Background and aims

Wildflower meadows are a low-maintenance landscape treatment that can improve urban biodiversity and achieve conservation outcomes, especially when designed to use plants from threatened grassy ecosystems. Cost-effective approaches to create meadows include direct seeding onto mined sand substrates that are placed onto site soils to supress weed competition and enhance sown plant establishment. However, waste subsoils diverted from landfill could provide a more sustainable alternative. This study compares a mined sand with a clay subsoil to understand the relative differences in sown plant establishment and root growth for a range of south-east Australian grassland species.

Methods

Germination, seedling emergence and root development were assessed for six species sown in an 80 mm deep cap of two low nutrient substrates (sand and clay subsoil) overlying a simulated site soil. Rhizoboxes were used to assess the rate at which plant roots could access soils beneath capping substrates.

Results

Sand and clay subsoil supported the establishment of the six sown species. Five species had significantly greater total root length, leaf area and aboveground biomass when sown in recycled subsoil, compared with sand.

Conclusion

Edaphic conditions affect the establishment of native grassland species in wildflower meadows. Compared to sand, recycled clay subsoils provide a more sustainable alternative for establishing designed wildflower meadows and can support rapid root and plant growth in south-east Australian grassland species.

中文翻译：

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粘土底土中的快速根系发育促进了本地草原物种的早期生长

 背景和目标

野花草甸是一种低维护的景观处理方法，可以改善城市生物多样性并实现保护成果，尤其是在设计使用来自受威胁草地生态系统的植物时。创建草地的具有成本效益的方法包括将播种到开采的沙子基质上，这些基质放置在现场土壤上，以抑制杂草竞争并促进播种植物的建立。然而，从垃圾填埋场转移的废弃底土可以提供更可持续的替代方案。本研究将开采的沙子与粘土底土进行了比较，以了解澳大利亚东南部一系列草原物种在播种植物生长和根系生长方面的相对差异。

 方法

对播种在模拟场地土壤上两种低营养基质（沙子和粘土底土）的 80 毫米深盖中的 6 个物种的发芽、幼苗出苗和根系发育进行了评估。根茎盒用于评估植物根系可以进入覆盖基质下土壤的速率。

 结果

沙子和粘土底土支持了六种播种的建立。与沙子相比，5 个物种在循环底土中播种时，总根长、叶面积和地上生物量显著增加。

 结论

Edaphic 条件影响了野花草甸中原生草原物种的建立。与沙子相比，回收的粘土底土为建立设计的野花草甸提供了更可持续的替代方案，并且可以支持澳大利亚东南部草原物种的根系和植物快速生长。