CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
capítulos de libros
Título:
Physiological traits on Osmorhiza depauperata, a biodiversity component in the Nothofagus forests of Southern Patagonia
Autor/es:
LENCINAS, MV; MARTÍNEZ PASTUR, G; ARENA, M; BUSSO, CA
Libro:
Frontiers in Biodiversity Studies
Editorial:
Bioscience Publications - Agrobios Editorial
Referencias:
Lugar: New Delhi; Año: 2012; p. 164 - 178
Resumen:
Osmorhiza depauperata (Apiaceae) is a perennial understory herb of the Patagonian Nothofagus (Nothofagaceae) forests, which survives and increases growth after harvesting. The objective was to evaluate the photosynthetic adaptation of greenhouse O. depauperata one-year-old seedlings to different light intensities and soil moisture availabilities, comparable to field conditions found in unmanaged and managed Nothofagus pumilio forests. CO2 gas exchanges were measured every month on seedlings growing in a greenhouse on Ushuaia city, under six treatments: three light intensities (4%, 26% and 64% of the natural incident irradiance) and two soil moistures levels (40-60% and 80-100% field capacity). Irrigation levels were obtained manually and different light intensities were generated by using two layers, one layer and without layer of black shade cloth. CO2 efflux was measured using an infra red gas analyzer (Model S151 - Qubit Systems). In the high light intensity treatments, seedlings reached its maximum photosynthetic adaptation (leaf light-saturated net photosynthesis rate of 6.0 µmol CO2 m-2 s-1 and light saturation point of 454.9 µmol photosynthetic photon flux density-PPDF m-2 s-1) compared to the lower light treatments (leaf light-saturated net photosynthesis rate of 4.5-4.9 µmol CO2 m-2 s-1 and light saturation point of 295.1-398.6 µmol PPDF m-2 s-1). Seedlings growing under low soil moisture conditions (40-60% soil water capacity) had higher leaf light-saturated net photosynthesis rate than plants grown under 80-100% soil water capacity (5.4 µmol CO2 m-2 s-1 and 4.8 µmol CO2 m-2 s-1, respectively). The efficiency of O. depauperata photosynthetic system improves with higher light availability, which capacitates this species to inhabit several contrasting environments as human being or introduced species impacted landscapes.