猫儿山不同海拔森林群落草本植物高度的影响因素

Factors Influencing Herbaceous Plant Height in Forest Communities at Different Altitudes in Mao’er Mountain

高度是草本植物生长状况与环境适应性的重要指标。基于猫儿山不同海拔森林群落草本植物调查数据,分析林下草本植物物种组成和平均高度特征;采用多元线性逐步回归法,研究草本植物高度与环境因子的关系。研究发现,低海拔(1100 m)常绿阔叶林草本层优势植物有狗脊(Woodwardia japonica)、里白(Diplopterygium glaucum)等,来自乌毛蕨科、里白科等;中海拔(1500 m)常绿落叶阔叶混交林草本层植物主要有宽叶薹草(Carex siderosticta)、瘤足蕨(Plagiogyria adnata)、狗脊等,来自莎草科、瘤足蕨科、乌毛蕨科等;高海拔(1900 m)常绿针阔叶混交林草本层植物主要有匙叶草(Latouchea fokiensis)、间型沿阶草(Ophiopogon intermedius)等,来自龙胆科、百合科等。随海拔升高,森林群落草本植物高度不断降低。草本植物高度在常绿阔叶林(1100 m)和常绿落叶阔叶混交林(1500 m)之间差异不显著,两者与常绿针阔叶混交林(1900 m)差异显著。不同海拔森林群落草本植物高度与空气温度呈极显著正相关(P<0.01),且空气温度对草本高度有较高的解释率(Radj2=0.748)。综上,空气温度是影响不同海拔梯度森林群落草本植物高度的主要驱动力。

Height is an important indicator of growth status and environmental adaptability of herbaceous plants.Based on survey data of herb communities at different altitudes of Mao’er Mountain,species composition and average height of herbaceous plants were analyzed.The relationship between herbaceous plant height and environmental factors was assessed by multivariate linear stepwise regression method.Results showed that dominant herbaceous plants in low-altitude evergreen broad-leaved forest(1100 m)were Woodwardia japonica and Diplopterygium glaucum,which represent Blechnaceae and Gleicheniaceae.The dominant herbaceous plants in mid-altitude evergreen and deciduous broad-leaved mixed forest(1500 m)were Carex siderosticta,Plagiogyria adnata and W.japonica,which represent Cyperaceae,Plagiogyriaceae,and Blechnaceae.The dominant herbaceous plants in high-altitude evergreen coniferous and broad-leaved mixed forest(1900 m)were Latouchea fokiensis and Ophiopogon intermedius,which represent Gentianaceae and Liliaceae.With increase of altitude,height of herbaceous plants in different communities decreased gradually.The height of herbaceous plants was not significantly different between evergreen broad-leaved forest(1100 m)and evergreen and deciduous broad-leaved mixed forest(1500 m),while difference between these two forests and the evergreen coniferous and broad-leaved mixed forest(1900 m)was significant.Herbaceous plant heights at different altitudes only had significantly positive correlation with air temperature(P<0.01)and air temperature had higher contribution(Radj2=0.748)on herbaceous plant heights.In summary,air temperature was driving force affecting heights of herbaceous plants at different altitudes.