Benthic Communities of Waldo Lake

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Benthic Communities of Waldo Lake Michelle Wood,
R. Castenholz. A. Johnson Center for Ecology
and Evolutionary Biology University of
Oregon Eugene, Oregon
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• UO has a long history with Waldo
  Lake
• 30 year collections with classes (Castenholz
  Wagner)
• Contributor to USFS Waldo Lake Science Plan
  (1999)
• Identified benthic communities as priority
  for
• Estimates of primary produciton and nitrogen
  fixation
• (Castenholz)

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Lake and Reservoir Management Vol. 16 (1-2),
2000 Johnson, A. C. and R. W. Castenholz Prelimin
ary observations of benthic cyanobacteria of
Waldo Lake and their contribution to lake primary
productivity Wagner, D.H., J.A. Christy and D.
W. Larson Deep-water bryophytes from Waldo
Lake, Oregon
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Liverwort/Moss community UV-Protect
ed Cyanobacterial Mats Living Stromatolite
Community Benthic Diatom/Cyanobacterial
Floc Key Properties Most of the chlorophyll is
associated with these communities Probably
support nitrogen-fixation Most in euphotic zone
and most are perennial
Four Major Benthic Communities
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Photometer Data Sept. 9, 2001
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Bryophyte (Liverwort/moss) community extensive
and occurs in deep and moderately shallow areas
Rates of Primary production? Status of deep
community?
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UV Protected Cyanobacterial Communities
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Scytonema sp. (400X)
UV Protected Cyanobacterial Communities

• Stigonema sp. (100X)

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Benthic cyanobacterial Communities, Free-living,
filamentous Mats Mostly lt50m, extensive lt20m

• Primarily Stigonema,
• Genus shows true branching
• Scytonomin in sheath (UV-protection)
• Heterocysts present in Waldo samples, and in
  cultures
• indicative of active N-fixation

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Benthic cyanobacterial Communities, Free-living,
filamentous Mats

• How many other taxa are associated with these
  communities? (Role of Scytonema)
• Aerial extent of communities?
• N-fixation and C-fixation in deep and shallow
  communities
• Competitive interactions with taxa which do not
  have UV-protection.
• Effects of eutrophication on growth and
  competitive interatctions.

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Modern Stromatolite Communities in Waldo
Lake Topic of A. Johnson thesis and continuing
work by Wood, Johnson, and Castenholz
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In cultures species seem to be ultra-oligophiles
with slow growth Unicells seem to be responsible
for mineralization Field Season 2004
additional work on biological community
elemental analysis for Fe, Si Laser confocal
microscopy N-fix and C-fix, UV/- In
development, corporate partnership for benthic
mapping/imaging (2004, 2005)
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Diatom Floc Community
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Diatom Floc community Anabaena (N-fixing
cyanobacteria) Leptolyngbya (UV-protected) Many
benthic diatoms QUESTIONS - Aerial
extent? Productivity? Sedimentation
rate? Grazers/Inverts?
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Benthic algal and bryophyte communities are
extensive Substantial questions remain
-- particularly aerial extent carbon fixation
rates nitrogen fixation rates Unique communities
exist in this oligotrophic area
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Michelles Take-home message Living
stomatolite communities are unique on a global
scale These communities probably require
ultraoligotrophic conditions and are,
therefore, indicators of the trophic status of
the lake These are slow-growing communities,
PLEASE TREAT WITH CARE
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THANKS TO DEIGH BATES USFS AND UO RESEARCH
OFFICEREP. PETE DEFAZIO