INVESTIGADORES
FRANZESE Jorgelina
artículos
Título:
Early competition between the exotic herb Rumex acetosella and two native tussock-grasses with different palatability and water stress tolerance
Autor/es:
FRANZESE J.; GHERMANDI L.
Revista:
JOURNAL OF ARID ENVIRONMENTS
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2014 vol. 106 p. 58 - 62
ISSN:
0140-1963
Resumen:
Semiarid grasslands in NW Patagonia (Argentina)
are dominated by Festuca pallescens
and Pappostipa speciosa, two native tussock
grasses that differ in water stress tolerance and in palatability to livestock.
Both species regenerate in gap microsites invaded by the exotic herb Rumex acetosella. We performed a
greenhouse experiment to study the effect of Rumex competition on early growth of the dominant tussock-grasses. In
February 2008 we used about 4-month-old seedlings to establish competition
treatments that simulated a dry or wet summer. Competition among grasses was
also quantified to relativize the effect of Rumex
competition on each grass species. Rumex seedlings had a negative impact on grass
seedlings, but it was not greater than that produced by any
co-dominant grass. Grass species did not differ in their
sensitivity to competition by Rumex or to water stress. In dry conditions, there was an
intense underground competition between grass species, but there was no evidence of underground
competition from Rumex. The low competitive
ability of Rumex under water stress may
indicate that its invasive potential from a seedling stage would be limited by
the aridity of the environment. Moreover, the high bud production of Rumex seedlings suggests an early contribution to the soil bud bank, a key eco-biologic trait
of this invasive species. Therefore, the estimation of the bud bank abundance
and the study of how vegetative regeneration may be interfering grass recruitment
should be considered in future research.