Lecture #6 - Water & Energy Flashcards
What are the 4 fundamental ecological processes?
Hydro Cycle
Energy Flow
Biogeochemical Cycling
Community dynamics
Out of the 4 fundamental processes, which one is a big driver of the other cycles?
Hydro
What is the hydro cycle driven by?
Solar energy
What does the hydro cycle do?
describes a series of processes by which water based from atmosphere to the earth and back to the atmosphere
What makes water unique
- all 3 states exist at the same time on earth
- high specific heat
- expands when cold (H bonds become rigid and molecule becomes crystallized)
Where is the majority of precipitation falling?
In the ocean
-only 1/4 of this falls on land surface
What mechanisms of precipitation transportation bring water from the tree canopy to the soil?
Streamflow and Through-flow
- also bring nutrients down to the ground
What happens the precipitation hits vegetation?
It usually just evaporates and doesn’t even enter the hydro cycle
What is Through-fall?
When water drips off vegetation to the ground
What is Streamflow?
When water runs down the stem/trunk and them onto the ground
What is surface water dependant on?
Soil texture
Soil moisture
Slope
Vegetation
What kind of surface causes drag of water?
Rougher and ones with lots of vegetation
What is the wilting point?
Water content when most plants wilt and fail to recover upon rewetting
What is Field Capacity?
Water remaining after free fringe has ceased
What is Hygroscopic Water?
A thin film of water around individual soil panic;es and heal together really tightly by the forces of ADHESION
- water is unavailable for uptake by plants
- can hold a lot of water
What is Capillary water?
When water accumulated around the open spaces of the individual particles held together by COHESION
-Water is available for water uptake
What is gravitational water?
When all the space is gone in-between the particles
-the we have free flowing water which is susceptible to gravitational forces
What is soil texture?
How big soil particles are
Which can hold more water, large or small particles?
small particles
-they have more surface area, so if you have a lot of them you’ll have more surface area to hold water
How can you lose water from soil?
Surface run off
High gravitational water
Transpiration
What is evaporation?
water changing from a liquid to a gaseous stat
What is transpiration?
Evaporation from moist surfaces of plants
Role of stomata?
Pores on leaf surfaces that regulate CO2 and water
-they need to be open for gas exchange and photosynthesis
What are ways in which humans are altering the weather cycle?
Withdrawing large amounts of freshwater
Clearcutting
Polluting surface and air
