马尾松树轮早材、晚材年表对气候因子响应的敏感性分析

为探究亚热带地区树木年轮早材、晚材宽度指标用于气候变化分析的敏感性差异,及全球气候变暖背景下亚热带不同地区马尾松径向生长可能受到的影响。在马尾松(Pinus massoniana)主要分布区的大致西缘、南缘、中心区、北缘和东缘5个典型的亚热带地区建立起马尾松早材、晚材宽度指标的树轮年表,与各地记录的标准化降水蒸发指数、降水、月均温、月最高温、月最低温5个气候因子多年的单月值及多月值数据进行相关分析。结果发现:(1)所有地点的马尾松早材年表和晚材年表的平均敏感度均较高(0.185～0.273),可用于气候重建工作。(2)同一样区早材和晚材年表的相关性较高,但早材对气候的敏感性高于晚材年表。(3)马尾松树轮宽度对气候要素的响应在不同的地域存在一定的差异与联系。生长季早期的气温升高会对西缘、南缘、中心区和东缘样区马尾松的径向生长产生有利影响,但在较为干旱的北样区,马尾松径向生长则易受到升温造成的水分抑制作用。(4)在不区分上一年或当年条件下,夏季的降水对5个样区马尾松径向生长具有高湿制约作用,秋冬季降水对马尾松径向生长具有有利作用。

Divergence Response of Earlywood,Latewood Chronologies of Pinus Massoniana to Climatic Factors

Abstract：To examine the divergence response of earlywood (EW), latewood (LW) width indicators of Pinus massoniana to climate factors and to determine what effects of radial growth of PM will be affected in different subtropical regions in the context of global climate change, we selected five study areas with typical spatial representations which are located in eastern, western, central, southern and northern areas of PM distribution approximate range respectively.The dendrochronologies series of EW and LW width were established in each area to analyze the correlation between the three types of ring width indicators chronologies and local climatic variables.The results showed that (1) The mean sensitivities of EW and LW width chronologies in all regions were higher.Most of significant correlations between both two types of chronologies and the climatic factors in each area were highly coincident.(2) Earlywood and latewood chronologies are very similar in all areas.However, the sensitivity of EW chronologies are more sensitive to climate factors.(3)The dendroclimatical relationships of Pinus massoniana have some differences and connections in different areas.In the early stage of growing season, the increase of temperature was helpful to the radial growth of Pinus massoniana in the areas with ample water.But in the northern area where water was relative deficient, the temperature increasing would be negative to the radial growth of Pinus massoniana.(4)Without distinguishing the previous year or the current year, summer precipitation has a restriction on the radial growth of Pinus massoniana in five sample areas, and autumn and winter precipitation has a favorable effect on the radial growth of Pinus massoniana.