Am J Bot. 1997 Apr;84(4):478.
Experimental microcosms (40 X 52 X 32 cm) containing an assemblage of eight tallgrass prairie grass and forb species in native prairie soil were maintained under mycorrhizal (untreated control) or mycorrhizal-suppressed (fungicide-treated) conditions to examine plant growth, demographic, and community responses to mycorrhizal symbiosis. The fungicide benomyl successfully reduced mycorrhizal root colonization in the fungicide-treated microcosms to only 6.4% (an 83% reduction relative to mycorrhizal controls). Suppression of mycorrhizas resulted in a 31% reduction in total net aboveground plant production and changes in the relative production of C4 and C3 plants. The C4 tallgrasses Andropogon gerardi and Sorghastrum nutans produced less plant biomass in the fungicide-treated microcosms, and had a greater ratio of reproductive to vegetative biomass. Cool-season C3 grasses, Koeleria pyramidata and Poa pratensis accumulated more biomass and were a significantly greater proportion of total community biomass in mycorrhizal-suppressed microcosms. Forbs showed variable responses to mycorrhizal suppression. The two legumes Amorpha canescens and Dalea purpurea had significantly lower survivorship in the fungicide-treated microcosms, relative to the controls. The results confirm the high mycorrhizal dependency and growth responsiveness of dominant prairie grasses, and indicate that differential growth and demographic responses to mycorrhizal colonization among species may significantly affect plant productivity and species relative abundances in tallgrass prairie.
实验微宇宙（40 X 52 X 32 厘米）包含了一组八种高草草原草和草本植物，种植在原生草原土壤中，在菌根（未处理对照）或菌根抑制（杀菌剂处理）条件下维持，以研究植物生长、种群动态和群落对菌根共生的反应。杀菌剂苯菌灵成功地将杀菌剂处理的微宇宙中的菌根根定植减少到仅 6.4%（相对于菌根对照减少了 83%）。菌根的抑制导致总地上植物净生产力减少 31%，并改变了 C4 和 C3 植物的相对生产力。C4 高草雀稗和柳枝稷的生物量在杀菌剂处理的微宇宙中减少，生殖生物量与营养生物量的比值更大。冷季 C3 草类，垂穗披碱草和草地早熟禾在菌根抑制的微宇宙中积累了更多的生物量，并且在总群落生物量中占更大的比例。草本植物对菌根抑制表现出不同的反应。两种豆科植物野胡枝子和紫菀属的存活率在杀菌剂处理的微宇宙中明显低于对照。结果证实了优势草原草的高度菌根依赖性和生长反应性，并表明物种之间对菌根定植的不同生长和种群动态反应可能会显著影响高草草原的植物生产力和物种相对丰度。
