摘要
提出了根据不同植物种在地形梯度上的分布格局测度和比较其生态位的思路。将地形分解为海拔、坡向、坡位和坡度 4个属性指标 ,作为多维生态位空间的环境梯度轴。根据对三峡大老岭地区米心水青冈 (Fagus engleri-ana)和亮叶水青冈 (F.lucida)群落样方及其地形因子调查 ,分析了两个种的多维生态位宽度及种间的生态位重叠。结果 :1)大老岭米心水青冈种群的生态位宽度总体上大于亮叶水青冈。亮叶水青冈在坡向梯度上的生态位较宽 ;米心水青冈在海拔、坡位和坡度梯度上的生态位较宽 ;2 )两个种在海拔、坡向、坡位和坡度梯度上的生态位重叠度分别为 0 .2 5 9、0 .831、0 .6 70、0 .6 76 ,其总体重叠度为 0 .0 87;3)亮叶水青冈和米心水青冈分布的海拔范围分别为 130 0～ 2 0 0 0 m和 145 0～ 2 6 0 0 m。米心水青冈主要分布于 NW80°～ NE80°之间的阴坡和半阴坡 ;亮叶水青冈集中于NW2 0°～ SW10°和 NE2 0°～ SE10°的半阴半阳坡。亮叶水青冈不见于沟谷底部 ,其重要值随坡位上升而增大 ;而米心水青冈在湿润稳定的中、下坡位重要值最高。米心水青冈适应的坡度范围很宽 ,主要在 2 0°～ 40°;而亮叶水青冈集中在 35°～ 45°的坡度范围。上述结果表明 :在景观尺度上 。
A new approach for the measurement of niche characteristics was employed which enables comparison between different plant species according to their distribution on a topographic gradient. Landform was analyzed with 4 attribute indices—elevation, aspect, location (position on slope) and slope—which were then viewed as a multidimensional environmental gradient. Using this model and the results of field sampling of Fagus engleriana and F. lucida communities and the topography of their habitats, multi dimensional niche breadths and niche overlaps were calculated for the two Fagus spp. The results suggest that: 1) the integrated niche width of F. engleriana is larger than that of F. lucida, the niche of F. lucida is wider on the aspect gradient, but F. engleriana is more broadly distributed on elevation, location and slope gradients; 2) niche overlaps of the two Fagus species are 0.259, 0.831, 0.670 and 0.676 on the elevation, aspect, location and slope gradients and the integrated nice overlap of the two species is 0.087; 3) the vertical ranges of F. lucida and F. engleriana are 1300 1950 m and 1450 2600 m respectively. F. engleriana prefers shaded and half shaded slopes at NW80 ° NE80 °; however, F. lucida population tends to concentrate on the half heliophilic and half shaded slope at NW20 ° SW10 °and NE20 ° SE10 °. F. luci da is absent at the valley bottom, and its importance value increases as the location uplifts; on the other hand, the importance values of F. engleriana are larger on the more stable and humid locations of type 1 and 3; the distribution range on slope gradient is wider for F. engleriana , with the majority on 20 40°, while F. lucida is concentrated in the range of 35 45°. The results indicate that topographic variables are efficient and effective indicators of gradients in plant species multidimensional niche space, and can properly reflect niche difference of different species at the scale of the landscape. Discussion of the reciprocal validation of the niche measurement on different environmental factors concludes the paper.
出处
《植物生态学报》
CAS
CSCD
北大核心
2001年第4期392-398,共7页
Chinese Journal of Plant Ecology
基金
国家自然科学基金重点项目 (No.39830 0 5 0 )
中国科学院植物研究所植被数量生态学开放研究实验室基金
