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Eugeniusz Pronin - One of the best experts on this subject based on the ideXlab platform.
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oxygen stable isotope composition of carbonate encrustations of two modern widely distributed morphologically different Charophyte species
Hydrobiologia, 2018Co-Authors: Eugeniusz Pronin, Mariusz Pelechaty, Karina Apolinarska, Andrzej PukaczAbstract:Oxygen (δ18O) and carbon (δ13C) stable isotope analyses are among the standard methods applied in the studies of past environment, including climate. In lacustrine sediments, δ18O and δ13C values can be measured in various carbonates including Charophyte encrustations. Application of the stable isotope record of lacustrine carbonates requires knowledge about the possibilities and limitations of the method. Thus, this study presents the oxygen stable isotope composition of carbonate encrustations precipitated by modern Charophytes (δ18OCARB) and of ambient waters (δ18OWATER). The study objects were widely distributed and morphologically different Charophyte species, large and branchy Chara tomentosa L. and small and slender Chara globularis Thuill. Each species was studied in five lakes located in western Poland, at three sites per lake. The study demonstrated that δ18OCARB values were similar for the two Charophyte species and were lake-dependent. δ18OCARB and δ18OWATER relationships were also similar for the studied Charophytes with carbonate encrustations 18O-depleted compared to ambient waters. The shift of mean δ18O values between C. tomentosa and C. globularis encrustations and ambient waters, 2‰ and 3.2‰, respectively, was evidenced in all studied lakes which may indicate potential applicability of δ18OCARB of the two species in paleolimnological studies.
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Discrepancies between the stable isotope compositions of water, macrophyte carbonates and organics, and mollusc shells in the littoral zone of a Charophyte-dominated lake (Lake Lednica, Poland)
Hydrobiologia, 2016Co-Authors: Karina Apolinarska, Mariusz Pełechaty, Eugeniusz ProninAbstract:The aim of this study was to better understand the relations between carbon and oxygen stable isotope values of ambient water, mollusc shells, macrophytes and their carbonate encrustations, commonly used in palaeolimnological studies. Water, molluscs and macrophytes were sampled from the littoral zone in Lake Lednica, NW Poland. The influence of carbon species assimilated during photosynthesis and the net intensity of photosynthesis resulting from the size of Charophyte species and the density of their stands were postulated to be the most important factors causing the species-specific δ^13C values of Charophyte thalli and encrustations. It was suggested that photosynthetic activity of Charophytes affected not only the δ^13C values of Charophyte encrustations but also mollusc shells by changing δ^13C values of DIC within Charophyte stands. In addition, incorporation of metabolic carbon into the shell was proposed as the main cause of both the ^13C depletion of mollusc shells relative to δ^13C values of DIC and the species-specific δ^13C values of shells. Mollusc shells were precipitated at the isotope equilibrium or close to the equilibrium with δ^18O values of lake water. Charophyte encrustations were found to be ^18O depleted due to the kinetic isotope effects during intense photosynthesis and thus fast precipitation of the calcite.
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Charophyte occurrence in ceratophyllum demersum stands
Hydrobiologia, 2014Co-Authors: Mariusz Pelechaty, Eugeniusz Pronin, Andrzej PukaczAbstract: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.
Andrzej Pukacz - One of the best experts on this subject based on the ideXlab platform.
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oxygen stable isotope composition of carbonate encrustations of two modern widely distributed morphologically different Charophyte species
Hydrobiologia, 2018Co-Authors: Eugeniusz Pronin, Mariusz Pelechaty, Karina Apolinarska, Andrzej PukaczAbstract:Oxygen (δ18O) and carbon (δ13C) stable isotope analyses are among the standard methods applied in the studies of past environment, including climate. In lacustrine sediments, δ18O and δ13C values can be measured in various carbonates including Charophyte encrustations. Application of the stable isotope record of lacustrine carbonates requires knowledge about the possibilities and limitations of the method. Thus, this study presents the oxygen stable isotope composition of carbonate encrustations precipitated by modern Charophytes (δ18OCARB) and of ambient waters (δ18OWATER). The study objects were widely distributed and morphologically different Charophyte species, large and branchy Chara tomentosa L. and small and slender Chara globularis Thuill. Each species was studied in five lakes located in western Poland, at three sites per lake. The study demonstrated that δ18OCARB values were similar for the two Charophyte species and were lake-dependent. δ18OCARB and δ18OWATER relationships were also similar for the studied Charophytes with carbonate encrustations 18O-depleted compared to ambient waters. The shift of mean δ18O values between C. tomentosa and C. globularis encrustations and ambient waters, 2‰ and 3.2‰, respectively, was evidenced in all studied lakes which may indicate potential applicability of δ18OCARB of the two species in paleolimnological studies.
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carbon dynamics in a hardwater lake effect of Charophyte biomass on carbonate deposition
Polish Journal of Ecology, 2014Co-Authors: Andrzej Pukacz, Mariusz Pelechaty, Marcin FrankowskiAbstract: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 carb...
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Charophyte occurrence in ceratophyllum demersum stands
Hydrobiologia, 2014Co-Authors: Mariusz Pelechaty, Eugeniusz Pronin, Andrzej PukaczAbstract: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.
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spatial structure of vegetation in a small Charophyte dominated lake
Biodiversity: Research and Conservation, 2013Co-Authors: Andrzej Pukacz, Mariusz PelechatyAbstract: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 releves. 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.
Mariusz Pelechaty - One of the best experts on this subject based on the ideXlab platform.
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co occurrence of the Charophyte lychnothamnus barbatus with higher trophy submerged macrophyte indicators
Aquatic Botany, 2018Co-Authors: Michal Brzozowski, Mariusz Pelechaty, Karol PietruczukAbstract:Abstract Lychnothamnus barbatus , one of the rarest and endangered Charophytes world-wide, is a bioindicator of low water trophy. This study was carried out in a moderately fertile water body hosting a large population of L. barbatus (Lake Kuźnickie, Poland). In this lake, L. barbatus co-occurs in submerged vegetation with higher trophy indicators, aquatic angiosperms Ceratophyllum demersum and Myriophyllum spicatum and the common Charophyte Nitellopsis obtusa . The study aim was to investigate the depth preferences of the above species and their proportions at sites they co-occur in the studied lake. Depth of occurrence and quantitative share of macrophytes were studied in a 1-m depth gradient along 12 transects in July 2016 and 2017. Physico-chemical water parameters evidenced meso-eutrophic status of the lake. Out of 23 taxa of aquatic macrophytes identified in Lake Kuźnickie high frequencies and abundances were recorded only for L. barbatus , N. obtusa , C. demersum and M. spicatum, thus being predominants in the lake’s vegetation. L. barbatus co-occurred with higher trophy indicators not only in the same lake but also at the same sites. Ceratophyllum demersum , M. spicatum and N. obtusa were negatively correlated with depth. Lychnothamnus barbatus preferred deeper sites than other predominants, as evidenced by ANOVA. Whilst M. spicatum showed no statistically significant relationship with L. barbatus , C. demersum and N. obtusa were negatively correlated with this endangered Charophyte. We postulate that due to shade tolerance and light use efficiency L. barbatus is a better competitor at deeper sites compared to angiosperms and N. obtusa .
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oxygen stable isotope composition of carbonate encrustations of two modern widely distributed morphologically different Charophyte species
Hydrobiologia, 2018Co-Authors: Eugeniusz Pronin, Mariusz Pelechaty, Karina Apolinarska, Andrzej PukaczAbstract:Oxygen (δ18O) and carbon (δ13C) stable isotope analyses are among the standard methods applied in the studies of past environment, including climate. In lacustrine sediments, δ18O and δ13C values can be measured in various carbonates including Charophyte encrustations. Application of the stable isotope record of lacustrine carbonates requires knowledge about the possibilities and limitations of the method. Thus, this study presents the oxygen stable isotope composition of carbonate encrustations precipitated by modern Charophytes (δ18OCARB) and of ambient waters (δ18OWATER). The study objects were widely distributed and morphologically different Charophyte species, large and branchy Chara tomentosa L. and small and slender Chara globularis Thuill. Each species was studied in five lakes located in western Poland, at three sites per lake. The study demonstrated that δ18OCARB values were similar for the two Charophyte species and were lake-dependent. δ18OCARB and δ18OWATER relationships were also similar for the studied Charophytes with carbonate encrustations 18O-depleted compared to ambient waters. The shift of mean δ18O values between C. tomentosa and C. globularis encrustations and ambient waters, 2‰ and 3.2‰, respectively, was evidenced in all studied lakes which may indicate potential applicability of δ18OCARB of the two species in paleolimnological studies.
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carbon dynamics in a hardwater lake effect of Charophyte biomass on carbonate deposition
Polish Journal of Ecology, 2014Co-Authors: Andrzej Pukacz, Mariusz Pelechaty, Marcin FrankowskiAbstract: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 carb...
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Charophyte occurrence in ceratophyllum demersum stands
Hydrobiologia, 2014Co-Authors: Mariusz Pelechaty, Eugeniusz Pronin, Andrzej PukaczAbstract: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.
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spatial structure of vegetation in a small Charophyte dominated lake
Biodiversity: Research and Conservation, 2013Co-Authors: Andrzej Pukacz, Mariusz PelechatyAbstract: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 releves. 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.
Adriana García - One of the best experts on this subject based on the ideXlab platform.
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Diversity and ecology of extant and Quaternary Australian Charophytes (Charales)
Cryptogamie Algologie, 2020Co-Authors: Allan R Chivas, Adriana GarcíaAbstract:Diversite et ecologie des Charophytes (Charales) actuelles et du Quaternaire d'Australie. La distribution biogeographique des Charophytes d'Australie (62 especes inventoriees) montre une grande proportion de taxons endemiques (62 %) et dioiques (45 %), ainsi que des especes qui ne developpent pas de gyrogonites (84 %). La presente etude s'appuie sur la recolte de Charophytes (Charophyta, Charales) de cent cinquante-deux localites et quarante-deux taxons ont ete identifies. Des facteurs ecologiques, en particulier la salinite et la profondeur d'eau, sont indiques parce que ce sont les principaux facteurs pour la distribution des Charophytes et qu'ils sont indicateurs d'une augmentation de la salinite dans certaines pieces d'eau en Australie. Les differentes especes ont ete rencontrees a des salinites entre 0 g L -1 et 58 g L -1 et a des profondeurs allant de quelques cm d'eau a 12 m. Les donnees sur la salinite et la profondeur d'eau sont resumees par des graphiques montrant les relations Salinite/Espece et Profondeur/Espece qui pourront etre utiles pour modeliser des changements dans les pieces d'eau et pour retracer des series paleo-ecologiques a l'aide de materiel fossile. Pour comprendre la distribution et l'ecologie de l'espece actuelle, il nous parait important d'inclure les donnees disponibles pour le Quaternaire australien qui se limitent a deux references sur le Pleistocene et une sur 1'Holocene. La methodologie paleolimnologique utilise les donnees de l'ecologie actuelle pour en deduire les changements environnementaux.
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carbon stable isotope composition of Charophyte organic matter in a small and shallow spanish water body as a baseline for future trophic studies
Journal of Limnology, 2015Co-Authors: María A. Rodrigo, Adriana García, Allan R ChivasAbstract:Quantitative descriptions of foodweb structure based on isotope niche space require knowledge of producers’ isotopic signatures. In freshwater ecosystems Charophytes are one of the main components of submerged vegetation and the feeding base for many herbivorous consumers, but knowledge about their organic carbon isotopic signatures is sparse. In this study, the δ 13 C organic values (and organic %C and %N) of the four species of submerged macrophytes (three Charophytes - Chara hispida , Nitella hyalina and Tolypella glomerata - and one angiosperm, Myriophyllum spicatum ) growing in a newly created shallow pond were measured monthly over a period of one year, to discern if i) all Charophyte species susceptible to being food for consumers and growing in the same waterbody have the same C isotopic composition; ii) the δ 13 C values of a Charophyte species change on a seasonal and spatial scale; iii) the different parts (apical nodes, internodes, rhizoids, reproductive organs, oospores) of a Charophyte species have the same isotopic composition. The δ 13 C, %C and %N values of organic matter in the sediments where the plants were rooted were also measured as well as several limnological variables. The δ 13 C values for the angiosperm (-13.7±0.7‰) indicated 13 C-enrichment, whereas the N. hyalina δ 13 C values were the most negative (-22.4±0.7‰). The mean δ 13 C value for C. hispida was -19.0±1.0‰ and -20.7±0.8‰ for T. glomerata. C. hispida δ 13 C values had a significant seasonal variation with 13 C-poor values in the cold season, and slight spatial differences. Statistically significant differences were found between Charophyte rhizoids ( 13 C-enriched) and the other parts of the thalli. The δ 13 C values in the sediments varied throughout time (-13‰ to -26‰). The C content was lower in the Charophytes than in the angiosperm and there were no large differences among the Charophytes. Charophyte fructifications were enriched in organic C compared to the thalli parts. The study provides an isotopic baseline for further studies for the elucidation of higher trophic-level relationships which are particularly complex in shallow water bodies where interactions between the pelagic and the benthic zones are intricate.
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the Charophyte lamprothamnium succinctum as an environmental indicator a holocene example from tom thumbs lagoon eastern australia
Alcheringa, 2002Co-Authors: Adriana García, Brian G Jones, Bryan E Chenhall, Colin V MurraywallaceAbstract:The palaeobiota from a middle to late Holocene succession in Tom Thumbs Lagoon, N.S.W., Australia, reflects a range of environmental conditions caused by sea-level changes and active estuarine sedimentation. At the base of the succession (∼ −0.4 m AHD) a thin bed, containing molluscs dated at 6.7 ka B.P. by radiocarbon and amino acid racemisation, and foraminifers is indicative of open estuarine conditions. From +0.35 m AHD towards the top of the sequence the Charophyte Lamprothamnium succinctum occurs in subrecent deposits. This species is characterised here by statistical measurements, and new characters are described and illustrated. The Charophytes record a drop in sea level and the establishment of a lower salinity artificial wetland. The investigation has also established that decalcification in Charophytes can be related to acidification produced by the release of organic acids, aggravated after 1928 by anthropogenic pollution.
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Charophyte Flora of South-eastern South Australia and South-western Victoria, Australia: Systematics, Distribution and Ecology
Australian Journal of Botany, 1999Co-Authors: Adriana GarcíaAbstract:The Charophytes (Charales, Charophyta) from south-eastern South Australia and south-western Victoria were studied on the basis of collections from 56 waterbodies, 39 of which included Charophytes. Chara globularis var. globularis (Thuillier) Wood, C. globularis var. virgata (KUtzing) Wood, C. fibrosa var. fibrosa (Agardh ex Bruzelius) Wood, C. fibrosa var. acanthopitys (Braun) Wood, C. hookeri Braun, C. preissii (Braun) Wood, Lamprothamnium macropogon (Braun) Ophel, Nitella ignescens Garcia, N. ungula Garcia, N. lhotzkyi (Braun) Braun, N. aff. lhotzkyi, and N. congesta (Brown) Braun were recognised. An identification key for these species makes determination possible. A brief characterisation of the environment where the Charophytes were found is provided, as a first approximation of the ecological requirements of Australian Charophytes. At this stage their distribution can be mainly related to salinity, with Charophytes living in fresh to hypersaline conditions (0.0–58.0 g L–1). Special attention is put on L. macropogon, a euryhaline calcifying species, which has the broadest distribution in the area. The floristic analysis shows endemism, dioecism and a high diversification of non-calcifying taxa as the main characteristics of the Charophyte flora analysed.
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Quaternary Charophytes from Salina del Bebedero, Argentina: their relation with extant taxa and palaeolimnological significance
Journal of Paleolimnology, 1999Co-Authors: Adriana GarcíaAbstract:Charophyte (Charales, green macroscopic algae) assemblages found in Quaternary shoreline sediments from Salina del Bebedero, Argentina, are described in detail, illustrated, and statistically analysed. Fossil gyrogonites, Late Pleistocene and Holocene in age, of Chara cf. hispida var. major (Hartman) Wood, Chara halina García, Chara hornemannii Wallmann, Chara bulbillifera (Donterberg) García, Lamprothamnium haesseliae Donterberg and Lamprothamnium succinctum (Braun ex Ascherson) Wood were identified. A comparison with extant Charophyte species of similar ecological requirements allowed for an accurate systematical determination and provided useful data for complementary palaeoecological and palaeobiogeographical approaches. On this basis, a reconstruction of palaeo-salinities for the Salina del Bebedero lake, represented by eleven palaeo-beaches, is proposed. Also the associations of Charophytes with the ostracods Cyprideis sp., Limnocythere sp., Pampacythere sp., Cypridopsis sp., Darwinula sp., Ilyocypris gibba (Randohr) Brady and Norman, and the foraminifers Ammonia sp., Elphidium gunteri Cole, Quinqueloculina sp., and one species of Discorbacea are analysed, since they are present in both the fossil and modern environments.
Antonio Vazquez - One of the best experts on this subject based on the ideXlab platform.
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Mineralogy and Sr–Mg geochemistry of Charophyte carbonates: a new tool for paleolimnological research
Earth and Planetary Science Letters, 2020Co-Authors: Pere Anadon, Rosa Utrilla, Antonio VazquezAbstract:The carbonate biominerals formed in the oogonial cells and on stems of Charophytes reveal intra-specific and species-to-species variations within the genus Chara. Calcite, high-magnesian calcite (HMC) and aragonite may be present in both oogonium and stem calcifications, and for the first time evidence is presented of polymineral calcification (HMC+aragonite) within single oogonial cells. The data indicate strong specific differences in the biological mechanisms of mineralization within this group of plants. Among the various species of the genus Chara studied, there is no correlation between the Charophyte carbonate mineralogy and the salinity of water where they formed: calcite, HMC and aragonite may all be present in Charophyte calcifications formed in low-salinity waters. On the contrary, there is an overall relationship between the mineralogy of these carbonates and the Mg/Ca ratio of the water in which they formed. Sr content in Charophyte calcite and high Mg-calcite reflect directly the Sr/Ca ratio of the host water, whereas Mg content in these carbonates probably depends on the temperature and the Mg/Ca ratio of the water. Partitioning coefficients for Mg and Sr for some widespread species are discussed. Our results indicate that Charophyte carbonates may be used as paleohydrochemical proxies and imply that special attention must be paid to the mineralogical control of Charophyte carbonates when they are to be used in isotopic studies. © 2002 Elsevier Science B.V. All rights reserved.Peer Reviewe
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mineralogy and sr mg geochemistry of Charophyte carbonates a new tool for paleolimnological research
Earth and Planetary Science Letters, 2002Co-Authors: Pere Anadon, Rosa Utrilla, Antonio VazquezAbstract:Abstract The carbonate biominerals formed in the oogonial cells and on stems of Charophytes reveal intra-specific and species-to-species variations within the genus Chara . Calcite, high-magnesian calcite (HMC) and aragonite may be present in both oogonium and stem calcifications, and for the first time evidence is presented of polymineral calcification (HMC+aragonite) within single oogonial cells. The data indicate strong specific differences in the biological mechanisms of mineralization within this group of plants. Among the various species of the genus Chara studied, there is no correlation between the Charophyte carbonate mineralogy and the salinity of water where they formed: calcite, HMC and aragonite may all be present in Charophyte calcifications formed in low-salinity waters. On the contrary, there is an overall relationship between the mineralogy of these carbonates and the Mg/Ca ratio of the water in which they formed. Sr content in Charophyte calcite and high Mg–calcite reflect directly the Sr/Ca ratio of the host water, whereas Mg content in these carbonates probably depends on the temperature and the Mg/Ca ratio of the water. Partitioning coefficients for Mg and Sr for some widespread species are discussed. Our results indicate that Charophyte carbonates may be used as paleohydrochemical proxies and imply that special attention must be paid to the mineralogical control of Charophyte carbonates when they are to be used in isotopic studies.