Abstract

CRUZ-RODRIGUEZ, Juan Antonio  and  LOPEZ-MATA, Lauro. Ontogenetic changes in seedling morphology of Manilkara zapota: analysis of ecological implications. Rev. Mex. Biodiv. [online]. 2010, vol.81, n.1, pp.81-86. ISSN 2007-8706.

In this work the variability in seedling morphology of one of the most abundant neotropical trees, Manilkara zapota, is described. These seedlings display morphological changes significantly related with their survival probabilities. The variation is described from observations of 552 seedlings with heights less than 35 cm, in a subtropical rain forest in the central portion of the state of Veracruz. From each seedling we gathered the following data: presence of cotyledons, height, number of leaves, length and shape of the leaves, cover, and specific leaf area (SLA). Based on leaf shape, 4 seedling variants were distinguished: a) seedlings with cotyledons, b) seedlings with elliptic leaves, c) seedlings with oblong leaves and, d) seedlings with oblong-lanceolated leave. The leaf size of the last-mentioned variant was of up to 30 cm length, which duplicates the size of the mature trees leaves. SLA showed a negative correlation with leaf size suggesting a high construction costs for large leaves which explains their absence in the first years of life. The development of large leaves is a non-continuous process that depends on the seedling reserves allowing them to take advantage of the scarce light in the understory.

Keywords : subtropical rain forest; seedling growth and survival; shade tolerant species; specific leaf area.