木林子国家级自然保护区天然林群落优势木本植物种间联结和稳定性

Interspecific Associations and Community Stability Changes of Dominant Woody Species of Natural Forest Communities in Mulinzi National Nature Reserve

摘要:

为探究木林子国家级自然保护区天然林群落结构变化，在原始老龄林(恢复100 a及以上)、皆伐后恢复40 a和25 a的次生林3个恢复阶段，设置45个20 m×20 m样地，采用方差比率法(VR)、χ²检验、Pearson相关检验、Spearman秩相关检验和M-Godron稳定性测定等方法研究优势木本植物的种间联结和群落稳定性。结果表明，恢复25 a、40 a的次生林植物群落在总体上呈现不显著正关联，恢复100 a的原始老龄林植物群落呈现显著正关联。χ²检验结果表明25 a、40 a植物群落均为不显著，100 a植物群落中只有2个种对联结性显著，种间联结较为松散。Pearson相关检验和Spearman秩相关检验结果表明大部分物种的种对间相关性不显著，呈现独立分布的格局。M-Godron稳定性结果表明不同恢复阶段植物群落均处于不稳定状态，但随着恢复年限的增加，群落的稳定性逐渐提高。不同恢复阶段种间联结性较弱，各物种呈现独立分布的状态，群落中的物种更迭较为频繁，说明植物群落仍处于演替进程中，正朝着稳定阶段发展。

Abstract:

In order to explore the changes of natural forest community structure in the national nature reserve, fourty-five 20 m×20 m plots were set up in three restoration stages, including original old forest (restored for 100 years or more), secondary forest restored for 40 and 25 years after clear-cutting. The interspecific association and community stability of dominant woody plants were studied by using Variance ratio (VR), χ² test, Pearson correlation test, Spearman rank correlation test and M-Godron stability test. The results showed that there was no significant positive association on the whole of dominant woody species in secondary forest restored for 25 and 40 years, but the significant positive association appeared in original aged forest restored for 100 years. The χ² test showed that the interspecific associations were not significant in 25 and 40 years plant communities, and only 2 species pairs in 100 years plant communities were significantly associated, and the interspecific associations were loose. The Pearson’s correlation coefficient test and Spearman’s rank correlation coefficient test also showed that the correlations among species pairs of most species were not significant, and displayed an independent distribution pattern. The M-Godron stability analysis showed that the plant community was in an unstable state at different stages, but the stability of the community gradually increased with restoration time. Therefore, interspecific correlation in the natural forest communities was weak at different restoration stages, and the species distributed independently and changed frequently, indicating that the community was still in the process of succession and was developing towards a stable stage.