木兰围场黑桦叶形态特征与叶面积估算模型研究

Study on leaf morphological characteristics and leaf area estimation model of Betula Dahurica in Mulan Weichang

为了解叶形态功能性状与环境的适应关系,探究叶形态特征,估算叶面积大小及其构建叶面积模型具有重要意义,以木兰围场天然次生林优势树种黑桦为研究对象,采用手持叶面积仪测量黑桦单叶叶面积(LA)、叶长(LL)、叶宽(LW)、叶周长(LP)及叶长×叶宽(LL×LW)指标,分析5个形态学指标的相关性;运用相关性和全子集回归分析方法,构建单变量和多变量最优模型。结果表明,叶面积变异程度最大,值为0.39,叶长、叶宽、叶长×叶宽、叶周长均与叶面积呈现显著相关性(R2=0.897、0.959、0.937、0.983)。从简便实用性强的角度,考虑选择单变量回归模型Y=0.225+0.642 X4,X4为叶长×叶宽;从拟合精确度高的角度考虑可选择多变量线性回归Y=-0.536-1.317 X1+0.78 X2+0.411 X3+0.585 X4(X1、X2、X3、X4分别是叶长,叶宽,叶周长,叶长×叶宽)。研究结果为该地区黑桦叶面积估算提供了简便方法,也为其他区域黑桦叶面积大小测量的方法提供参考。

In order to understand the relationship between leaf morphological functional traits and environmental adaptation,it was of great significance to explore leaf morphological characteristics,estimate leaf area size and construct leaf area model.Taking the Betula Dahurica of the dominant species of natural secondary forest in mountainous area of northern Hebei Province,as the study object.In this study,single leaf area(LA),leaf length(LL),leaf width(LW),leaf perimeter(LP)and leaf length×leaf width(LL×LW)indexes of the Betula Dahurica,the dominant species of natural secondary forest in the northern Hebei mountains,were measured by handheld leaf area meter,and the correlation of 5 morphological indexes was analyzed.By using correlation and full subset regression analysis,the univariate and multivariate optimal models were constructed.The results showed that the greatest degree of variation in leaf area,with a value of 0.39.Leaf length,leaf width,leaf length×leaf width and leaf perimeter showed significant correlated with leaf area(R2=0.897,0.959,0.937 and 0.983).From the perspective of simplicity and practicability,the univariate regression model Y=0.225+0.642 X4 was selected,and the X4 was the length of the leaf×the width of the leaf.From the perspective of high fitting accuracy,multivariate linear regression Y=-0.536-1.317 X1+0.78 X2+0.411 X3+0.585 X4 could be selected(X1,X2,X3,and X4 were leaf length,leaf width,leaf circumference,and leaf length×leaf width,respectively).The results provided a simple method for estimating the leaf area of the Betula dahurica in this area and a reference for methods for measuring the leaf area of the Betula dahurica in other areas.