INVESTIGADORES
BERTILLER monica Beatriz
artículos
Título:
Phenology of Festuca pallescens in relation to topography in north-western Patagonia
Autor/es:
BERTILLER, MONICA B.; IRISARRI, MARIA P.; ARES, JORGE O.
Revista:
JOURNAL OF VEGETATION SCIENCE
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 1990 vol. 1 p. 579 - 584
ISSN:
1100-9233
Resumen:
The phenological changes in populations ofFestuca pallescens (St. Yves) Parodi at differenttopographic positions and exposure along an altitudinalgradient (600 - 1100 m) were investigated during twogrowing seasons in northwestern Patagonia. Stepwisemultiple regression analysis was used to describe therelationship between phenology and environment duringthe entire growing season. Analysis of variance was alsoperformed at each sample date to detect significantenvironmental factors influencing phenology at differentsites. The sum of maximum air temperatures was identified as the environmental variable best correlated withthe seasonal variation of phenological events of Festucapallescens over the period of two growing seasons, explaining 93.2 % of the total variance. Significant differences between sites were observedat each sample date. Main effects of altitude and topographic position and two-way interactions between altitude and topographic position, and topographic positionand exposure were also detected as significant. Phenology was delayed at increased altitude. Differences in phenology between topographic sitesat the same altitude were not detected during the entiregrowing season and were only observed in the reproductive phase. At this time, the phenology was significantlydelayed at high topographic positions on the slopes ascompared with low and mid positions. At high altitudesin the valley (950 m a. s. l.), where steep slopes andhumid conditions prevail, phenology was delayed onwestern exposures and low positions. The results adequately summarize and quantify the effect of spatial andtemporal environmental variation on the phenologicaldevelopment of Festuca pallescens in northwesternPatagonia.