evpp 550 waterscape ecology and management lecture 9 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
EVPP 550 Waterscape Ecology and Management – Lecture 9 PowerPoint Presentation
Download Presentation
EVPP 550 Waterscape Ecology and Management – Lecture 9

Loading in 2 Seconds...

play fullscreen
1 / 21

EVPP 550 Waterscape Ecology and Management – Lecture 9 - PowerPoint PPT Presentation


  • 219 Views
  • Uploaded on

EVPP 550 Waterscape Ecology and Management – Lecture 9. Professor R. Christian Jones Fall 2007. Lake Biology – Overview Habitat Regions. Littoral zone Z total < z PZ Bottom is within photic zone Trophogenic: Psyn>Resp Autotrophs and heterotrophs

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'EVPP 550 Waterscape Ecology and Management – Lecture 9' - bowie


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
evpp 550 waterscape ecology and management lecture 9

EVPP 550Waterscape Ecology and Management – Lecture 9

Professor

R. Christian Jones

Fall 2007

lake biology overview habitat regions
Lake Biology – OverviewHabitat Regions
  • Littoral zone
    • Ztotal < zPZ
    • Bottom is within photic zone
    • Trophogenic: Psyn>Resp
    • Autotrophs and heterotrophs
    • Supports benthic algae, rooted macrophytes which add structure
    • Substrate-associated plants and animals are characteristic
lake biology overview habitat regions3
Lake Biology – OverviewHabitat Regions
  • Pelagial zone
    • Ztotal > zPZ, z < zPZ
    • Open water within photic zone
    • Trophogenic: Psyn>Resp
    • Autotrophs and heterotrophs
    • Species that can suspend in water column or actively swim are characteristic
lake biology overview habitat regions4
Lake Biology – OverviewHabitat Regions
  • Profundal zone
    • Ztotal > zPZ, z > zPZ
    • Open water and bottom below photic zone
    • Tropholytic zone: Resp > Psyn
    • Heterotrophs only
    • both suspended and substrate associated
lake biology overview biotic communities
Lake Biology – OverviewBiotic Communities
  • Plankton
    • “wanderers”
    • Suspended in the water column
    • May demonstrate limited mobility, but location chiefly controlled by currents
    • Found principally in the pelagic region, but sometimes also in littoral or profundal
    • Phytoplankton: “plant”-like/photoautotrophs
      • Algae, cyanobacteria
    • Zooplankton: “animal”/heterotrophs
      • Rotifers, cladocera, copepods
lake biology overview biotic communities6
Lake Biology – OverviewBiotic Communities
  • Benthos
    • Organisms associated with the bottom & sediments
    • Found in both littoral and profundal
    • Phytobenthos
      • Includes aquatic macrophytes and benthic algae
    • Zoobenthos
      • Invertebrates of many groups
      • Most diverse in the littoral
lake biology overview biotic communities7
Lake Biology – OverviewBiotic Communities
  • Periphyton
    • Attached microbial community
    • “slime” growing on underwater surfaces
    • Coats macrophytes, rocks, logs, etc.
    • Includes algae, bacteria, protozoa, and microinvertebrates
lake biology overview biotic communities8
Lake Biology – OverviewBiotic Communities
  • Nekton
    • Organisms controlling their own movements
    • Can move freely and inhabit all lake zones
    • Includes fish and larger invertebrates
lake biology phytoplankton
Lake Biology - Phytoplankton
  • Characteristics
    • “plant” component of the plankton
    • Primary producers
    • All have chlorophyll a
    • Conduct standard photosynthesis
    • H2O + CO2 + light  (CH2O) + O2
    • All require N, P, trace elements
    • Some also can utilize DOM or even may feed suplementally on bacteria
lake biology phytoplankton10
Lake Biology - Phytoplankton
  • Characteristics
    • Vary in taxonomy and morphology
    • All divisions of eukaryotic algae represented
      • Greens, diatoms, dinoflagellates, cryptophytes, euglenoids
      • Cyanobacteria (blue-green algae) can be very important
      • Range from very small unicells (<1 um) to large colonies and filaments (up to 1 mm or more)
      • Size categories: 0.2-2 um picoplankton, 2-30 um nanoplankton, 30-200 um microplankton
lake biology phytoplankton11
Lake Biology - Phytoplankton
  • Adaptations
    • Avoid sinking
      • General morphology: hairs, projections, anything to increase friction
      • Flagella: can swim against gravity
      • Lower density: gas vacuoles, lipids
    • Nutrient uptake
      • Sinking: breaks down boundary layer facilitation diffusion
      • Small size: higher surface area/volume
lake biology phytoplankton12
Lake Biology - Phytoplankton
  • Adaptations
    • Predation avoidance
      • Colonial habitat
      • Projections
      • Indigestable muscilage
    • Reproduction
      • Mostly asexual: binary fission, autocolony formation
      • Sexual: When stressed some produce zygote, diatoms use zygote to restore size
lake biology phytoplankton13
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Light
      • Light energy required for photosynthesis
      • Light varies with latitude, season, time of day, cloud cover, attenuation coefficient, depth
      • Photosynthesis shows an assumptotic relationship to light
      • To estimate photosynthetic production in the field, need to account for time of day and depth variations in light
lake biology phytoplankton14
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Light
      • Photosynthetic rate/primary production quantified by measuring either: O2 production or C-14 uptake
      • Can use either:
        • Bottle string in situ
        • P-I curve in lab extrapolated to field condition using light extinction and ambient light data
lake biology phytoplankton15
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Nutrients
      • N required for proteins, amino acids
      • P required for ATP, nucleic acids
      • Si for diatom frustules
      • Trace metals in enzymes
      • Vitamins by some algae
      • Nutrients can be taken up in excess of current need for future use (luxury uptake)
lake biology phytoplankton16
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Nutrients
      • P generally limiting in most fw systems, but sometimes N
      • Si for diatoms, Mo for N fixers
      • Relationship between P and:
        • Cell size
        • Chl a
        • Pico biomass
        • Group biomass
lake biology phytoplankton17
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Grazing
      • Spines and projections may increase effective size and inhibit grazing
      • Cladocerans esp Daphnia are most efficient grazers
      • Heavy grazing may reduce abundance and productivity of phytoplankton
      • Light to moderate grazing may actually stimulate production by increasing nutrient availability
      • Differential grazing may favor certain cyanobacteria and colonial green algae by removing their competitors since they are resistant to grazing
      • Nanoplankton vs. Daphnia
lake biology phytoplankton18
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Parasites
      • Chytrid and biflagellate fungi
        • Infect desmids and diatoms
      • Viruses
        • Can infect cyanobacteria
    • Sedimentation
lake biology phytoplankton19
Lake Biology - Phytoplankton
  • Factors affecting growth
    • Washout
      • Important in lakes receiving large inputs of water
        • Mainstem reservoirs, urban lakes
      • Washout processes may not be simple
        • Displacement without mixing - Linear decrease in plankton with time
        • Complete mixing – exponential decline in plankton with time
      • Washout may keep plankton low even when nutrients are available