ABSTRACT
I investigated the size, composition and persistence of the seed-bank in primary forests, secondary forests and old-fields in southern Mexico. I also assessed the contribution of the seed-bank to regeneration relative to other propagule sources. In all habitats, I removed by hand all plants and litter and excluded the seed-rain. For one year, I counted the number of plant species (5-50 cm tall) emerged and grouped them into different growth-forms: trees, shrubs, palms, herbs, woody lianas, epiphytes and hemi-epiphytes. A total of 95 species emerged. The seed-bank size, composition and persistence showed strong variation among successional stages. Emergence was low for primary and secondary forests, but high for old-fields (19, 26, and 68 plants per m-2, respectively). Herbs were the most abundant in the seed-bank and palms the less. Time had a negative effect on seed-bank size in primary forests and old-fields; whereas for secondary forests size remained constant throughout the year. The number of emerged plants in different growth-forms changed significantly across time for all successional stages. Overall, the seed-bank provided a greater number of plants in old-fields relative to other propagule sources combined. The results showed that forest modification alters the input of propagules throughout the seed-bank for different plant growth-forms.
ABSTRACT
Esta investigación realiza una evaluación ex-post de la sustentabilidad en espacios rurales relacionados con el ecoturismo, centrada en un estudio comparativo de tres empresas enclavadas en la Reserva de la Biosfera Montes Azules (REBIMA) y una empresa más ubicada fuera de ella, todas en el municipio de Ocosingo, Chiapas, México. 75% de los entrevistados son hombres con edad promedio de 36 años, siete años de escolaridad y 1,9 hectáreas. La principal fuente de ingresos es el ecoturismo, que presenta una relación beneficio-costo venida a menos de 2,7 a 1,7, entre 2007 y 2011, respectivamente. La evidencia indica un desequilibrio en el acceso a subsidios, donde la pertenencia étnica desempeña un rol trascendental.
This research performs an ex-post evaluation of the sustainability in rural spaces related to ecotourism, focused on a comparative study of three companies located in the Montes Azules Biosphere Reserve (MABR) and another company located outside, all of them in the town of Ocosingo, Chiapas, México. 75% of respondents are male with an average age of 36 years, seven years of schooling and 1,9 hectares. The main source of income is ecotourism, which presents a cost-benefit relationship that has ran down from 2,7 to 1,7 between 2007 and 2011, respectively. The evidence indicates an imbalance in the access to subsidies, where the ethnical ownership plays a transcendental role.
