Maleri R, Reinecke S A, Mesjasz-Przybylowicz J, Reinecke A J
Department of Botany and Zoology, University of Stellenbosch, Matieland, South Africa.
Arch Environ Contam Toxicol. 2007 Apr;52(3):363-70. doi: 10.1007/s00244-005-0132-6. Epub 2007 Mar 9.
Ultramafic soils are characterized by high concentrations of heavy metals of natural origin-such as chromium, cobalt, manganese, and nickel-as well as a shortage of primary nutrients. This can result in extremely disadvantageous living conditions for all soil-dwelling organisms. Responses to these conditions were addressed by studying growth, cocoon production, and fecundity of earthworms as endpoints of sublethal effects and how this influences the reproductive system and, consequently, population development. Mature specimens of two ecophysiologically different species of earthworms, Eisenia fetida (Savigny) and Aporrectodea caliginosa (Savigny), were exposed for 56 days to an uncontaminated soil and ultramafic soils collected from six ultramafic sites in the Barberton greenstone belt. In all ultramafic soil samples, the specimens of both species grew slower than those in the control soil. In A. caliginosa, an autotomization of the tail section was observed at higher concentrations of heavy metals. At high levels of heavy metals such as manganese, chromium, nickel, and cobalt, a significantly lower cocoon production was recorded for E. fetida, and at medium levels, a time delay in cocoon production was found. A. caliginosa showed an increase in production at medium levels and a decrease at high levels of heavy metals. In both species, no correlation between growth and cocoon viability was found, indicating different target levels for toxicants present in ultramafic soils. To determine effects of these soils on population dynamics, hatching success may be a more useful endpoint of reproduction.
超镁铁质土壤的特点是天然来源的重金属（如铬、钴、锰和镍）含量高，以及缺乏主要养分。这可能导致所有土壤生物的生存条件极为不利。通过研究蚯蚓的生长、茧产量和繁殖力作为亚致死效应的终点，以及这如何影响生殖系统，进而影响种群发展，来探讨对这些条件的反应。将两种生态生理特征不同的蚯蚓——赤子爱胜蚓（Savigny）和背暗异唇蚓（Savigny）的成熟个体暴露于未受污染的土壤以及从巴伯顿绿岩带的六个超镁铁质地点采集的超镁铁质土壤中56天。在所有超镁铁质土壤样本中，两个物种的个体生长速度均慢于对照土壤中的个体。在背暗异唇蚓中，在重金属浓度较高时观察到尾部自割现象。在锰、铬、镍和钴等重金属含量较高时，赤子爱胜蚓的茧产量显著降低，在中等含量时，发现茧产量出现时间延迟。背暗异唇蚓在重金属含量中等时产量增加，在含量较高时产量降低。在两个物种中，均未发现生长与茧活力之间存在相关性，这表明超镁铁质土壤中存在的有毒物质具有不同的目标水平。为了确定这些土壤对种群动态的影响，孵化成功率可能是更有用的繁殖终点。
