Cazzavillan Anna, Gerdol Renato, Marrocchino Elena, Vaccaro Carmela, Brancaleoni Lisa
Department of Environmental and Prevention Sciences, University of Ferrara, C.so Ercole I d'Este 32, 44121 Ferrara, Italy.
Plants (Basel). 2024 Aug 16;13(16):2280. doi: 10.3390/plants13162280.
Bedrock geology is crucial in structuring alpine plant communities. Old studies mainly focused on the compositional differences between alpine plant communities on carbonate rocks and crystalline rocks, i.e., calcareous vs. siliceous vegetation. Increasing attention is being paid to bedrock types other than calcareous or siliceous ones, viz. those which have intermediate geochemical characteristics between pure calcareous and pure siliceous ones. Among these types of 'intermediate' bedrocks, calc-schists and serpentines are generally characterized by vegetation comprised of a mixture of basiphilous and acidophilous species. We selected several sites in alpine grasslands in the Western Italian Alps, on calc-schist and serpentine bedrocks, located at 2500 ± 100 m above sea level. X-ray fluorescence quantification of major and trace elements, combined with stereomicroscopic examination of bedrock samples with a petrographic approach, revealed a much broader range of bedrock types than recognized by inspection of geological maps. The vegetation investigated in our study was mostly composed of a set of species found more or less frequently in alpine silicicolous or calcicolous plant communities of the Alps and other European mountains. The carbonate content in the bedrock was one of the main drivers of variation in grassland vegetation, not necessarily related to soil pH. There were no distinctive species uniquely characterizing grassland vegetation on serpentines or calc-schists.
基岩地质在构建高山植物群落方面至关重要。以往的研究主要关注碳酸盐岩和结晶岩上的高山植物群落之间的组成差异，即钙质植被与硅质植被。除了钙质或硅质基岩类型之外，越来越多的注意力正投向其他基岩类型，即那些在纯钙质和纯硅质基岩之间具有中间地球化学特征的基岩类型。在这些“中间”基岩类型中，钙质片岩和蛇纹岩通常以由喜碱和嗜酸物种混合组成的植被为特征。我们在意大利西部阿尔卑斯山海拔2500 ± 100米的高山草甸中，选取了位于钙质片岩和蛇纹岩基岩上的几个地点。通过对主要和微量元素进行X射线荧光定量分析，并结合采用岩石学方法对基岩样本进行体视显微镜检查，发现基岩类型的范围比通过地质图检查所识别的范围要广泛得多。我们研究中所调查的植被大多由在阿尔卑斯山及其他欧洲山脉的高山硅质或钙质植物群落中或多或少频繁出现的一组物种组成。基岩中的碳酸盐含量是草地植被变化的主要驱动因素之一，不一定与土壤pH值相关。在蛇纹岩或钙质片岩上，没有独特的物种能唯一地表征草地植被。
