Ecology and conservation of endangered species the case of Magnolias

One of the aims of conservation biology is to protect and maintain rare and endangered species in their natural habitats. With fossil remains dating back to between 50 and 65 million years, Magnoliaceae is an ancient family with approximately 330 species of trees and shrubs, half of them native to Asia and the other half to the American continent. The Magnolia genus comprises trees and shrubs from temperate to tropical environments, such as evergreen and deciduous species, distributed between 40 and 3,300 m above sea level. Magnolias have been used in traditional folk medicine in both continents. Many taxa of Magnolia can produce molecules with medical potential for the treatment of cancer, for example, as well as for the production of pesticides in agriculture. The great number of primary species in northern as well as in tropical ecosystems makes the study of this family an important endeavor from both ecologic and conservation perspectives. Genetic studies show that whereas some populations present a high diversity, diversity is low in others, and there are populations with very low density. The few existing demographic studies of magnolias show a population growth rate (λ) of over one. The individuals whose contribution to λ is greater in M. dealbata are those measuring over 10 cm in diameter, and in M. schiedeana and M. mexicana, those with a diameter of less than 5 cm. It is possible to keep long-standing seed banks of magnolias, and the best pre-germinate treatments are: Stratification at 4-10oC for only 13 days, for some tropical magnolias, and cold stratification (0 to 8°C) for a period of 3 to 6 months for temperate-climate magnolias. Since, as the evidence shows, magnolias are plants of intermediate and late-successional status, successional reforestation seems to be the most appropriate reforestation strategy; i.e., to plat the magnolias where a previous cover of fastgrowing plants of different species at their early successional stages already exists. As a great deal of magnolias has a good sprouting capacity, and sprouts grow much faster than seedlings, they can quickly occupy the existing gaps. These entire traits are important to consider in any reintroduction, conservation or restoration programs.

Bibliographic Details

Main Authors:	Sánchez Velásquez, Lázaro Rafael autor 14728, Pineda López, María del Rosario autora 14726, Vásquez Morales, Suria Gisela Doctora autor/a 12549, Avendaño Yáñez, María de la Luz autora
Format:	Texto biblioteca
Language:	eng
Subjects:	Magnoliáceas, Población vegetal, Fitogeografía, Ecología vegetal,
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