Establishment strategy of a rare wetland species Sparganium erectum in Korea

Abstract

Background: To reveal establishment strategy of Sparganium erectum, we tried to find realized niche of adults through field survey and effects of water level on the establishment process through mesocosm experiments. Results: In the field survey, the height and coverage of community living in deeper water were greater than those of community living in shallow water. There was no statistically significant difference (p > 0.05) in the means of water and soil properties between the two communities. In mesocosm experiments, we found no correlation between water levels and germination rates, but S. erectum seedlings have characteristics of post germination seedling buoyancy when S. erectum seeds germinated in inundation conditions. Shoot height, total leaf length, and survival rates of sinking seedlings in shallow water levels at −5, 0, and 5 cm were higher than those in deeper water levels at 10 and 20 cm. Floating seedlings established in water levels of 3 and 6 cm only. The seedlings could live up to 6 weeks in floating state but died if they were unable to establish. Conclusions: The water level around adult S. erectum communities in the field were different from the water level at which S. erectum seedlings can survive in the mesocosm experiments. The findings provided not only understanding of S. erectum habitat characteristics but also evidence to connect historical links between the early seedlings stage and adult habitat conditions. We suggested the logical establishment strategy of S. erectum based on the data.

Vegetation and water characteristics of floating mat in a coastal lagoon as the habitat for endangered plant species

“…Micro-topography is of importance in terms of habitat heterogeneity for biodiversity. In wetland ecosystems, water level difference by micro-topography as a physical environment is the most influential factor in determining vegetational components and subsequent biodiversity (Park et al 2013;Nam et al 2014;Byun et al 2017;Kim et al 2017). In our study, water level difference rather than water chemistry appeared to determine the vegetation of the floating mat (Table 1).…”

Effect of initial planting on vegetation establishment in different depth zones of constructed farm ponds

“…The time when the species composition between the two ponds became similar differed by depth zone. Seedlings of emergent hydrophytes are known to establish at shallow shores of wetlands and gradually expand to deeper zones through rhizomes (Kim et al 2017). In the deep zone, expansion of emergent hydrophytes was delayed in the unplanted pond because plants in the unplanted pond began to establish from seed germination compared to rhizomes in the planted pond.…”

“…In this context, to increase plant species diversity in a restored wetland, diverse ranges of depth zones have been proposed (Ahn & Dee 2011). Most studies on the relationship between water depth and vegetation are focused on experimental responses or natural distribution of plants (Kim et al 2017; An et al 2018). In contrast, studies that evaluate the efficiency of different restoration approaches depending on water depth are insufficient.…”

Effects of water levels and soil nutrients on the growth of Iris laevigata seedlings

“…laevigata may use similar survival strategy to Menyanthes trifoliate and Cicuta virosa, which live on floating mat with low nutrient and low competition level (Lee 2012, Shin et al 2015, Kim et al 2017. However, since the seedling growth characteristics associated with soil nutrients can vary depending on the competition, further studies focusing on competition is needed.…”