Water level drawdown induces a legacy effect on the seed bank and retains sediment chemistry in a eutrophic clay wetland

The lack of extreme water level fluctuations in managed, non-peat forming wetland ecosystems can result in decreased productivity through the loss of heterogeneity of these ecosystems. Stochastic disruption, such as a water level drawdown, can effectively reverse this effect and return the wetland to a more productive state, associated with higher biodiversity through new vegetation development. Yet, aside from the effect on vegetation dynamics, little is known about longer-term effects (30 years) of a water level drawdown, hereafter referred to as legacy effects, and how this may impact future water level drawdowns.
Here, we aim to unravel the legacy effects of a water level drawdown, stand alone and along a water level gradient, on seed bank properties and nutrient availability in a eutrophic clay wetland. To identify these, we studied the hydrologically managed nature reserve Oostvaardersplassen in the Netherlands. Here, one section was subjected to a multi-year water level drawdown ..., 2.1 Study site
The study was conducted in Oostvaardersplassen in the Netherlands (coordinates: 52.456857, 5.355935). This eutrophic clay wetland of about 5600 ha consists of a 3600 ha marsh and a 2000 ha dryer border zone. This study took place in the marsh part. The marsh is characterized by large water bodies, reed vegetation and willow forests. Oostvaardersplassen is part of the polder Zuidelijk Flevoland, which is located in the former Zuiderzee estuary, a marine habitat (see van Leeuwen et al., 2021 for a detailed description). For water safety reasons the decision was made to separate the inland Zuiderzee from the North Sea through the construction of a dike, named the Afsluitdijk. After completion of the construction and within five years, the Zuiderzee transformed into a freshwater lake, IJsselmeer. In this freshwater lake, several polders were established to create land for agriculture; Zuidelijk Flevoland was reclaimed in 1968. Since Oostvaardersplassen is located in, what was..., , # Water level drawdown induces a legacy effect on the seed bank and retains sediment chemistry in a eutrophic clay wetland

[https://doi.org/10.5061/dryad.z08kprrnc](https://doi.org/10.5061/dryad.z08kprrnc)

This datafile is part of a study that shows how a previously induces water level drawdown affects seed bank composition and sediment chemistry, 30 years after the event. The samples were collected in a nature reserve in the Netherlands, Oostvaardersplassen. The datafile is split in three sections in accordance with the manuscript and covers (1) soil samples collected from the field in June 2021. Afterwards soil was sieved and left in the greenhouse for germination quantification; (2) soil samples collected from the field in November 2021. Afterwards nutrient analyses have been done on the samples; (3) intact soil cores collected from the field in November 2020 for a 8-week indoor mesocosm experiment to assess nutrient availability and seedbank composition under three different water...