Prosopis Tamarugo

Economic plants have been defined by SEPASAT as those plants that are utilised either directly or indirectly for the benefit of Man. Indirect usage includes the needs of Man's livestock and the maintenance of the environment; the benefits may be domestic, commercial or aesthetic. Economic plants constitute a large and so far uncalculated percentage of the quarter of a million higher plants in the World today. However, it has been calculated that 10% (25 000) of these species are now on the verge of extinction and extinction means that a genetic resource that could be of benefit to Man will be lost for ever. Furthermore, for every species lost an estimated 10-30 other dependent organisms are also doomed. Fewer than 1 per cent of the World's plants have been sufficiently well studied for a true evaluation of the potential floral wealth awaiting discovery, not only in the rain forests, which man is now actively destroying at a rate of 20 ha a minute, but also in the very much neglected dry areas of the World.

One of the Major functions of this publication is to compare nutritional chemistry of as many plant species as possible.

This volume, fifth in the series High-Tech and Micropropagation, contains 24 chapters arranged in the following three sections: I. Vegetables and Fruits: garlic, Amaranthus, Brassica oleracea, pepper, watermelon, cassava, banana, Myrtus communis, passionfruit, Polymnia sonchifolia, pepino, and spinach. II. Grasses: bamboos, Caustis dioica, Dendrocalamus, Miscanthus x giganteus, sugarcane. III. Trees: Aegle marmelos, Eucalyptus, Fraxinus excelsior, Juglans cinerea, Pinus virginiana, Prosopis, and Ulmus. This book is of use to research workers, advanced students, and teachers in the fields of horticulture, forestry, botany, and plant biotechnology in general, and also to individuals interested in industrial micropropagation.

This multi-authored volume contains peer-reviewed chapters from leading researchers and professionals in silvopastoral systems topic in Southern South America (Argentina, Chile and South Brazil). It is a compendium of original research articles, case studies, and regional overviews and summarizes the current state of knowledge on different components and aspects (pasture production, animal production, trees production, carbon sequestration, conservation) of silvopatoral systems in native forests and tree plantations. The main hypothesis of the book is that farmers have integrated tree and pasture/grassland species in their land use systems to reach higher production per unit of land area, risk avoidance, product diversification, and sustainability. These production systems also impact positively in main ecosystem processes. Management of these productive systems, Policy and Socioeconomic Aspects provide great opportunities and challenges for farmers and policy makers in our region. The book is unique on this subject in Southern South America and constitutes a valuable reference material for graduate students, professors, scientists and extensionists who work with silvopastoral systems.

Desertification (land degradation in arid, semi-arid and dry sub-humid areas resulting mainly from adverse human impacts) is the main environmental problem of dry lands, which occupy more than 40 per cent of the total global land area. The phenomenon threatens about 3.6 billion hectares and currently affects the livelihood of about 900 million people. Thl! world is now losing annually about 1.5 million hectares of total irrigated lands (240 million hectares) due mostly to salinization, mainly in drylands. Salt affected soils are widely distributed throughout the arid and semi-arid regions, and particularly severe in China (7 million ha), India (20 million ha), Pakistan (3.2 million ha), USA (5.2 million ha), as well as Near East, southern Europe and elsewhere. Demands on production have increased the pressure on existing productive land and moved the limits of production onto increasingly marginal lands. Wise land-use practices have yet to be developed for such conditions. The Executive Director of UNEP reported to the Governing Council in February 1992 concerning the "Status of Desertification and Implementation of the United Nations Plan of Action to Comtat Desertification (PACD)". The Report concludes that major efforts to implement the PACD had gJne into supporting measures rather than concrete corrective field operations. Little evidence of progrl!ss was found in irrigated croplands, rainfed croplands or rangelands. It was recommended that every piece of land should be used in keeping with its ecological characteristics, natural capabilities and constraints.