A woody plant community and tree-cacti associations change with distance to a water source in a dry Chaco forest of Argentina
2017
In semiarid regions, livestock is concentrated around water sources generating a piosphere pattern (gradients of woody vegetation degradation with increasing proximity to water). Close to the water source, livestock may affect the composition, structure and regeneration strategies of woody vegetation. We used the proximity from a water source as a proxy of
grazing pressure. Our objectives were (1) to compare woody vegetation attributes (richness, diversity, species composition, density and
basal area) and ground cover between sites at two distances to a water source: near (higher
grazing pressure) and far from the water source (lower
grazing pressure), and (2) to quantify and
compare casesof spatial association among the columnar cacti
Stetsonia coryne(Salm-Dyck) Britton and Rose (Cactaceae), and the dominant tree
Bulnesia sarmientoiLorentz ex Griseb. (
Zygophyllaceae). We used a paired design with eight pairs of rectangular plots distributed along a large and representative natural water source. We found lower total species richness, plant density and soil cover near than far from water source, and more cases of spatial associations between the two species studied. Our results show evidence of increased livestock impacts around water sources. However, we found no difference in terms of species composition or
basal areaat near versus far sites. We conclude that
grazing pressuremight be changing some attributes of the
woody plantcommunity, and that the association of young trees with thorny plants (
grazingrefuge) could be a regeneration mechanism in this semiarid forest with high
grazing pressure.
Keywords:
-
Correction
-
Source
-
Cite
-
Save
49
References
6
Citations
NaN
KQI