RESUMEN
ResumenLos especímenes silvestres de Vanilla planifolia G. Jack forman parte del acervo genético primario, los cuales solo se han reportado en Oaxaca, México. Por ello se evaluó la distribución de esta especie con el objetivo de ubicar y describir características ecológicas en zonas potenciales de distribución. La metodología empleada consistió de cuatro etapas: 1) Elaboración de una base de datos con registros de herbario;2) Construcción de la distribución potencial basado en los registros históricos de herbario para la especie, mediante el modelo de máxima entropía (Maxent), con el uso de 22 variables bioclimáticas como predictoras; 3) Realización de búsquedas sistemáticas de individuos in situ con base en los registros de herbario y las áreas de distribución potencial en 24 municipios, para conocer la situación y la distribución del hábitat actual, y 4) Descripción mediante factores ambientales de los nichos ecológicos potenciales generados por MaxEnt. La revisión de las colecciones de herbarios reportó un total de 18 registros de V. planifolia, comprendidos entre 1939 y 1998.La búsqueda sistemática de individuos en campo ubicó 28 plantas distribuidas en 12 sitios sobre 95 364 Km2. Las variables que contribuyeron con mayor valor porcentual para determinar la estimación del modelo de distribución potencial en vainilla son precipitación del periodo más lluvioso (61.9 %), régimen de humedad del suelo (23.4 %) y precipitación del cuatrimestre más lluvioso (8.1 %). El hábitat potencial de la especie se distribuyó en cuatro zonas; trópico húmedo del golfo de México, templado húmedo, trópico húmedo y templado húmedo del pacifico. La precipitación anual osciló de 2 500 a 4 000 mm, con lluvias en verano y porcentaje de precipitación invernal de 5 a 10 %. El régimen de humedad y clima predominantes fueron údico tipo I (330 a 365 días de humedad) y cálido húmedo (Am/A(C) m). Las plantas se ubicaron en altitudes de 200 a 1 190 msnm, en laderas accidentadas, que por lo general están al pie de sistemas montañosos de 1 300 a 2 500 metros de altitud. En condiciones naturales la distribución de la especie no se limita a selva alta perennifolia, dado que se ubicó en bosque mesófilo de montaña y bosque tropical perennifolio. La ubicación de nuevos especímenes de V. planifolia en condiciones silvestres reduce un 66 % del área potencial de distribución, y la fragmenta, al pasar de ser una zona continua a convertirse en tres zonas geográficamente separadas. La reducción del hábitat se debió a un aumento en el número de plantas ubicadas, lo que define las condiciones ambientales a un nivel más exacto. Por lo anterior, se pueden emprender o diseñar acciones de conservación enfocadas a áreas más específicas dentro del estado de Oaxaca, México.
AbstractWild specimens of Vanilla planifolia represent a vital part of this resource primary gene pool, and some plants have only been reported in Oaxaca, Mexico. For this reason, we studied its geographical distribution within the state, to locate and describe the ecological characteristics of the areas where they have been found, in order to identify potential areas of establishment. The method comprised four stages: 1) the creation of a database with herbarium records, 2) the construction of the potential distribution based on historical herbarium records for the species, using the model of maximum entropy (MaxEnt) and 22 bioclimatic variables as predictors; 3) an in situ systematic search of individuals, based on herbarium records and areas of potential distribution in 24 municipalities, to determine the habitat current situation and distribution; 4) the description of the environmental factors of potential ecological niches generated by MaxEnt. A review of herbarium collections revealed a total of 18 records of V. planifolia between 1939 and 1998. The systematic search located 28 plants distributed in 12 sites in 95 364 Km2. The most important variables that determined the model of vanilla potential distribution were: precipitation in the rainy season (61.9 %), soil moisture regime (23.4 %) and precipitation during the four months of highest rainfall (8.1 %). The species potential habitat was found to be distributed in four zones: wet tropics of the Gulf of Mexico, humid temperate, humid tropical, and humid temperate in the Pacific. Precipitation oscillated within the annual ranges of 2 500 to 4 000 mm, with summer rains, and winter precipitation as 5 to 10 % of the total. The moisture regime and predominating climate were udic type I (330 to 365 days of moisture) and hot humid (Am/A(C) m). The plants were located at altitudes of 200 to 1 190 masl, on rough hillsides that generally make up the foothills of mountain systems, with altitudes of 1 300 to 2 500 masl. In natural conditions, distribution of the species is not limited to high evergreen forests, since it was also found in mountain mesophyll and tropical evergreen forests. The location of new specimens of V. planifolia in its wild condition reduces the potential distribution area by 66 %. This area is fragmented into three geographically separated areas. Habitat reduction was due to the increased number of located plants that define the environmental conditions into a more accurate level. Conservation actions can thus be designed and implemented, focusing on more specific areas within the state of Oaxaca, Mexico.
Asunto(s)
Vanilla/clasificación , Estaciones del Año , Biodiversidad , Geografía , MéxicoRESUMEN
Wild specimens of Vanilla planifolia represent a vital part of this resource primary gene pool, and some plants have only been reported in Oaxaca, Mexico. For this reason, we studied its geographical distribution within the state, to locate and describe the ecological characteristics of the areas where they have been found, in order to identify potential areas of establishment. The method comprised four stages: 1) the creation of a database with herbarium records, 2) the construction of the potential distribution based on historical herbarium records for the species, using the model of maximum entropy (MaxEnt) and 22 bioclimatic variables as predictors; 3) an in situ systematic search of individuals, based on herbarium records and areas of potential distribution in 24 municipalities, to determine the habitat current situation and distribution; 4) the description of the environmental factors of potential ecological niches generated by MaxEnt. A review of herbarium collections revealed a total of 18 records of V. planifolia between 1939 and 1998. The systematic search located 28 plants distributed in 12 sites in 95 364 Km(2). The most important variables that determined the model of vanilla potential distribution were: precipitation in the rainy season (61.9 %), soil moisture regime (23.4 %) and precipitation during the four months of highest rainfall (8.1 %). The species potential habitat was found to be distributed in four zones: wet tropics of the Gulf of Mexico, humid temperate, humid tropical, and humid temperate in the Pacific. Precipitation oscillated within the annual ranges of 2 500 to 4 000 mm, with summer rains, and winter precipitation as 5 to 10 % of the total. The moisture regime and predominating climate were udic type I (330 to 365 days of moisture) and hot humid (Am/A(C) m). The plants were located at altitudes of 200 to 1 190 masl, on rough hillsides that generally make up the foothills of mountain systems, with altitudes of 1 300 to 2 500 masl. In natural conditions, distribution of the species is not limited to high evergreen forests, since it was also found in mountain mesophyll and tropical evergreen forests. The location of new specimens of V. planifolia in its wild condition reduces the potential distribution area by 66 %. This area is fragmented into three geographically separated areas. Habitat reduction was due to the increased number of located plants that define the environmental conditions into a more accurate level. Conservation actions can thus be designed and implemented, focusing on more specific areas within the state of Oaxaca, Mexico.
Asunto(s)
Vanilla/clasificación , Biodiversidad , Geografía , México , Estaciones del AñoRESUMEN
Se estudió los caracteres relacionados con el ambiente, la planta y la semilla, que considera el campesino en la selección de variedades de haba (Vicia faba L.) y se analizó el proceso de generación y transmisión del conocimiento campesino, así como su importancia en el uso, manejo y conservación de la semilla. Se usó un enfoque cuantitativo mediante un cuestionario y el método descriptivo de encuesta muestral, y un enfoque cualitativo mediante observación y entrevista directa a 74 campesinos del grupo étnico náhuatl del Municipio de Tlatlauquitepec, Sierra Norte de Puebla, México. El tamaño de muestra se determinó por componente de marco de lista. Los principales caracteres relacionados con el ambiente en el cultivo de haba, considerados por el campesino, son humedad (80%), color (74%) y fertilidad del suelo (62%); en planta, resistencia a heladas (81%), sanidad (76%) y precocidad (55%); y en grano, sanidad (93%), y sanidad y tamaño (55%). Los campesinos que seleccionan cuatro o más caracteres relacionados con ambiente, planta y semilla, son quienes contribuyen al mejoramiento genético de la especie, por integrar una mayor cantidad de conocimientos y ejercer mayor presión selectiva. El conocimiento campesino sobre los caracteres de haba se genera por un proceso complejo de interrelaciones, en que se conjugan saberes sobre su entorno, el comportamiento de la especie en determinada condición y un conocimiento heredado perfeccionado por la experimentación. En este proceso va implícita la conservación de la diversidad de recursos genéticos locales de la especie.
This study is aimed at documenting the characters related with the environment, the plant and the seed that peasants take into account in the selection of local varieties of faba bean (Vicia faba L.). The process of generation, and transmission of rural knowledge and their use importance, handling and seed conservation were analyzed. A quantitative approach was used through a questionnaire and the descriptive method of sampling survey; a qualitative approach was also used, by observation and direct interviews to 74 peasants from the Municipality of Tlatlauquitepec, Sierra Norte de Puebla, Mexico. The main characters related with the environment in the faba bean crop that are considered by the peasant are soil humidity (80%), soil colour (74%) and fertility (62%); in relation to the plant features, cold resistance (81%), plant health (76%), and precocity (55%); and in relation to grain aspect, grain health (93%), and grain health and size (55%). The peasants selecting four or more characters of the beans, in relation to the environment, plant and seed, contributed more to the improvement of the species, as they integrated more knowledge and exerted higher selective pressure. The rural knowledge about the characters in faba bean is created through a complex process of interrelations, where knowledge is conjugated with environment and species behaviour at one particular condition, and an inherited knowledge transmitted by generations that is constantly improved by experimentation. In this process is implicit the conservation of local genetic resources of the species.
Foram estudados os caracteres relacionados com o ambiente, a planta e a semente, considerados pelo camponês na seleção de variedades de fava (Vicia faba L.) e se analisou o processo de geração e transmissão do conhecimento camponês, bem como sua importância no uso, manejo e conservação da semente. Utilizou-se um enfoque quantitativo mediante um questionário e o método descritivo de pesquisa amostral, e um enfoque qualitativo mediante observação e entrevista direta a 74 camponeses do grupo étnico nahuatl do Município de Tlatlauquitepec, Serra Norte de Puebla, México. O tamanho da amostra foi determinado por componente de marco de lista. Os principais caracteres relacionados com o ambiente no cultivo de fava, considerados pelo camponês, são umidade (80%), cor (74%) e fertilidade do solo (62%); em planta, resistência a geadas (81%), sanidade (76%) e precocidade (55%); e em grão, sanidade (93%), e sanidade e tamanho (55%). Os camponeses que selecionam quatro ou mais caracteres relacionados com ambiente, planta e semente, são aqueles que contribuem ao melhoramento genético da espécie, por integrar una maior quantidade de conhecimentos e por exercer maior pressão seletiva. O conhecimento camponês sobre os caracteres da fava é gerado por um processo complexo de inter-relações, nas que se conjugam saberes sobre seu entorno, o comportamento da espécie em determinada condição e um conhecimento herdado aperfeiçoado pela experimentação. Neste processo vá implícita a conservação da diversidade de recursos genéticos locais da espécie.