关键词: 北方粳稻, 空壳率, 低温处理, 影响, 幼穗形成期

Abstract: Based on 2×2 contingency table, and by using quantitative analysis methods, this paper studied the interspecific relationships amongst 595 species pairs of the 35 dominant woody species of Sambucus williamsii community in Taiyue Mountain Nature Reserve. Variance analysis showed that the interspecific correlation of the 35 dominant populations was not significant, and that the distribution of the species was relatively independent. The χ² test showed that amongst the 595 species pairs, 239 pairs were positively correlated, while 349 pairs were negatively correlated, and the correlation ratio was 0.68. Pearson’s correlation coefficient test showed that 174 pairs were positively correlated, while 421 pairs were negatively correlated, and the correlation ratio was 0.41. Spearman’s rank correlation coefficient test showed that 218 pairs were positively correlated, 377 pairs were negatively correlated, and the correlation ratio was 0.58. Compared to the χ² test, the Pearson’s correlation coefficient and Spearman’s rank correlation coefficient tests had higher sensitivity. For vast majority of the 595 species pairs, their interspecific relationships did not reach significant levels, indicating that the S. williamsii community in Wulu Mountain Nature Reserve was of obviously secondary succession. Based on the ways of adaptation to the environment and the leading ecological factors, and facilitated by principal components analysis, the 35 dominant populations were divided into three ecological species groups.

Key words: young ear formation period, north japonica, influence, low temperature treatment, shell rate