INVESTIGADORES
SRUR Ana Marina
artículos
Título:
GRAZING-INDUCED MORPHOLOGICAL AND GROWTH RATE CHANGES IN ANARTHROPHYLLUM RIGIDUM, A PATAGONIAN LEGUMINOUS SHRUB
Autor/es:
SRUR A. M.; GOLLUSCIO, R. A.; VILLALBA R.; HODARA, K.
Revista:
Dendrochronologia
Editorial:
ELSEVIER GMBH, URBAN & FISCHER VERLAG
Referencias:
Lugar: ALEMANIA; Año: 2013
ISSN:
1125-7865
Resumen:
Grazing influences the morphology and growth rate of shrubs, and
consequently, their population dynamics. It has been shown that grazing
directly affects the growth of shrubs. On the other hand, the reduction
of grass biomass by herbivores reduces soilwater competition between
grasses and shrubs, and indirectly, could enhance the growth of shrubs.
However, the assessment of the long-term effects of grazing on the
growth of shrubs in the arid Patagonia has been hampered by the lack of
long and homogeneous records of plant population dynamics and primary
production. In this study, we combined growth-ring and allometric
analyses to assess the long-term effect of grazing on individuals of Anarthrophyllum rigidum, a leguminous shrub widely distributed across the Patagonian steppe. A. rigidum
has evergreen leaves rich in proteins that constitute an important
complement to the diet of sheep, particularly in winter when the
abundance of grasses is reduced. Our observations indicate that
individuals of A. rigidum nearby the water source used by livestock were smaller in size (35.5 cm vs. 67.39 cm), presented a larger number of basal branches (23 vs. 12), and showed slower rates of growth (8.2 mm year−1vs. 14.3 mm year−1) than individuals located far from the water source. This first quantification of the long-term effects of grazing on A. rigidum
in the dry Patagonian steppe suggests that beneficial effects of
grazing through the reduction of grasses that compete with shrubs for
soilwater should be more obvious for livestock non-preferred than
preferred shrubs