【摘要】 辽宁省地处东北地区南部,横跨暖温带和中温带,植物区系复杂多样。为了掌握草地类型分布及其植物区系特征,本研究基于气象数据和野外植物调查数据,对辽西低山丘陵区草地类型进行划分,并分析其植物区系特征。结果表明:辽宁省伊万诺夫湿润度在0.3～1.2之间,辽西低山丘陵区属于半干旱区;温性草原类共出现436种植物,暖性灌草丛类共出现298种。根据优势种特征将温性草原类划分为3个草地型,暖性灌草丛类划分为4个草地型。温带分布型属在温性草原类和暖性灌草丛类中分别占59.40%和60.50%,远高于热带分布型的22.00%和20.20%,植物区系具明显的温带性质,暖性灌草丛类中广泛分布着黄背草(Themeda triandra)、白羊草(Bothriochloa ischaemum)等热带分布型的喜暖性植物,成为草本层的优势种。温性草原类的植物区系丰富度指数为5.512,高于暖性灌草丛类的4.980,温带分布型和热带分布型的相互渗透特征明显。更多还原

【Abstract】 Liaoning Province is located in the southern part of Northeast China,spanning the warm temperate and middle temperate zones,and has a complex and diverse flora. In order to grasp the distribution of grassland types and their flora characteristics,based on meteorological data and field plant survey data,grassland types in the low hills of western Liaoning were classified and their flora characteristics were analyzed. The results showed that the Ivanov moisture index in Liaoning Province ranged from 0.3 to 1.2,and the low mountains and hilly of western Liaoning province belonged to the semi-arid zone;436 species of plants appeared in the warm grassland classes and 298 species appeared in the warm shrub grassland classes. According to the characteristics of the dominant species,the warm grassland classes were divided into three grassland types,and warm shrub grassland classes were divided into four grassland types. The temperate areal-type,accounted for 59.40% and 60.50% of the warm grassland classes and warm shrub grassland classes respectively,were higher than the tropical areal-type which were 22.00% and 20.20% respectively. The flora was distinctly temperate in nature,and the warm shrub grassland classes such as Themeda triandra and Bothriochloa ischaemum became the dominant species in the herbaceous layer,which were widely distributed in the warm shrub grassland classes. The flora richness index was 5.512 for the warm grassland classes,which was higher than 4.980 for warm shrub grassland classes,and the interpenetration between temperate and tropical distribution types was evident.更多还原