Lecture 5

Question 1

Changes When transitioning to a Floodplain River (5)

Answer 1

1. Depth/Width Increase
2. Turbidity Increases then decreases
3. Plants: submeg to emg
4. Formation of swamps
5. More Planktonic communities

Question 2

River Continuum Concept (Upstream)

Answer 2

• CPOM
• Shredders
• Riverine

Question 3

River Continuum Concept (Downstream)

Answer 3

• FPOM
• Collectors
• Lacustrine

Question 4

River Continuum Concept (transition from upstream to downstream)

Answer 4

CPOM to FPOM
Shredders to Collectors
Riverine to Lacustrine
This assumes equilibrium conditions

Question 5

Flood Stage (Hydrograph)

Answer 5

Environmental flows to flooding of floodplain (swamp, marsh, wet grassland or forest)

Question 6

Depositional River

Answer 6

Sorted sediments leads to heterogeneity of habitats to high biodiversity

Question 7

What is Avulosion

Answer 7

Rapid abandonment of a river channel to the formation of a new channel and potential flooding

Question 8

Floodplain and Wetlands (Connectivity - what is it)

Answer 8

The way different systems feed into water systems or the outer area or in and out of the two

Question 9

Floodplain and Wetland (Connectivity - all the different ones)

Answer 9

• Hyporheic
• Floodplain
• Wetlands

Question 10

What is the Hyporheic Connectivity

Answer 10

River to and from groundwater

Question 11

What is the Floodplain Connectivity

Answer 11

River to and from the soil (ephemeral)

Question 12

What is Wetlands Connectivity

Answer 12

Surface water to and from soil
These are area where water covers/close to the soil surface for part/all year with aquatic plants

Question 13

Biochemical Processes in Floodplains

Answer 13

• Increase in residence time
• Change in Redox potential
• Increased microbes
• Increased plant diversity
• N cycling leads to denitrification
• P cycling
• Biodiversity and Abundance

Question 14

Ecosystem Services of Floodplains (7)

Answer 14

1. Sources of food and freshwater
2. Regulating climate
3. Recharging groundwater
4. Ameliorating pollution
5. Providing erosion control
6. Reducing impacts of storms and floods
7. Providing spiritual, recreation, aesthetic, and education

Question 15

What sources of Food and Nutrients do Floodplains provide (3)?

Answer 15

1. Fiber and fuel
2. Raw materials for biochemical and industrial uses
3. Genetic material related to crop plants

Question 16

What is a Marsh?

Answer 16

• Relatively shallow
• Herbaceous
• Flooded wetland mineral soils
• Frequent or continuously flooded

Question 17

What is a Bog?

Answer 17

• Acidic soils
• low-lying areas (kettle holes)
• Where OM accum. > decay
• Contain mosses and other aquatics

Question 18

What is a Swamp?

Answer 18

• Relatively deep wetland
• Woody + herbaceous + stagnant
• Peaty soils (OM)
• Anaerobic (peat = acidic)

Question 19

Swamp Production:

Answer 19

1. Grazing decreases
2. Transport
3. Detritivores
4. Fires
5. Microbial loss
6. Retained as peat

Question 20

Swamp Chemistry:

Answer 20

1. Extremely hypo/anoxic (decreases composition)
2. Waterlogged soils leads to reducing (increased free electrons and low Redox Potential)

Question 21

Swap Components:

Answer 21

Trees, floating mats, sedges, rushes, grass vs. Restionaceae (SH)

Question 22

Features of Emergents in Swamps (How Can They Survive Flooding)

Answer 22

• Air to roots
• Aerial roots
• Xeromorphic leaves

Question 23

Ecology of Aquatic Plants

Answer 23

1. Microhabitats
2. Spawning, egg laying, and nursery sites
3. Cover from predators
4. Source of labile organic matter (DOM)
5. Entangle organic matter
6. Stabilize and accumulate fine sediments (diversity increases which leads to lower velocity)
7. Remove NO3 and PO4 via uptake
8. Community remove NO3 via denitrification and anammox in deoxygenated soft sediments

Question 24

Ecology of Arctic Aquatic Plants

Answer 24

• Filamentous/thalloid algae (reds/Nostoc)
• Few plants

Question 25

Ecology of Temperate Aquatic Plants

Answer 25

- Lots of vascular (submergents) - Algae and mosses

Question 26

Ecology of Tropical Aquatic Plants

Answer 26

Diverse vascular (Podostemonads)

Question 27

Characteristics of Submerged Plants

Answer 27

1. Strap-shaped, dissected/lobed, and thin leaves (without hairs) with chloroplasts in the epidermis 2. Reduced/absent cuticle 3. Absent/Non-functional stomata 4. Absorb CO2 or HCO3 (certain algae and plants) through the epidermis 5. Lacunae or large air spaces 6. May exhibit heterophylly (different leaves under/on/above) 7. Fibers/woody tissue absent 8. Reduced root system 9. Heavy reliance on vegetative reproduction via stolons, rhizomes, tubers, and turions (winter buds)

Question 28

Photosynthesis in Aquatic Plants

Answer 28

Carbon Limitation: DIC source, pH, transport

Question 29

Photosynthesis and DIC Flux

Answer 29

Mass transfer limitation occurs at low U and depends on the concentration of DIC

Question 30

Flux Equation:

Answer 30

J = U x C

Question 31

Natural vs. Channelized Floodplain River Results in:

Answer 31

1. Uniform, straight, deepened embanked channels 2. Dry and flattened flooplains 3. Loss of spatial heterogeneity leads to 4. Loss of habitats

Question 32

Advantages of Chanalization

Answer 32

- Irrigation - Flood control - Transportation

Question 33

Disadvantages of Channelization

Answer 33

- Loss of wetlands - Increased erosion - Divert flood downstream

Question 34

Disease of Floodplains

Answer 34

- Malaria - Mosquito-vectored disease - Snail-vectored diseases

Question 35

Controls for Diseases of Floodplains

Answer 35

Pesticides, wetland drainage moves to mosquito nets on beds

Question 36

How disease in Wetlands move through population

Answer 36

Irrigation projects lead to increased wetlands, which leads to increased snail populations and increased mosquito habitats