论文部分内容阅读
海拔与坡位是气象因子和立地因子的综合表现。坡位影响环境因子在空间上的分布状况,与海拔共同营造物种生存的小生境,形成群落多度格局。本文选用5个描述种-多度关系的生态位模型(断棍模型BSM、生态位优先占领模型NPM、生态位重叠模型ONM、随机分配模型RAM、优势优先模型DPM),对北京东灵山辽东栎林的乔、灌、草3个层沿海拔梯度分别在上、中、下坡位进行群落多度格局调查。结果表明:在乔木层,从低海拔到高海拔、从下坡位到上坡位,能很好地反应群落多度格局变异的模型有由RAM、NPM向DPM过渡的趋势;能很好地拟合灌木层群落多度格局的生态位模型依次是NPM、BSM、RAM,DPM在高海拔地段拟合的效果也很好;BSM在草本层的拟合效果最好,其次是NPM和ONM。协方差分析表明,海拔和坡位都没有对辽东栎林的群落多度格局产生显著影响。
Elevation and slope position is a comprehensive manifestation of meteorological factors and site factors. Slope position affects the distribution of environmental factors in space, together with the altitude to create species habitat niche, the formation of community abundance pattern. In this paper, we selected five ecological niche models (BSM, NPM, ONM, RAM, and DPM) to describe the species-abundance relationship of Quercus liaotungensis Three layers of forest, irrigation and grasses were surveyed on the upper, middle and downhill slope along the altitude gradient respectively. The results showed that in the arbor layer, from low altitude to high altitude and from downhill to uphill, the model that could well reflect the variation of community abundance pattern had the transition from RAM to NPM to DPM. The niche models for fitting the multi-degree pattern of shrub layer community were NPM, BSM, RAM and DPM. The fitting effect of BSM in the herb layer was the best, followed by NPM and ONM. Analysis of covariance showed that neither altitude nor slope position had a significant effect on the abundance pattern of Quercus liaotungensis forest.