INVESTIGADORES
ARANIBAR julieta Nelida
congresos y reuniones científicas
Título:
Efecto del pastoreo y la influencia de las plantas vasculares en la distribución de costras biológicas en la región de Ñacuñán, Desierto del Monte, Mendoza.
Autor/es:
DIANA A. GÓMEZ CAVIERES; JULIETA N. ARANIBAR; MARÍA S. TABENI; IRENE GARIBOTTI; PABLO E. VILLAGRA
Lugar:
Buenos Aires
Reunión:
Congreso; IV Reunión Binacional de Ecología; 2010
Institución organizadora:
Asociación Argentina de Ecología
Resumen:
Disturbance by domestic grazing is recognized as the most widespread stressor of biological soil crust
(BSC) communities. To assess the recovery of the BSC after grazing exclusion, we estimated the
composition, cover, and spatial distribution of biological soil crusts, and their influence on soil nitrogen in
a protected area after 40 years of grazing exclusion (Reserve MaB of Ñacuñán), and in its surrounding
grazed matrix in the central Monte Desert. We considered two spatial scales: at the landscape scale we
estimated vegetation and BSC cover in paired grazed and ungrazed sites of Larrea shrublands; at the
microsite scale we assessed the influence of the dominant vascular plant, Larrea cuneifolia, on crust cover,
and the influence of crust cover on soil nitrogen concentration. Grazing has a negative impact on soil
crusts, which only develop under the protection of vascular plants in grazing areas. Grazing exclusion
favors crust recovery, allowing black, lichen dominated crusts to develop in exposed areas between shrub
canopies. The cover of the moss-dominated crusts was not significantly different at any of the two spatial
scales analyzed. Soil nitrogen was higher in areas under L. cuneifolia and without BSC cover, suggesting
that litterfall inputs currently exceed those from soil crust N2 fixation, perhaps because crust function has
not yet recovered.