Exam 2 Flashcards
1
Q
Important redox reactions in water bodies
A
- Aerobic respiration (needs oxygen)
- Dissimilatory nitrate reduction (denitrification)
- Iron reduction (increases alkalinity)
- Sulfate reduction (anaerobic)
- Methane fermentation
2
Q
Importance of P to organisms
A
- Needed for ADP and ATP
- nucleic acids, phospholipids
3
Q
Redfield Ratio
A
- Ratio of number of atoms of each element
- used to compare needs of phytoplankton with available nutrient ratios
4
Q
Algal mass vs total P
A
- Trophic state of lake is often strongly related to P loading
- Algal mass is also related to the growth rate of the phytoplankton
5
Q
Sources of P
A
- weathering of P-containing rocks
- marine deep ocean sediments
- anthropogenic P - cultural eutrophication
6
Q
PP
A
- particulate phosphate
- often largest source of P in lakes
7
Q
How is Fe present in oxygenated waters
A
Fe^+3
ferric
8
Q
Iron trap for P
A
- less available P for algae when there is oxygen at sediment-water interface
- because Fe^+3 precipitates and traps the P from dissolving into lake
9
Q
Critical point for eutrophication
A
- when hypolimnion becomes anoxic
- iron is reduced and becomes soluble
- more P is released which increases internal P recycling and loading
10
Q
Sulfur trap for Fe
A
- Lake must be eutrophic enough for sulfate reduction
- Iron sulfides precipitate and bind Fe
- if enough FeS precipitates then it can create iron poor water
11
Q
Trophic level
A
-contain functionally similar organisms that utilize similar food resources
12
Q
Trophic dynamics
A
-transfer of energy from one part of the ecosystem to another
13
Q
Bottom up control
A
- limited by nutrient availability
- if you increase primary producers then everything above also increases
14
Q
Top down control
A
- predators control abundance in ecosystem
- increase in tertiary consumers, decrease in 2nd consumers, increase in primary consumers, decrease in primary producers
15
Q
Omnivory
A
- feeding on several trophic levels at once
- common in aquatic systems
16
Q
Mixotrophy
A
-both a primary producer and a heterotroph
17
Q
Ontogeny
A
- diet shifts during development
- may change the food level an organism feeds on
18
Q
Microbial loop
A
- food web of smaller organisms
- bacteria, heterotrophic flagellated and ciliates that can use DOM or eat each other
19
Q
Eubacteria
A
- bacteria that have peptidoglycan cell membrane
- present in less extreme environments
20
Q
Archaea
A
- bacteria that have pseudopeptidoglycan cell membrane
- common in more extreme environments
21
Q
Characteristics of bacteria
A
- small prokaryotic cells
- tolerate wide range of conditions
- 20 minute generation times
22
Q
Role of bacteria in lakes
A
- Decomposers
- fix nitrogen from atm into useable form
- some pathogenic
- autotrophic bacteria produce OM
23
Q
Controls of bacteria growth
A
- temperature
- acquisition of nutrients and controls of growth
24
Q
Assimilative
A
- incorporate elements/nutrients into the cell
- cellular process of bacteria growth
25
Dissimilative
- get energy from the substance
- don't incorporate elements
- cellular process of bacteria growth
26
Sources of DOM for nutrients and bacteria growth
- algae (main source of DOM)
| - macrophytes, watershed...
27
Controls of bacteria attrition (loses)
- Grazing (bacteria fed on by microzooplankton)
- Viruses
- Seasonal patterns
- "kill the winner" - control of bacteria by microzooplankton and viruses
28
How are FW systems have the most imperiled extinction rates
- watershed issues (agriculture/deforestation/pollution)
- overexploitation
- invasive species
- climate change
29
Standard measures of biodiversity
- Genetic diversity
- species richness
- species diversity and evenness
30
More diverse systems are often characterized by:
- moderate productivity
- moderate disturbance
- larger area
- larger spatial hetereogeneity
31
Littoral zone
- zone of lakes from high water area to area with no attatched plants
- highly productive
- defined by macrophytes
32
Welands
- intermittently to permanently flooded regions
- saturation with water and duration of flooding are dominant factors that determine soil development and types of plants/animals
33
Structural importance of aquatic macrophytes
- define the littoral zone
- slow currents and increase sedimentation
- may reduce turbidity
- habitat
- increase diversity and biomass of other sp
34
Functional importance of aquatic macrophytes
- pump of nutrients from sediments to water
- can retain nutrients
- compete with algae for nutrients and light
- high rates of evapotranspiration can decrease water level
- biomass becomes detritus and is eaten by waterfowl and wildife
35
Adaptations of macrophytes
- reduced supportive tissue (water is buoyant)
- underwater leaves have no/reduced cuticle (water loss not important)
- leaves only a few cells thick and finely divided (reduced light)
36
Mechanisms of aquatic macrophytes to obtain C
- Assimilation of HCO3^-
- Arenchyma with lacunae
- Heterophylly
37
Physical zonation of aquatic macrophytes
- temperature
- light
- pressure
- wind and waves
- substrate
38
Biological zonation of aquatic macrophytes
- Competition
| - Herbivory
39
Potamogeton
- pond weed
- rhizomes can anchor sediments
- variable shape and size
- ROOTED SUBMERSED
40
Myriophyllum
- water milfoil
- invasive spp and native spp
- deleterious effects of invasive spp
- ROOTED SUBMERSED
41
Elodea
- water weed
- invaded Europe
- fish habitat and food for some spp
- ROOTED
42
Vallisneria
- wild celery, tape grass, eel grass
- common in wide variety of habitats
- ROOTED SUBMERSED
43
Chara
- muskgrass, stonewort
- Charophyte (not a higher plant)
- precipitates calcium carbonate
- ROOTED SUBMERSED
44
Nymphaea
- water lily
| - ROOTED FLOATING
45
Scirpus
- bulrush
- cosmopolitan with many spp
- triangular stems and reduced leaves
- ROOTED EMERGENT
46
Typha
- cattail
- common in wetlands
- ROOTED EMERGENT
47
Ceratophyllum
- coontail
- underwater flowers and mobile pollen
- makes modified leaves than can anchor and loosely root them
- UNROOTED SUBMERSED
48
Utricularia
- bladderwort
- carnivorous
- UNROOTED SUBMERSED
49
Eichornia
- water hyacinth
- not many things eat it
- major effects on physical, chemical, biological properties of waterways
- UNROOTED FLOATING
50
Lemna
- duckweed
- single root
- UNROOTED FLOATING
51
Characteristics of rooted submersed macrophytes
- access to nutrients in sediments
| - little/no cuticle on leaves
52
Characteristics of rooted floating macrophytes
- access to nutrients in sediments
- leaves mostly or entirely floating on surface
- top surface of leaves has cuticle
53
Characteristics of rooted emergent macrophytes
- access to nutrients in sediments
- leaves have cuticle
- rhizomes stabilize shoreline and sediment
- very productive (lots of sunlight)
54
Characteristics of unrooted submersed macrophtyes
- no/minimal access to nutrients from sediments
| - little or no cuticle on leaves
55
Characteristics of unrooted floating macrophytes
- enitre plant floating
- no/minimal access to nutrients from sediments
- cuticle on top
56
Characteristics of filamentous algae
- concentrated in littoral zone
- must grow in shallow water where there is adequate light but can go deeper than macrophytes
- no roots or leaves
- obtain nutrients from sediments or water
57
Spirogyra
- Charophyta
- spiral-shaped chloroplast
- nuisance for swimming but not toxic
- increased by invasive mollusca
- GREEN ALGAE
58
Cladophora characteristics
- Chlorophyta
- nuisance for swimming but not toxic
- increased by invasive mollusks
- GREEN ALGAE
59
Periphyton
- biofilm of algae, cyanobacteria, and heterotrophic microbes
- live attached to other objects
- attached in euphotic zone
60
Alternate stable states
- same place can have alternative dominant communities
| - ex: macrophytes verus phytoplankton
61
Lacustrine wetland
-associated with lakes (littoral zone)
62
Palustrine wetland
-inland wetland without flowing water and non-tidal
63
Bogs
- peat forming perennial wetland
- sphagnum moss dominated communities
- water source is rainwater
- low in nutrients and primary production
- form acidic peats
- high plant diveristy
64
Fens
- peat forming perennial wetland
- recieve nutrients from sources other than precip (usually GW)
- may range from acidic to non acidic (poor -> med -> rich fens)
- peat can develop due to lack of decomposition in acidic areas OR to high production in less acidic areas
65
Swamps
- non peat forming
- mineral soils
- ground permanently or seasonally submerged
- vegetation dominated by trees
66
Marshes
- non peat forming
| - frequently wet areas with herbaceous vegetation adapted to saturated soil conditions
67
Wet meadows
- non peat forming
- grasslands with water logged soil near the surface
- without standing water for most of the year
68
Ecosystem services of wetlands
- waterfowl and amphibian habitat
- can improve water quality by trapping sediments and excess nutrients
- can accumulate/remove some pollutants
69
Shredders
- biters and chewers
- take large food and produce small bits
- herbivorous or detrivorous
70
Scrapers
- feed on periphyton
| - specialized mouthparts scrape substrates
71
Collectors
- spin nets or use setae to collect organic matter
- feed on fine particulate organic mater
- filter with nets, hairs
72
Predators
- carnivorous
| - swallow prey whole or bite pieces
73
River continuum concept
- streams change predictably as you go from the headwaters to the high order rivers
- predictable physical features change (stream velocity, width/depth of stream)
- predictable biological features change (structure of community and community functions)
74
Food pulse concept
-explains how the periodic inundation and drought (flood pulse) control the lateral exchange of water, nutrients and organisms between the main river channel (or lake) and the connected floodplain
75
Human impacts on rivers
- short residence time and linkage of rivers with landscape
| - damming (artificial lake effect)
76
How does damming impact rivers
- decrease and alter patterns of flow
- changes in sediment load
- alter temp downstream
- changes in species at all trophic levels downstream
77
Importance of lake benthos
- half the lakes productivity is related to benthos
| - benthic pelagic coupling
78
Patrick principle
-number and kinds of spp present reflects specific environmental stresses
79
Benthic invertebrates
- most adaptations to stream life
- wide phylogenetic diversity
- live on bottom of streams and lakes
- can be good indicators of water quality
80
Phylum Mollusca
- Gastropoda
| - Bivalvia
81
Gastropoda
-use a radula (toothed structure) to scrape surfaces
82
Bivalvia
- unionid mussels
| - Dreisenid mussels
83
Phylum Platyhelminthes
| Class Turbellaria
- flatworms
- non-segmented
- mobile
- consume small animals and detritus
84
Phylum Annelida
-contains subclasses Oligochaeta and Hirudinea
85
Subclass Oligochaeta
- segmented and live in mud/silt
| - important in biomonitoring
86
Subclass Hirudinea
- leeches
- most are ectoparasites
- some scavengers
87
Phylum Porifera
- sponges
- filter feeders
- some make resistant stages for overwintering
88
Phylum Cnidaria
- Hydra
- Cnidoblasts/nemtocysts for predation
- some are benthic, some benthic and pelagic
89
Phylum Nematoda
- roundworms
- ubiquitous
- diverse feeding habits
90
Phylum Arthropod
- Subphylum Crustacea
- Subphylum Hexapoda
- Subclass Acari
91
Subphylum Crustacea
- crayfish, amphipods, isopods
| - wide diet ranges
92
Subclass Acari
- water mites
- predators
- larvae can parasitize aquatic insects
93
Hexapoda (subphylum) Insecta includes:
- Plecoptera
- Trichoptera
- Ephemeroptera
- Odonata
- Diptera
- Coleoptera
94
Plecoptera
- Stone flies
- mostly in temperate regions
- cool, clean streams of low order
- tolerant of low pH
95
Trichoptera
- caddis flies
- worldwide distribution (not ant)
- free living and case building spp
96
Ephemeroptera
- mayflies
- worldwide distribution (not ant)
- gills for respiration
- sensitive to low pH
- do not feed as adults
97
Odonata
- dragonflies and damselflies
- worldwide predators (not ant)
- stalk their prey
98
Diptera
- true flies
- midges
- black flies
99
Coleoptera
- beetles
| - aquatic beetles live in water as larvae and adults
100
Common characteristics of phytoplankton
- all have chlorophyll a
| - have a simple structure (unicellular or multicellular)
101
Algal phyla based on:
| Phytoplankton classification
- Reproduction (sexual and asexual)
- Biochemical criteria (pigments, cell walls)
- Morphological criteria (are they flagellated? types of flagella)
- genetic differences (16S or 18S RNA)
102
Special adaptations for pelagic life (phytoplankton)
- Flagellae (allows them to change height in water column)
- Gas vaculoes (buoyancy)
- mixotrophy
103
Cyanobacteria characteristics
- prokaryotic
- chlorophyll a
- secondary pigments (phycobilins and carotenoids)
- Akinete (dormant cell)
- some are toxic
- frequent bloom specie in summer
104
Common cyanobacteria taxa
- Oscillatoria
- Anabaena
- Microcystis
- Spirulina
105
Chlorophyta characteristics
- green algae
- pigments: chlorophyll a and b
- eukaryotic
- possible ancestors of higher plants
- common as phytoplankton and benthic algae
106
Common taxa in chlorophyta
- Spirogyra
- Chlamydomonas
- Scenedesmus
- Desmids
107
Chlamydomonas
- flagellated
| - colonizes with Volvox and other genera
108
Scenedesmus
- colonizes of different sizes
| - some spp can change morphology based on chemicals released from zooplankton
109
Desmids
- two half cells with mirror image
| - common in low pH and low productivity lakes
110
Cryptophyta
- eukaryotic
- chlorophyll a and c
- no cell walls
- unicellular
- common genus: Cryptomonas
111
Chrysophyta
- eukaryotic
- chlorophyll a and c
- naked cell wall with cellulose/pectin
112
Common taxa in Chysophyta
- Ochromonas (single cell)
- Mallomonas (has silica plates with spicule)
- Dinobryon (makes lorica out of cellulose)
113
Diatoms
- Eukaryotic
- chlorophyll a and c
- have frustules made of 2 silica valves
- epitheca and hypotheca
- dense due to low Si content
- unicellular or colonial
114
Centric diatoms
- radially symmetrical in valve view
- mostly pelagic
- cyclotella
115
Pennate diatoms
- Bilaterally symmetrical
- mostly benthic
- many have raphe
- Navicula (have raphe)
- Asterionella (collonial and pelagic)
116
Dinoflagellates
- Eukaryotic
- Chlorophyll a and c
- cellulose cell wall - can be armed with theca
- common in hardwater lakes
- contains Ceratium and Peridinium
117
Euglenophyta
- Eukaryotic
- cholorphyll a and b
- have pellicles (strips of protein) in cell membrane
- has the red eyespot
118
Rhodophyta
- red algae
- mostly marine (3% in FW)
- branched growth makes them large
119
NPP
= GPP - E - R
- GPP = gross primary production (amnt of carbon taken and used)
- E = excretion
- R = respiration
120
Oxygen change methods: light and dark bottle
- Light: PS and respiration occurs, O conc should increase
- Dark: Only respiration occurs, O conc should decrease
- R = I - D (I is initial condition)
- NPP = L - I
- GPP - L - D
121
Factors affecting phytoplankton growth
- light
- temperature
- nutrients
122
Compensation point
- point where PS = respiration
- point where there is insufficient light for positive growth
- affected by water clarity and algal blooms
- becomes shallower with hgih numbers of plants
123
Ways to avoid sinking
- be small
- have more surface area (high SA/V)
- have spines and protrusions
- high lipids, low Si
124
Adaptations to avoid sinking
- lipid accumulation
- Gas vesicles
- ionic regulation
- active swimming
125
Photoinhibition
-point where PS decreases at high irradiance
126
Critical mixing depth
- theoretical depth of water mixing where if the pycnocline is at the depth, phytoplankton use up stored excess carbon as they are mixed from shallow to deep and back
- they break even
- always deeper than compensation depth
127
What is Ks
- half saturation constant
- substrate conc where growth rate is half of the max
- lower Ks is more efficient at taking up nutrients when low conc
128
How to determine the limiting nutrient
- Liebig's law of the minimum (only 1 thing limits growth of a cell at any time)
- Stoichiometry
- Bioassay techniques
129
Why dont cells have large spines to increase drag
-increases the phytoplanktons radius and volume which would make them sink faster
130
Ombrotrophic
- characteristic of bogs
| - dependant on atm moisture for nutrients
131
Unionid mussels `
- filter feeders
- in Phyllum Mollusca
- diverse and some are imperiled
132
Assemblage
-individuals of similar types of spp in the same area
133
Heterocyst
-differentiated cyanobacterial cell that carries out nitrogen fixation
