南亚热带常绿阔叶林取样技术研究

 本文研究了样地取样技术和无样地取样技术在南亚热带常绿阔叶林的应用。认为中心点四分法无样地取样技术具有较高的精度和效率,完全适用于南亚热带常绿阔叶林。 应用中心点四分法无样地取样技术所获得的能反映群落真实特征的中心点数目,称为“最小点数”。评定最小点数,可应用种类数目与中心点数目的相关曲线,即“种一点数曲线”;以及优势种重要值与中心点数的相关曲线,即“重要值一点数曲线’。据研究南亚热带常绿阔叶林的最小点数为20—22点。 “重要值—面积曲线”与“重要值一点数曲线”是评定最小面积与最小点数的测度新方法,在某种意义上较“种一面积曲线”更为理想。

Studies on Sampling Techniques of the South-Subtropical Evergreen Broad-Leaf Forest in Guangdong Province, China

The south-subtropical evergreen broad-leaf forest of Mt. Dinghu has been studied by using both the "quadrat method" and "point-centred quarter method". Twenty 10 × 10m. quadrats and fourty point-centred quarter samples were restricted at random (partial random) and arranged in the same stand. Minimal area of the quadrat samples of the arborescent strata is 1000–1200m2 and that of the undergrowth is eight to ten 2Ï2m. small quadrats. It is indicated by species-area curves (Fig. 1, 2, 4). We suggest a concept of "minimal point number", which is determined by the correlation curve between species and point-centred quarter number. This correlation curve is termed "species-point number curve" (Fig. 3.), which indicated minimal point number of the south-subtropical evergreen broad-leaf forest is 20 to 22 point-centred quarter samples. It has been shown that the point-centred quarter method has higher precision and higher efficiency than the quadrat samples as judged by importance value, percentage of similarity and coefficient of community (Table 1, 2, 3). So that, the point-centred quarter method is suitable for the south-subtropical evergreen broad-leaf forest used as a sampling technique.