The restoration of degraded ecosystems and landscapes is challenging, because returning to the original state is often socio-economically unfeasible. A novel approach is to construct new ecosystems to improve the functioning of degraded landscapes. However, the development of novel ecosystems is largely driven by the pre-construction hydrogeophysical and ecological conditions of the soil. In Lake Markermeer, a deteriorating freshwater lake in the Netherlands, a large archipelago is currently being constructed to boost the ecological functioning of the lake. Hence, islands – with wetlands and with more elevated and dryer areas – have been created to sustain biodiversity and key biogeochemical functions such as nutrient cycling. The islands are constructed from lake-bottom sediments. To study how two potentially important drivers, water level and bioturbation, affect soil characteristics in a novel wetland ecosystem, we experimentally tested the effects of water level (-30, -10 and 5 cm), and bioturbation by earthworms (Lumbricus rubellus) and Tubifex spp. in a microcosm experiment. We demonstrate that a high water level prevents soil subsidence, soil crack formation and carbon dioxide (CO₂) emissions, and affects nitrogen cycling. In dryer soils, the presence of earthworms strongly increases CO₂ emissions next to reducing soil crack formation, while Tubifex spp. in wetter soils hardly affect soil characteristics. Our findings highlight the important roles of both water level and bioturbation for the functioning of novel soils, which likely affects vegetation development in novel ecosystems. This knowledge can be used to aid the construction and nature development of novel wetlands.

退化的生态系统和景观的恢复具有挑战性，因为恢复原始状态通常在社会经济上是不可行的。一种新颖的方法是构建新的生态系统以改善退化景观的功能。然而，新生态系统的发展在很大程度上是由土壤的施工前水文地球物理和生态条件驱动的。在荷兰日益恶化的淡水湖 Markermeer 湖，目前正在建造一个大型群岛，以促进湖泊的生态功能。因此，人们创建了带有湿地和更多高地和干燥地区的岛屿，以维持生物多样性和关键的生物地球化学功能，例如养分循环。这些岛屿由湖底沉积物构成。为了研究两个潜在的重要驱动因素，Lumbricus rubellus ) 和Tubifex spp。在一个微观实验中。我们证明高水位可防止土壤沉降、土壤裂缝形成和二氧化碳 (CO ₂ ) 排放，并影响氮循环。在干燥的土壤中，蚯蚓的存在大大增加了 CO ₂排放量，同时减少了土壤裂缝的形成，而Tubifex spp。在潮湿的土壤中几乎不影响土壤特性。我们的研究结果强调了水位和生物扰动对新型土壤功能的重要作用，这可能会影响新型生态系统中的植被发育。这些知识可用于帮助新型湿地的建设和自然发展。