摘要
以长江中下游淡水湿地湖里沼泽为对象,研究了种子库在小尺度空间范围的水平分布格局。在沼泽中选择地表植被分布比较均一的16m×4m大小的方形区域,按1m间隔获取64个内径7·8cm、深5cm的圆柱状土样,通过幼苗萌发法鉴定每个土样的种子库组成。采用2个格局指数(离散系数和Lloyd平均拥挤指数)以及Moran空间自相关系数分析了种子库中优势种的空间分布格局。结果显示种子库由17个物种组成,多年生的锐棱荸荠(Eleocharisacutangula)和龙师草(E·tetraqueter)是种子库中密度最大的物种。两个格局指数显示7个分布频率大于10%的物种的种子全部为聚集分布。MoransI统计分析显示其中只有3个物种为显著的正的空间自相关,表明这3个物种的种子斑块大小超过了目前的两个取样单位之间的距离(1m),而其它4个物种的种子斑块则小于这个尺度。
The small-scale heterogeneity of seed bank was analysed in Huli marsh, a freshwater wetland. Sixty-four soil cores were collected from a 16m × 4m grid area in December 2003. Two indices of pattern detection （variance/mean ratio and Lloyd＇ s index of mean crowding） and Moran＇s I statistic of spatial autocorrelation were computed. In total, 17 species were detected from the seed bank. Two perennials, Eleocharis acutangula and E. tetraqueter, had greatest seed density in the seed bank. For all 7 species with frequency higher than 10%, the seed pattern was aggregated as indicated by two indices of pattern detection. Moran＇ s I statistic of spatial autocorrelation was significantly greater than E（I） at p = 0.05 for three species. However, the other four species showed no significant difference from E（I） even though they were classed as having an aggregated distribution by the other indices. This suggests that the patch size of the four species is smaller than the distance between two sample unites （ 1 m）.
出处
《生态学报》
CAS
CSCD
北大核心
2006年第8期2739-2743,共5页
Acta Ecologica Sinica
基金
国家重点基础研究发展规划资助项目(2002CB412300)
中国科学院知识创新工程重大资助项目(KSCX2-1-10)~~
关键词
空间格局
种子库
淡水湿地
扩散
spatial pattern
seed bank
freshwater marsh
dispersal
