Lecture - Chapter 3/4 Aquatic and Terrestrial Environment

Question 1

Biosphere

Answer 1

Living things are found on every part of the Earth, from high mountains to deepest oceans and extreme environments.

But most occur within a thin layer of Earth’s surface, from the tops of trees to the surface soil layers, and within 200 meters of the surface of the oceans

Question 2

Lithosphere

Answer 2

Earth’s surface crust and upper mantle

Question 3

Troposphere

Answer 3

The lowest layer of the atmosphere

Question 4

Aquatic environment

Answer 4

75-95% of all living cells are water. 75% of earths surface is water.

Question 5

Aquatic systems are divided into two categories

Answer 5

Fresh water and saltwater (marine)

Question 6

Hydrologic cycle

Answer 6

Freshwater -> terrestrial and marine ecosystems.

Driven by solar radiation by providing energy for evaporation of water

Question 7

Evaporation

Answer 7

Transformation of water from liquid to gaseous state

Question 8

Transpiration

Answer 8

Evaporation of water from living parts of plants

Question 9

Evapotranspiration

Answer 9

Total evaporation = ground surface + transpiration

Question 10

Transpiration

Answer 10

Happens through leaf openings called stomates and rates can be controlled by variation in degree of opening and number of stomates per leaf surface area

Question 11

Physical Properties of Water

Answer 11

Polar covalent bonds
Hydrogen bonds
- high specific heat
- can store lots of heat with small increase in temperature
- less seasonal variability in temperature
- aids thermal regulation of organisms
Special density 
- ice less densethan water
Cohesion
- surface tension

Question 12

Light decreases exponentially with depth

Answer 12

The ocean is blue because blue is absorbed less efficiently
More likely to be scattered back to the surface than other wavelengths
Red and UV light is most effectively absorbed by water

Question 13

Temperature change with water depth

Answer 13

Water temperature declines with depth slower than the amount of solar radiation

Question 14

Mixed layer/epilimnion

Answer 14

Warm, low density, temperature roughly same as surface water

Question 15

Thermocline

Answer 15

Transition layer, rapid temperature and density change. Acts as physical barrier that prevents mixing of surface and deep layers. Causes stratification

Question 16

Deep Water/Hypolimnion

Answer 16

Cold, high-density

Question 17

Ocean benthic zones

Answer 17

Sparsely populated with temperatures near freezing, low light and very high pressure

Question 18

Deep ocean adaptations

Answer 18

Bioluminescence
Coloration
Large eyes
Large teeth

Question 19

Diffusion of oxygen

Answer 19

Oxygen diffuses from the atmosphere to the surface water

OXygen content may also stratify in the summer in temperate zone waters. Surface waters have highest O content due to diffusion at the surface an photosynthesis in the photic zone. Decomposers reduce O content in the benthic zone.

Moving water contains lots of oxygen.

Question 20

OMZ

Answer 20

Oxygen minimum zones, regions below the productive surface layer of the ocean where oxygen is low at about 500-1000m

• no surface diffusion
• no photosynthesis
• separated from atmosphere by density stratification
• respriation of organic material sinking from above

Question 21

Carbonic acid

Answer 21

regulated H20 PH

Uptake and release of CO2 shifts PH
Loss of CO2 offset by diffusion from the atmosphere

Question 22

Terrestrial environment

Answer 22

The physical environment shapes the dominant terrestrial vegetation types of the earth, referred to as biomes. Such plant communities then determine the distribution and abundance of animals.

Question 23

Biomes

Answer 23

Terrestrial biomes are characterized by growth forms of the dominant plants such as leaf deciduousness or succulence

Question 24

Constraints on land

Answer 24

gravitational force
dessication
temporal and spatial variability

Question 25

leaf area index

Answer 25

foliage density
the vertical gradient of light is determined by the foliage density

the toaly one-sided area of leaf tissue per unit ground surface area. The greater the LAI, the lower the light penetration through the canopy

Question 26

How do nutrients enter the ecosystem?

Answer 26

Nutrients enter ecosystems through the chemical breakdown of minerals in rocks or through fixation of atmospheric gases

All nutrients are ultimately derived from abiotic sources: minerals in rocks and gases in the atmosphere

Question 27

Minerals

Answer 27

solid substances with characteristic chemical rpoperties

Question 28

rocks

Answer 28

collections of different minerals

Question 29

weathering

Answer 29

elements are released from rock minerals by this physical and chemical breakdown

Question 30

soil

Answer 30

a mix of mineral particles, organic matter, water and organisms.

Question 31

ion exchange capacity

Answer 31

the abilit of ions to bind to soil aprticles depends on the total number of positively or negatively charged sites

Question 32

Cation exchange capacity

Answer 32

the total number of negatively charged sites. a basic measure of soil quality

Question 33

saturation

Answer 33

when soil has more water than the pore space can hold and excess water drains

Question 34

field capacity

Answer 34

when the water fills all the pore spaces of the soil and is held by capillary forces

Question 35

wilting point

Answer 35

when plants can no longer extract water from the soil

Question 36

available water capcity

Answer 36

the amount of water retained between field capacity and wilting point

Question 37

leaching

Answer 37

loss to ground water.

soil capacity to absorb cations measured by titrating with Hydrogen