Study on Biodiversity of the Gaoligong Mountains——Ⅰ Determination of the Minimum Sampling Area for Semi-moist Evergreen Broadleaved Forest

The species-area curve and the important value-area curve of the plant community were formulated based on the investigation into 3 600 m² (60 m×60 m) sample plot set in the semi-moist evergreen broad-leaved forest in the Gaoligong Mountains. The results showed that the minimum areas determined by species-area curve were consistently around 2 000 m², being too large to be applied in the mountainous areas with complex topographies. Compared to the species-area curve, the important value-area curve could fully and objectively reflect the positions and roles of different species playing in the plant communities, so it was more helpful to determining the minimum area of plant communities. Consequently, the minimum sampling area for semi-moist evergreen broad-leaved forest in the Gaoligong Mountains was calculated to be 600 m², whereas the minimum sampling areas for shrub layer and herb layer was 180 m². All the results suggested that the important value-area curve be a more practical method for minimum area determination for plant communities in the studied area.