Forest understory plants in eastern North America experience heavy white-tailed deer browse and impacts associated with invasive species, including of non-native earthworms. Deer and earthworms are well-recognized ecosystem engineers due to their ability to alter understory plant dynamics. We examined interactive effects of earthworms and deer on four woodland ferns (Adiantum pedatum, Polystichum acrostichoides, Dryopteris marginalis, and Dennstaedtia punctilobula) using field and common garden experiments. In the field we planted ferns into fenced and deer-accessible plots in areas with and without earthworms. In a common garden, we assessed both fern responses to different earthworms and fern effects on earthworm survival and biomass. Venue was important in determining experimental outcomes. In the field, A. pedatum and P. acrostichoides showed higher survival and P. acrostichoides grew taller or produced more fronds in worm-invaded areas. Deer presence/absence was not a significant explanatory variable. In the common garden, earthworms had no discernible effect on ferns, but fern species identity varied in its effect on earthworm survival and leaf litter decomposition. Our findings indicate that, contrary to many other understory species, common ferns benefit or are unaffected by earthworms. That we obtained different and even contradictory results in different venues should encourage investigators to validate common garden findings in the field.

北美东部的林下植物经历了繁重的白尾鹿浏览，并遭受了与包括非本地including在内的入侵物种相关的影响。鹿和earth具有改变林下植物动态的能力，因此是公认的生态系统工程师。我们研究了and和鹿对四种林地蕨类植物（铁线蕨，多角草、,鳞毛虫和马鞭草）的交互作用。）进行田间试验和常见的花园试验。在田间，我们在有ns和没有without的地区，将蕨类植物种植在有栅栏和鹿可接近的土地上。在一个公共花园中，我们评估了蕨类对不同earth的反应以及蕨类对earth存活和生物量的影响。场地对于确定实验结果非常重要。在田间，小脚草和顶头P. acrostichoides存活率更高，顶头P. acrostichoides在蠕虫入侵的地区长得更高或产生更多的叶状体。鹿的有无并不是一个重要的解释变量。在普通花园中，earth对蕨类植物没有明显的影响，但是蕨类物种的身份在其对survival生存和叶片凋落物分解的影响方面有所不同。我们的发现表明，与许多其他林下种相反，普通蕨类植物有益于或不受or影响。我们在不同的地点获得了不同甚至矛盾的结果，应该鼓励研究人员验证该领域常见的花园发现。