INVESTIGADORES
LENCINAS Maria Vanessa
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.