INVESTIGADORES
PREMOLI IL'GRANDE andrea Cecilia
congresos y reuniones científicas
Título:
Adaptive and plastic responses of Nothofagus pumilio with elevation. VI Southern Connection Congress
Autor/es:
MATHIASEN P. & A.C. PREMOLI
Lugar:
Bariloche
Reunión:
Congreso; VI Southern Connection Congress; 2010
Resumen:
Contrasting conditions along altitudinal gradients impose differential selection pressures over plants which may show adaptive and plastic responses. Many of the differences found at contrasting altitudes in the dominant tree of high-elevation forests Nothofagus pumilio, were demonstrated to have a genetic basis. The objective is to evaluate the adaptive nature of these differences at contrasting elevations. A reciprocal transplant experiment of N. pumilio seedlings was performed in Challhuaco Valley at 41°S latitude, Argentina. In the year 2005, 220 seedlings from low and high elevation were reciprocally transplanted and monitored during three consecutive growing seasons. Measurements of growth, mortality, leaf morphology, and phenology were recorded. Our results show that plant origin determines growth habit. Plants from high altitude seedlings never overgrew low altitude ones, suggesting genetically fixed responses. In contrast, low altitude seedlings attained greatest plant height under extreme conditions in high altitude as a result of plasticity and/or greater genetic diversity. We found a significant effect of elevation for most leaf traits. Also, leaf characters at low elevation differed between origins suggesting significant genetic controls. Similarly, phenology yielded fixed genetic responses. The results from this study show adaptive and plastic responses of N. pumilio which will allow local survival to changing environmental conditions in Patagonia.