Exotic winter annual grasses (Bromus spp.) are a problem in North American rangelands. Defoliation, litter, and mosses are thought to regulate invasive annual Bromus species. We conducted a field experiment that tested effects of mechanical mowing and fungicide applications on Bromus arvensis, other and total graminoids, forbs, litter, and moss. Treatments caused litter biomass and moss cover to vary, which enabled testing whether litter and mosses explain variation in B. arvensis biomass. Two yr after cessation of experimental treatments, mowing treatments caused persistent reductions in B. arvensis, total graminoid, and litter biomasses but had no effect on other graminoid and forb biomasses. We detected a positive relationship between litter and B. arvensis. Fungicide applications increased moss cover and other and total graminoid biomasses, thereby suggesting mosses and several graminoids were released from the suppressive effects of biota (e.g., lichen, pathogenic fungi) susceptible to the fungicide. We found no relationship, however, between moss cover and B. arvensis. In temperate and semiarid ecosystems, mowing during flowering and before seed drop coupled with removal of clippings is likely to help control invasive bromes and fungicide additions may increase grass production.

在北美的牧场上，异国冬季一年生禾草（Bromus spp。）是一个问题。人们认为落叶，凋落物和苔藓可以调节一年生入侵性布鲁姆斯物种。我们进行所测试的机械割草和杀真菌剂的应用效果的现场实验田雀麦，其他和总禾草，杂类，垫料，和苔藓。处理导致凋落物生物量和苔藓覆盖率发生变化，从而能够测试凋落物和苔藓是否能解释野菜双歧杆菌生物量的变化。停止实验处理后的两年，割草处理导致欧文氏杆菌持续减少，总的类动物体和凋落物生物量，但对其他类动物体和福布斯生物量没有影响。我们发现凋落物与B. arvensis之间存在正相关。施用杀真菌剂会增加苔藓的覆盖率以及其他和总类蠕虫的生物量，从而表明苔藓和一些类蠕虫因对杀真菌剂敏感的生物群（例如地衣，致病真菌）的抑制作用而释放。但是，我们发现苔藓覆盖与野菜双歧杆菌之间没有任何关系。在温带和半干旱的生态系统中，开花期间和种子掉落前的修剪与去除修剪的修剪可能有助于控制入侵性溴，添加杀菌剂可能会增加草的产量。