大兴安岭北部樟子松树木生长与气候因子的关系

 在大兴安岭北部漠河(MH I、MH II 2个样点)、塔河蒙克山(MKS)、满归(MG)地区共采集樟子松(Pinus sylvestris var. mongolica)年轮样芯139个, 成功地建立了MH I、MH II、MKS和MG 4个样点的樟子松差值年表, 最长达377年(1631–2007年, 有效年表为1743–2007年)。樟子松年轮指数与气候因子的响应函数分析表明, 气温是这4个样点樟子松径向生长的主要限制因子。但4个样点限制其生长的月份有所差异, 漠河的2个样点樟子松年轮指数与6月气温负相关, 满归和塔河蒙克山樟子松年轮指数与前一年10月气温正相关。樟子松年表与区域气候的冗余分析(redundancy analysis, RDA)基本与响应函数分析的结果一致, 进一步验证了气温对大兴安岭北部樟子松生长的限制作用。该研究为全球变暖下大兴安岭北部樟子松林的经营管理及区域气候重建提供了基础数据。

Climate-tree growth relationships of Pinus sylvestris var.mongolica in the northern Daxing'an Mountains, China

Aims Daxing’an Mountains, the northernmost and largest forest area in China, showed significant warming in the 20th century. Scots pine (Pinus sylvestris var. mongolica) is one of the two major conifer tree species in the boreal forests of these mountains. Our objective was to detect possible influence of climate change on boreal forests in this area through dendroclimatology. Methods We investigated climate-growth relationships of Scots pine using tree ring-width chronologies (total of 139 cores) developed from Mohe, Mengkeshan and Mangui in the northern Daxing’an Mountains. Four residual chronologies were developed from the cross-dated ring width series using the program ARSTAN. The relationships between climate and tree-ring index were analyzed using bootstrapped response functions analysis of the software DENDROCLIM2002. Redundancy analysis (RDA), a multivariate “direct” gradient analysis, and its ordination axes are constrained to represent linear combinations of supplied environmental variables. It was carried out on the four Scots pine chronologies and 24 climate variables for 1973–2006 using the program CANOCO. STATISTICA for Windows, release 6.0 (StatSoft Inc., Tulsa, Oklahoma, USA) was used for other statistical analysis. Important findings Tree growth from the four sites showed different responses to local climates. Response analysis showed that the chronologies of Mohe I and Mohe II were negatively correlated with June temperature of the current year, while the chronologies of Mangui and Mengkeshan were positively correlated with October temperature of the previous year. The analysis indicated that temperature is the major limiting factor for the growth of Scots pine in the northern Daxing’an Mountains. Redundancy analysis between four Scots pine chronologies and regional climate data verified this conclusion.