Restoration of wetland vegetation using soil seed banks: lessons from a project in Lake Kasumigaura, Japan

Abstract

The restoration of degraded wetland ecosystems and the recovery of wetland biodiversity are important global issues. Generally, wetland restoration projects include activities to recover vegetation. A promising revegetation technique is one in which soil seed banks are utilized as the source of plant recolonization. Using such a technique, a pilot project to restore lakeshore vegetation was launched at Lake Kasumigaura, Japan, in 2002. In the project, lake sediments containing the seed banks were spread thinly (~10 cm) on the surfaces of artificial lakeshores, which were constructed in front of concrete levees and had microtopographic variations. In total, 180 species, including six endangered or vulnerable species and 12 native submerged plants that had disappeared from the above-ground vegetation of the lake, were recorded in five recreated lakeshores (total area, 65,200 m 2 ) during the first year of the restoration. The distribution of each restored species at the sites suggested the importance of microtopographic relief for recolonizing species-rich lakeshore vegetation. Furthermore, the origin of the source seed banks affected the species composition of the restored vegetation. On the other hand, the restoration sites were subject to exotic plant invasions. Here, we report lessons learned from the Lake Kasumigaura restoration project as a contribution to the establishment of ecologically sound revegetation techniques.

Temporary wetland restoration after rice cultivation: is soil transfer required for aquatic plant colonization?

“…Short-term observations are not sufficient in predicting community dynamics (Collinge and Ray, 2009;Mesléard et al, 1991;Weiher et al, 1996). An initial success may be compromised by long-term mortality, undesired successional trajectories, and does not reflect long-term success (Dawe et al, 2000;Fahselt, 2007), although long-term studies confirm a beneficial role of soil transfer in wetland restoration (Balcombe et al, 2005;Nishihiro et al, 2006;Reinartz and Warne, 1993). Long-term monitoring of changes in plant communities of restored wetlands is required to evaluate the potential of this technique for restoring or creating Mediterranean temporary wetlands.…”

“…It is often used in wetland restoration and has already shown promising results: the imported soils contribute considerably to species richness and native wetland species establishment, indicating that soil transfer may enhance the success of wetland restoration projects compared to natural colonization (e.g. Balcombe et al, 2005;Nishihiro et al 2006;Reinartz and Warne, 1993). Moreover, this technique could be the most efficient method for transferring a large number of temporary wetland plant species that have a short life cycle but can produce large quantities of seeds and rapidly form a large seed bank (Mouronval and Baudoin, 2010).…”

Responses of Soil Seed Bank and Vegetation to the Increasing Intensity of Human Disturbance in a Semi-Arid Region of Northern China

“…A nature-based solution was considered as a cost-effective long-term solution for land degradation; it focused on improving soil quality and restoring vegetation to enhance the sustainability of the degraded land [8]. Soil seed bank has been considered as a promising method for restoring vegetation [9], but its influencing factors have not yet been fully understood [10].…”

Quantitative evaluation of water-level effects on “regeneration safe-sites” for lakeshore plants in Lake Kasumigaura, Japan

“…• C and 1153.6 mm, respectively (1996-2005 average (Sakurai 1981, Nishihiro andWashitani 2007). The loss of submerged vegetation might accelerate the area decrease of the emergent vegetation.…”

“…In Lake Kasumigaura, the second largest lake in Japan, the species richness of lakeshore vegetation has been rapidly declining since the implementation of a new water-level policy in the mid-1970s, which stabilized the water level throughout the year (Miyawaki et al 2004, Nishihiro andWashitani 2007). Our previous studies in the remnant lakeshore reedmarsh suggest that although species rich soil seed banks are still retaining in the soil, the opportunity for seed germination and/or seedling establishment is largely reduced by the inundation (Nishihiro et al 2004a(Nishihiro et al , 2004b.…”