Tropical natural vegetation

It can be seen that most areas sensitive to acid deposition are in Southeast China, and that the insensitive is in the Northwest. The sensitive areas, including the catchment of the Changjiang (Yangtze) River and the wide areas to the southward, are warm and rain-abundant. The natural vegetation is the Tropic Rain Forest, Seasonal Rain Forest, and Subtropical Evergreen Forest ecosystems. The dominant soils in these areas are acid Ferralsols, with obvious accumulation of iron and aluminum. These soils can tolerate approximately 0.8-1.6g/m /yr. of sulfur from acid deposition and belong to the intermediate sensitivity class 3. In Northwest China, the climate is semiarid or arid. The predominant ecosystems are Dry Steppe and agroecosystems, with spots of Deciduous Forest or Mixed Forest ecosystems. The soils represented by Xerosol and Alpine types are carbonate-rich and saline. Consequently, they are resistant to acidification. 

The problems related to safe and durable roofs for low cost houses are usually more difficult than those for walls and other elements of the house. For that reason, various kinds of low-cost fibre reinforcement are used in regions where cellulose pulp (in Nordic countries) and natural vegetal fibres (in tropical and subtropical countries) are available (cf. Section 5.7). 

Because Venezuela is located in the American tropics, all vegetation types growing there are characteristically of a tropical nature, not only with reference to the thermic regime, but especially... 

Sarmiento, G. 1992. A conceptual model relating environmental factors and vegetation formations in the lowlands of tropical south America. Pages 583-601. in P. A. Furley, J Proctor, and J. A. Ratter, editors. Nature and Dynamics of Forest-Savanna Boundaries. Chapman and Hall, London. 

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