天山云杉球果大小性状的地理变异规律

Geographic Variation of Cone Size of Picea schrenkiana var.tianschanica in the Tianshan Mountains of Xinjiang

选择新疆境内天山山脉从西到东处于不同经度位置(81°05′—93°41.5′E,约12个经度范围)5个地点(昭苏、巩留、乌苏、乌鲁木齐和哈密)的天山云杉林进行垂直样带取样测定,分析天山云杉球果大小性状(长、宽及长宽比)随海拔梯度与经度的地理变化规律,以期为天山云杉种群保护、优良种源选育及其合理利用提供依据。结果表明:同一经度位置不同海拔范围内天山云杉球果大小性状发生不同的变化。天山云杉的球果长和球果长宽比随着海拔的增加总体上呈现逐渐减小的趋势,而球果宽则总体上随海拔梯度变化不显著。各经度位置天山云杉球果宽较球果长的性状稳定性高。天山云杉球果性状随海拔、经度和坡度的变化而发生变异,球果长的变异主要受海拔和坡度的影响,球果宽的变异则主要受经度的影响,而海拔、经度、坡度对球果长宽比都有显著影响。

Based on the natural distribution of Picea schrenkiana var. tianschanica in Xinjiang Uygur autonomous region, three cone size traits （cone length, cone width, and cone length/width ratio） were measured for the cones collected from natural stands of P. schrenkiana var. tianschanica in five sites （Zhaosu, Gongliu, Wusu, Urumqi and Hami） of different longitudes（81°05′- 93°41.5′ E） in Tianshan Mountains with similar latitude. Cones were collected from the lower limit to the upper limit of P. schrenkiana var. tianschanica. The aim is to analyze the variation of cone size traits along the altitudinal and longitudinal gradient. The results showed that the cone size varied with different range of altitude in each longitude site. The cone length and the ratio of cone length to width decreased along the altitudinal gradient, while the cone width did not significantly change along the altitudinal gradient. The variation of cone width was lower than that of cone length at each site of longitude. The cone size traits varied with altitude, slope and longitude. The variation of cone length was mainly influenced by the altitude and slope, while the variation of cone width was mainly influenced by the longitude, however, variation of the ratio of cone length to width was influenced by altitude, slope and longitude.