Above- and below-ground nutrient tissue concentration and leaf pigment changes in Patagonian woody seedlings grown under light and soil moisture gradients

R SOLER ESTEBAN; G MARTÍNEZ PASTUR; MV LENCINAS; A MORETTO; PL PERI

JOURNAL OF PLANT NUTRITION

TAYLOR & FRANCIS INC

Lugar: London; Año: 2011 vol. 34 p. 2222 - 2236

0190-4167

To manage primary forests more effectively, it is important to understand the basis of plant regeneration eco-physiology, and their plasticity to changes in environmental factors. The objective was to evaluate above- and below-ground nutrient tissue concentration and leaf pigment changes in N. pumilio seedlings grown in light intensity and soil moisture gradients. Six treatments with three light intensities (4%, 26% and 64% of the natural incident irradiance) and two soil moisture levels (40-60% and 80-100% soil capacity) were set up under greenhouse controlled conditions. Nutrient tissue (C, N, P, Mg, K and Ca) and pigment (chlorophylls and carotenoids) concentrations were measured on seedlings during summer. Seedlings varied their nutrient tissue concentration, both in above- and below-ground biomass, as well pigment leaf content, according to the availability of light and soil moisture contents. C, N, Mg, K and Ca increased in low light intensity and soil moisture treatments, while P decreased. Nutrient tissue concentration were higher in above- than in below-ground biomass. Chlorophylls were lower in high light treatments, while carotenoids increased their content. Beside this, all pigments were greater in low soil moisture content treatments. These changes are closely related to their photosynthetic plasticity and biomass compartmentalization. Plants growing in high light environments were more efficient in the use of the nutrients per biomass unit, while seedlings growing in shaded environments needed more nutrients to produce the same quantity of vegetal tissue biomass.