Relationship between masson pine tree-ring width and NDVI in North Subtropical Region Responses of Pinus sylvestris var. mongolica radial growth to climate warming in Great Xing’an Mountins: A case study in Mangui. Tree ring analysis on relation of Pinus massoniana growth to climate factors The drought events recorded in tree ring width in Helan Mt. over past 100 years THE EFFECTS OF ACID RAIN ON POPULUS EURAMERICANA TREE RING WIDTH AND WOOD PROPERTIES