Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "The decline of a Pinus nigra Arn. reforestation stand on a limestone substrate: the role of nutritional factors examined by means of foliar diagnosis. | Ann. Sci. For. 55 1998 567-576 Inra Elsevier Paris 567 Original article The decline of a Pinus nigra Arn. reforestation stand on a limestone substrate the role of nutritional factors examined by means of foliar diagnosis Enrico Cenni Filippo Bussotti Lorenzo Galeotti Laboratory of Applied and Forest Botany Department of Plant Biology University of Florence Piazzale delle Cascine 28 1 50144 Florence Italy Received 6 June 1997 accepted 26 November 1997 Abstract - The Austrian black pine reforestation projects on Monte Morello near the heavily populated metropolitan area of Florence Italy have been affected for many years now by a severe decline consisting of widespread crown yellowing. To investigate the causes of this decline foliar diagnosis methods were used to monitor the nutritional status of ten trees sampling and analysing every year between 1989 and 1992 the current year needles c needles from the previous year c 1 and from the year before that c 2 . The parameters examined were both chemical nitrogen sulphur magnesium potassium calcium manganese iron and lead and morphological needle length flat projection dry weight specific dry weight and water content . The findings show a considerable calcium accumulation as the needles age accompanied by an increase in dry weight and specific dry weight as well as a marked antagonism to manganese. The influence of the nearby metropolitan area of Florence is suggested by the accumulation of lead. Inra Elsevier Paris afforestation calcium iron leaf senescence I manganese I Pinus nigra subsp. nigra I chlorosis Resume - Le dépérissement des reboisements de Pinus nigra Arn. sur substrat calcaire le role des facteurs nutritỉonnels étudiés à 1 aide du diagnostic foliaire. Les reboisements de pin noir d Autriche dans le Monte Morello près de Fimportante zone urbaine de Florence Italie sont affectes depuis maintenant plusieurs années d un severe dépérissement consistant en un jaunis-sement très frequent des couronnes. Pour .
