Chapter 15

Question 1

Green Wall of China

Answer 1

300 million trees planted to keep out the dust storms of the Gobi desert

Question 2

Soil

Question 3

Weathering Process

Answer 3

The material is slowly broken down and fragmented into smaller and smaller pieces, such as rock to soil. Can take a veeeeeery long time.

Organisms play role in breaking down material

Question 4

Soil Forming Factors

Answer 4

Weathering

Soil organisms respire and form CO2; it diffuses into the soil and mixes with soil water to become carbonic acid. Lichens also produce acids

Question 5

Topography

Answer 5

a region’s surface features

i.e. presence of valleys, or mountains

Question 6

Soil Composition

Answer 6

45% mineral particles

5% organic matter

25% water

25% air

organisms reacts in soil-> some die, decompose, fertilize soil

Question 7

Humus

Answer 7

mix of organic compunds

binds to nutrient material ions, holds water

Detritivores break down humus

Question 8

soil water

Answer 8

water in soil

rain fills pore space

Question 9

soil air

Answer 9

air in soil

water drains, pulls air into pore space

Question 10

Leaches

Answer 10

percolates, moves down through soil layers

Question 11

Illuviation

Answer 11

deposition of leached material in lower layers of soil

Question 12

Soil Horizons

Answer 12

Horizontal organization of soil from the organic surface, to the underlying parent material, bedrock

Question 13

O-Horizon

Answer 13

rich in organic material

plant litter accumulates, is decomposed

sometimes, O is absent, but sometimes it is dominent

Question 14

Soil Profile

Answer 14

Vertical section of soil showing the horizons from the surface to the plant material

Question 15

A-Horizon

Answer 15

topsoil, dark, rich, organic accumulation, humus

nutrient deprived from leaching

Question 16

E-Horizon

Answer 16

An occaisional occurance

develops between A and B

leached material from A

Question 17

B Horizon

Answer 17

Lighter colored

less nutrients, more minerals

clay and aluminium accumulation

Question 18

C- Horizon

Answer 18

Weathered peices of parent material

saturated with groundwater

borders solid parent material

Question 19

Ecosystem Services

Answer 19

maintain soil fertility by decomposition

prevent soil erosion

cleanse water

important enviromental benefits from ecosystems

Question 20

Soil Organisms

Answer 20

Millions of micro-organisms

bacteria

fungi

Question 21

Castings

Answer 21

bits of soil that have past throught the digestive tract of an earthworm

Question 22

mycorrizae

Answer 22

symbiotic relationships between fungi and vascular plant roots

assist plants in absorbing enough nutrients from the soil

Question 23

Mycelium

Answer 23

Threadlike roots of a mycorrizal fungus

transfers nutrients from soil to plant

Question 24

Nutrient Cycling

Answer 24

The path of nutrients from the enviroment, to organisms, back to the environment

includes abiotic processes