Mariusz Pełechaty

The in situ influence of Ceratophyllum demersum on a phytoplankton assemblage

The in situ influence of Ceratophyllum demersum on a phytoplankton assemblage The aim of this work was to present a quantitative and qualitative analysis of a phytoplankton assemblage under the influence of Ceratophyllum demersum L. during a two-year field study. Literature data obtained under laboratory conditions indicate that C. demersum may cause a decrease in the blue-green algae biomass, which is considered to be evidence of the significance of allelopathy. The observations reported in the current paper indicated that there was no clear effect on cyanoprokaryota whereas decreases in the quantity of Cryptophyta, Dinophyta, Chlorophyta, and Chrysophyceae are noted.

Horizontal distribution of phytoplankton as related to the spatial heterogeneity of a lake – a case study from two lakes of the Wielkopolski National Park (western Poland)

This study compares phytoplankton communities within macrophyte communities and mid-lake sites along transects in two lakes of the Wielkopolski National Park. Water samples were collected in August 1998 to characterize the phytoplankton communities at these locations and for the physical-chemical analysis of the water. There was phytocoenotic differentiation associated with the sites and the specific water properties in the two lakes, especially between the phytolittoral and mid-lake sites. In addition, there was strong negative correlation in abundance between Aphanizomenon flos-aquae and Aphanizomenon issatschenkoi along the Lake Jarosławieckie transect.

Carbon Dynamics in a Hardwater Lake: Effect of Charophyte Biomass on Carbonate Deposition

ABSTRACT: The photosynthetic activity of phytoplankton (in pelagial) and macrophytes (in littoral) is considered to be one of the main factors affecting the carbon cycle in lakes. This concerns in particular hardwater ecosystems, where most of the carbon is available in the form of Ca- or Mg-bicarbonates. In such ecosystems charophytes (macroscopic green algae, forming dense meadows) are regarded as the most effective carbonate producer due to the HCO3 — utilization and the formation of thick CaCO3 encrustations. Calcium carbonate and biomass production of charophytes were studied in a small and shallow charophyte-dominated Lake Jasne (Western Poland). Fresh and dry weight of plants, percentage contribution of calcium carbonate and production of CaCO3 per 1 m2 were studied at three depths (1, 3 and 5 m) in three sample sites (each sampled area — 0.04 m2). Additionally, physical-chemical parameters of water samples were studied. It was found that the dry weight of charophytes and the values of calcium carbonate were similar for all sites but varied for depth of sampling. The dry weight exceeded 2000 g m-2 (average 1165 g m-2) at the most shallow sample sites. CaCO3 encrustations constituted from 39.5% at the depth of 5m, to over 82% of the charophyte dry weight at the depth of 1m. The maximum and average values of carbonates precipitated by charophytes were 1696 g m-2 and 891 g m-2, respectively, and exceeded results reported so far. The results of physical-chemical analyses revealed no statistically significant differences between all the sample sites. Nevertheless, distinct correlations were found between dry weight of charophytes, carbonates precipitated by charophytes and some physical-chemical properties of water from the sample sites. The results highlight the habitat engineering role of charophytes, evidenced in particular by great amounts of biomass influencing sedimentary processes and biogeochemical cycle within littoral zone.

Effects of grass carp introduction on macrophyte communities in a shallow lake

In 2002, 2005 and 2007 vegetation and physicochemical properties of pelagial water were investigated in a shallow mid-forest lake. In 2002, the highest phytocoenotic diversity was recorded; charophytes and vascular submerged macrophytes formed their own extensive communities. After stocking with grass carp (Ctenopharyngodon idella Val.) in 2002, reduction of water transparency, as well as changes in qualitative and quantitative composition of macrophyte communities were observed. Submerged vegetation declined during subsequent growing seasons. Charophyte meadows vanished first.The introduction of grass carp appeared to be a potential trigger for the rapid changes observed in the vegetation.

Seasonality of Water Chemistry, Carbonate Production, and Biometric Features of Two Species of Chara in a Shallow Clear Water Lake

The objective of this study was to analyze the temporal variability of biometric features and the carbonate production of two charophytes: Chara polyacantha A. Braun and Chara rudis A. Braun against the background of the physical-chemical properties of water. The investigation was carried out in a small, mid-forest Lake Jasne (western Poland). It is a polymictic, mesotrophic, hardwater ecosystem dominated by charophyte vegetation. Each month, 10 individuals of each species were characterized in terms of morphometric features, fresh and dry weight, and the percentage of calcium carbonate. Additionally, physical-chemical parameters of the water were studied. The results of physical-chemical analyses indicated similar habitat conditions for both species. Despite smaller dry weight C. polyacantha was characterized by greater morphological variability and higher rates of growth and percentage share of calcium carbonate in dry mass than C. rudis. The percentage of calcium carbonates in dry mass did not differ significantly between the species and exceeded 60%, reaching the maximum (76% in C. polyacantha) in July and August. For both species, distinct correlations between the structure of biomass and morphological features were found. The obtained results show the great importance of charophyte vegetation in carbon cycling and functioning of lake ecosystems.

Charophyte occurrence in Ceratophyllum demersum stands

The hornwort Ceratophyllum demersum is a loosely attached to the bottom or free-floating vascular macrophyte, which builds dense stands in nutrient-rich waters. The hornwort stands are usually monospecific communities with a negligible contribution of other aquatic plants. However, some published literature data and our own observations evidenced the co-occurrence of densely growing Ceratophyllum and other macrophytes, including charophytes, which by contrast to hornwort are indicative of clear and less productive waters. Thus, the aim of this study was to identify the charophyte species growing in C. demersum stands and to define the environmental conditions promoting this co-occurrence. In 18 natural lakes of Western Poland, 60 stands of Ceratophyllum demersum were studied in the years 2001–2005. A total of 25 species built the studied stands. As many as eight charophyte species, 13 vascular plants, two moss species and one filamentous alga co-occurred with C. demersum. Among charophytes rare to Poland Charapolyacantha and Nitella gracilis were identified. Nitellopsisobtusa and Chara globularis revealed the highest frequencies along with Myriophyllum spicatum. Morphology of lakes combined with water quality, particularly transparency, appeared to regulate the coexistence of charophytes and C. demersum, macrophytes usually competing with each other.

Spatial structure of vegetation in a small charophyte dominated lake

Abstract The aim of the paper was to recognize the current spatial structure and organization of vegetation and the diversity of charophytes on an ecosystem scale of a small, outflow Lake Jasne (Western Poland). The lake is characterized by limited anthropogenic pressure and forested catchment basin. The study was performed in the vegetative season 2010. The vegetation was studied along transect, using the mid-European Braun-Blanquet method of phytosociological relevés. Additionally, basic physical-chemical parameters were measured, to characterize habitat conditions of the lake. The results of physical-chemical analyses evidenced high water quality, and obtained parameter values were typical for mesotrophy. The vegetation survey revealed that almost 70% of the lake’s bottom was overgrown by vegetation. The transects documented the structure of phytolittoral typical for chara-lake and the spatial dominance of charophytes in the studied lake (charophyte meadows reached up to 64% of the phytolittoral area). Charophytes were also defining the maximum depth extent of vegetation in Lake Jasne, reaching 5.6 m. As many as 10 charophyte species were stated: Chara virgata, Ch. aspera, Ch. filiformis, Ch. globularis, Ch. intermedia, Ch. polyacantha, Ch. rudis, Ch. tomentosa, Nitella flexilis and Nitellopsis obtusa, out of which 7 build their own communities. The large number of species (10 of 35 identified so far in Poland) and communities (7 of 30 identified in Poland), as well as their share in phytolittoral, define Lake Jasne as a valuable refuge of European natural habitat, code 3140.

Interrelationships between macrophytes (including charophytes) and phytoplankton and the ecological state of lakes

Abstract Multidisciplinary investigations of 30 lakes (mid-Western Poland) were carried out in the years 2001–2004. Micro- and macrophyte vegetation was studied against the background of abiotic conditions. Significantly higher biomass of phytoplankton was found in nutrient rich shallow lakes without both charophyte and vascular submersed vegetation as well as in lakes with only poorly developed vascular communities. Visibly better abiotic conditions and the lowest phytoplankton biomass were observed in deeper lakes with diverse macrophyte (and particularly charophyte) vegetation. Lakes with poorly developed charophyte vegetation represented transitional conditions and biomass. Nevertheless, in some (mostly shallow) lakes, where submersed vegetation and particularly charophyte communities were well developed, phytoplankton biomass was rather low and the transparency was high despite eutrophic conditions. Additionally, in those lakes macrophyte vegetation was not only abundant but also diverse with rare, valuable or even unexpected communities of high bioindicator value. Interestingly, an opposing situation with abundant phytoplankton and bad light conditions was also documented in shallow lakes with submersed vegetation. In those lakes, however, only vascular macrophytes developed dense but homogeneous (monospecific) beds. The results are discussed regarding interrelationships between macrophyte vegetation and phytoplankton assemblages.

The phytosociological characteristic and habitat requirements of the Phragmitetum communis (Gams, 1927) Schmale 1939 phytocoenoses in the lakes of the Wielkopolski National Park

In the summers of 1996 and 1997, the phytosociological investigations of phytocoenoses of Phragmitetum communis were carried out. Samples of the water and the substrate were also analyzed. Phytosociological characteristic was presented, and ranges of physical and chemical properties of habitats were found. It was also found that phytocoenoses of the investigated association have an indicative value in relation to definite properties of the water and the substrate, and could be indicators of the habitat conditions. Comparison of habitat requirements of phytocoenoses investigated in the Wielkopolska region (the Wielkopolski National Park, Western Poland) to those investigated in north-eastern region of Poland (Klosowski, 1992) pointed out the indicative value to be partly the same and partly different in different regions.

Dry weight and calcium carbonate encrustation of two morphologically different Chara species : a comparative study from different lakes

Abstract Two charophyte species (Chara tomentosa Thulli. 1799 and Chara globularis L. 1753) were studied to assess their biomass and CaCO3 production in seven hard-water lakes in Western Poland. In each lake, samples of ten individuals from three study sites were collected for dry weight (DW) and calcium carbonate content (% CaCO3) analyses. Additionally, physicochemical parameters of water collected from the above sampling sites were analyzed. No significant differences were found between the study sites in each lake for any of the analyzed parameters. In all the lakes, DW of C. tomentosa (0.60 ± 0.23 g indiv.-1) was significantly higher and more differentiated than DW of C. globularis (0.11 ± 0.08 g indiv.-1), suggesting species-specificity. The CaCO3 content in DW for C. tomentosa was higher (58.8-70.9%) than in C. globularis (50.1-68.3%), however, it did not reflect the DW differentiation, suggesting lake-specificity. The physicochemical properties of water revealed clear lake-to-lake differentiation. Different correlations between dry weight and calcium carbonate content and lake characteristics were found for each species. The results showed that DW and % CaCO3 are closely related to habitat conditions and different factors may influence the individual biomass of each species.