Lecture 5 Flashcards
Changes When transitioning to a Floodplain River (5)
- Depth/Width Increase
- Turbidity Increases then decreases
- Plants: submeg to emg
- Formation of swamps
- More Planktonic communities
River Continuum Concept (Upstream)
- CPOM
- Shredders
- Riverine
River Continuum Concept (Downstream)
- FPOM
- Collectors
- Lacustrine
River Continuum Concept (transition from upstream to downstream)
CPOM to FPOM
Shredders to Collectors
Riverine to Lacustrine
This assumes equilibrium conditions
Flood Stage (Hydrograph)
Environmental flows to flooding of floodplain (swamp, marsh, wet grassland or forest)
Depositional River
Sorted sediments leads to heterogeneity of habitats to high biodiversity
What is Avulosion
Rapid abandonment of a river channel to the formation of a new channel and potential flooding
Floodplain and Wetlands (Connectivity - what is it)
The way different systems feed into water systems or the outer area or in and out of the two
Floodplain and Wetland (Connectivity - all the different ones)
- Hyporheic
- Floodplain
- Wetlands
What is the Hyporheic Connectivity
River to and from groundwater
What is the Floodplain Connectivity
River to and from the soil (ephemeral)
What is Wetlands Connectivity
Surface water to and from soil
These are area where water covers/close to the soil surface for part/all year with aquatic plants
Biochemical Processes in Floodplains
- Increase in residence time
- Change in Redox potential
- Increased microbes
- Increased plant diversity
- N cycling leads to denitrification
- P cycling
- Biodiversity and Abundance
Ecosystem Services of Floodplains (7)
- Sources of food and freshwater
- Regulating climate
- Recharging groundwater
- Ameliorating pollution
- Providing erosion control
- Reducing impacts of storms and floods
- Providing spiritual, recreation, aesthetic, and education
What sources of Food and Nutrients do Floodplains provide (3)?
- Fiber and fuel
- Raw materials for biochemical and industrial uses
- Genetic material related to crop plants
What is a Marsh?
- Relatively shallow
- Herbaceous
- Flooded wetland mineral soils
- Frequent or continuously flooded
What is a Bog?
- Acidic soils
- low-lying areas (kettle holes)
- Where OM accum. > decay
- Contain mosses and other aquatics
What is a Swamp?
- Relatively deep wetland
- Woody + herbaceous + stagnant
- Peaty soils (OM)
- Anaerobic (peat = acidic)
Swamp Production:
- Grazing decreases
- Transport
- Detritivores
- Fires
- Microbial loss
- Retained as peat
Swamp Chemistry:
- Extremely hypo/anoxic (decreases composition)
- Waterlogged soils leads to reducing (increased free electrons and low Redox Potential)
Swap Components:
Trees, floating mats, sedges, rushes, grass vs. Restionaceae (SH)
Features of Emergents in Swamps (How Can They Survive Flooding)
- Air to roots
- Aerial roots
- Xeromorphic leaves
Ecology of Aquatic Plants
- Microhabitats
- Spawning, egg laying, and nursery sites
- Cover from predators
- Source of labile organic matter (DOM)
- Entangle organic matter
- Stabilize and accumulate fine sediments (diversity increases which leads to lower velocity)
- Remove NO3 and PO4 via uptake
- Community remove NO3 via denitrification and anammox in deoxygenated soft sediments
Ecology of Arctic Aquatic Plants
- Filamentous/thalloid algae (reds/Nostoc)
- Few plants
Ecology of Temperate Aquatic Plants
- Lots of vascular (submergents)
- Algae and mosses
Ecology of Tropical Aquatic Plants
Diverse vascular (Podostemonads)
Characteristics of Submerged Plants
- Strap-shaped, dissected/lobed, and thin leaves (without hairs) with chloroplasts in the epidermis
- Reduced/absent cuticle
- Absent/Non-functional stomata
- Absorb CO2 or HCO3 (certain algae and plants) through the epidermis
- Lacunae or large air spaces
- May exhibit heterophylly (different leaves under/on/above)
- Fibers/woody tissue absent
- Reduced root system
- Heavy reliance on vegetative reproduction via stolons, rhizomes, tubers, and turions (winter buds)
Photosynthesis in Aquatic Plants
Carbon Limitation: DIC source, pH, transport
Photosynthesis and DIC Flux
Mass transfer limitation occurs at low U and depends on the concentration of DIC
Flux Equation:
J = U x C
Natural vs. Channelized Floodplain River Results in:
- Uniform, straight, deepened embanked channels
- Dry and flattened flooplains
- Loss of spatial heterogeneity leads to
- Loss of habitats
Advantages of Chanalization
- Irrigation
- Flood control
- Transportation
Disadvantages of Channelization
- Loss of wetlands
- Increased erosion
- Divert flood downstream
Disease of Floodplains
- Malaria
- Mosquito-vectored disease
- Snail-vectored diseases
Controls for Diseases of Floodplains
Pesticides, wetland drainage moves to mosquito nets on beds
How disease in Wetlands move through population
Irrigation projects lead to increased wetlands, which leads to increased snail populations and increased mosquito habitats
