The Northeast Region of Brazil has a land area of over I.5 million km2 and extends over tropical and equatorial latitudes from 18' S in the State of Bahia to 1' S in the State of Maranhão. Although representing only about 18% of the national territory, it is the home of approximately 35% of Brazil's 160 millions inhabitants (IBGE, 2000). The Northeastern region of Brazil, in the States of Bahia, Paraiba and Rio Grande do Norte are responsible for 100% of sisal production. Precipitation is the key environmental factor of ecological significance for the region and can be characterized by three major zones trending east to west. First is a narrow humid coastal strip in the cast (known as Zone of Mata) which receives an average of 1,250 mm to over 2,000 mm of rainfall per annum. Behind this humid zone there is a middle one with moisture deficiency (subject to periodic droughts) which accounts for the largest portion of the Northeast. Most of this zone receives less than 1,000 mm of annual rainfall, with an extreme low of less than 300 mm in some areas. The third zone is one of high rainfall, over 2,000 mm per year, in western Maranhão. Reflecting this wide diversity of moisture conditions are natural vegetation patterns ranging from tropical rainforest (“Atlantic Rain Forest”) to semi-arid thorn scrub (“Caatinga”). This system has been under severe pressure due to the lack of economical alternatives to support the population living in those areas.