Prunus serotina and Robinia pseudoacacia are the most widespread invasive trees in Central Europe. In addition, according to climate models, decreased growth of many economically and ecologically important native trees will likely be observed in the future. We aimed to assess the impact of these two neophytes, which differ in the biomass range and nitrogen-fixing abilities observed in Central European conditions, on the relative aboveground biomass increments of native oaks Quercus robur and Q. petraea and Scots pine Pinus sylvestris. We aimed to increase our understanding of the relationship between facilitation and competition between woody alien species and overstory native trees. We established 72 circular plots (0.05 ​ha) in two different forest habitat types and stands varying in age in western Poland. We chose plots with different abundances of the studied neophytes to determine how effects scaled along the quantitative invasion gradient. Furthermore, we collected growth cores of the studied native species, and we calculated aboveground biomass increments at the tree and stand levels. Then, we used generalized linear mixed-effects models to assess the impact of invasive species abundances on relative aboveground biomass increments of native tree species. We did not find a biologically or statistically significant impact of invasive R. pseudoacacia or P. serotina on the relative aboveground biomass increments of native oaks and pines along the quantitative gradient of invader biomass or on the proportion of total stand biomass accounted for by invaders. The neophytes did not act as native tree growth stimulators but also did not compete with them for resources, which would escalate the negative impact of climate change on pines and oaks. The neophytes should not significantly modify the carbon sequestration capacity of the native species. Our work combines elements of the per capita effect of invasion with research on mixed forest management.

中文翻译：

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入侵树种对温带森林中橡树和松树地上生物量增量没有影响


Prunus serotina 和 Robinia pseudoacacia 是中欧分布最广的入侵乔木。此外，根据气候模型，未来可能会观察到许多具有重要经济和生态意义的本地树木的生长减少。我们旨在评估这两种新生植物对本地橡树 Quercus robur 和 Q. petraea 以及苏格兰松 Pinus sylvestris 的相对地上生物量增量的影响，它们在生物量范围和固氮能力方面有所不同。我们旨在增加我们对木本外来物种与林上原生树木之间促进和竞争之间关系的理解。我们在波兰西部的两种不同的森林栖息地类型和不同年龄的林分中建立了 72 个圆形样地（0.05 公顷）。我们选择了具有不同研究新手丰度的图，以确定效应如何沿定量侵袭梯度缩放。此外，我们收集了所研究的本地物种的生长核心，并计算了树木和林分水平的地上生物量增量。然后，我们使用广义线性混合效应模型来评估入侵物种丰度对本地树种相对地上生物量增量的影响。我们没有发现入侵的 R. pseudoacacia 或 P. serotina 对沿入侵者生物量定量梯度的本地橡树和松树的相对地上生物量增量或入侵者占总林分生物量的比例有生物学或统计学上的显着影响。这些新人没有充当本地树木生长的刺激器，也没有与他们争夺资源，这将加剧气候变化对松树和橡树的负面影响。 新生植物不应显着改变本地物种的碳封存能力。我们的工作将入侵的人均效应要素与混交林管理研究相结合。