浙江维管植物生长型与生活型性状的地理分布格局及其驱动机制

Geographical distribution patterns and driving mechanisms of growth and life forms of vascular plants in Zhejiang Province,China

植物形态性状沿环境梯度的格局变化可反映物种与环境关系的空间分布格局,对研究植物群落构建和植被地理格局形成与维持机制具有重要意义.基于首版《浙江植物志》的3439种维管植物生长型和生活型性状和分布数据,统计和分析两种性状的地理分布格局及其环境驱动机制.结果表明:(1)浙江省维管植物的生长型性状中,木本植物占37.2%,草本植物占62.8%;在生活型性状中,木本植物的落叶(56.7%)多于常绿(43.3%),草本植物的多年生(76.4%)大于一年生(21.8%).(2)生长型和生活型性状呈现从西到东、由西南向东北递减的地理分布格局.高值位于浙南仙霞岭山脉、洞宫山脉和浙西北天目山脉,低值位于浙东北杭嘉湖平原和舟山群岛.(3)相关性分析表明,木本和草本生长型大都与湿润指数、年均降水和海拔高度呈显著正相关,与最暖月均温呈显著负相关;木本生活型大都与湿润指数、年均降水和海拔高度呈显著正相关,与最暖月均温呈显著负相关,草本生活型只与极端低温和年均温呈较显著负相关.逐步回归分析表明,水分因子中的湿润指数和年均降水分别为浙江植物生长型和木本生活型的主导环境因子,热量因子中的极端最低温为草本生活型的主导环境因子,综合反映水热格局的海拔高度则对生长型和生活型所占比例的影响最大.总之,浙江维管植物生长型和生活型性状自西/西南向东/东北递减的分布格局与区域水热条件的梯度变化密切相关.

Changes in plant morphological traits along environmental gradients reflect the spatial distribution pattern of species–environment relationships and have important implications for illustrating the mechanisms of formation and maintenance of plant community construction and vegetation geographical patterns.Based on the plant traits and distribution data of 3439 species of vascular plants obtained from the first edition of“Zhejiang Flora,”this study analyzes the geographical distribution pattern of growth forms and life forms of vascular plants in Zhejiang Province and their environmental mechanisms.The results showed that,(1)the growth-form traits of Zhejiang vascular plant species were 37.2%woody and 62.8%herbaceous.For life-form traits,the number of deciduous plants(56.7%)was greater than that of evergreen plants(43.3%)in woody species,whereas in herbaceous species,perennials(76.4%)were more abundant than annuals(21.8%).(2)The growth-and lifeform traits generally showed a pattern of gradual decrease from west to east and from southwest to northeast.A high number of traits occurred in the mountain ranges of Xianxia Ling and Donggong Shan in southern Zhejiang and Tianmu Shan in northwestern Zhejiang,whereas a low number of traits appeared in the Hang-Jia-Hu Plains and Zhoushan Archipelago in northeastern Zhejiang.(3)Correlation analysis showed that most woody and herbaceous growth forms were significantly and positively correlated with the moisture index(MI),mean annual precipitation(MAP),and altitude and were significantly and negatively correlated with the mean temperature of the warmest month(MTWA).The evergreen and deciduous woody life forms were mainly significantly and positively correlated with MI,MAP,and altitude and had a significant negative correlation with MTWA.The annual,biennial,and perennial herbaceous life forms were less significantly and negatively correlated with only the minimum temperature(Tmin)and mean annual temperature(MAT).Stepwise regression analysis further indicated that MI and MAP were the dominant environmental factors for the growth form and woody life form among the water variables,and Tmin was the driving factor for the herbaceous life form among the thermal variables.Altitude,which comprehensively reflects the hydrothermal conditions,had the greatest impact on the proportion of growth and life forms in all vesicular plants.In general,the spatial distribution patterns of growth and life forms in Zhejiang Province,with gradual decreases from west and southwest to east and northeast,are closely related to the regional gradients of water-thermal conditions.