Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Density and population structure of the natural regeneration of Scots pine (Pinus sylvestris L.) in the High Ebro Basin (Northern Spain). | 277 Ann. For. Sci. 58 2001 277-288 INRA EDP Sciences 2001 Original article Density and population structure of the natural regeneration of Scots pine Pinus sylvestris L. in the High Ebro Basin Northern Spain Santiago C. Gonzalez-Martinez and Felipe Bravo Departamento de Producción Vegetal y Silvopiscicultura University of Valladolid at Palencia Avda. de Madrid 57 34004 Palencia Spain Received 18 February 2000 accepted 21 August 2000 Abstract - This paper presents the analysis of 11 natural regenerated stands in native Scots pine forests located in the High Ebro Basin Northern Spain . The natural regeneration showed a continuous age distribution early height differentiation and a high stability in the height position of seedlings. Total density and main crop trees selected for future commercial harvest density models were developed to study the relationship between natural regeneration and site variables. Soil sand content was an important ecological factor distinguishing two groups of plots. Hardwood and Ericaceae species competition were the main factors that explained total density but only in soils with low sand content. Intensive herbivore grazing was proposed to produce a strong reduction of viable seedlings. Thus vegetation-control treatments and limitation of cattle grazing in regeneration areas are highly recommended in the native Scots pine forests of the High Ebro Basin. natural regeneration population structure Pinus sylvestris Mediterranean region Spain Résumé - Densité et structure des peuplements de Pin sylvestre Pinus sylvestris L. régénérés naturellement dans le Haut-Bassin de l Ebre Nord de l Espagne . Dans cet article sont analyses 11 peuplements régénérés naturellement situés dans les forets autochtones de Pin sylvestre du Haut-Bassin de l Ebre Nord de l Espagne . La régénération naturelle a été caractérisée par une distribution continue de l âge une différenciation en hauteur précoce et une stabilité dans les classes de hauteur des plantules. .
