Sexual reproduction under fluctuating water levels in an amphibious plant Schoenoplectus lineolatus (Cyperaceae): a waiting strategy?

Abstract

Sexual reproduction of an amphibious macrophyte Schoenoplectus lineolatus (Fr. et Stav.) T. Koyama (Cyperaceae) was observed in three irrigation ponds with different water regimes in Hyogo Prefecture, western Japan. In each pond, inflorescence formation, flowering (anthesis), and seed set were recorded at three water depths (shallow, middle, and deep). Inflorescence formation was observed under submerged conditions in the three ponds. In Oku-ike Pond, anthesis was observed when the water level dropped in August and early September. Flowers opened after the emergence of the inflorescence into the air. In contrast, anthesis did not occur, despite inflorescence formation, in the other two ponds with no water level drop or a short period of water level drop. Submerged inflorescences could not set seeds unless pollination had already occurred in the air. Finally, inflorescence formation under submerged conditions was considered to be a waiting strategy for water drawdown in the irrigation ponds where marked water level decreases occur from summer to autumn. Anthesis can quickly start soon after the emergence of inflorescences.

Effects of Eutrophication and Different Water Levels on Overwintering of Eichhornia crassipes at the Northern Margin of Its Distribution in China

“…In some ranges, precipitation was also low in winter, which leads to a decline in the water levels of lakes and rivers. Water level is an important factor affecting the growth and reproduction of aquatic plants in freshwater ecosystems (Chambers and Kalff, 1985; Ishii and Kadono, 2004; Deegan et al, 2006; Smith and Brock, 2007; Xiao et al, 2007; Xie et al, 2008). Moreover, water is usually considered to be a temperature buffer to prevent aquatic plants from direct damage by freezing in winter (You et al, 2013).…”

The Ups and Downs of Life on the Edge: The Influence of Water Level Fluctuations on Biomass Allocation in two Contrasting Aquatic Plants

“…Differences in growth and reproduction have been measured in response to differences in static depth (Froend et al 1993;Grace 1993;Blanch et al 1999a, b) or average depth (Rea and Ganf 1994a) and drawdown can facilitate reproduction (Ishi and Kadono 2004). The distribution of different depths over time can be used to classify water regime and is correlated to aspects of plant community dynamics (Brownlow et al 1994).…”

Submerged Vegetation and Water Quality Degeneration From Serious Flooding in Liangzi Lake, China

“…Among lakes, the factors influencing the submerged macrophyte distribution, diversity, and abundance include light availability (Middelboe and Markager, 1997; Phillips et al, 2016; Zhang et al, 2016; Verhofstad et al, 2017), water temperature (Scheffer et al, 1992; Short et al, 2016), nutrient enrichment (Sand‐Jensen et al, 2008), bottom substrate (Andersson, 2001), herbivory (Marklund et al, 2002; Sponberg and Lodge, 2005), and the water level (Wilcox and Meeker, 1991). In shallow lake ecosystems, water level fluctuations are the main factor affecting the biomass and spatial distribution of aquatic plants and are an important ecological factor affecting their growth and reproduction (Gafny and Gasith, 1999; Strand and Weisner, 2001; Ishii and Kadono, 2004; Deegan et al, 2007; Schneider et al, 2018).…”