Resumo

PAIS BOSCH, Ana I; TECCO, Paula A; FUNES, Guillermo  e  CABIDO, Marcelo. Efecto de la temperatura en la regeneración de especies leñosas del Chaco Serrano e implicancias en la distribución actual y potencial de bosques. Bol. Soc. Argent. Bot. [online]. 2012, vol.47, n.3-4, pp.401-410. ISSN 1851-2372.

The effect of temperature in the regeneration of Mountain Chaco woody species and implications on the current and potential distribution of forests. Temperature influences the distribution of woody species by acting on processes associated with the regenerative phase of the plants. We analyzed its influence on the altitudinal distribution of the montane Chaco woodland and its potential coexistence with high mountain Polylepis woodlands in the Sierras Grandes of Córdoba, at central western Argentina. We evaluated the regeneration of two tree species occurring in the montane Chaco woodland (Ruprechtia apetala and Lithraea molleoides) and the dominant tree in the high mountain woodlands (Polylepis australis), so spanning the complete altitudinal gradient of these mountain ranges (900-2700 masl). Species' potential germination was evaluated in the laboratory by germination essays under four thermo-periods, representing the temperatures along the altitudinal gradient. Seedling emergence and survival was additionally assessed in the field, across seven altitudinal sites. P. australis germinated in the four thermo-periods and in the seven altitudinal field levels. L. molleoides showed no germination at low temperatures (10/5ºC) in laboratory, though germinated and survived throughout the altitudinal gradient in the feld. R. apetala was the most restricted species, neither settling above 1500 m a.s.l. in the field nor germinating at low temperatures in the laboratory. Our results suggest that, at least in terms of sapling recruitment, the altitudinal belt between 1400-1700 m a.s.l. in the Sierras Grandes of Córdoba, has the potential to host a transitional community, with woody elements of both montane chaco and high mountain woodlands.

Palavras-chave : Regeneración; Temperatura; Gradiente altitudinal; Chaco Serrano; Límite superior de bosques; Regeneration; Temperature; Altudinal gradient; Montane Chaco Woodland; Upper limits of forests.

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