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Leopoldo Magno Coutinho. Um outro fator a ser considerado seria o fogo natural pirobiomas. The terms phytophysiognomy and formation were proposed practically at the same time. The term biome, proposed later, only added the element fauna to the phytophysiognomic and climatic uniformity of the formation concept. Several conceptual modifications have been presented by a number of authors along time, adding other environmental factors to the original concept of biome, as soil for example.
Walter proposed an essentially ecological concept, considering biome as an area of uniform environment, belonging to a zonobiome, which is defined by the climatic zone where it is found. This concept takes into consideration other important ecological factors, as altitude and soil, which then constitute orobiomes and pedobiomes. Another factor to be considered is natural fire pyrobiomes. Biome and morphoclimatic and phytogeographical domain are not synonyms, since the latter does not necessarily have a uniform environment.
The tropical savanna biome is a complex of phytophysiognomies, a complex of formations, which represents a gradient of ecologically related biomes, reason enough to consider this complex as a biological unit.
Key words: formation, biome, zonobiome, domain, savanna. Hoekstra et al. The formation and climax are identical, and, hence, the same great community may be termed a formation or, for the sake of emphasis, a climax formation".
Examples are the tropical rain forest, the mangrove swamp, the cacti desert, the grass steppe, Segundo Font Quer , este termo teria sido criado por Clements. In a given biome the life form of the climatic climax vegetation Whittaker definiu bioma como "A major kind of community, conceived in terms of physiognomy, on a given continent, is a biome or formation. Formation is used when the concern is with plant communities only, biome when the concern is with both plants and animals Fisionomia, estrutura e ambiente devem ser considerados ao se definir um bioma.
Um mesmo tipo de bioma pode ter floras diferentes. Segundo Whitaker , "A community-type on a given continent defined by growth-form dominance and major features of environment is a formation. A grouping of similar formations occurring in similar climates of the different continents is a formation-type Ecologists concerned with animals as well as plants have often used as corresponding units the biome and biome-type.
Concordando com Dajoz , Crawley afirmou que: "The great biomes of the world show a remarkable degree of convergence in their physiognomy, despite wide differences in the taxonomic affinities of their floras The classification of the living world using this biogeographical, rather than a taxonomic, approach is particularly useful because it allows the development of general statements concerning the function and the future of these units Although the tropical savanna grasslands of Brazil, Kenya, India and Thailand comprise different plant and animal species, they have much in common in terms of their architecture, seasonal growth and productivity, life forms of animals and plants, and the ways in which they have been used by human population.
Management practice are similar in different geographic areas, hence much that can be learned from one region can be applied to another. Of course biomes contain species, but species are not the category used to group plants as they are found in biomes. Biomes are identified by the dominant life form Because life form looks so distinctive, biomes are recognizable by how they look on first glance. The first impression of vegetation is called vegetational physiognomy.
Colinvaux definiu bioma como um "ecosystem of a large geographic area in which plants are of one formation and for which climate sets the limits". Ele considera todo o ecossistema. No caso de Walter , eles correspondem aos Zonobiomas ou biomas zonais.
Neste sentido eles se aproximam um pouco do conceito de Walter Alguns exemplos de biomas no Brasil. Todavia, a grande maioria dos autores nacionais e internacionais, aceita o Cerrado como sendo um bioma de savana.
Goedert l. These savannas form a continuum of physiognomic types ranging from closed woodlands with a heliophytic grass understorey, through open savanna woodlands to treeless edaphic grasslands. In all areas Kranz syndrome or C 4 grasses dominate the herbaceous layer while the woody component, at the moist end of the moisture gradient, comprises fire tolerant trees and shrubs.
Marico Meguro, Dra. Waldir Mantovani e Dr. Ab'Saber, A. Community Ecology. In: S. Dodson; N. Langston; M. Turner; S. Carpenter; J. Kitchell; R. Jeanne; A. Allen, Contrib. Oxford University Press Inc. Toward a unified ecology. Columbia University Press. In: Atlas Nacional do Brasil.
The caatingas dominium. Natural Ecosystems. New York, McMillan. Dynamics of Vegetation. New York, The H. Wilson Co. Ecology 2.
O conceito de cerrado. Biogeography: an ecological and evolutionary approach. Fifth Edition. London, Blackwell Scientific Publications. The Structure of Plant Communities. In: M. Crawley ed. Plant Ecology. Oxford, Blackwell Science.
Ecologia Geral. Rio de Janeiro, Ed. The cerrado vegetation of Brazil. The Botanical Review 38 : Pinto org. Rio de Janeiro, Editora Nova Fronteira. Barcelona, Editorial Labor. Paris, Sect. Solos dos Cerrados. A physiognomic analysis of the "cerrado vegetation" of Central Brazil.
Journal of Ecology 59 : Vegetation Diversity and Classification Systems. In: A. Shugart eds. Global Change Biology 6 : Determination of world plant formations from simple climatic data. Science : Southern African Savannas. In: B. Walker eds. Ecology of Tropical Savannas. Ecological Studies 42 : Concepts of Ecology. New Jersey, Prentice-Hall Inc. Stuttgart, Verlag Eugen Ulmer. Aims and Methods of Vegetation Ecology. Fundamentals of Ecology.
diagrama de holdridge.pdf
Sistema de classificació de zones de vida de Holdridge