Plant traits and environment: floating leaf blade production and turnover of waterlilies

Abstract

Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba, Nuphar lutea, Nymphaea candida. The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/Bmax) of the three species ranged from 1.35–2.25. The ratio Vegetation period (Period with floating leaves)/Mean leaf life span ranged from 2.94–4.63, the ratio Growth period (Period with appearance of new floating leaves)/Vegetation period from 0.53–0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba, may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.

Initial decomposition of floating leaf blades of waterlilies: causes, damage types and impacts

“…Leaves developed during 53 to 73% of the vegetation period of 135 to 199 days (Klok & Van der Velde, 2017). Loss of leaf tissue tended to increase during the vegetation period (Fig.…”

“…The actual area was defined as the potential area minus the area that was missing. The potential leaf area was calculated by using a quadratic regression to relate it to leaf length (Van der Velde & Peelen-Bexkens, 1983; Klok & Van der Velde, 2017; Table 2). Specifically, undamaged, fully green floating leaves randomly sampled outside the plots were taken to the laboratory where both length and area were measured to establish relationships of the form: …”

“…Six representative plots of 1 m 2 were laid out in the center of mono-specific stands, each containing one rhizome apex per plot. A non-destructive method was used to tag all floating leaves individually within the plots (Klok & Van der Velde, 2017). Newly unrolled leaves were tagged with uniquely numbered Rotex tape fixed around the petiole just under the leaf blade.…”

“…The phases of initial decomposition can be studied well in floating leaf blades (laminae) of large-leaved plants such as waterlilies (Nymphaeaceae) which exist for a relatively long time, on average 38–48 days, and whose turnover is low (P/B max 1.35–2.25 yr −1 ) (Klok & Van der Velde, 2017). Waterlilies occur worldwide (Conard, 1905; Wiersema, 1987; Padgett, 2007) and in many types of water bodies differing in physico-chemical conditions (Van der Velde, Custers & De Lyon, 1986).…”

Peer Review #1 of "Initial decomposition of floating leaf blades of waterlilies: causes, damage types and impacts (v0.2)"

“…Manuscript to be reviewed Furthermore, leaves are colonized by microorganisms, which make the tissue more attractive for detritivorous macroinvertebrates (Rogers & Breen, 1983). The phases of initial decomposition can be studied well in floating leaf blades (laminae) of large-leaved plants such as waterlilies (Nymphaeaceae) which exist for a relatively long time, on average 38-48 days, and whose turnover is low (P/B max 1.35-2.25 yr -1 ) (Klok & van der Velde, 2017). Waterlilies occur worldwide (Conard, 1905;Wiersema, 1987;Padgett, 2007) and in many types of water bodies differing in physicochemical conditions (van der Velde, Custers & de Lyon, 1986).…”