摘要
选择受密度影响较小的负二项分布K值 ,描述玉米上二点叶蝉自然种群在 3个海拔高度上的空间格局及时序动态。在玉米生育期间 ,二点叶蝉种群即可作聚集分布亦可作均匀分布。 4月中下旬 ,二点叶蝉种群呈均匀分布 (K <0 ) ;5月份 ,呈聚集分布 (K >0 ) ;6月上中旬呈均匀分布 (K <0 ) ;6月下旬至 7月上旬呈聚集分布 (K >0 ) ,表现为扩散→聚集→再扩散→再聚集的总趋势。K值亦表明 ,5月份高海拔聚集强度最高 ,6月下旬至 7月上旬则低海拔的聚集强度最高。根据Taylor的幂函数法和Iwao的M -X回归方程的系数 ,高。
The K value of negative binomial distribution less affected by density was chosen to describe the spatial and temporal patterns of the natural population of Cicadulina bipunctella (Mats) at three elevations.Spatial distribution information of the population showed either clumped (aggregated) or uniform patterns during the period of maize growth.The population of C.bipunctella distributed uniformity (K<0) at the last twenty days in April,and spatial aggregation (K>0) in May,then dispersal (K<0) from the first ten-day period to the middle ten days of June and aggregation (K>0) again from the last ten-day period of June to the first ten-day period of July.The high elevation had the highest degree of aggregation in May,followed by the low elevation from the last ten-day of June to the first ten-day of July according to the K values.Based on the coefficients of Taylor's power law and Iwao's M *-X regression,the degree of aggregation of the high elevation and the middle elevation were higher than the low elevation during the whole period of maize growth.
基金
国家自然科学基金资助项目 ( 3 0 0 70 5 0 4)
关键词
二点叶蝉
自然种群
负二项分布
昆虫
时空动态
Cicadulina bipunctella
Temporal and spatial dynamics
Negative binomial distribution
