黄连木群落种间联结指数—等级格局模型研究

Interspecific associations of Pistacia chinensis community and association index-rank pattern model

种间联结能够反映植物群落中物种间的关系和群落的稳定程度,对群落的物种多样性保护和资源可持续利用具有重要意义。采用总体相关性VR检验,χ2检验,联结系数AC,点相关系数PCC和匹配系数JI、OI、DI 7个指标,以崂山黄连木群落为研究对象,在群落尺度上研究群落组成物种的种间联结,在种群尺度上研究黄连木(不分雌雄)、雌黄连木、雄黄连木与其他物种的种间联结,进而对种间联结指数进行秩相关分析,研究黄连木与群落中其他物种的相关性以及雌、雄黄连木的差异性。结果表明:黄连木群落总体相关性不强,呈现显著的负联结;黄连木种群(不分雌雄)与其他物种均表现为负联结,分雌雄时雄性黄连木呈现正联结的比例(72.7%)明显高于雌株(27.3%),且雌株种群高的繁殖代价和觅养行为导致其与固氮植物辽东桤木呈现正联结,与出现频率较高的小米空木呈现极显著负联结(P<0.01);黄连木(不分雌雄)、雄性黄连木的秩相关方程均为直线型,雌性黄连木为凹曲线型,3个联结指数JI、AC、PCC秩相关方程的斜率均为负值,且斜率的绝对值为黄连木雌株>黄连木雄株>黄连木(总体)。首次提出了种间联结指数--等级(秩次)格局模型(association index-rank pattern model),模型中斜率的绝对值能够反映物种与群落中其他物种联结的紧密程度,斜率绝对值越大说明物种间的联结变动越大。这为深入研究种间联结关系提供了新的模型手段,确立的分析方法为雌雄异株植物的种间联结研究提出了新的思路。

Interspecific association, which reflects the interspecific relationships and community stability,is an important index in the conservation of biodiversity and the sustainable utilization of plant community. Seven indicators, including over all correlation test VR, X2 statistics test, coupling coefficient AC, point correlation coefficient PCC and matching coefficients of JI, OI, DI, were calculated to indicate the interspecific association of Pistacia chinensis community. At the community level, we analyzed the interspecific association of species and at the population level, we analyzed the association between male and female P. chinensis, male or female P. chinensis and the other species. We also use Spearman＇s rank correlation models to calculate the relevance between P. chinensis and the other species and find the differences between female and male P. chinensis. The results were shown in the followings： The wholerelevance of P. chinensis community was not strong with significantly negative correlation. Significantly negative correlation was found between P. chinensis population and the other species. The positive correlation between male P. chinensis and the other species（72.7% ）was higher than that between female P. chinensis and the other species（27.3% ）. The positive correlation between female P. chinensis and the nitrogen fixation Alnus sibirica and the significantly negative correlation between female P. chinensis and Stephanandra incise with high frequency in the community might be due to the breeding cost and the foraging behaviors. The rank correlation equations of male and female P. chinensis and male P. chinensis were all linear, while that of female P. chinensis was concave curve. The slope of rank correlation equation of three joint index JI, AC and PCC was negative. The absolute value of the slope ranked in the order of female 〉 male 〉 the whole of female and male P. chinensis. The association index-rank pattern model was first used in the paper, where the absolute value of the slope could reflect the level of tightness between the central species and the others in the community. When the absolute value of the line gradient was larger, the stage of interspecific association was more unstable. This provides a new model to further reveal the interspecific association and a novel idea to analyze the interspecific association of the dioecious plants.