tailieunhanh - Báo cáo lâm nghiệp: "Growth versus storage: responses of Mediterranean oak seedlings to changes in nutrient and water availabilities."

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Growth versus storage: responses of Mediterranean oak seedlings to changes in nutrient and water availabilities. | Ann. For. Sci. 64 2007 201-210 INRA EDP Sciences 2007 DOI forest 2006104 201 Original article Growth versus storage responses of Mediterranean oak seedlings to changes in nutrient and water availabilities Virginia Sanz PÉREZa Pilar Castro DÍEZa Fernando Valladares0 a Departamento de Ecología Universidad de Alcalá Alcalá de Henares 28871 Madrid Spain b Institute de Recursos Naturales Centro de Ciencias Medioambientales CSIC Serrano 115 28006 Madrid Spain Received 31 March 2006 accepted 15 June 2006 Abstract - We compare dry mass DM and storage of starch St and nitrogen N in seedlings of three Mediterranean oaks two evergreens Quercus coccifera L. and Q. ilex L. subsp. ballota Desf. Samp and one deciduous Q. faginea Lam. across different scenarios of nutrient and water availabilities. Three fertilization 5 50 and 200 mg of N per plant and growing period and watering 28-39 55-71 and 70-85 g H2O 100 gAj gravimetric soil water treatments were applied to current-year seedlings between May and October 2002 in two independent experiments. The three species showed a similar response to fertilization storing nitrogen instead of increasing biomass in agreement with adaptations to nutrient-poor habitats. However they differed in their responses to water reflecting the different water requirements in the field Q. coccifera from arid zones showed no response to water regarding DM and St Q. faginea from humid zones required higher water availability to simultaneously increase growth and storage while Q. ilex spanning over most of the water availability range exhibited a balanced increase of both functions when water increased moderately. In the two evergreen species N concentration increased with water supply whereas the reverse occurred in Q. faginea. The latter species favoured growth over storage at moderate water supply according to its more competitive strategy although it was the species which accumulated more St and N at the end of the experiments autumn . .