Miller R M, Jastrow J D, Reinhardt D R
Environmental Research Division, Argonne National Laboratory, 9700 S. Cass Avenue, 60439, Argonne, IL, USA.
Biological Sciences Department, The University of Illinois at Chicago, 60680, Chicago, IL, USA.
Oecologia. 1995 Jul;103(1):17-23. doi: 10.1007/BF00328420.
External hyphae of vesicular-arbuscular mycorrhizal (VAM) fungi were quantified over a growing season in a reconstructed tallgrass prairie and an ungrazed cool-season pasture. In both sites, hyphal lengths increased throughout the growing season. Peak external hyphal lengths were 111 m cm of soil in the prairie and 81 m cm of soil in the pasture. These hyphal lengths calculate to external hyphal dry weights of 457 μg cm and 339 μg cm of soil for prairie and pasture communities, respectively. The relationships among external hyphal length, root characteristics, soil P and soil moisture were also determined. Measures of gross root morphology [e.g., specific root length (SRL) and root mass] have a strong association with external hyphal length. Over the course of the study, both grassland communities experienced a major drought event in late spring. During this period a reduction in SRL occurred in both the pasture and prairie without a measured reduction in external hyphal length. Recovery for both the pasture and prairie occurred not by increasing SRL, but rather by increasing external hyphal length. This study suggests that growth is coordinated between VAM hyphae and root morphology, which in turn, are constrained by plant community composition and soil nutrient and moisture conditions.
在重建的高草草原和未放牧的冷季牧场中，对泡囊-丛枝菌根（VAM）真菌的外部菌丝在一个生长季节内进行了定量分析。在这两个地点，菌丝长度在整个生长季节都有所增加。草原中外部菌丝的峰值长度为每平方厘米土壤111米，牧场中为每平方厘米土壤81米。这些菌丝长度分别对应草原和牧场群落中每平方厘米土壤457微克和339微克的外部菌丝干重。还确定了外部菌丝长度、根系特征、土壤磷和土壤水分之间的关系。粗根形态指标[如比根长（SRL）和根质量]与外部菌丝长度有很强的关联。在研究过程中，两个草原群落都在春末经历了一次严重干旱事件。在此期间，牧场和草原的SRL均下降，但外部菌丝长度未出现可测量的减少。牧场和草原的恢复并非通过增加SRL，而是通过增加外部菌丝长度来实现。这项研究表明，VAM菌丝和根形态之间的生长是协调的，而这又受到植物群落组成以及土壤养分和水分条件的限制。
