Mycorrhizal suppression alters plant productivity and forb establishment in a grass-dominated prairie restoration
Mycorrhizal suppression alters plant productivity and forb establishment in a grass-dominated prairie restoration
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DOI：
10.1007/s11258-011-9940-0
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发表时间：
2011-06
期刊：
影响因子：
1.7
通讯作者：
Kathryn N. S. McCain;G. Wilson;J. Blair
中科院分区：
文献类型：
--
作者：
Kathryn N. S. McCain;G. Wilson;J. Blair
恢复的根本目标是重建具有代表性的原生植被的植物多样性。然而，许多草原恢复或保护保护区遗址已经播种了暖季草，导致以草为主的低多样性恢复，不具有原生草地的代表性。这些优势草是强真菌营养的，而许多从属的forb物种似乎不太依赖菌根共生。因此，控制丛枝菌根真菌（AMF）可能有助于促进草为主草原恢复中牧草物种的建立和生长。为了评估菌根对恢复后的高草草原生产力和群落组成的潜在影响，我们在美国堪萨斯州东北部康扎草原进行了为期4年的草地恢复试验。在研究开始时，我们将12种不同程度菌根依赖的草本植物的种子添加到草为主的样地中。在四个生长季节中，重复试验田每两周施用一次杀菌剂（topsinm®），并与未施用AMF的对照试验田进行比较，以评估AMF对恢复高草草原植物物种组成、生产力、叶片组织质量和多样性的影响。施用Topsin成功地将根中的菌根定植量相对于对照地块的根减少了约60-80%。4年的菌根抑制降低了优势草的生产力，增加了植物物种的丰富度和多样性。这些结果强调了菌根作为恢复高草草原植物生产力和群落动态的中介的重要性，并表明暂时抑制AMF会降低优势C4草的生产力，并允许种子牧草的建立。
A fundamental goal of restoration is the re-establishment of plant diversity representative of native vegetation. However, many prairie restorations or Conservation Reserve Program sites have been seeded with warm-season grasses, leading to grass-dominated, low-diversity restorations not representative of native grasslands. These dominant grasses are strongly mycotrophic, while many subordinate forb species appear to be less dependent on mycorrhizal symbiosis. Therefore, manipulating arbuscular mycorrhizal fungi (AMF) may be useful in promoting establishment and growth of forb species in grass-dominated prairie restorations. To assess the potential role of mycorrhizae in affecting the productivity and community composition of restored tallgrass prairie, we conducted a 4-year field experiment on an 8-year-old grassland restoration at the Konza Prairie in northeastern Kansas, USA. At the initiation of our study, seeds of 12 forb species varying in degree of mycorrhizal dependence were added to established grass-dominated plots. Replicate plots were treated bi-weekly with a soil drench of fungicide (Topsin-M®) over four growing seasons and compared to non-treated control plots to assess the role of AMF in affecting plant species composition, productivity, leaf tissue quality, and diversity in restored tallgrass prairie. Topsin applications successfully reduced mycorrhizal colonization of grass roots to approximately 60–80% relative to roots in control plots. Four years of mycorrhizal suppression reduced productivity of the dominant grasses and increased plant species richness and diversity. These results highlight the importance of mycorrhizae as mediators of plant productivity and community dynamics in restored tallgrass prairie and indicate that temporarily suppressing AMF decreases productivity of the dominant C4 grasses and allows for establishment of seeded forb species.