Lüftenegger G, Foissner W, Adam H
Institut für Zoologie der Universität Salzburg, Akademiestrasse 26, A-5020, Salzburg, Austria.
Oecologia. 1985 Jul;66(4):574-579. doi: 10.1007/BF00379352.
Previously published field studies have suggested that the concept of r/K selection may be applied to terrestrial ciliates. A census was taken of the dominant groups, the Colpodea and Polyhymenophora, to determine species composition and absolute abundances in climatically unpredictable alpine and predictable lowland sites. In addition, two typical representatives of each of the two taxa (Colpoda aspera and Grossglockneria acuta, and Blepharisma undulans and Gonostomum affine, respectively) were selected for examination under laboratory conditions. Variables investigated were: the C/P index (ratio of Colpodea to Polyhymenophora), fertility, tolerance of altered environmental conditions, incidence in predictable or unpredictable biotopes, opportunism, competitive ability, and body size. Our own observations were supplemented by reference to the literature.The field census produced a higher C/P index in the unpredictable sites than in the predictable ones. The experiments show that C. aspera and G. acuta are less sensitive to changes in temperature and exhibit a more rapid rise in individual density as well as a higher number of individuals than do B. undulans and G. affine, although the former species have longer generation times at low temperatures. The explosive increase in number of individuals can be ascribed to the special reproductive strategy of the Colpodea (quadripartition in cysts). These results imply that the Colpodea are more r-selected as compared with the Polyhymenophora. That might be an explanation for their wide distribution and high density in unfavourable terrestrial habitats.
此前发表的实地研究表明，r/K选择的概念可能适用于陆生纤毛虫。对优势类群，即肾形虫目和多膜纲进行了普查，以确定在气候不可预测的高山地区和可预测的低地地区的物种组成和绝对丰度。此外，从这两个分类单元中各选出两个典型代表（分别是粗糙肾形虫和尖锐格洛克纳虫，以及波动喇叭虫和近缘嗜口虫），在实验室条件下进行研究。所调查的变量包括：C/P指数（肾形虫目与多膜纲的比例）、繁殖力、对环境条件变化的耐受性、在可预测或不可预测生物群落中的发生率、机会主义、竞争能力和体型。我们自己的观察结果通过参考文献得到了补充。实地普查显示，在不可预测的地区，C/P指数高于可预测的地区。实验表明，与波动喇叭虫和近缘嗜口虫相比，粗糙肾形虫和尖锐格洛克纳虫对温度变化的敏感度较低，个体密度上升更快，个体数量也更多，尽管前一种在低温下的世代时间更长。个体数量的爆发式增长可归因于肾形虫目的特殊繁殖策略（在包囊中进行四分分裂）。这些结果表明，与多膜纲相比，肾形虫目更倾向于r选择。这可能解释了它们在不利的陆地生境中广泛分布和高密度存在的原因。
