Kolonisation in fen ponds

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Kolonisation in fen ponds

• Judith Sarneel
• Utrecht University

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Dramatic decrease of typical fen speciesWater
quality improvedWhy are there no new
colonisation events?
Chara Stratiotes Menyanthes
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Colonisation
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Dispersal What is mechanism, what are the
effects?
Isolated ponds currents by wind hydrochory gt
wind driven
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But
The desired species typically grow in sites
sheltered from the wind, whereas the majority of
seeds are transported to exposed banks.
Azza, et al 2007
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Can this difference be explained by differences
in germination and establishment?
Comarum palustris
Glyceria maxima
Calla palustris
Mentha aquatica
Berula erecta
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SW NE
At first more seedlings at downwind sites
gtlight Later on, highest numbers at lee, upwind
sites Steeper decrease at NE banks gtwaves
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Clonal expansion

• Under which circumstances do species colonise the
  water from the bank?
• What is the effect of eutrophication on the
  colonisation of fen ponds?

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• We will relate all kinds of environmental
  variables
• (chemical, morphological, management)
• To
• The colonised distance as
  measured in the field

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April
Mei
Juni
Juli
September
Juni 2006
Sept 2007
Mesocosm experiment with different nutrient
treatments to water and peat
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Met dank aan