Alien woody species are successful invaders, frequently used for afforestation in regions like semi-arid lands. Shrubs and trees create important microhabitats in arid areas. Understorey vegetation in these habitats has unique species composition and coexistence. However, the impact of solitary woody species on understorey vegetation is less understood. This study evaluated the effect of native (Juniperus communis) and invasive solitary conifers (Pinus nigra) on surrounding vegetation, where individuals were relatively isolated (referred to as solitary conifers). The field study conducted in Pannonic dry sand grassland in 2018 recorded plant and lichen species presence around six selected solitary conifers. Composition and pattern of understorey vegetation were assessed using 26 m belt transects with 520 units of 5 cm × 5 cm contiguous microquadrats. Compositional diversity (CD) and the number of realized species combinations (NRC) were calculated from the circular transects. Results showed native conifer J. communis created more complex, organized microhabitats compared to alien P. nigra. CD and NRC values were significantly higher under native conifers than invasive ones (p = 0.045 and p = 0.026, respectively). Native species also had more species with a homogeneous pattern than the alien species. Alien conifers negatively affected understorey vegetation composition and pattern: some species exhibited significant gaps and clusters of occurrences along the transects under P. nigra. Based on our study, the removal of invasive woody species is necessary to sustain habitat diversity.

外来木本物种是成功的入侵者，经常用于半干旱地区等地区的造林。灌木和树木在干旱地区创造了重要的微生境。这些栖息地的林下植被具有独特的物种组成和共存。然而，人们对孤独木本物种对林下植被的影响知之甚少。本研究评估了原生针叶树（杜松）和入侵性单生针叶树（黑松）对周围植被的影响，其中个体相对孤立（称为单生针叶树）。 2018 年在潘诺尼克干沙草原进行的实地研究记录了六种选定的孤立针叶树周围存在的植物和地衣物种。使用 26 m 带样线和 520 个 5 cm × 5 cm 连续微样方单位评估林下植被的组成和格局。根据圆形样线计算组成多样性（CD）和实现的物种组合数量（NRC）。结果表明，与外来针叶树黑松树相比，本地针叶树J. communis创造了更复杂、更有组织的微生境。原生针叶树下的 CD 和 NRC 值显着高于入侵针叶树（分别为p = 0.045 和p = 0.026）。本地物种也比外来物种拥有更多具有同质模式的物种。外来针叶树对林下植被的组成和格局产生了负面影响：一些物种沿着黑松下的横断面表现出显着的间隙和集群。根据我们的研究，清除入侵木本物种对于维持栖息地多样性是必要的。