Plant Ecology

, Volume 213, Issue 8, pp 1209–1220

Elevational patterns in the vascular flora of a highly diverse region in southern Mexico

Authors

    • Sociedad para el Estudio de los Recursos Bióticos de Oaxaca, A.C
    • Departamento de Ecología y Recursos Naturales, Facultad de CienciasUniversidad Nacional Autónoma de México
  • Jorge A. Meave
    • Departamento de Ecología y Recursos Naturales, Facultad de CienciasUniversidad Nacional Autónoma de México
Article

DOI: 10.1007/s11258-012-0077-6

Cite this article as:
Salas-Morales, S.H. & Meave, J.A. Plant Ecol (2012) 213: 1209. doi:10.1007/s11258-012-0077-6

Abstract

We examined general and family-specific patterns of vascular plant richness along a large elevational gradient (0–3,670 m a.s.l.), assessed the continuity of these patterns and analysed their potential underlying causes in a high diversity region of the Sierra Madre del Sur, Oaxaca, Mexico. We used a vascular plant database constructed previously. The gradient was divided into 18 200-m elevation belts. To examine elevational patterns of richness, we used both observed and estimated (interpolated) species richness, as well as genus and family observed richness, for each belt. A generalised linear model (GLM) was used to assess the effect of altitude on area-corrected species richness (standard area = 100 km2), and a numerical classification of the elevational belts based on species richness was performed. Overall, richness at the three taxonomic levels decreased with elevation, but some individual families departed from this pattern. A sharp drop in species richness was observed at 1,800 m, and the dendrogram separated two elevational floristic groups at this elevation. The GLM revealed a significant negative effect of elevation on species richness. Despite this overall decreasing pattern for vascular plants along this extensive gradient, an examination of some family-specific patterns revealed the existence of other elevation–diversity relationships, indicating taxon-specific responses to elevation. The most noticeable discontinuity in species richness, at ca. 1,800 m, is likely related to a critical temperature isocline.

Keywords:

Altitudinal gradient Area effect Environmental-limitation hypothesis Habitat heterogeneity Oaxaca

Copyright information

© Springer Science+Business Media B.V. 2012