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Environment


Costa Rican biomass programme
Does deforestation affect climate?
Test results of cloud seeding
Protecting pheasants
Oceanography in Ethiopia
Philippine crocodiles threatened
Germ-plasm banks started in us
European birds and butterflies join endangered list as habitats change

Costa Rican biomass programme

A new biomass energy project has been launched in Costa Rica by the Instituto Tecnológico de Costa Rica, an institution of higher education specializing in science and technology, and the Citizens' Energy Corporation, a private, non-profit energy company designed to assist low-income people in meeting their energy costs. The project is designed to help reduce Costa Rica's dependence upon expensive oil imports.

Phase one of the project will involve the development of a series of plastic bag biodigesters to provide methane gas for small- and medium-sized farms from animal manure. The second phase will be an attempt to redesign the coffee-drying process now being employed so that less oil is consumed. In phase three, an attempt will be made to use forestry and sawmill wastes to produce various energy generating gases, liquids and solids.

Does deforestation affect climate?

New research has shown that modifications in the earth's vegetation cover through such processes as deforestation and afforestation can significantly affect rainfall and other components of weather. The qualification is that such modifications must be of a large magnitude and occur over a large horizontal area.

The assumption, of course, has been that increased vegetation cover would increase rainfall and that decreases in vegetation cover would lower it. Underlying this assumption is a correlation between rainfall and "evapotranspiration", or the loss of water into the air from the soil, by evaporation, and from the vegetation growing on that soil, by transpiration.

An atmospheric general circulation model developed by the Goddard Laboratory for Atmospheric Sciences, using equations for mass, momentum, moisture and energy expressed through a numerical, spherical grid and comparing a "wet-soil" model with a "dry-soil" model, has shown that large changes in vegetation cover do affect rainfall. However, vegetation alone is not the crucial factor but rather the interrelationship among moisture in the soil, vegetation and energy (primarily sunlight) needed to convert water into airborne water vapour. (Science, Vol. 215, No. 4539, 19 March 1982, p. 1500-1502).

Test results of cloud seeding

A new series of cloud-seeding tests conducted by the US National Oceanic and Atmospheric Administration (NOAA) have failed to confirm the "suggestive but statistically weak positive results" of a 1978 test, according to a recent article in Science (Vol. 217, No. 4556, 16 July 1982. p. 234-236).

The tests, conducted in south Florida, were based on statistically rigorous drug trials. The first series of tests in 1978, called FACE-1, showed a 25-percent increase in rainfall on days with seeding compared to days without.

Experimenters, however, pointed to two factors which they think make the test results not as pessimistic as it might seem: first, that the FACE-2 tests were conducted on 51 days rather than 75 because of a lack of appropriate seeding days, and that this reduced sample could have affected the final results; secondly, that one day with unusually heavy rain occurred on a day when the seeding was done with a "placebo" (inert sand) rather than the theoretically rain-inducing silver iodide particles, and that this could have distorted the statistics.

"The whole process of cloud-seeding," say two statisticians intimately involved with the tests, "seems to be far more complex than we thought before FACE-2. Most researchers are coming to the conclusion that you have to know your clouds."

For now, at least, further cloud seeding experiments will probably be halted until more is known about clouds and other physical processes of weather.

Protecting pheasants

The World Pheasant Association, which already has members in 50 different countries, has now added a chapter in Thailand as of September 1981. Other countries that have formed chapters include Belgium, the Netherlands, Luxembourg, France, the Federal Republic of Germany, India, Malaysia, Nepal and Pakistan. The Thai chapter, like those already existing, has the dual purpose of trying to maintain a blend of private aviculture and official conservation.

Thailand's immediate aim, however, will be to assist in the propagation of the green peafowl (Pavo muticus imperator) from local stock in areas where it is being threatened or has, in fact, already been eliminated. Eventually Thailand's chapter hopes to initiate efforts to propagate other indigenous Galliformes such as partridge and quail. The new chapter's address is: World Pheasant Association Thailand, c/o ACW, 4 Customs House Lane, Bangkok 5, Thailand.

Oceanography in Ethiopia

Oceanographers are studying the Galla Lakes, which lie along the Ethiopian Rift south of Addis Ababa, in the hope of gaining information about ocean processes. This is because these particular lakes, like the ocean, are a closed system, receiving both water and dissolved salts but losing only water (through evaporation) while the salts remain.

Research results to date have shown that minerals such as magnesium, potassium and sodium, instead of precipitating, are combining with clays to form new minerals. This process is called "reverse weathering". Whether the same process can be inferred to occur also in the ocean is still controversial, but researchers expect that further study of the Ethiopian lakes will provide some answers.

Philippine crocodiles threatened

An effort has been started by the Philippine Ministry of Natural Resources, in conjunction with the joint Smithsonian institute-World Wildlife Fund Philippine Crocodile Project, to protect two species of Philippine crocodiles. At present the effort is being confined to the gathering of information and the conducting of research, but it is hoped that direct action to ensure their preservation can be employed in the near future.

The two species are the Philippine crocodile (Crocodylus mindorensis) and the Pacific estuarine crocodile (Crocodilus porosus). Many people, few of whom can distinguish between the two species, incorrectly consider both as dangerous to people and livestock. The Pacific estuarine crocodile is much larger, however, and reported to be rarely vicious, unlike the small Philippine crocodiles. With no crocodile sanctuaries yet established in the country, the result has been considerable poaching of both species indiscriminately out of fear and out of a desire to cash in on the crocodiles, valuable skin.

However, the two crocodiles perform at least three valuable ecological functions, according to Charles A. Ross of the Philippine Crocodile Project and Ceferino P. Datuin of the Ministry of Natural Resources (see "Crocodiles in peril", Tiger Paper, Vol. VIII, No. 4, p. 19). These are (i) to inhibit the encroachment of aquatic plants in the waterways by their constant movements; (ii) to maintain residual water-holes which serve as restocking reservoirs for smaller aquatic organisms; (iii) to enrich the nutrient content of estuaries and lakes by creating water-borne particles (faeces) that are excellent food for invertebrate animals and fish.

Germ-plasm banks started in us

A series of germ-plasm banks for agricultural researchers and genetic engineers is being established in the United States under the aegis of the Department of Agriculture (USDA). The germ-plasm banks which are, in effect, libraries for seeds, represent one part of an effort to collect and preserve thousands of varieties of germ-plasm, the cellular material that determines the heredity of plants and animals.

Spearheading the effort through the USDA is the National Plant Germplasm System, a network of educational institutions, federal and state agencies and industrial sources that cooperate in germ-plasm work.

The first germ-plasm bank, the Northwest Plant Germplasm Repository, is already in operation in Corvallis, Oregon, at Oregon State University. This facility currently stores about 1500 individual clones, 700 of them being varieties of pear, and the eventual goal is to bring this number up to 12000. A second bank at the University of California in Davis is now nearing completion. The facility there will concentrate upon stone fruits, grapes, walnuts, almonds and pistachios. Most of the work here will be done on a 28 hectare outdoor site, perhaps using trees halfway between commercial size and dwarf size.

A third bank, to be used by the New York State agricultural experimentation station, will be located in Geneva, New York. When completed, its focus will be on apples and Eastern grapes. Beyond these first three, there are plans to build nine more germ-plasm banks.

European birds and butterflies join endangered list as habitats change

The number of threatened bird species in Europe has increased from 59 in 1974 to 73 at the present time. Of the 96 species of butterfly previously identified as threatened, 15 are now on the verge of extinction.

This deteriorating situation is a direct result of the destruction of particular habitats, or biotopes, suitable to individual species, according to the European Committee for the Conservation of Nature and Natural Resources (CDSN), a part of the Council of Europe. Destruction of biotopes, CDSN says, has been primarily caused by pollution and by drainage of wetlands.

In addition to publishing the results of studies on birds and butterflies, CDSN also conducted studies on European dry grasslands and alluvial forests. At its annual meeting, held in Strasbourg, 2-5 March 1982, the committee decided to conduct further studies on dunes, ecosystems and alpine and sub-alpine vegetation. Finally, it recommended that areas representative of the threatened biotopes and fauna species concerned be identified for the European network of biogenetic reserves.

PHOTO CREDITS

p. 3, Burgers, FAO; p. 6, 7, 10, 11, Christensen, FAO; p. 27, 29, Hyman, FAO; p. 40, UNICEF/FAO; p. 43, Pasca, FAO; p. 45, Tortoli, FAO; p. 47, Ciparisse, FAO; p. 47, 48, Mattioli, FAO.

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