天山北坡雪岭云杉树轮宽度年表梯度特征分析

在天山北坡不同区域间隔海拔高度100 m左右采集5个树轮梯度年表,分析树木径向生长沿海拔高度变化的规律。结果发现:在树轮年表特征中,平均轮宽、树龄和敏感度等存在海拔梯度变化,平均轮宽和敏感度随海拔升高而降低,而平均树龄则与海拔高度呈正相关。高海拔采样点在同一区域和不同区域间一致性最好,低海拔采样点次之,而森林中部最差,东部和中部低海拔区域采样点的一致性要好于西部,坡向、坡度等小生境的差异也是影响树轮生长垂直变化规律的重要因素。存在同时影响不同海拔高度树轮生长的环境要素,西部和中部高海拔树木对该要素的响应更显著,在更为干旱的天山北坡中部和东部,对树木径向生长的影响较大的环境因子要多于西部伊犁地区。

Gradient chronology feature of Picea Schrenkiana in the north slope of Tianshan Mountains,China

Tree-ring cores were taken at different elevations of the five sampling on the north slopes of tianshan Mountains and every site interval about 100 meters apart. sites tree-ring width chronologies of Picea schrenkiana were determined using standard dendrochronological methods.Analysis the feature of tree ring width choronology for different elevations. The average growth volume, tree age, and sensitivity have changes in elevation gradient, and the average growth volume and sensitivity decrease with elevation, while the average tree age is positively related to altitude. The high altitude picking points have the best consistency between the same and different regions, followed by the low altitude picking points, while the middle part of the forest is the worst, and the Eastern and central low-altitude picking points have better consistency than the western part. The difference of small habitats such as slope direction and slope are important factors that have affected the vertical change of tree growth along the elevation gradient. There are environmental factors that affect the growth of tree rings at different altitudes at the same time, and the response of high altitude chronology is more significant in the West and middle. In the middle and east of the northern slopes of Tianshan Mountains,there are more environmental factors affecting the radial growth of trees than the Yili area.