Museum of Natural History, Faculty of Biological Sciences, University of Wrocław, Wrocław, Poland.
Department of Botany, Faculty of Biological Sciences, University of Wrocław, Poland.
PLoS One. 2022 Apr 12;17(4):e0266868. doi: 10.1371/journal.pone.0266868. eCollection 2022.
Most of Central European rocky scrub communities formed by Cotoneaster integerrimus, Juniperus communis and Amelanchier ovalis are included in the association Cotoneastro-Amelanchieretum (= Junipero-Cotoneasteretum). However, this leads to the creation of syntaxon whose internal diversity is so great that it seems necessary to examine validity of its existence in the current form. This diversity entails species composition, habitat requirements and geographical distribution. Therefore, we posed the following objectives: i) to investigate the variability of species composition of the rocky scrub; (ii) to determine if there are ecological differences between the communities distinguished by species variability; (iii) to determine the geographical ranges of individual syntaxa. Altogether we analyzed 387 phytosociological relevés from Central Europe. Vegetation types of rocky scrubs were identified using the unsupervised K-means algorithm and detrended correspondence analysis. Mean Ellenberg's indicator values were applied to identify the environmental gradients shaping the plant communities. Obtained results confirmed the validity of dividing this broadly defined syntaxon into six distinct vegetation units. In order to present the studied communities in a broader context, we included into our analyses other rocky scrub with the occurrence of Cotoneaster sp. and A. ovalis, which formed the remaining three clusters. The observed differences in species composition were further supported by significant differences in soil reaction, temperature and continentality between the syntaxa. Moreover, the distinguished communities differed among one another in geographical range. Our study provides a new typology of the selected type of natural rocky scrub vegetation in Central Europe which involves environmental aspects, hence better reflects community-habitat relationships. This study also indicates a need for further revision of the classification of other types of natural scrub communities. Such classification should be based on modern data analysis methods and should primarily focus on lower vegetation units at pan-European scale.
中欧以欧李、圆叶柳和刺柏为优势种的石质灌丛群落大多归入 Cotoneastro-Amelanchieretum（= Junipero-Cotoneasteretum）。然而，这导致了组合的创建，其内部多样性如此之大，以至于似乎有必要检查其当前形式的存在的有效性。这种多样性涉及物种组成、生境要求和地理分布。因此，我们提出了以下目标：i）调查石质灌丛物种组成的可变性；(ii) 确定通过物种可变性区分的群落之间是否存在生态差异；(iii) 确定各个语法的地理范围。总共我们分析了来自中欧的 387 个植物社会学的记录。使用无监督 K-均值算法和去趋势对应分析来识别石质灌丛植被类型。应用平均 Ellenberg 指标值来确定塑造植物群落的环境梯度。得出的结果证实了将这个广义定义的语法分为六个不同的植被单元的有效性。为了更广泛地介绍所研究的群落，我们还将其他含有欧李和圆叶柳的石质灌丛包括在分析中，这些群落形成了其余的三个聚类。观察到的物种组成差异进一步得到了语法之间土壤反应、温度和大陆性显著差异的支持。此外，区分开来的群落彼此之间在地理范围上也存在差异。我们的研究为中欧选定类型的自然石质灌丛植被提供了一种新的分类法，涉及环境方面，因此更好地反映了群落-生境关系。这也表明需要进一步修订其他类型的自然灌丛群落的分类法。这种分类应该基于现代数据分析方法，并且应该主要集中在泛欧尺度上的较低植被单元。
