迭山北坡云冷杉林火烧迹地灌木树种种间关联性

Interspecific Association of Shrub Species in Burned Site of Picea asperata-Abies fabri Forest on the Northern Slope of Dieshan Mountains

[目的]揭示青藏高原东北边缘迭山北坡云冷杉林火烧迹地灌木树种种间关联性。[方法]在调查数据的基础上,基于2×2列联表采用方差比率法(VR)、χ^(2)检验、联结系数(AC)和Jaccard相似系数(PC)4种方法,研究火烧迹地灌木群落17种灌木的种间关联性。[结果]总体联结性VR值等于0.93;χ^(2)检验显示有9个种对达到极显著正联结,2个种对达到显著联结,125个种对呈不显著联结;联结系数AC值在[0.6,1]的种对共有27对、在[0.2,0.6)的种对共有9对、在[-0.2,0.2)的种对共有40对,在[-0.6,-0.2)的种对共有13对,在[-1,-0.6)的种对共有47对;Jaccard相似系数PC值在[0.57,1]的种对共有17对、在[0.29,0.57)的种对共有12对、在[0,0.29)的种对共有107对,各研究方法得到的结果基本相似,但各检验方法存在一定的差异,结果显示各种对间的关联性不强,达到显著和极显著的种对很少,群落物种间总体联结性呈不显著负联结趋势。[结论]火烧迹地灌木树种种间的关联性不强,群落稳定性不高,灌木树种种间联结性主要受植物生物学特性、生态适应性和人为活动、土壤、气候、竞争以及化感作用等方面影响。

[Objective]To reveal the interspecific association of shrub species in the burned area of Picea asperata-Abies fabri forest on the north slope of Dieshan mountains,the northeastern margin of Qinghai-Tibetan Plateau.[Method]Based on the field survey data,the interspecific association of 17 shrub species in the burned area was studied by using variance ratio method(VR),chi-square(χ^(2))test,association coefficient(AC)and Jaccard similarity coefficient(PC)with 2×2 contingency table.[Result]The VR value of overall association was equal to 0.93;χ^(2)test showed that 9 species pairs reached extremely significant positive association,2 species pairs reached significant association,125 species pairs showed no significant association;there were 27 species pairs with the AC value of[0.6,1],9 species pairs with the AC value of[0.2,0.6),40 species pairs with the AC value of[-0.2,0.2),13 species pairs with the AC value of[-0.6,-0.2),and 47 species pairs with the AC value of[-1,-0.6);the value of Jaccard was similar,there were17 pairs with PC value of[0.57,1],12 pairs with PC value of[0.29,0.57)and 107 pairs with PC value of[0,0.29).The results obtained by each research method were basically similar,but there were some differences among the test methods.[Conclusion]The correlation among the pairs is not strong,few species pairs are significant or extremely significant,and the overall association among species in the community shows no significantly negative trends.The results show that the interspecific association of shrub species is not strong and the community stability is not high.The interspecific association of shrub species is mainly affected by plant biological characteristics,ecological adaptability and human activities,soil,climate,competition and allelopathy.