秦巴山地植物多样性空间分异及其与气候因子的关系

Spatial Differentiation of Plant Diversity and Its Relationship with Climatic Factors in Qinling-Daba Mountains

秦岭—大巴山作为中国暖温带和亚热带气候过渡区,是中国生物多样性研究的热点地区之一,气候对秦巴山地植物多样性空间分布影响巨大。本文基于秦巴山地及邻区种子植物物种数据库,首先分析了植物目、科、属、种多样性,乔木、灌木、草本多样性以及中国特有种多样性的空间分布规律,以阐明植物多样性在秦巴山地过渡带上的空间分布特点;其次,结合秦巴山地的气温和降水数据,对植物多样性和环境指标进行空间叠加分析,揭示其在空间分布上的协同变异规律;再次对植物目、科、属、种,乔木、灌木、草本以及中国特有种进行聚类,并将结果展布在空间上,以显示秦巴山地植物在空间上的聚类规律;最后总结植物多样性突变位置的气候特征,并据此确定亚热带和暖温带划分的植物指标。研究结果表明:1)该区目、科、属、物种多样性,乔木、灌木多样性均呈现由南到北逐渐减少的空间分布格局,植物科、属多样性具有较明确的分界线,物种多样性具有明显的过渡带,而这条分界线处和过渡带内气候指标的变化范围稳定,南多北少的分界线位置大致均在东部伏牛山(南召县、内乡县、商南县、郧县)—中部太白山以南(镇安县、石泉县、洋县)—西部秦岭南坡(勉县、武都区、文县、平武县);2)南多北少的过渡带覆盖东部伏牛山南坡—神农架北坡之间宽阔的地区,中部太白山南坡—米仓山北坡相对较窄的区域,西部几乎为一条线,与分界线位置基本重合;3)在中国特有种多样性方面,秦巴山地内部明显高于秦巴山地邻区,进一步印证了秦巴山地内部的过渡性强烈。本文的研究结果可为秦巴山地植物多样性保护提供科学依据,有助于人类理解生态环境对森林生态系统的影响。

As the climatic transitional zone of warm temperate and subtropical in China,Qinling-Daba Mountains has been one of the hotspots of biodiversity research in China.The climate showed a great impact on the spatial distribution of plant diversity in Qinling-Daba Mountains.Based on the seed plant species database of Qinling-Daba Mountains and its adjacent areas,firstly,this paper analyzed the spatial distribution pattern of order,family,genus,species diversity,tree,shrub,herb diversity,and diversity of species endemic to China,and described the spatial distribution characteristics of plant diversity in the transitional zone of Qinling-Daba Mountains.Secondly,combined with the temperature and precipitation data of Qinling-Daba Mountains,we revealed their synergistic variation characteristics in spatial distribution by carrying out the spatial overlay analysis of plant diversity and environmental indicators.Thirdly,plant orders,families,genera,species,arbors,shrubs,herbs,and endemic species of China were clustered,and the clustering results were shown spatially,thus clearly showing the spatial clustering law of plants in Qinling-Daba Mountains.Finally,we summarized the climatic characteristics of the mutation location of plant diversity and determined the plant indicators for the division of subtropical and warm temperate zones.The results showed that the diversity of orders,families,genera,and species,and the diversity of trees and shrubs had a spatial distribution pattern gradually decreasing from south to north.The diversity of plant families and genera had a clear boundary,and the species diversity had an obvious transitional zone.The dividing line of more in the south and less in the north was roughly located in Funiu Mountains in the eastern(Nanzhao County,Neixiang County,Shangnan county and Xunxi county)-south of Taibai Mountains in the middle(Zhen'an County,Shiquan County,and Yang county)-Mian County,Wudu District,Wen County and Pingwu County in the western,that was,the south flank of Qinling Mountains.The transitional zone with more in the south and less in the north covers the wide area between the south slope of Funiu Mountains and the north slope of Shennongjia in the eastern.The relatively narrow area between the south slope of Taibai Mountains and the north slope of Micang Mountains in the middle was almost a line in the west,which almost coincides with the boundary.In terms of the diversity of endemic species in China,the internal Qinling-Daba Mountains were higher than the external,which further confirmed the strong transition in Qinling-Daba Mountains.The results can provide scientific evidence for the protection of plant diversity in Qinling-Daba Mountains,and help human beings understand the impact of the ecological environment on the forest ecosystem.