关键词: 潜在补充量, 养殖池塘, 干塘, 桡足类, 休眠卵

Abstract: Betula platyphylla forest is one of the major vegetation types in Taiyue Mountain of Shanxi, China. Our objective was to explore B. platyphylla population structure and its spatial distribution pattern in this region. Three plots were established according to the diverse age structures of the B. platyphylla population. The B. platyphylla population structure and its spatial distribution at different developmental stages were examined by means of the “spacefortime” substitution approach. The point pattern and fractal analyses including boxcounting dimension analysis, information dimension analysis, and correlation dimension analysis were used in this study. It was found that the diameterclass structure of the B. platyphylla population indicated a typical “spindle” shape, suggesting a declining trend. The young and middle B. platyphylla population was found to show an aggregated distribution pattern, whereas the mature one exhibited a random distribution pattern. It was suggested that along with population development, the spatial distribution of B. platyphylla population varied from aggregation to randomness. The analysis of boxcounting dimension indicated that the degree of the occupied space of B. platyphylla population followed an order of middleaged trees>mature trees>nearmaturity trees. The analysis of information dimension indicated that the changing degree of pattern intensity of B. platyphylla population followed an order of nearmaturity trees>middleaged trees>mature trees. The analysis of correlation dimension showed that the individual spatial correlation of B. platyphylla population followed an order of middleaged trees>mature trees>nearmaturity trees. It was suggested that there were consistent results from population diameterclass structure analysis, point pattern analysis and fractal analysis. All these results revealed the spatial distribution pattern of secondary pioneer community after the destruction of the zonal climax community.

Key words: aquaculture ponds, copepod, potential recruitment, resting eggs, desiccation.