.

Subterranean waters are exploited without any controls, INETER director Claudio Gutiérrez told Tierramérica. "There is no data on how much the aquifers are being depleted."

To draft the map, financed by the Swedish Development Agency, a network of small wells will be created to measure the levels of the reservoirs.

The priority of the effort is the aquifer that extends through the western departments of León and Chinandega, the largest in the country. Measurements will also be made in the Rivas isthmus and in the central municipalities of Malacatoya and Tipitapa.

TEGUCIGALPA - Honduran farmers will halt use of methyl bromide pesticide on fruit crops like melon, watermelon and bananas beginning in April.

The agricultural sector in Honduras consumes 686 tons annually of methyl bromide, a gas that depletes the ozone layer and harms human health, according to the Secretariat of Environment and Natural Resources.

The government has created a plan for the gradual elimination of this chemical to ensure the export of toxin-free fruits and to comply with the rules of the World Trade Organization.

Excessive exposure to methyl bromide affects the respiratory and nervous systems and can cause gastro-intestinal problems. Elimination of the pesticide will begin in southern Honduras, where melon and watermelon crops are concentrated. Farmers will implement organic farming methods.