Stratification Of Tropical Forests As Seen In Leaf Structure

The studies presented in this volume are meant to The reason why we know relatively little about close some gaps in our knowledge of leaf anatomy inner leaf structure of trees from tropical humid of trees in tropical humid forests. Although xero forests is that the leaf anatomy of only a few species morphy of the foliage in tropical humid forests has or genera or - at the most - of an entire family has been much discussed, the statements have generally been studied in detail up to the present. Most of been based on sporadic anatomical studies of part i these studies are, therefore, of taxonomic interest. cular species or genera, a complete area of the size They cannot be included in this study because they of 155. 5 ha has certainly never been considered. do not supply the same information or amount of The present studies analyse an entire inventory of a data presented here. Anatomical studies are very time consuiming because the material first has to be given region in which the number of species and the number of individuals is very well known. This fact prepared and cut before observation can begin. In allows the elaboration of many ecological aspects, vestigation of about 50 characteristics in 230 species which was the main intention of the author.

This volume is the last contribution of a series of With the present book, a further gap concern studies concerned with the plant material of one ing leaf morphology and leaf venation, as well and the same area of Venezuelan Guiana. The as some structural peculiarities of physiological importance, is closed so that an exhaustive survey studies originated through a collaboration with the forest engineer Dr. B. Rollet, the FAO expert in of bark and leaf morphology and anatomy as well forest inventory who collected the material of tree as of fruit and seed structure of the plants of a barks, leaves, fruits and seeds in Venezuelan certain well-known area is herewith given. Not Guiana around the "Rio Grande", "EI Paraiso", only were hundreds of species studied, but and "EI Dorado" camps. In the first place, tree structural characteristics were related to "forest barks of about 280 species of dicotyledons stratification", i. e. to the different micro climatic belonging to 48 families were studied (family by conditions in the forest, as the height of the trees family) by Roth in separate publications which and shrubs studied was known. It is of common mainly appeared in Acta Botanica Venezuelica knowledge that in the lower forest layers, light is a and in Acta Biol6gica Venezuelica (see the bibli limiting factor, while humidity is sufficiently avail ography in Roth 1981).

Our knowledge of the structure and dispersal of "Plants, seeds and currents" in the Westindies tropical fruits and seeds is very limited up to the and Azores. Van der Pijl with his extensive know present day, though richness of species and variety ledge of tropical plants offers a great selection of of forms is overwhelming in the tropical forests. detailed information on the subject" Principles of Morphology of tropical fruits and seeds has always dispersal in higher plants" (1972, and earlier pa of botanists from many pers). The author who has earned most merits in attracted the curiosity countries and information may be obtained from the field of seed and fruit predation, chemical defenses of plants, and animal-plant interactions is books and publications concerned with taxonomy. Ulbrich's "Biologie der Friichte und Samen" Janzen. He and his collaborators have thrown new of tropical fruits and seeds (1928) gives examples light on this subject. Nonetheless, a large unknown and their dispersal methods. The two volumes by field still remains ahead of us, especially regarding Van der Roosmalen (1977) dealing with the de a detailed knowledge of fruit and seed dispersal of scription of tropical plants were of utmost value to tropical plant species. me, as the area considered, Surinam, is close to The great opportunity for my own studies was Venezuelan Guiana and because both regions have the fruit and seed collection of Dr.

Our knowledge of the ecology of tropical rain-forest trees is limited, yet a good understanding of the trees is essential to unravelling the workings of the forest itself. This book aims to summarise contemporary understanding of the ecology of tropical rain-forest trees, with particular emphasis on comparative ecology.

Taking readers out of the laboratory and into the humid tropical forests, this comprehensive volume explores the most recent advances occurring in tropical plant ecophysiology. Drawing on the knowledge of leading practitioners in the field, this book synthesizes a broad range of information on the ways in which tropical plants adapt to their environment and demonstrate unique physiological processes. This book is arranged into four sections which cover resource acquisition, species interactions, ecophysiological patterns within and among tropical forest communities, and the ecophysiology of forest regeneration. These sections describe plant function in relation to ecology across a wide spectrum of tropical forest species and growth forms. How do different species harvest and utilize resources from heterogeneous tropical environments? How do patterns of functional diversity reflect the overwhelming taxonomic and morphological diversity of tropical forest plants? Such fundamental questions are examined in rich detail. To illuminate the discussions further, every chapter in this book features an agenda for future research, extensive cross referencing, timely references, and the integration of ecophysiology and the demography of tropical species where the data exist. Tropical Forest Plant Ecophysiology provides plant scientists, botanists, researchers, and graduate students with important insights into the behavior of tropical plants. Biologists and foresters interested in tropical ecology and plant physiological ecologists will also benefit from this authoritative and timely resource.

The Sixth International Conference on Mediterranean Climate ecosystems was held at Maleme (Crete), Greece, from September 23 to September 27, 1991. This conference had as its theme 'Plant-Animal Interactions in Mediterranean-type Ecosystems'. Most of the papers presented to that meeting have already been published (see Thanos, C.A. ed., 1992, Proceedings of the VI International Conference on Mediterranean Climate Ecosystems, Athens, 389 pp.). These 57 papers were all necessarily short. But the theme of plant-animal interactions was considered by the Organizing Committee to be so important to a fundamental understanding of the ecology of Mediterranean-climate ecosystems and to an enhanced management ·of those systems that various international research scientists were invited to prepare longer contributions on major aspects of the overall theme. The Book that follows represents the result of those invitations. All five regions of Mediterranean climate are represented - Chile, California, southern Australia and the Cape Province of South Africa, as well as the Mediterranean Basin itself.

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.

Nature conservation.