Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Nutrient concentrations in Pinus radiata D Don needles in the Basque Country (Spain): preliminary classification of parameters and sites. | Ann Sci For 1993 50 23-36 Elsevier INRA 23 Note Nutrient concentrations in Pinus radiata D Don needles in the Basque Country Spain a preliminary classification of parameters and sites JM Mesanza 1 H Casado 1 FJ Castillo 2 Departamento de Fisica Aplicada II Facultad de Farmacia Universidad del Pais Vasco 01007 Vitoria 2 Departamento de Production Agraria Universidad Publica de Navarra 31006 Pamplona Spain Received 23 March 1992 accepted 25 September 1992 Summary This work presents the first results on nutrient concentrations in Pinus radiata needles in the Basque Country Spain . Current year and 1-yr-old needles collected at different sites were analyzed for calcium magnesium potassium phosphorus nitrogen and manganese content. Our results indicate some differences between sites seasons and needles of different ages. Nutrient levels are sufficient in general for tree nutritive requirements but some low concentrations of magnesium and especially phosphorus found in 1-yr-old needles indicate the possibility that some trees may show signs of deficiency in the near future. In turn nitrogen and manganese concentrations are in many cases higher than those usually found in this species and may give rise to growth disorders nitrogen or toxicity manganese . We present here a preliminary classification of sites and parameters based on the principal component analysis. Our results show the utility of this method to differentiate appropriate sites for the adequate development of Pinus radiata. nutrient cation needle Pinus radiata I deficiency classification Resume Concentration en elements nutritifs des aiguilles de Pinus radiata D Don dans le Pays Basque Espagne classification préliminaire des paramètres et des sites. Ce travail présente les premiers résultats concernant la concentration en elements nutrifis des aiguilles de Pinus radiata dans le Pays Basque Espagne . Des elements nutritifs calcium magnesium potassium phosphore azote et manganese ont été analyses dans des .
