An Analysis of the Degree of Importance of Plant Families in
作者：Liu Jinbiao Lu Jiashi Huang Min Song Riyun
【摘要】 Abstract: The study was undertaken to determine the degree of importance of plant families in the medicinal ferns of Guangxi Zhuang Autonomous Region, China. A regression residual analysis was carried out on the number of medicinal ferns and the total number of ferns in each family for 56 fern families in the region. According to the residual values the 56 families were divided into 31 high use families and 25 low use families.
【关键词】 medicinal ferns； regression residual analysis； Guangxi
1 Introduction
The region has an area of 236 700 square kilometres, 34.37% of the area is covered by forests. Guangxi has a humid subtropical monsoon climate, which is characterized by plenty of sunshine, moderately high temperatures and abundant precipitation. The average annual temperature ranges from 16℃ to 22.7℃. Guangxi's mild climate is ideal for a great variety of plants. The region has over 1 670 genera of plants in 280 different families, nearly 8 000 types of plants. The ferns of Guangxi have recently been described by Zhou et al［1］. in which the medicinal ferns of Guangxi have been listed by Fang et al［2］. The present study was undertaken to determine the degree of importance of plant families in the medicinal ferns of Guangxi.
2 Methods
The details to analyze the relationship between the number of medicinal species and the total number of species in each family using the method of regression residual analysis has been described in several earlier publications［3～5］. In this method, a standard liner regression analysis was carried out and the regression residuals calculated. Fig. 1 displays a regression analysis on the number of medicinal ferns per family against the total number of ferns in each family for the 56 fern families in Guangxi utilizing the data from the published results［1～2］. In this figure, the predicted number of medicinal ferns per families of varying sizes is represented by the regression line; the residual is represented graphically by the vertical distance from the actual datum point to the corresponding point in the regression line; the regression equation states the relationship between the predicted values of medicinal ferns per family (PV) and the total number of ferns in the corresponding family (TF), according to the equation the predicted values of medicinal ferns per family should be equal to the total number of ferns in the corresponding family times 0.1824 plus 0.8176. These predicted values are show in Table 1. Subtracting the predicted values from the number of medicinal ferns in the corresponding family gives us the residual values for each family. The residual values are also show in Table 1.
Fig 1 Regression analysis of medicinal ferns and total ferns in each family of Guangxi（略）
Table 1 Results of regression analysis of 56 fern families in Guangxi
3 Results and analysis
The results of the regression analysis are present in Table 1, in which the families have been ranked in descending order, from the highest positive residual to the lowest negative residual. Families with large positive are the ones used more often than chance alone would allow, while families with large negative values are used less often than chance would allow. According to the residual values (ranging from 27.0 to -13.5) the 56 ferns families were divided into 31 high use families (Rank 1 to 31) and 25 low use families (Rank 32 to 56). Among the high use families with medicinal ferns of larger than the predicted number are Polypodiaceae, Selaginellaceae, Pteridaceae, Huperziaceae and Davalliaceae. Among the families with medicinal ferns of less than the predicted number are Athyriaceae, Dryopteridaceae, Aspidiaceae, Thelypteridaceae and Hymenphyllaceae.
Analysis of the data is shown in Table 2. It shows marked differences between the high use families and the low use families. There are 401 ferns in 31 high use families while 449 ferns in 25 low use families. Only 10.0% of plant has been used medicinally in low use families, while 40.1% of ferns are used medicinally in high use families. It also reveals that contributions of low use families as producers of ferns used in traditional medicines is hidden by the contributions of high use families. Furthermore the data allow us to differentiate those high use families which produce many medicines (e.g. Polypodiaceae) from those which produce few (e.g. Athyriaceae).
Table 2 Number and percentage of medicinal ferns in high use families and low use families（略）
4 Conclusions
The method of regression residual analysis allows us to identify: (a) plant families which represent substantial sources of medicinal ferns (Such as Polypodiaceae, Selaginellaceae, Pteridaceae) in Guangxi Zhuang Autonomous Region; (b) families which are apparently not substantial sources of medicinal ferns (Such as Athyriaceae, Dryopteridaceae, Aspidiaceae) in the region.
【】
1 Zhou H G, Li H, Huang Y Y, et al. The Preliminary Study on Pteridophyte Flora from Guangxi, China. Beijing: China Meteorological Press, 2000.
2 Fang D, Sha W L, Chen X X, et al. The List of Medicinal Plants of Guangxi. Nanning: Guangxi People's Publishing House, 1986.
3 Girach R. D, Shaik A. A, Singh S. S, et al. The medicinal flora of Similipahar forests, Orissa State, India. Journal of Ethnopharmacology. 1999, 65: 165～172.
4 Kapur S. K, Shahi A. K, Sarin Y. K, et al. The medicinal flora of Majouri- kirchi forests (Jammu and Kashmir State), India . Journal of Ethnopharmacology. 1992, 36: 87～90.
5 Moerman D. E. An analysis of the food plants and drug plants of native North America. Journal of Ethnopharmacology. 1996, 52: 1～22.
