Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487.
Mycologia. 2004 Jan-Feb;96(1):57-65.
The concentrations and relative abundances of aquatic hyphomycete conidia in water were followed during a three-year study in two headwater streams at Coweeta Hydrologic Laboratory, North Carolina, using the membrane-filtration technique. After a one-year pretreatment period, one of the streams was enriched continuously with inorganic nutrients (N+P) for two years while the other stream served as the reference. This ecosystem-level nutrient manipulation resulted in concentrations of aquatic hyphomycete conidia in the water of the treated stream that were 4.5-6.9 times higher than the concentrations observed during the pretreatment period and in the reference stream. Nutrient enrichment led to an increase in the number of fungal species detected on each sampling date. Changes in dominance patterns and relative abundances of individual species also were detected after treatment. Nutrient addition stimulates the reproductive activity of aquatic hyphomycetes, their colonization success and fungal-mediated leaf-litter decomposition. Such changes in the activity of the fungal community might affect higher trophic levels in lotic ecosystems.
在北卡罗来纳州考维塔水文实验室的两项为期三年的研究中，我们采用膜过滤技术，跟踪了水中水生丝孢真菌孢子的浓度和相对丰度。经过一年的预处理期后，其中一条溪流连续两年被无机养分（N+P）富化，而另一条溪流则作为对照。这种生态系统水平的养分操纵导致处理溪流中水生丝孢真菌孢子的浓度比预处理期和对照溪流中观察到的浓度高 4.5-6.9 倍。养分富化导致在每个采样日期检测到的真菌物种数量增加。处理后还检测到优势模式和个别物种相对丰度的变化。养分添加刺激了水生丝孢真菌的繁殖活性、它们的定殖成功以及真菌介导的凋落物分解。真菌群落活性的这种变化可能会影响流水生态系统中的更高营养级。
