Wardle D A, Yeates G W
AgResearch, Ruakura Agricultural Centre, Private Bag 3123, Hamilton, New Zealand.
Landcare Research, Private Bag, Private Bag 31902, Lower Hutt, New Zealand.
Oecologia. 1993 Mar;93(2):303-306. doi: 10.1007/BF00317685.
The relative importance of predation and competition (resource limitation) in influencing the components of a below-ground food-web consisting of three trophic levels (bacteria and fungi; bacterial-feeding and fungal-feeding nematodes; and top predatory nematodes) was estimated using microbial biomass and nematode frequency data collected throughout a 1-year period in two agro-ecosystems. The study suggested that bacterial and fungal biomass were likely to be regulated by grazing and competition respectively, and that these differences were likely to be attributed to the biological (probably morphological) differences between bacteria and fungi, in contrast to the predictions of the hypothesis of Hairston et al. (1960). Top predatory nematodes were sometimes strongly related to the microbial but not microbial-feeding trophic levels, indicating that microbial biomass may directly influence top predator numbers, and that the intermediate level may simply serve as a conduit by which resources pass from the bottom to top trophic levels. This study also suggests that the detritus food-web acts as two distinct (bacterial-and fungal-based) compartments.
利用在两个农业生态系统中全年收集的微生物生物量和线虫频率数据，估算了捕食和竞争（资源限制）在影响由三个营养级（细菌和真菌；以细菌为食和以真菌为食的线虫；以及顶级捕食性线虫）组成的地下食物网组成部分方面的相对重要性。该研究表明，细菌和真菌生物量可能分别受捕食和竞争的调节，并且与海尔斯顿等人（1960年）假说的预测相反，这些差异可能归因于细菌和真菌之间的生物学（可能是形态学）差异。顶级捕食性线虫有时与微生物营养级密切相关，但与以微生物为食的营养级无关，这表明微生物生物量可能直接影响顶级捕食者的数量，并且中间营养级可能仅仅是资源从底层营养级传递到顶层营养级的一个通道。这项研究还表明，碎屑食物网作为两个不同的（基于细菌和基于真菌）部分发挥作用。
