Wardle D A, Parkinson D, Waller J E
Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., T2N 1N4, Calgary, Alberta, Canada.
Ruakura Agricultural Centre, Private Bag, Hamilton, New Zealand.
Oecologia. 1993 May;94(2):165-172. doi: 10.1007/BF00341313.
The role of interspecific competition in fungal communities in natural substrates is poorly understood because fungi do not form easily definable populations. A new approach to investigating fungal competition, using natural substrates containing a range of known biomass concentrations of each of two species, is described. Relative competitive success of each species is assessed over time in terms of propagule production and substrate colonisation by each species. In an agricultural soil Mucor hiemalis usually out-competed Trichoderma harzianum. After 27 days, the success of both species in the mixtures was independent of the initial biomass concentration of either species, although the success of T. harzianum in these mixtures was substantially inhibited relative to the T. harzianum monocultures. In a forest soil, T. polysporum maintained a competitive advantage over M. hiemalis, and induced M. hiemalis to produce propagules rather than mycelia. Coexistence of both species always occurred in both experiments, and in the forest soil experiment the two-species mixtures all contained a higher total microbial biomass than the monocultures of either species by day 47, suggesting some niche differentiation.
种间竞争在自然基质中真菌群落里所起的作用还鲜为人知，因为真菌不会形成易于界定的种群。本文描述了一种新的研究真菌竞争的方法，该方法使用含有两种已知生物量浓度范围的自然基质。通过各物种的繁殖体产生和基质定殖情况，随时间评估每个物种的相对竞争成功率。在农业土壤中，毛霉通常比哈茨木霉更具竞争力。27天后，两种菌在混合物中的成功情况与任一物种的初始生物量浓度无关，不过相对于哈茨木霉单培养物，哈茨木霉在这些混合物中的成功受到了显著抑制。在森林土壤中，多孢木霉相对于毛霉保持竞争优势，并诱导毛霉产生繁殖体而非菌丝体。在两个实验中两种菌总是共存，并且在森林土壤实验中，到第47天时，所有两物种混合物的总微生物生物量都高于任一物种的单培养物，这表明存在一定的生态位分化。
