INVESTIGADORES
BARQUEZ ruben Marcos
artículos
Título:
Species richness of non volant small mammals along elevational gradients in Northwestern Argentina
Autor/es:
FERRO L. IGNACIO; BARQUEZ R.M.
Revista:
BIOTROPICA
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Hoboken, NJ, USA; Año: 2009 vol. 41 p. 758 - 767
ISSN:
0006-3606
Resumen:
The Nevados del Aconquija (5500 m) and Cumbres Calchaquies (4600 m) are isolated mountain ranges that contain at least three physiognomic units in their easternslopes: Neotropical rainforests, Andean grasslands and High Andean Steppes. Despite phytogeographical similarities, the two ranges differ in the amount and spatialdistribution of rainfall over the elevation gradient. We studied terrestrial small mammals by direct trapping in two altitudinal transects on the eastern slope of the twomountain ranges. We recorded the changes in richness and species composition, as well as the relationships between species and microhabitats at each altitudinal level.The results show a similar structure of the small mammal assemblage in the two ranges. The largest differences, in terms of species composition, were registered at lowerelevation forests, and faunal affinities increased with elevation to the point of finding identical species composition at the top of the mountains. Species richness showeda clear curvilinear pattern with a peak at the upper limit of the forests. Our findings suggest that total rainfall has an important influence on the composition andabundance of small mammal species but apparently not on the species richness along the elevation gradient. The highest values of species richness were observed at thesites where a contact between two different physiognomic units exists. These results indicate that habitat heterogeneity plays an important role in allowing the juxtapositionof small terrestrial mammal assemblages of the highlands and lowlands at a given point, contributing significantly to the considerable diversity of speciesobserved in intermediate altitudinal sites.