Succession of the Slope Vegetation of Expressways (III)
A Belttransect Method for the Analysis of the Relation between the Slope Vegetation and the Site Factors
1978 Volume 42 Issue 2 Pages 2-7
Details
1978 Volume 42 Issue 2 Pages 2-7
In the first and second reports were discussed a reconnaissance method and a quadrate method of vegetation survey for the diagnostic study of succession of the slope vegetation on expressways. There were many types of communities under the various site factors. It is important to recognize the site factors that al e primarily responsible for the control of the species combination of the plant community.
This time the author plan to ellaborate on a belttransect method for the analysis of the relation between the slope vegetation rand the site factors, especially the location on cutting or embankment.
He made a case study on Meishin expressway, Tomei expressway, and Chuo expressway. Selection of stands for sampling of belttiansect was done for each typical vegetation. Width of belt is 2m and the belt is cut every 2m.
Date were recorded in each 2m×2m quadrate according to Braun-Blanquet method. The number of belttransect was 26. The analysis of the date was made as follows.
1. The location on the slopes were classified into 5 categories; upper part of cutting, lower part of cutting, top of embankment, upper part of embankment, lower part of embankment.
2. The life form spectra and the number of degree of succession was calculated in each part of slopes to compare the plant communities and the location on the slopes.
3. Height growth of Pinus densiflora was recorded to analysis the relation between the growth and the location on the slopes.
After these analysis, the results were as follows.
The succesion is more progressive on the cutting slopes, especially on the upper part of cutting slopes. The reason of this is thought that the upper part of cutting slopes neighbours the forest communities upon the cutting slopes. But the height growth of Pinus densiflora is better on the lower part of slopes, because the soil of the lower part of slopes is deep and more moderately moist.
