Lakes - Central GIG progress report July 2004 Presented by Sandra Poikane Joint Research Centre Institute for Environment and Sustainability Inland and Marine Waters Unit
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Central GIG - Lakes <
Common IC types Lowland, very shallow, calcareous, Lowland, shallow, stratified, calcareous Lowland,shallow , siliceous, vegetation dominated by Lobelia
Discussion on Intercalibration parameters Chlorophyll a Phytoplankton – species composition Macrophyte vegetation - species composition, abundance
Chlorophyll a - relatively easy ! What kind of chlorophyll data to ask? - average value of vegetation season - maximum value of late summer How to aggregate data ? The mean value would be the most appropriate
Chlorophyll a - relatively easy ! What time period to choose ? The vegetation period (described as April – October or 2 weeks after ice – break) Sampling method ? to report the sampling methods, preferably surface sample Analyses methods ? to report the extraction methods, anyway data should be comparable between different methods How many years ? if possible, average and maximum values for the last 5 years
Biomass (% of the total biomass) Phytoplankton species composition Which parameter ? Abundance (cells/l) Biomass (mg/l) Biomass (% of the total biomass) Numerical scale for dominant species
Phytoplankton species composition to ask for 5 dominant taxa (even in case, if there are no pronounced dominants) to choose late summer dominant species dominance based on biovolume or considering the typical cell volume to provide numerical scale for dominant species (see table) species or genus level
Macrophyte vegetation
Macrophyte vegetation 5 dominant taxa and maximal colonized water depth and the covered area (in % of lake ?) use of ECOFRAME classification of abundance (5 levels) only submerged plants genus or species level based on cover of littoral of deep lakes (3 – 15 m) or whole lakes for very shallow lakes (< 3 m)
Common metrics for macrophyte vegetation ? 3 possibilities for a common metric: submerged covered area a list of indicator species which are present in reference conditions deep lakes (>3 m): maximum colonised water depth
Overview Quality element Common metric possible? (Possible) indicator Options for intercalibration Phytoplankton biomass yes Chl a 1 or 2 Phytoplankton composition no 3 Submerged macrophytes abundance 1)%submerged macrophytes 2)maximum colonised water depth 2 Submerged macrophytes composition probably indicator macrophytes species 3, probably 2
Data template for chlorophyll, P, Secchi, supporting data, pressure data
Thank you for attention ! Deep hard light lakes (3-15 m, > 165 µS/cm, < 150 mgPt/l)