Colour in Irish lakes

Free, Gary; Allott, Norman; Mills, Paul; Kennelly, C.; Day, Shawn

doi:10.1080/03680770.1998.11898139

Cited by 2 publications

(2 citation statements)

References 5 publications

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“…Transparency is less critical for species with elodeid growth forms, which can grow higher in the water column towards the light. Colour is a key determinant of Secchi disc transparency and photosynthetically active radiation extinction in Irish lakes (Free et al, 2000(Free et al, , 2005. It is considered to be the reason for the lower depths of colonization of Isoetes in Finland (Rrslett and Brettum, 1989) and has also been related to lower isoetid abundance in Sweden (Jensen, 1979) and Canada (France and Stokes, 1988).…”

Section: Discussionmentioning

confidence: 99%

The identification, characterization and conservation value of isoetid lakes in Ireland

Free

Bowman

McGarrigle

et al. 2008

Aquatic Conservation

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ABSTRACT1. Soft-water, oligotrophic isoetid lakes are vulnerable to eutrophication, acidification and alkalinization. As a result of these pressures a large proportion have undergone substantial deterioration in several European countries. The understanding of these systems has been limited by either a lack of lakes close to natural conditions or through receiving less focus in broader scale macrophyte surveys. This has resulted in a dearth of information on specific lake types in their natural condition. Sixty-eight soft-water lakes in Ireland were studied in order to achieve a better understanding of the biological and environmental conditions defining such lakes.2. Eight groups of lakes were identified using cluster analysis and indicator species analysis. Three groups were representative of isoetid-rich lakes displaying a high frequency of occurrence of Isoetes lacustris, Lobelia dortmanna or Eriocaulon aquaticum together with the almost ubiquitous Littorella uniflora. Canonical variates analysis indicated that alkalinity, total phosphorus (TP), catchment area, altitude, moors and heathlands, mean transect depth, colour and lake area were significant variables discriminating among the eight groups. Soft-water lakes with high amounts of isoetids tended to be less exposed, have broad shallow littoral zones with a high transparency and be situated in smaller catchments. Total phosphorus and alkalinity were typically low, although one group of isoetid-rich lakes had higher mean TP and alkalinity values. This group may contain lakes under threat from nutrient enrichment and alkalinization and also lakes that have higher TP and alkalinity naturally.3. Lakes with a prevalence of isoetids supported a greater diversity of macrophytes and chironomids indicating that such lakes may represent suitable conservation targets as they act as surrogates for soft-water lakes of high biodiversity. Other factors favouring a focus on isoetids in conservation strategies are their importance as a functional component in soft-water lakes and their sensitivity to lake and catchment environmental change.

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Section: Discussionmentioning

confidence: 99%

The identification, characterization and conservation value of isoetid lakes in Ireland

Free

Bowman

McGarrigle

et al. 2008

Aquatic Conservation

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“…On the other hand, light availability seems to be one of the most important factors for Isoëtes survival, as seen by Free et al . () in Ireland. This feature is often linked to the degree of eutrophication, because the increase in nutrient levels can enhance the growth of epiphytic algae on sporophylls (Sand‐Jensen and Borum, ).…”

Section: Discussionmentioning

confidence: 99%

A cost‐effective model for preliminary site evaluation for the reintroduction of a threatened quillwort

Abeli

Barni

Siniscalco

et al. 2012

Aquatic Conservation

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ABSTRACT1. The choice of suitable sites for establishment of a new population of a species is the first step in a translocation programme. However, evaluation of a large number of sites can be demanding of time and money; practitioners need time-and costeffective evaluation tools.2. A predictive model for the preliminary evaluation of potential reintroduction sites was developed using the endangered quillwort Isoëtes malinverniana as a case study. The reliability of three water habitat variables (pH, conductivity, and clarity) as predictors of the presence/absence of I. malinverniana was tested. Three sets of logistic models were produced on the basis of the mean values of pH and conductivity measured over 3, 4 and 6 months to understand whether frequency of measurement affected the reliability of the models. Models of each set were ranked according to AIC and their reliability was then tested using data from the literature.3. The conductivity of water and pH were the most effective predictors of the suitability of sites for the reintroduction of I. malinverniana. In particular there was a negative relationship between the presence of I. malinverniana and these variables.4. Because of seasonal fluctuations in the variables considered, at least 4 months monitoring are required to obtain reliable results. Despite this, the method is still advantageous in terms of costs, compared with repeated measurements of a wide range of chemical characteristics at a large number of sites.5. The main goal of this method is to limit expensive chemical analysis to a few sites chosen after the exclusion of unsuitable sites, through application of the model.Considering the similar ecophysiological features of quillworts from oligotrophic waters, the same model or conceptual framework could be applied to other quillworts and isoetid species growing in degraded areas and needing active conservation.2

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Colour in Irish lakes

Cited by 2 publications

References 5 publications

The identification, characterization and conservation value of isoetid lakes in Ireland

The identification, characterization and conservation value of isoetid lakes in Ireland

A cost‐effective model for preliminary site evaluation for the reintroduction of a threatened quillwort

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