Biomass dynamics of charophyte-dominated submerged macrophyte communities in Myall Lake, NSW, Australia

Abstract

The dynamics of submerged macrophytes were studied in a large and shallow near-pristine lake in New South Wales, Australia. The objectives were to investigate the seasonal dynamics in biomass of Chara fibrosa, Nitella hyalina and Najas marina both in time and space, and to characterise the underlying relationship between the plant biomass and both the gyttja and water depths. Charophytes were most densely grown in the north-east bays of the lake compared to the north-west bays. Average biomass of Chara fibrosa was highest at the north-east bays of this lake (e.g. 210 g d.w m −2 ) followed by north-west bays (e.g. 148 g d.w/m 2 ), South-west bays (e.g. 60 g d.w/m 2 ) and lastly central deep area of the lake (e.g. 31 g d./m 2 ). A similar trend was displayed by Nitella hyalina biomass where at the north-east bays the biomass was the highest (e.g. 167 g d.w m −2 ) followed by north-west bays (e.g. 128 g d.w/m 2 ), south-west bays (e.g. 38 g d.w/m 2 ) and central deep area of the lake (e.g. 23 g d.w/m 2 ). During the summer season the maximum total biomass of charophytes at Corrigans bay was recorded (e.g. 300 g d.w/m 2 ), mostly being dominated by Nitella hyalina. Total biomass of charophyte was reduced during the winter season (e.g. 50 g d.w m −2 ). Najas marina biomass remained low both in time and space except in May at Bibby harbour and Shelly beach where its biomass peaked (e.g. 276 and 175 g d.w m −2 respectively). Gyttja depth showed a positive relationship with total charophyte biomass (r 2 = 0.70; p < 0.01) and it seemed to favour the growth of charophytes at the expense of other submerged macrophytes, e.g. Myriophyllum sp. and Vallisneria sp. Water depth displayed a negative relationship with total charophyte biomass (r 2 = −0.94; p < 0.01). Both Chara fibrosa and Nitella hyalina correlated positively with gyttja depth (r 2 Chara-gyttja) = 0.69, r 2 Nitella-gytja) = 0.65; p < 0.01) and negatively with water depth (r 2 Chara-depth = −0.94, r 2 Nitella-depth = −0.93; p < 0.01). Najas marina correlated positively only with water depth (r 2 = 0.67, p < 0.01).

Primary production dynamics of dominant hydrophytes in Lake Provala (Serbia)

“…Numerous authors [11,21,32,[43][44][45][46] have emphasized that there is a direct relationship between the primary production dynamics of macrophytes and light regime, temperature, water depth, sediment composition and the amount of available nutrients. Here we show that these ecological factors affected the primary production in Lake Provala.…”

Seasonal Changes in the Content of Photosynthetic Pigments of Dominant Macrophytes in the Bardača Fishpond Area

“…At the investigated site, a wide fluctuation of physical and chemical parameters was recorded during the research period, which can be considered as the main cause of variations in the content of photosynthetic pigments (Maksimović et al, 2019). Research (Shilla, Dativa, 2008;Dar et al, 2012Dar et al, , 2013 indicates that temperatures significantly determine the level of chlorophyll biosynthesis in most macrophytes and that the highest concentrations of chlorophyll are measured at a maximum atmospheric temperature. The same authors state that a reduction in total chlorophyll content during the season can occur due to a relatively lower temperature in the initial growth stage causing delay in blooming or due to early macrophyte decay caused by a sudden increase in temperature during peak growth.…”

Ecological Productivity Studies of the Dominant Aquatic Macrophytes in Kapla Beel, Assam North East India

“…The high phosphorus content in the water samples of the wetland was due to agricultural runoff and also due to discharge of water containing detergents used by the people of the surrounding areas of the wetland. There is a direct relationship between the primary productivity of aquatic macrophytes and the physico-chemical properties of water like water temperature, intensity of light, water depth, sediment composition and the amount of available nutrients in the water body (Shilla and Dativa, 2008). The inflow and outflow of water, nutrient loading and entry of harmful materials i.e.…”