【目的】树种的地理分布特征反映了气候趋势,同时气候变化也反作用于树种分布,它们之间的相互关系可为研究树种地理分布和起源,制定保护策略提供理论依据。【方法】以位于3级地理阶梯天然分布的刺柏属(Juniperus)8种为研究对象,通过对222个样点的气候、海拔数据进行方差、变异系数分析,以及线性回归、主成分与线性判别分析,比较和确定限制刺柏树种地理分布格局形成的主导因子。【结果】年均气温、昼夜温差月均值、等温性、极端最高温、年温度变化范围、年均降水量、降水量季节性变化、最冷季降水量、海拔、干旱指数在8种分布区间存在显著差异(P<0.001);其中等温性、年温度变化范围、年均降水量、海拔、干旱指数的方差来自树种间,剩余5个因子的方差主要来自树种内。昼夜温差月均值、等温性、极端最高温、年温度变化范围、降水量季节性变化的变异系数在20%左右,限制性强。经纬度与等温性、极端最高温、年温度变化范围、降水量季节性变化、海拔显著相关,其中与等温性、海拔因子为负相关。年温度变化范围、等温性、降水量季节性变化、极端最高温、海拔是驱动刺柏属8种地理分布差异的主要因子,并且温度载荷大于降水量。8种分布格局大致分为兴安圆柏(J. sabina var. davurica)、杜松(J. rigida)、叉子圆柏(J. sabina)、新疆方枝柏(J. pseudosabina)分布于干冷区,祁连圆柏(J. przewalskii)、大果圆柏(J. tibetica)、方枝柏(J. saltuaria)、滇藏方枝柏(J. indica)分布于暖湿区。【结论】温度(等温性、极端最高温、年温度变化范围)、水分(降水量季节性变化)和海拔共同作用驱动着刺柏属8种的地理分布,并且温度影响大于水分影响,海拔因子重新调整了相同经纬度地区的水热状况。本研究表明刺柏属树种喜生于冷湿环境,体现出其泛北极植物区系的特征;提出了刺柏属8种适宜分布区的温度、水分和海拔高度的均值与范围,可为今后异地栽种提供理论参考。

【Objective】The geographical distribution characteristics of tree species reflect climate trends, while climate change in turn influences their distribution. The interaction between these provides a theoretical basis for studying the geographical distribution and origin of tree species, as well as formulating conservation strategies.【Method】Taking eight naturally distributed species of the Juniperus across the three-level geographical terrains as the research subjects, this study employed analysis of variance (ANOVA), coefficient of variation, linear regression analysis, principal component analysis (PCA), and linear discriminant analysis (LDA) on climate and altitude data from 222 sampling sites. The aim was to compare and identify the dominant factors restricting the formation of the geographical distribution pattern of Juniperus species.【Result】Significant differences (P<0.001) were observed among the eight species in terms of annual mean temperature, mean diurnal range, isothermality, the max temperature of the warmest month, temperature annual range, annual precipitation, precipitation seasonality, precipitation of the coldest quarter, altitude, and aridity index. Among these factors, the variance in isothermality, temperature annual range, annual precipitation, altitude, and aridity index originated primarily from interspecific differences, while the variance in the remaining five factors originated mainly from intraspecific variations. The coefficients of variation for mean diurnal range, isothermality, the max temperature of the warmest month, temperature annual range, and precipitation seasonality were approximately 20%, indicating strong restrictive effects. Latitude and longitude were significantly correlated with isothermality, the max temperature of the warmest month, temperature annual range, precipitation seasonality and altitude, with negative correlations observed for isothermality and altitude.The temperature annual range, isothermality, precipitation seasonality, the max temperature of the warmest month, and altitude were the main drivers of geographical distribution differences among the eight Juniperus species, and the contribution of temperature-related factors exceeded that of precipitation-related ones. The eight species were roughly divided into two groups: the dry-cold zone group, including J. sabina var. davurica, J. rigida, J. sabina and J. pseudosabina; and the warm-humid zone group, including J. przewalskii, J. tibetica, J. saltuaria and J. indica.【Conclusion】Temperature (isothermality, the max temperature of the warmest month, temperature annual range), moisture (precipitation seasonality), and altitude collectively drive the geographical distribution of each Juniperus species, with temperature exerting a greater influence than moisture. Altitude readjusts the hydrothermal conditions in areas with the same latitude and longitude. This study presents the mean values and ranges of temperature, moisture, and altitude for the suitable distribution areas of the eight species, providing a theoretical reference for future ex-situ cultivation.The findings indicate that Juniperus species prefer cold and humid environments, reflecting their characteristics as part of the Holarctic flora.