亚热带八个阔叶林内不同分布型植物的性状和生态习性差异

Differences in traits and ecological behaviors between plants of different distribution patterns in eight subtropical broad-leaved forests

关键词:  分布型, 生态位, 生态指示值, 亚热带森林, 中国森林生物多样性监测网络

Key words:  distribution pattern, niche, ecological indicatior value, subtropical forest, Chinese Forest Biodiversity Monitoring Network

摘要:

组成我国亚热带地区植被的植物区系来源多样。为了解共同生活在该地区的不同区系成分间在生态位上存在何种差异,以提高对该地区生物多样性维持机制的认识,该研究以中国亚热带地区8个阔叶林动态样地内木本被子植物群落为研究对象,通过采用谱系线性回归和方差分析(ANOVA)等统计方法,分析了温带和热带分布型属植物在生活史性状(叶习性和生长型)和生态习性(Ellenberg生态指示值)上的差异。结果表明:(1)对于涉及的265个属,分布型属具有一定的谱系保守性(Pagel's λ=0.935, P<0.001)。(2)温带分布型属含落叶阔叶植物和乔木较多,热带分布型属则以常绿阔叶植物和灌木为主。(3)与热带分布型属植物相比,温带分布型属植物所处环境具有较强光照、较低温度和湿度,且在控制了叶习性和生长型的影响后,两者间的生态习性差异仍然存在。(4)对于所有植物,或者对于不同叶习性和生长型功能群而言,温带与热带分布型属植物的相对优势(物种数的比值)均受到年平均气温的影响。该研究结果有助于理解区系来源对亚热带阔叶林内木本被子植物的生活史性状和生态习性均具有重要影响,以及不同区系来源的植物在我国亚热带阔叶林内的地理更替受到年平均气温的驱动。

Abstract:

The plants that comprise the vegetation of Chinese subtropics are diverse with respect to geographical distribution patterns. Understanding how the plants with different geographical distribution patterns that live together in this region differ in their ecological niches, would advance our knowledge of species coexistence mechanisms. Here, based on the data of woody angiosperm community composition in eight broad-leaved forest dynamics plots widely distributed in the Chinese subtropics, by adopting statistical methods such as phylogenetic linear model and analysis of variance(ANOVA), we examined the differences in life history traits, including leaf habit and growth form, as well as ecological behaviors(i.e., Ellenberg indicator values), between the plants of temperate distribution pattern genera and the plants of tropical distribution pattern genera. The results were as follows:(1)For the 265 study genera, distribution pattern genus showed a significant phylogenetic signal(i.e., Pagel's λ = 0.935, P< 0.001).(2)The temperate distribution pattern genera comprised a higher ratio of deciduous broad-leaved plants and trees than the tropical distribution pattern genera, and there were more evergreen broad-leaved plants and shrub in tropical distribution pattern.(3)The plants of temperate distribution pattern genera exist in environments with high light, low temperature and water compared with the plants of tropical distribution pattern genera, regardless of the effects of leaf habit and growth form were controlled or not.(4)For all the plants, or for each leaf habit or growth form group separately, the ratio of species richness of the temperate distribution pattern genera to the tropical distribution pattern genera in the forest was controlled by mean annual temperature(MAT). The findings imply that the plants of temperate and tropical distribution pattern genera differe in both their life history traits as well as their ecological behaviors, and the geographical turnover of plants of these two distribution patterns in the Chinese subtropical broad-leaved forests is largely controlled by MAT.