INVESTIGADORES
DEFOSSE Guillermo Emilio
artículos
Título:
Effects of Topography, soil moisture, wind and grazing on Festuca seedlings in a Patagonian grassland.
Autor/es:
DEFOSSÉ, G.E.; BERTILLER, M. B. ; ROBBERECHT, R.
Revista:
JOURNAL OF VEGETATION SCIENCE
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 1997 vol. 8 p. 677 - 684
ISSN:
1100-9233
Resumen:
The effects of topography, soil moisture, wind and grazing on the
emergence and survival of seedlings of Festuca spp. were examined
in the steppe zone of Patagonia, Argentina. Ungrazed and grazed field
treatment plots were established on a plain and a north facing slope at the
Media Luna Ranch (43 36 S, 71 25 W). On the leeward and windward sides of
each of 15 Festuca plants,0.1 x 0.4 m quadrats were censused bimonthly
for seedling emergence and survival for three growing seasons.
Three categories were distinguished: recently germinated and up to the first
leaf, two to four leaves, and from five leaves and up to one tiller. Soil
moisture content, litter cover and frost heaving effects were also determined
for each treatment at each sampling date. Festuca spp. Showed two
emergence peaks, one in late fall and the other in early to mid-spring.
Seedling emergence was significantly correlated with soil moisture content in
the 0-5 cm of the soil during the three growing seasons. Seedlings that emerged
in the fall had higher survivorship than those that emerged in the
spring. Seedling emergence and survival was significantly (p 0.01) lower
on slopes, in the grazing treatment and on windward sides of adult plants.
In this grassland, an increase in the availability of safe sites for
seedling emergence and survival might be achieved by protecting vegetation from
grazing, particularly on north-facing slopes.