Green roofs are known to mitigate the negative effects of urban consolidation by offering diverse ecosystem functions compared to non-vegetated roofs. However, the support for native biodiversity might be improved by using native plant species. In a mesocosm experiment, we studied the suitability of three commercial green-roof growth substrates for the establishment of 27 native plant species from dry sandy grasslands of northwestern Germany over the course of four years. The substrates were mineral-based, but differed in the layering of organic matter. Total establishment rates reached 44–59% in Year 4, indicating the general suitability of the substrates. During the first weeks after seeding, with light irrigation, the vascular plant cover was greater in the similar substrates Zincolit® Plus (Z) and Zincolit® Plus-Leicht (ZL) with their compost-based organic mulch layers than in the substrate Sedumteppich (ST) with its organic matter evenly admixed with the mineral aggregates. In Years 2 and 3, however, the vascular plant cover was greater in the ST substrate, likely due to the better availability of water and nutrients from the organic matter compared to the dry surface-mulch layer variants Z and ZL. After severe drought events, the decline in plant cover was more pronounced in the ST substrate, likely representing a trade-off between lush growth and a susceptibility to drought. An indicator-species analysis revealed differences in species composition between the ST and Z/ZL substrates. Annual plant species were indicators of the ST substrate. Perennials, such as Thymus pulegioides and Achillea millefolium, were typical of the Z and ZL substrates. In addition to the general suitability of the tested standard substrates for target species establishment, the study indicated that a combination of different layers of substrate components resulted in different vegetation patterns that may have a positive effect on green-roof biodiversity.

众所周知，与非植被屋顶相比，绿色屋顶可以通过提供多样化的生态系统功能来减轻城市整合的负面影响。但是，可以通过使用本地植物物种来改善对本地生物多样性的支持。在中观实验中，我们在四年的时间里研究了三种商业屋顶绿化生长基质在德国西北部干燥沙质草原建立 27 种本地植物物种的适用性。基质以矿物为基础，但有机质的分层不同。第 4 年的总建立率达到 44-59%，表明基质的普遍适用性。在播种后的最初几周，通过轻度灌溉，具有堆肥基有机覆盖层的类似基质 Zincolit® Plus (Z) 和 Zincolit® Plus-Leicht (ZL) 中的维管植物覆盖率高于有机质与矿物质均匀混合的基质 Sedumteppich (ST) 中的维管植物覆盖率聚合。然而，在第 2 年和第 3 年，ST 基质中的维管植物覆盖率更大，这可能是因为与干燥的表面覆盖层变体 Z 和 ZL 相比，有机质中水分和养分的可用性更高。在严重干旱事件之后，ST 基质中植物覆盖度的下降更为明显，这可能代表了茂盛生长和干旱敏感性之间的权衡。指示物种分析揭示了 ST 和 Z/ZL 底物之间物种组成的差异。一年生植物物种是 ST 底物的指标。多年生植物，Thymus pulegioides和Achillea millefolium是典型的 Z 和 ZL 底物。除了测试标准基质对目标物种建立的普遍适用性之外，该研究表明，不同层基质成分的组合导致了不同的植被模式，这可能对屋顶绿化生物多样性产生积极影响。