Lecture 6 - DA Flashcards
Between aquatic and terrestrial environments, which has more phyla?
Aquatic, therefore more diverse.
What kinds of terrestrial environments have huge diversity?
Forests, rainforests, mainly from insects.
What are two differences between aquatic and terrestrial environments that had an impact on how they evolved?
Movement - the need to move through water vs air.
Water - absorbs light, creating a gradient.
What effect do currents have on aquatic systems? How does it affect distribution versus a terrestrial environment?
Currents allow easier movement and distribution of organisms compared to a terrestrial one. Therefore, aquatic organisms are more distributed than terrestrial ones.
What is the dominant primary producer in aquatic environments and terrestrial ones?
Aquatic - phytoplankton
Terrestrial - large plants
The dominant primary producers are different in aquatic and terrestrial environments. How does each affect energy flow to higher trophic levels in each, and why? What does this reflect about the energy flow?
Aquatic - Phytoplankton are very small, and fed on by small primary consumers, which are fed on by small fish, which are fed on by larger fish etc. More steps are needed to reach higher trophic levels.
Terrestrial - Large plants can be fed on directly by large primary consumers, and less steps are needed to reach higher trophic levels.
Reflects how much energy can be passed to higher levels.
Between aquatic and terrestrial systems, which has more benthic/unmoving organisms, and why?
More in aquatic systems, because they can filterfeed, and use water to distribute gametes.
Terrestrial organisms must move around to find food and mates.
Between terrestrial and aquatic environments, what are the nutrients present in the dominant medium like (soil vs. water)? What consequence does this have?
Nutrients are present in soil at high concentrations, while in water, they are more dilute.
Nutrients are therefore often a limiting factor in aquatic systems, and not so in terrestrial systems.
Name 3 storage compartments for water in the hydrologic cycle. Give an example for each if applicable.
Atmosphere - clouds
Land - ice/groundwater
Water bodies - inland/marine
Name 3 movements between storage compartments in the hydrologic cycle, with an example for each.
Atmosphere to land - precipitation
Land to water bodies - surface/groundwater runoff
Water bodies to atmosphere - evaporation
Define evapotranspiration. What consequence does this mechanism have?
Plants open stomata for gas exchange to uptake CO2 and expel O2, and water is lost in the process.
This drives the uptake of water from the roots of the plant however.
What are the contributing factors of water moving from water bodies to the atmosphere?
Evaporation from sunlight/heat, but also evapotranspiration, a high contributor, especially in rainforests.
What dominates over land, precipitation or evaporation? What happens to the excess?
Precipitation > evaporation.
Excess precipitation is carried to oceans by surface/groundwater runoff.
Most precipitation over land originates from where?
From evaporation of the ocean.
What dominates over oceans, evaporation or precipitation?
Evaporation > precipitation
Order the following by retention time of water, from lowest to highest. Ground water Inland bodies Ocean Atmosphere Polar ice
Atmosphere Inland bodies Groundwater Ocean Polar ice
Name 5 human activities that can influence water distribution.
Damming rivers Land clearing Redirecting rivers Exploiting groundwater Anthropogenic climate change
Define limnology.
Study of lakes, rivers, wetlands
Define lentic.
Standing water systems - lakes, ponds
Define wetland.
Transition zone between terrestrial and aquatic systems.
What is the soil like in wetlands? Are there any rooted aquatic vegetation?
Soil is waterlogged at least part of the year.
Have some rooted aquatic vegetation.
Define catchment.
Area around land drained by a river system - also a watershed/drainage basin.
Do lakes have a catchment?
Yes.
What is the water saturation at the surface of a catchment like? What is this zone called, and what does water movement here dictate?
Surface isnt saturated, and the water moves freely, infiltrating down this area. This is the unsaturated zone. Water movement here dictates how water overall moves.
What defines the saturated zone of a catchment? What is the surface of this definition called?
Is defined by a line below which the water is saturated, the surface is the water table.
Can water still move freely into the saturated zone?
Yes.
Define aquifer.
Reserve of water.
Does water move freely just below the water table? What kind of aquifer is this area? What about far deeper down?
Water can move freely just below the water table, and is an unconfined aquifer.
Deeper down, water is saturated but not moving freely, and is a confined aquifer.
Define lag time.
Time taken for water to go across the land, into a stream.
How does vegetation promote infiltration in water movement?
Entrapment under litter and root channels in soil.
How does vegetation reduce erosion, and what effect does this have on water movement?
Promotes soil stability, reducing erosion, and preventing muddy waters.
How does vegetation reduce water runoff?
Producing high transpiration rates.
What is a consequence of no vegetation after heavy rainfall?
Rivers rise more rapidly, and also return to base flow more rapidly as well.
Describe the effects of forest clearcutting on the following Stream velocity UV light Temperature Nutrient levels Organic matter
Stream velocity - increases UV light - barrier removed, more light Temperature - increases due to more UV Nutrients - accelerates loss Organic matter - accelerates loss
Define epilimnion.
Epilimnion - surface layer mixed by wind or temperature driven currents.
Define metalimnion. Which two layers is it found between?
Metalimnion - region of the thermocline, the transition between the epilimnion and hypolimnion.
What is the photic zone, what occurs here, and why?
Is the epilimnion, where net primary production occurs, as there is enough light.
Where is the profundal zone found?
The upper metalimnion.
Where is the aphotic zone, what occurs here, and why?
Is the lower hypolimnion, where net respiration occurs, as there isnt enough light for photosynthesis.
What manner of creatures live in the aphotic zone?
Benthic.
What are two features of the aphotic zone?
Stagnant, and no gas exchange with the atmosphere.
Define lacustrine.
Related to or associated with lakes.
What is the littoral region?
The shore.
What two factors affect water density, and when is freshwater most dense?
Temperature and salinity.
Freshwater is densest at 4*C.
