Theses and Dissertations

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Andrew McDonald

Second Advisor

Dr. Timothy Brush

Third Advisor

Dr. Alejandro Fierro Cabo


The Tamaulipan Biotic Province falls within a biogeographic ecotone between temperate North America, the neotropics and the Chihuahuan Desert, and has consequently been defined as “Tamaulipan brushlands.” No quantitative, comparative study has ever been undertaken on the many and varied plant communities that occur in the region. This study compares eight remnant, primary plant communities to test the null hypothesis that the province comprises a single definable vegetation type. Four 50 x 10 m belt-transects were established at each site and woody plants taller than 1 m were recorded to determine species frequency, density, stratification and dominance. Community diversity was calculated using Shannon-Weiner and Simpson indexes. Permutational multiple analysis of variance (PerMANOVA) and Nonmetric Multidimensional Scaling (NMS) examined the relationship between plant community composition and compared their degrees of similarity. Results indicate all eight sites maintain distinct plant communities.

Alternate abstract:

La Provincia Biótica Tamaulipeca se posiciona en un ecotono biogeográfico entre Norte America templado, los neotrópicos y el Desierto Chihuahuense, y consequentemente se a definido como “matorral Tamaulipeco.” Ningún estudio cuantitativo se a desarollado para enfrentarse a las diversas comunidades vegetatles que ocurren el la región. Éste studio compara ocho communidades remanentes de vegetación primaria para probar la hipótesis nula que la provincia consiste de un solo tipo de vegetación definable. Cuatro transectos de 50 x 10 m fueron establecidos en cada sitio y plantas leñosas arriba de 1 m fueron documentadas para determiner la frequencia, densidad, estratificación y dominancia de especies. La diversitdad de comunidades fue calculada usando los índices de Shannon-Weiner y Simpson. Técnicas de Análisis de Permutaciones y Multiple ANOVA y Escalamiento Multidimensional No Métrico (NMS) examinaron la relación entre la composición de comunidades vegetales y compararon su grado de similitud. Resultados indican que cada de los ocho sitios mantienen comunidades vegetales distintas.


Copyright 2019 Raziel I. Flores. All Rights Reserved.

Included in

Biology Commons