| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4402861 | Procedia Environmental Sciences | 2012 | 9 Pages |
Tree-ring chronology, which is dating accurate, continuous, high resolution, high correlation to climate factors, etc., is one of the primary materials in the study of past global climate. Trees at moist high altitudes such as Pinus aiwanensis, exist false tree-rings commonly, so the cross-dating is difficult. This paper proposes a solution to a two-step compositive cross-dating by subsection, which is preliminary cross-dating by rings according to dendrology, next measuring the tree-ring width by routine tree-ring climatology to test cross-dating. According to characteristics of Pinus aiwanensis tree-rings, first, draw concentric circles at obvious boundaries to acquire subsections on tree-ring photos and analyze variation of ring from the pith to the east, west, south and north direction in subsection to find false tree-rings, next preliminary cross-dating. This paper establishes the tree-ring width(TRW) and density(TRD) chronologies of Pinus aiwanensis, and analyses correlation between tree-ring index and climate factors such as temperature, precipitation, sunshine hours, etc.The results show that: For Pinus aiwanensis at moist high altitudes exist false tree-rings commonly, two-step cross-dating by subsection is introduced, which is preliminary cross-dating by rings according to dendrology, next measuring the TRW by routine dendroclimatology to test cross-dating and analyze variation of ring in subsection, so that the cross-dating is much accurate and reliable. The correlation between tree-ring components and annual mean temperature shows that: Pinus aiwanensis TRW and TRD have a positive correlation to annual mean temperature and sunshine hours, the tree-ring have a negative correlation to annual mean precipitation and frost days. On adequate moisture conditions, high temperature and sunshine hours have a positive effect on tree growth, too much rainfall is antiblastic. The TRW have a positive correlation to early spring temperature, the TRD have a significant correlation to summer temperature and sunshine hours. Early spring temperatures and sunshine hours have an effect on Pinus aiwanensis TRW, summer temperature and sunshine hours have a particularly important effect on TRD. In view of the significance level, the TRD have a significant correlation to temperature.
