COMPOSICIÓN Y ESTRUCTURA DE LA VEGETACIÓN EN TRES SITIOS DEL ESTADO DE NUEVO LEÓN, MÉXICO

Abstract

During the summer of 2004, a study of the
status of woody vegetation was performed at
three sites in the Tamaulipan thornscrub. The
sites were located in the municipalities of
Los Ramones (S1), China (S2) and Linares
(S3) in the state of Nuevo Leon, Mexico. At
each site three random transects (50 m X 7
m) were laid out, and relative abundance,
relative dominance and relative frequency
were estimated along each transect. In addition, dasometric parameters, such as height
and crown diameter, were determined. Plant
diversity was estimated by the ShannonWiener index, and similarity between sites
was calculated using the Jackard index. A
total of 1 741 individual plants belonging to
20 families were registered. Fabaceae had
the highest number of species (10) followed
by Euphorbiaceae (4) and Rhamnaceae
(4), Rutaceae (3) and Cactaceae (2). The
other 15 families were represented by only
one species. The Shannon index showed
that there were no statistical differences in
biodiversity between sites; however, the
Jackard index showed similarity among
species only between S1 and S2. The most
frequent species in the three sampling sites
were Acacia rigidula (255) followed by
Viguera stenoloba (171), Havardia pallens
(167), Karwinskia humboldtiana (132),
Forestiera angustifolia and Castela texana
(125). This group represented about 56% of
the total. Less frequent species were: Condalia spathulata (7), Ebenopsis ebano (7),
Condalia hookeri (6), Wedelia acapulcensis
(5), Cordia boissieri (4), Acacia farnesiana
and Yucca treculeana with (3), Helietta
parvifolia (2), Croton torreyanus (1) and
Prosopis sp. (1), and they represented only
about 2%. S3 registered the highest species
richness with a little more than 100% of
that of S1 or S2. That Linares was the site
with the greatest species diversity might
have been due to the higher precipitation
recorded historically.