北京山区河岸带植物群落种-面积关系

种-面积关系是群落生态学的基本问题之一,是了解植物群落结构的重要途径。为摸清北京山区河流河岸带植物群落调查最小样方面积,在北京市怀柔区怀九河河岸带沿线,采用基于河岸带立地条件逐步扩大样地面积的方法布设50个80m长样地,调查计算并拟合不同类型河岸带所需的最小样地面积。研究结果表明:北京市怀柔区怀九河河岸带植物种数255种,隶属于70科185属。通过聚类分析将怀九河河岸带分为自然河岸带、近自然河岸带、人工岸坡乔灌草河岸带、人工岸坡观赏性乔灌草河岸带、人工岸坡疏乔灌草干砌石河岸带和人工岸坡浆砌石河岸带6种类型。根据赤池信息量准则AIC可知自然河岸带、近自然河岸带、人工岸坡乔灌草河岸带和人工岸坡疏乔灌草干砌石河岸带优先选取S=c-ae~(-bA),人工岸坡观赏性乔灌草河岸带优先选取S=aA/(1+bA),人工岸坡浆砌石河岸带优先选取S=c/(1+ae~(-bA))。满足相同比例植物种调查,不同类型河岸带所需最小样地面积存在明显差异,当满足河岸带植物调查80%植物种时,人工岸坡浆砌石河岸带(84m~2)和自然河岸带(217m~2)所需样地面积较小,其次是人工岸坡疏乔灌草干砌石河岸带(362m~2),近自然河岸带(450m~2)和人工岸坡乔灌草河岸带(460m~2)所需样地面积相似,而人工岸坡观赏性乔灌草河岸带所需样地面积最大为571m~2。所得出的河岸带植物调查最小样地面积对于河岸带生物多样性保护和指导河岸带生态修复具有重要意义。

Specie-area relationship of riparian plant community in the mountainous areas of Beijing

The species-area relationship is one of the fundamental subjects in community ecology research and an important way to understand plant community structure. Different sampling methods have significantly differing effects on the species-area relationship. In order to realize the minimum area of riparian community in the mountainous areas of Beijing that should be sampled to determine the species richness, we employed a method where the sampling area was gradually expanded. Surveys of the riparian sites were undertaken and the minimum sampling area required for different types of riparian habitats along the Huaijiu River was calculated. The results show that there were 255 plant species, belonging to 70 families of 185 genera. By using clustering analysis, we divided the Huaijiu riparian habitat into six typical classes, including natural riparian, near-natural riparian, artificial bank plant riparian, artificial bank ornamental plant riparian, artificial bank sparse plant dry-stone riparian, and artificial bank masonry riparian. According to the Akaike Information Criterion, the best estimation model for natural riparian, near-natural riparian, artificial bank plant riparian, and artificial bank sparse plant dry-stone riparian is S=c-ae^-bA, for artificial bank ornamental plant riparian this is S=aA/(1+bA), and for artificial bank masonry riparian this is S=c/(1+ae^-bA), whereA is sample area, S is the species number in A, a, b, c is parameters to be estimated and e is the base of the natural log. To meet the criterion that the same proportion of plant species are surveyed, it is obvious that there exist significant differences for different types of riparian habitat type. For the criterion that 80% of the plant species in a riparian habitat is to be surveyed, a sampling area of 84m² was required for artificial bank masonry riparian, which was the smallest. This was 217m² for natural riparian, followed by the artificial bank sparse plant dry-stone riparian (362m²), near-natural riparian (450m²), and artificial bank plant riparian (460m²). The largest area of 571m² was required for artificial bank ornamental plant riparian. These results are very important for conservation of plant diversity in riparian habitats, as they provide a guide to minimum areas required for protection and ecological restoration.