1-6: The Hydrosphere, Water Flashcards
1
Q
Definition of ecology
A
The scientific study of the interactions that determine the distribution and abundance of organisms.
2
Q
Definition of the environment
A
Biotic and abiotic factors outside the organisms
3
Q
Definition of abundance
A
The population size
4
Q
Definition of distribution
A
Where organisms are found
5
Q
What is population ecology?
A
Study of trends and fluctuations in the number of individuals of a particular species at a particular time and place.
Looks at birth and death rates, predators and prey
6
Q
What is ecosystem ecology?
A
Entire lakes, forests, wetlands, etc
7
Q
What are observations?
A
Changes in abundance or system functioning over time or space, often using comparisons
8
Q
Methods of approach
A
Observations
Experiments
Mathematical models
9
Q
What is an ecosystem?
A
A biological community of interacting organisms and their non-living environments
10
Q
What is central to biomes?
A
The soil ecosystem
11
Q
How much of the earth’s surface is made up of water?
A
70%
12
Q
The 3 process that keep water moving in the water cycle
A
Evaporation: water is heated by the sun
Condensation: vapour forms clouds
Precipitation: water falls as rain, hail, snow, sleet
13
Q
How much of the earth’s water is freshwater lakes, rivers, and streams?
A
0.25%
14
Q
Why is freshwater important to the biosphere?
A
Moves water in and out of ecosystems
Transports natural substances, eg. nutrients
15
Q
Why is freshwater important to humans?
A
Transport
Irrigation
Disposal of waste
16
Q
What is plankton?
A
Floating microorganisms
Movement depends on currents
Found in freshwater and marine
17
Q
What is nekton?
A
Swimming microorganisms
Navigate at will
Swim faster than current
18
Q
What is neuston?
A
Microorganisms resting or swimming at the surface
19
Q
What is an epipelic biofilm?
A
A film on the surface made of algae, fungi and bacteria
20
Q
What does epibenthos mean?
A
Attached to or clinging to plants
eg. crabs, snails
21
Q
What does benthos mean?
A
Attached/living in or on bottom sediments
22
Q
What communities do you find in lakes and ponds?
A
Plankton
Nekton
23
Q
What communities do you find in flood plains?
A
Plankton
Nekton
24
Q
What communities do you find in permanent wetlands?
A
Benthos
25
What communities do you find in mudflats?
Epipelic biofilms
26
What freshwater invertebrates do you find in rivers and streams?
```
Flatworms
Molluscs
Segmented worms
Crustacea
Insects- mayflies, stoneflies, etc
```
27
What do worms indicate?
Poor water quality, as they are found in low O2
28
What do mayflies indicate?
Good water quality, as they are found in high O2
29
Zooplankton features
From 0.3-3.2mm
Feed on phytoplankton
Eg. copepods, rotifers, crustaceans
30
Phytoplankton features
The abundance dictates the colour of the water
| Very green = bloom
31
Shredder examples
Caddis flies
Isopods
Crayfish
32
Grazer examples
Mayflies
| Gastropods
33
Collectors in the water column examples
Diptera
| Trichoptera
34
Collectors in the sediment examples
Worms
Diptera
Bivalves
35
Predator examples
Leeches
Stoneflies
Dragonflies/damselflies
Beetles
36
Properties of lakes and ponds
Stratification
| Wind-induced turbulence
37
Properties of floodplain wetlands
Periodic desiccation
| Competition between algae and macrophysics
38
Properties of permanent wetlands
Periodic flooding
39
Properties of estuary mudflats
Desiccation
Exposure to salt water
Competition at mud surface
40
Properties of estuary outflow
Mixing with salt water
Turbidity
Grazing in the water column
41
How does river classification work?
The larger number, the further down the river the part is
Eg. 4th order rivers are much bigger and towards the end than 1st order, which are by the source
River flow is unidirectional
42
What is a riffle?
Fast flowing river over rocks, shallow
| Home to organisms with adaptations to anchor to rocks, logs and other debris
43
What is a pool?
Slow flowing river over sediment, deep
Often hold fish eg. trout
Study in Santa Barbara: 31 found in pools, only 18 in rapids
44
What is a run?
Like a riffle, but with smooth surface for light to penetrate
Deeper than riffles
Trout use them for feeding as don't need much energy to fight currents
45
What is thermal stratification?
When there is a change of temperature at different depths of a lake
There is also oxygen depletion due to reduced re-aeration from the atmosphere
46
When can stratification occur?
Not in rivers- too fast flowing and shallow
| Can occur in slow, deep-flowing rivers
47
What are the river classifications based on nutrient richness?
Oligotrophic
Mesotrophic
Eutrophic
Hypereutrophic
48
What does oligotrophic mean?
Low N and P
Low biomass
Typically deep
49
What does mesotrophic mean?
Moderate amount of nutrients
50
What does eutrophic mean?
High N and P
High biomass
Typically shallow
51
Properties of water
Wide temperature range- liquid form for most of the year
Wide density range- limits the rate of sedimentation
High absolute viscosity- limits the mixing of water, sedimentation of biota, and flow in lotic systems
High surface tension- allows attachment of invertebrates to the surface eg. pond skaters
52
What is an environmental gradient?
A gradual change in abiotic factors through space and time
Eg. altitude, temperature, depth, soil humidity
Species abundance usually changes along environmental gradients
53
What is an ecotone?
A transitional area of vegetation between two plant communities
It has some characteristics of each bordering community
54
Features of a high-gradient stream
```
Steep sloped
Narrow V-shaped valleys
'Young streams'
Rapid water flow
Can erode
```
55
Features of a low gradient-river
Sluggish moving waters
Carry small amounts of very fine sediment
Wider, less rugged valleys
River can meander
56
Biological role of Carbon
Photosynthesis
| pH
57
Biological role of Oxygen
Aerobic respiration
| Oxidation reactions
58
Biological role of Nitrogen
Amino acids/proteins
Ammonia and nitrate
Limiting
59
Biological role of Phosphorus
Nucleotides (DNA, RNA, ATP)
Polyphosphates
Limiting
60
Biological role of Silicon
Cell wall of diatoms and other algae
| Limiting
61
Where is most nitrogen?
Fixed in the soil
62
What fixes nitrogen in water?
Cyanobacteria (blue-green algae)
| Occurs in heterocysts
63
Where is inorganic nitrogen gained from in lakes?
Groundwater and surface run-off
| Largely NO3- and NH4+
64
What is NH4+ influenced by
pH
65
What is the main source of phosphorous (P) to plants
Phosphate (PO4)
66
What is P availability increased by
Low dissolved oxygen
| Low pH
67
Features of a deep (over 5m) lake
Have a photic zone- a part of the water column receiving sunlight
Distinction between shoreline (littoral) and central zone
In photic zone, get macrophytes and algal mats
In aphotic zone, get mainly bacteria
68
What is the littoral zone?
Where land meets water
| Enough light for plants to grow
69
What is the pelagic zone?
Open water
| Too deep for rooted plants to grow
70
What is the benthic zone?
Bottom of the lake
Animals live here
Thick mud at bottom
71
Profundal/abyssal zone
Deepest part of the open water
| Only in lakes over 200m deep
72
Shallow (under 6m) lake features
Photic zone is the whole of the water column
Too shallow for stratification
Benthic community as light can penetrate
73
Erosional rivers/streams features
Photic zone is throughout water column
| There is more allochthonous material than autochthonous
74
What does allochthonous mean?
Imported material, eg. leaves
75
What does autochthonous mean?
Produced within system, eg. phytoplankton
76
Depositional rivers/streams features
Photic zone is throughout water column
More autochthonous input than allochthonous
Low flow, fine sediment
Anoxic conditions
77
What are lakes influenced by?
Structure (morphology) and hydrology (flow in/out of the lake)
Interactions with surrounding environment
Climate
78
Structure of lake basin is important for...
Water flow
Nutrient accumulation
Light penetration
Mixing of the water column
79
What is holomictic mixing?
Mixes from top to bottom
80
What is meromictic mixing?
Does not completely mix
| Typically very deep lakes
81
What is monomictic mixing?
Does not freeze
| One long mixing period throughout winter
82
What is dimictic mixing?
Mixes once in autumn, once in spring
| Covered in ice in winter
83
What is polymictic mixing?
Mixes frequently throughout the year
| Usually shallow lakes
84
What is amictic mixing?
No mixing
| Covered in ice all year round
85
Winter stratification of Rostherne Mere
No surface warming
Wind-induced mixing
No stratification
86
Summer stratification of Rostherne Mere
Surface warming
Less wind-induced mixing
Stratification
87
Winter phytoplankton primary production (PP) in Rostherne Mere
Low PP due to low light and temperature
88
Spring PP in RM
Increased PP
89
Winter nutrients in RM
High N and P due to a low PP
90
Spring nutrients in RM
Decrease, due to an increased PP
91
Diatom features
Unicellular/colonial
Adapted to low light and low temperature
Require silicon
92
Green algae features
Unicellular/colonial
| Require high nutrients and stratified water
93
Dinoflagellate features
Unicellular
| Adapted to high temperatures and low nutrients
94
Cyanobacteria features
Blue-green algae
Usually colonial
Adapted to high temperatures, low light and low nutrients
Resistant to grazing- only eaten by rotifers and protozoa
95
Cyanobacteria pigment
Chlorophyll-a
96
What is Anabaena?
A cyanobacteria
Three specialised cells:
1. Vegetative cells: have gas vesicles which provide buoyancy and allow light absorption
2. Spore-resisting stages and can adapt in harsh conditions
3. Heterocysts capable of nitrogen fixations
97
Zooplankton bloom
Peak in spring
| Clear water phase when phytoplankton have all been eaten
98
Name for flowing water
Lotic
99
Name for standing water
Lentic
100
Lotic water features
Shallower than most lakes
Fast, unidirectional flow
Less likely to have stratification
Not influenced by phytoplankton/zooplankton
101
What happens at the erosional zone?
Water velocity is high
| Net re-suspension
102
What happens at the depositional zone?
Water velocity is low
| Net deposition
103
Impact of high water flow on benthic microorganisms
Organisms are dispersed
Nutrients are dispersed
Create microenvironments
104
What animals do you find with a small particle size?
Deposit feeders
| Eg. midge larvae
105
What animals do you find with a large particle size?
Predatory species and grazers
| Eg. stoneflies, mayflies
106
What animals do you find in detritus?
Lots of collectors
107
What is the drainage basement/watershed?
The total area drained by tributaries that feeds a main channel
108
What is a river system?
A network of streams that drains an area of land
| Main river + tributaries
109
What are tributaries?
Smaller streams/rivers that flow into larger ones
110
3 types of biota found in lotic systems
Phytoplankton
Periphyton
Macrophytes
111
Where is phytoplankton found?
Slow flowing rivers
| High temperatures, high light intensity
112
What is periphyton?
Lives on substrate or larger plants
| Unicellular and filamentous algae
113
What are macrophytes?
Large plants
Floating-leaved: eg. Duckweed
Free-floating: not rooted to substrate, eg. Water fern
Submerged: eg. Water crowfoot
114
Fish adaptations to running water
Streamlining- both ends are narrow
Flattened ventral surfaces
Live around large stones and boulders
Refuge in overhanging trees and macrophytes
Different dissolved oxygen (DO) requirements
115
Major invertebrate taxa in running waters
```
Leeches
Worms
Snails
Bivalves
Water louse
Water shrimp
Midges
Mayflies
Stoneflies
Beetles
```
116
What breaks down large allochthonous particles?
Shredders
117
What do the filterers and collectors eat?
Fine organic particulate material (FPOM)
118
Adaptations to running water
```
Differing O2 LC50s (lethal conc of O2 required to kill 50% of the population)
Flattened body
Hooks on limbs/other parts of body
Streamlining
Orientate themselves to flow
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