Restoration treatments in Bromus tectorum (cheatgrass)-invaded sagebrush habitat have often produced poor results. This is perhaps due to multifaceted ecological changes associated with cheatgrass invasion like reduced water availability, altered nutrient availability, and shifts in soil microbial communities. We tested whether suppressing cheatgrass, altering nutrient availability, and inoculating with soil microbes improved restoration success. We conducted field experiments in Idaho, Utah, and Arizona where we transplanted seedlings of Artemisia tridentata ssp. tridentata (basin big sagebrush) and Elymus elymoides (squirreltail). Growth and survivorship of both species were higher in sites with greater precipitation and lower cheatgrass abundance. Significant nutrient modification effects were seen in Utah, where cheatgrass abundance was highest and soil nutrients were most limiting. In Utah, we observed an increase of 14% in survivorship for squirreltail in response to carbon addition, and 119% increase in growth of sagebrush with phosphorus addition. Inoculating plants with sagebrush rhizosphere soil or a commercial arbuscular mycorrhiza at the time of planting did not significantly affect growth, survivorship, arbuscular mycorrhizal fungi colonization, or extraradical mycorrhizal hyphae length for either plant species. The largest effects on seedling growth (+384%) and survivorship (+262%) were observed in response to the suppression of cheatgrass using a weed barrier cloth and associated with increased water availability. Interactions between suppressing cheatgrass, altering nutrient availability, and inoculating with soil microbes were not significant. Direct reduction of cheatgrass was shown to be more effective than targeting soil legacy effects associated with cheatgrass with regards to restoration outplanting success.

中文翻译：

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水是山艾树在被草木入侵的生态系统中恢复成功的关键

在Bromus tectorum (cheatgrass) 入侵的山艾树栖息地进行修复处理通常效果不佳。这可能是由于与欺骗草入侵相关的多方面生态变化，如水的可用性降低、养分可用性的改变以及土壤微生物群落的变化。我们测试了抑制欺骗草、改变养分可用性和接种土壤微生物是否能提高恢复成功率。我们在爱达荷州、犹他州和亚利桑那州进行了田间试验，在那里我们移植了三齿蒿的幼苗。tridentata（盆地大山艾树）和Elymus elymoides（松鼠尾）。在降水量较大且金雀草丰度较低的地方，这两种物种的生长和存活率都较高。在犹他州观察到显着的养分改良效应，那里的金雀花丰度最高，土壤养分最有限。在犹他州，我们观察到添加碳后，松鼠尾的存活率增加了 14%，添加磷后山艾树的生长增加了 119%。在种植时用山艾树根际土壤或商业丛枝菌根接种植物不会显着影响这两种植物的生长、存活、丛枝菌根真菌定植或自由基外菌根菌丝长度。对幼苗生长 (+384%) 和存活率 (+262%) 的最大影响是在使用杂草屏障布抑制金雀花的反应中观察到的，并且与增加的水可用性有关。抑制金雀花、改变养分有效性和接种土壤微生物之间的相互作用并不显着。在恢复种植成功方面，直接减少金雀花比针对与金雀花相关的土壤遗留效应更有效。