Seed ecology and pre-germinative treatments in Magnolia schiedeana Schlecht, an endangered species from Mexico

摘要

The life stages of dispersal and survival of seeds in soil are essential facets of demographic study. The successful pre-germination seed treatments are needed in order to support reintroduction programs and conservation of endangered species. This study encompassed seed survival at different depths and removal of M. schiedeana. Also we tested the efficacy of several pre-germinative treatments of M schiedeana seeds. Seeds of M schiedeana survived for two years in the soil, suggesting the ability to form a persistent seed bank. The viability of seeds, buried for two years in the soil at different depths (soil surface, 5, 10 and 15 cm), did not differ significantly (P>0.05). With exposure to vertebrates, removal of seeds was 100% during the first month, whereas the exclusion of vertebrates resulted in removal of only 32% of seeds after one year (chi(2) = 13.75, P<0.05). The most successful pre-germinative treatments were 1) "48 h" treatment, where mechanically scarified seeds were placed in a layer of wet, sterilized river sand, incubated at 4-10 degrees C for 13 days and subsequently soaked with sterile water for 48 h soaking seeds in water at room temperature (18 +/- 2 degrees C), and 2) the "30 degrees C" treatment, where mechanically scarified seeds placed in warm water (30 degrees C) until the water had cooled to room temperature, and then soaked in sterile water for 48 h (both 84% germination). However, the "30 degrees C" treatment had longer period of germination (35 +/- 2.3 days).