Resumen

LOPEZ-GOMEZ, Víctor et al. Slope orientation effect in population structure and ecomorphology of Neobuxbaumia tetetzo (Cactaceae). Bot. sci [online]. 2012, vol.90, n.4, pp.453-457. ISSN 2007-4476.

Slope orientation modifies field microclimatic conditions. Despite this well-known pattern, there is few empirical evidence of its influence on plant populations, and even lesser for cactus populations. Our goals were to determine the effect of N and S slope orientation on some population attributes (total stem area, density and size structure) and ecomorphology (number branch and orientation) of Neobuxbaumia tetetzo (Cactaceae) taller than 1.5 m in Valle de Zapotitlán, Puebla. In southerly slope, N. tetetzo showed higher density and a higher tendency of branches to northeast orientation than N. tetetzo in northerly slope. In the northern slope cacti had a higher number of branches than in the southern one. We conclude that slope orientation showed a remarkable effect on density, size structure, and ecomorphology of N. tetetzo; nevertheless, it is needed to obtain microclimatic records at the study site to clarify our understanding about slope orientation effect on N. tetezo population.

Palabras llave : branch orientation; density; giant columnar cactus; size structure.