• Potential management of Chamaedorea seifrizii (Palmae), a non-timber forest product from the tropical forest of Calakmul, Southeast Mexico

      López-Toledo, Leonel; Horn, Christa M.; López-Cen, A.; Collí-Díaz, R.; Padilla, A. (2011)
      Leaves and seeds of Chamaedorea (xate) palms are important non-timber forest products (NTFPs). In the Calakmul region (Yucatan Peninsula) of Mexico, several communities have sporadically collected and sold seeds of C. seifrizii since 1980. However, harvesting has intensified recently, raising concerns about overexploitation....
    • The soil seed bank in abandoned tropical pastures: source of regeneration or invasion?

      López-Toledo, Leonel; Martínez-Ramos, Miguel (2011)
      We assessed the availability of both pioneer and non-native species in the soil seed bank of old-growth forest and recently abandoned pasture, to evaluate whether the soil seed bank in these pastures represents a source of regeneration of species from adjacent old-growth forest or of invasion by non-native species. Our study was conducted at Selva Lacandona, Chiapas, Mexico. Soil samples were randomly collected from 6 sites in old-growth forest, and 6 sites in abandoned pastures. Seedlings from soil samples were identified and classified into pioneer, non-native (weeds/graminoids), and other forest species. Pioneer species seeds were virtually absent in pastures, but represented ~30% of seeds in the forest. Non-native species comprised ~99% of the soil seed bank in pastures. In the forest, soil seed bank density of weeds and graminoids decreased with increasing distance (up to 4 km) from agricultural fields, and comprised up to 25% (Mean ± 1SE= 16 ± 7) of the seed bank. Our results show a near total elimination of pioneer species from the soil seed bank in pastures, and considerable invasion of the borders of the Montes Azules reserve by seeds of non-native species. Thus, in the region studied, the soil seed bank in abandoned pastures represents a source of invasion by non-native species into old-growth forest rather than a potential source of forest regeneration.