Kennedy C R, Guégan J F
Department of Biological Sciences, Hatherly Laboratories, Exeter University.
Parasitology. 1994 Aug;109 ( Pt 2):175-85. doi: 10.1017/s0031182000076289.
The relationships between regional species richness and local species richness were examined in respect of helminth parasite communities in 32 species of freshwater fish in the British Isles. Fish were divided into 5 categories, for each of which the goodness of fit of the relationship to linear, exponential and power function models was tested. For all categories of fish combined, there was a significant, positive curvilinear relationship. Nested within this were two other patterns. For introduced fish, a linear model provided the best fit; for euryhaline and relict species it was impossible to determine the best model, but for the other categories the relationship was curvilinear and was best fitted by a power function model. The linear relationship found for introduced fish was interpreted as a temporary situation, reflecting the shortage of time for the communities to become saturated. It corresponded to the linear part of the curvilinear relationship of the other categories, which is believed to represent the fundamental form of the relationship for parasite communities. The communities reached a saturation level of richness, corresponding to the asymptote of the curve, which fell well below regional species richness. Explanations for local saturation are discussed, but neither community structure nor supply-side ecology can yet be preferred. It is concluded that local patterns in helminth community richness, in contrast to those in fish assemblages, are not significantly influenced by patterns on a larger, regional spatial scale and so regional species richness is not a key determinant of local species richness, nor does a knowledge of regional patterns improve predictability of local patterns.
我们研究了不列颠群岛32种淡水鱼的蠕虫寄生虫群落中区域物种丰富度与局部物种丰富度之间的关系。鱼被分为5类，针对每一类测试了其与线性、指数和幂函数模型关系的拟合优度。对于所有类别的鱼综合来看，存在显著的正曲线关系。在这之中还嵌套着另外两种模式。对于外来鱼类，线性模型拟合效果最佳；对于广盐性和残遗物种，无法确定最佳模型，但对于其他类别，关系呈曲线状，幂函数模型拟合效果最佳。在外来鱼类中发现的线性关系被解释为一种暂时情况，反映出群落达到饱和所需时间的短缺。它与其他类别的曲线关系中的线性部分相对应，据信这代表了寄生虫群落关系的基本形式。群落达到了一个丰富度饱和水平，对应于曲线的渐近线，该水平远低于区域物种丰富度。文中讨论了局部饱和的解释，但群落结构和供应侧生态学都还无法成为首选解释。得出的结论是，与鱼类组合不同，蠕虫群落丰富度的局部模式不受更大区域空间尺度模式的显著影响，因此区域物种丰富度不是局部物种丰富度的关键决定因素，了解区域模式也无法提高局部模式的可预测性。
