Non-native, invasive plants are often strong competitors that have large effects on ecosystem functioning. While limited experimental evidence suggests invasive species can change soil carbon (C) and nitrogen (N) processes, little is known about how they alter biogeochemistry in the field. We examined soils collected from beneath native and non-native, invasive woody plants in a temperate forest in central New York, USA, to test whether invaders change rhizospheric C and N processes compared to that of common native species. We hypothesized that a combination of high-quality leaf and root litter and greater rates of rhizospheric deposition of invaders would enhance the quality of soil organic matter, leading to greater measured rates of C and N mineralization. We removed soil cores from directly below the canopy of 105 individuals of 8 native and 3 invasive species of shrubs and small trees, each paired with an adjacent sample to account for site effects on soil properties. We measured inorganic N pools, percent soil C and N, and potential C and N mineralization rates with 10-day laboratory incubations. Contrary to our hypothesis, we found that invaders did not significantly alter any of the measured soil traits. Instead, root biomass per sample, which did not vary by nativity, was a better predictor of potential mineralized C and N. This suggests plant tissue quantity controls available C and N pools, and plants that produce more roots are able to better stimulate microbial activity. Thus, understory invaders do not appear to alter soil biogeochemistry in this forest unless they drive large changes in forest root mass.

非本地的入侵植物通常是强有力的竞争者，会对生态系统的功能产生重大影响。尽管有限的实验证据表明，入侵物种可以改变土壤碳（C）和氮（N）的过程，但人们对它们如何改变田间生物地球化学知之甚少。我们检查了从美国纽约中部温带森林中的本土和非本土，入侵木本植物的下方收集的土壤，以测试入侵者与普通本土物种相比是否改变了根际C和N过程。我们假设高质量的叶和根凋落物以及较高的入侵者的根际沉积速率相结合将提高土壤有机质的质量，从而导致测得的C和N矿化速率更高。我们从8种原生灌木和3种入侵树种的灌木和小树的105个个体的冠层正下方移除了土壤核心，每一个都与相邻的样本配对以说明对土壤特性的场地影响。我们通过10天的实验室温育测量了无机氮库，土壤碳和氮的百分比以及潜在的碳和氮矿化率。与我们的假设相反，我们发现入侵者并未显着改变任何测得的土壤性状。取而代之的是，每个样品的根生物量（随生化而变化）可以更好地预测潜在的矿化碳和氮。这表明植物组织数量可控制可用的碳和氮库，而产生更多根的植物能够更好地刺激微生物活动。从而，