Rillig Matthias C, Field Christopher B, Allen Michael F
Carnegie Institution of Washington, Department of Plant Biology, 260 Panama Street, Stanford, CA 94305, USA e-mail:
Center for Conservation Biology, University of California, Riverside, CA 92521-0334, USA, , , , , , US.
Oecologia. 1999 Jun;119(4):572-577. doi: 10.1007/s004420050821.
Root, arbuscular-mycorrhizal (AM), soil faunal (protozoa and microarthropods), and microbial responses to field exposure to CO for six growing seasons were measured in spring 1997 in two adjacent grassland communities. The grasslands showed contrasting root responses to CO enrichment: whereas root length was not affected in the sandstone grassland, it was greater in the serpentine grassland, as was specific root length. AM fungal hyphal lengths were greater in the sandstone, but were unaffected in the serpentine community. This lent support to the hypothesis that there may be a tradeoff in resource allocation to more fine roots or greater mycorrhizal extraradical hyphal length. AM root infection was greater in both communities at elevated CO, as was the proportion of roots containing arbuscules. Our data on total hyphal lengths, culturable and active fungi, bacteria, and protozoa supported the hypothesis that the fungal food chain was more strongly stimulated than the bacterial chain. This study is one of the first to test these hypotheses in natural multi-species communities in the field.
1997年春季，在两个相邻的草原群落中，对丛枝菌根（AM）根、土壤动物区系（原生动物和小型节肢动物）以及微生物在六个生长季节中对田间暴露于一氧化碳的反应进行了测量。这两个草原对二氧化碳富集呈现出截然不同的根系反应：在砂岩草原中，根长未受影响，而在蛇纹石草原中，根长以及比根长均有所增加。砂岩中AM真菌的菌丝长度更长，但在蛇纹石群落中未受影响。这支持了以下假设：在资源分配上，可能存在向更多细根或更长的菌根根外菌丝长度的权衡。在二氧化碳浓度升高的情况下，两个群落中的AM根感染率均更高，含丛枝的根的比例也是如此。我们关于总菌丝长度、可培养和活性真菌、细菌以及原生动物的数据支持了以下假设：真菌食物链比细菌链受到的刺激更强。这项研究是最早在野外自然多物种群落中检验这些假设的研究之一。
