Topic
Lemanea
About: Lemanea is a research topic. Over the lifetime, 59 publications have been published within this topic receiving 1053 citations.
Papers published on a yearly basis
Papers
TL;DR: Investigation of factors that control d 13 C of algae in riffle habitats across a gradient in stream size and productivity in northern California found considerable seasonal and spatial variation in d 13C of the green alga Cladophora glomerata, microalgal-influenced epilithic biofilms, and their herbivores.
Abstract: Spatial and temporal variations in stable carbon isotope ratios (i.e., d 13 C) of primary producers are common but poorly understood features of isotopic characterizations of aquatic food webs. I investigated factors that control d 13 C of algae (concentration and d 13 C of inorganic carbon, algal fractionation, and growth rates) in riffle habitats across a gradient in stream size and productivity in northern California. There was considerable seasonal and spatial variation in d 13 C of the green alga Cladophora glomerata, microalgal-influenced epilithic biofilms, and their herbivores. Algal and herbivore d 13 C were depleted in 13 C in small, unproductive tributary streams (244‰ to 230‰) compared with more productive sites downstream (231‰ to 223‰). The majority of variation in algal d 13 Co f Cladophora and epilithic biofilms was determined by dissolved CO 2 (CO2aq) via effects on d 13 Co f CO 2aq and photosynthetic fractionation. In contrast, two other taxa (the cyanobacterium Nostoc pruniforme and the red alga Lemanea sp.) showed little variation in d 13 C or fractionation in response to varied inorganic carbon availability because of their distinct modes of inorganic carbon acquisition. Although variation in algal d 13 C might complicate use of d 13 C to resolve consumer diet sources under some circumstances, better understanding of such variation should improve the use of d 13 C techniques in aquatic food web studies.
239 citations
TL;DR: The growth habit of Cladophora and, particularly, Ranunculus means that the high water velocity in the Burn does not necessarily prevent C depletion effects around the plants, thus providing a possible role for HCO3-use by these plants.
Abstract: CO2-and O2-exchange characteristics and δ13C values have been measured in a rhodophycean haptophyte (Lemanea mamillosa), a chlorophycean haptophyte (Cladophora glomerata) and a magnoliophyte rhizophyte (Ranunculus sp.) from a 5 m stretch of the Dichty Burn near Dundee. Light-and CO2-saturated rates of photosynthesis are greatest on a dry weight basis for Cladophora and lowest for Lemanea; the order is reversed on a surface area basis. The CO2 concentration at pH 6.5 at which photosynthesis is half-saturated is 25-40 μM, with Lemanea rather lower than Cladophora or Ranunculus; these half-saturation values are similar to the free CO2 concentration in the Burn water. Lemanea cannot use HCO 3- in photosynthesis, while Cladophora and Ranunculus can. Despite being within a factor or two of saturation with free CO2 in terms of the bulk water concentration, the growth habit of Cladophora and, particularly, Ranunculus means that the high water velocity in the Burn does not necessarily prevent C depletion effects around the plants, thus providing a possible role for HCO 3- use by these plants. Lemanea lives in the fastest-growing parts of the Burn, and its growth habit insures that it is exposed to this high water velocity, thus minimising CO2 depletion during photosynthesis despite the low surface/volume ratio for this plant. δ13C measurements on the inorganic C in the Burn water are consistent with at least part of its excess (above air-equilibrium) inorganic C levels coming from heterotrophic activity. Lemanea has the most negative δ13C value of the three plants, consistent with CO2 use and small diffusion resistances. Ranunculus has the least negative δ13C value, consistent with some CO2 depletion and/or HCO 3- use in situ related to a high diffusion resistance in a rhizophyte which does not have to obtain all of its N and P from the bulk water but can obtain some from the sediments. Cladophora is intermediate, suggesting some CO2 depletion and/or HCO 3- use in this densely growing haptophyte.
123 citations
TL;DR: In this article, a study of the concentrations of zinc, cadmium and lead in populations of the red alga Lemanea growing in fast-flowing rivers in Britain, Ireland and Sardinia (Italy).
53 citations
TL;DR: The absence of HCO3 - use is discussed in relation to the “bipolar band growth” of florideophytes, and to the relative availability of C, N and P and light in these haptophytic algae.
Abstract: Rates of photosynthesis at light saturation as a function of CO2 concentration and rates of dark respiration, are reported for the freshwater red algae Lemanea mamillosa and Batrachospermum sp., and are related to their ecological strategies. The CO2 compensation concentration in these two algae is pH-independent in the range pH 6·5–8·9, and is of a magnitude which suggests that these algae are unable to use HCO3 - in photosynthesis, and lack a “CO2 concentrating mechanism”. This is related to the relatively high CO2/HCO3 - ratio in the natural habitats of the algae, in contrast with the seawater in which most rhodophytes live and in which some red algae exhibit characteristics of HCO3 - use. The absence of HCO3 - use is also discussed in relation to the “bipolar band growth” of florideophytes, and to the relative availability of C, N and P and light in these haptophytic algae.
50 citations
TL;DR: Habitat choice, plant morphology and anatomy, and plant biochemistry are responsible for this lack of limitation by inorganic C transport in the growing gametophyte which lacks HCO3 transport and a CO2 concentrating mechanism.
Abstract: Field measurements of the growth rate of the red freshwater macroalga Lemanea mamillosa in the Dighty Burn, together with measurements of water velocity, [CO 2 ], [NO 3 − ], [NH 3 +NH 4 + ] and [phosphate] have been made between february and july. This period covers the growth of the erect gametophyte and later of the carpasporophyte inside the gametophyte
46 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2018 | 1 |
| 2016 | 2 |
| 2015 | 1 |
| 2012 | 2 |
| 2011 | 3 |