https://www.socictopen.socict.org/files/original/e7b6b7a1409fdb36bd3a35c2efa63f3e.pdf 9d2c4fd5862678bed5f882c3d93e9db8 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Agricultura sostenible Description An account of the resource Dominio científico: Agricultura sostenible Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Species diversity, structure and dynamics of two populations of an endangered species, Magnolia dealbata (Magnoliaceae) Creator An entity primarily responsible for making the resource Lázaro R Sánchez-Velásquez, María del Rosario Pineda-López Description An account of the resource Little is known about the ecology and demography of the genus Magnolia. Magnolia dealbata Zucc. is an endangered species endemic to Mexico. Two contrasting populations of M. dealbata (one from the grasslands and other from a secondary cloud forest) were studied. We asked the following questions: (a) Are size structure (diameter at breast height, DBH) and infrutescence production significantly different between the two populations? (b) What are the populations’ growth rates (&#955;) based on an initial 1987 study? (c) Are the associated species diversity indices of these M. dealbata populations significantly different? The results show no significant differences between the population size structure (p=.094); the growth rates of the populations were 0.992 in grassland and 1.053 in secondary cloud forest. The number of infrutescences produced in year 2001 and DBH relationship were significantly linear (p.01) between their slopes. The diversity indices were not significantly different (p>.05), and only 54% of the species were common to both sites. Our study suggests that both populations are relatively stable and that the management history could impact more on the species composition than on the diversity indices. Rev. Biol. Trop. 54 (3): 997-1002. Epub 2006 Sept. 29.La ecología y demografía del género Magnolia han sido poco estudiadas. Magnolia dealbata Zucc. es una especie endémica de México y es considerada en peligro de extinción. Se estudiaron dos poblaciones contrastantes de M. dealbata (una dentro de un pastizal y la otra dentro de vegetación secundaria del bosque mesófilo de montaña -bosque de niebla-). Buscamos respuestas a las siguientes preguntas: (a) ¿La estructura de tamaños y la producción de frutos de ambas poblaciones son significativamente diferentes? (b) ¿Cuáles son las tasas de crecimiento poblacional (&#955;), tomando como población inicial un estudio de 1987? (c) ¿Son significativamente diferentes los valores de diversidad de especies de ambas poblaciones? No hallamos diferencias significativas entre la estructura de tamaños de ambas poblaciones (p=.094). Las tasas de crecimiento poblacional de las poblaciones en pastizal y en el bosque secundario de neblina fueron 0.992 y 1.053, respectivamente. El número de infrutescencias por individuo producidas en 2001 y su relación con el diámetro a la altura del pecho fueron significativamente lineales, y no hubo diferencias significativas entre sus pendientes (p>.1). Los índices de diversidad no fueron significativamente diferentes (p>.05) y sólo el 54 % de las especies fueron comunes entre sitios. Las poblaciones parecen relativamente estables y el historial de manejo en ambas comunidades podría afectar más a la composición de especies que a los índices de diversidad. Date A point or period of time associated with an event in the lifecycle of the resource 2006 Subject The topic of the resource Diversidad, Diversity, Magnolia dealbata, México, POPULATION, bosque nuboso, cloud forest, endangered species, especie en peligro de extinción, infrutescences, infrutescencia, población Source A related resource from which the described resource is derived Revista de Biología Tropical Publisher An entity responsible for making the resource available Vicerractoría Investigación Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Biology (General) Relation A related resource <a href="http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S0034-77442006000300033" target="_blank" rel="noreferrer noopener">http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S0034-77442006000300033</a>