INVESTIGADORES
BERTILLER monica Beatriz
artículos
Título:
Quantitative assessment of shrub-grass mosaic development in grazed shrublands: an example in the Patagonian Monte (Argentina).
Autor/es:
PAZOS, G.O.; ARES, J.O.; BERTILLER, M.B
Revista:
JOURNAL OF ARID ENVIRONMENTS
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Año: 2010 vol. 74 p. 998 - 1002
ISSN:
0140-1963
Resumen:
Grazing alters the spatial structure of shrubs and perennial grasses in desert shrub communities. The
resulting spatial distribution of shrubgrass patches constitutes a sensitive indicator of the integrated
result of grazing impacts on them. While several procedures were developed to estimate the size of
shrub clumps, metrics of the geometry of the interacting grass matrix received less attention. In this
study, we conceptualised the spatial structure of shrubgrass patches as consisting of two components:
a grass crown of ill-defined outer borders (the grass component) encircling a shrub clump (the shrub
component). We fitted exponential functions to autocorrelograms of spatially explicit shrubgrass cover
data surveyed at different locations of the Patagonian Monte (Argentina) differing in livestock grazing
pressure. After that, we derived two metrics from the function parameters that quantitatively estimate
the size of both the shrub and the grass components of shrubgrass patches. The patterns of variation of
these metrics are consistent with field measurements and observations previously reported for the
studied areas, indicating that they are sensitive indicators of the state of development of the shrubgrass
mosaic under different grazing pressures. These results suggest that its applicability to similar semi-arid
shrublands deserves further attention.