Thum Martin
Zoologisches Institut der Universität München, Seidlstrasse 25, D-8000, München 2, Federal Republic of Germany.
Oecologia. 1989 Nov;81(3):401-411. doi: 10.1007/BF00377091.
A field study of two carnivorous plant species, Drosera intermedia and D. rotundifolia, was carried out in a small silting-up bog in Southern Bavaria (FR Germany). Various parameters of undisturbed individuals of both species were measured for a period of two years and subjected to a partial correlation analysis. The importance of prey as a limiting factor for various fitness parameters was confirmed for both species. Other factors may occasionally also be limiting, e.g. assimilation area and water supply. Benefits obtained from the prey are partly transferred to the next year via the winter bud. The importance of the relative demonstrated: Plants of D. rotundifolia showed higher fitness values in higher positions, those of D. intermedia in lower positions. Growth characteristics of both species tended to influence the height of their own position in a corresponding direction: D. intermedia downwards and D. rotundifolia upwards. In both species negative effects of intraspecific neighbourhood were evident, whereas interspecific effects were not detectable. Plants of D. intermedia tend to influence their neighbourhood situation by changing their position by rhizome-like stem growth. In D. intermedia the decision to reproduce by seeds or axillary buds seems to be made at least partially already in the year before. D. rotundifolia was only observed reproducing by seeds. In spite of different catching characteristics (plant shape, plant size, microhabitats, prey spectra), the general catching success, measured as prey biomass per plant biomass, was equal in both species of sundew. This agrees with earlier findings that in this bog both species have the same biomass per ground area.
在德国巴伐利亚南部（前西德）一个正在淤塞的小沼泽中，对两种食肉植物——中间茅膏菜（Drosera intermedia）和圆叶茅膏菜（D. rotundifolia）进行了实地研究。对这两个物种未受干扰的个体的各种参数进行了为期两年的测量，并进行了偏相关分析。证实了猎物作为各种适合度参数的限制因素对这两个物种都很重要。其他因素偶尔也可能是限制因素，例如同化面积和水分供应。从猎物获得的益处部分通过冬芽传递到下一年。相对位置的重要性得以体现：圆叶茅膏菜的植株在较高位置表现出更高的适合度值，中间茅膏菜的植株在较低位置表现出更高的适合度值。这两个物种的生长特征都倾向于在相应方向上影响其自身所在位置的高度：中间茅膏菜向下，圆叶茅膏菜向上。在这两个物种中，种内邻域的负面影响都很明显，而种间影响则未被检测到。中间茅膏菜的植株倾向于通过类似根茎的茎生长来改变其位置，从而影响其邻域情况。在中间茅膏菜中，通过种子或腋芽繁殖的决定似乎至少部分在头一年就已做出。仅观察到圆叶茅膏菜通过种子繁殖。尽管这两种茅膏菜具有不同的捕虫特征（植株形状、植株大小、微生境、猎物谱），但以每株植物生物量的猎物生物量来衡量的总体捕虫成功率在这两个物种中是相等的。这与早期的研究结果一致，即在这个沼泽中，这两个物种每单位地面面积的生物量相同。
