Chapter 2

Question 1

A horizon

Answer 1

biologically active soil layer consisting of mixture of mineral materials, such as clay, silt and sand, as well as organic material, derived from overlying O horizon

Question 2

B horizon

Answer 2

subsoil in which materials leached form above accumulate.

-may be rich in clay, OM, iron and other materials

Question 3

biome

Answer 3

distinguished primarily by their predominant plants and are associated with particular climates.
-consist of distinctive plant formations

Question 4

boreal forest

Answer 4

(taiga) - northern forests that occupy the area south of arctic tundra.
- though dominated by coniferous trees they also contain aspen and birch

Question 5

caliche

Answer 5

calcium carbonate rich hardpan soil horizon; extent of caliche formation can be used to determine age of desert soils

Question 6

C horizon

Answer 6

soil layer composed of largely unaltered parent material, little affected by biological activity

Question 7

climate diagram

Answer 7

standardized form of representing average patterns of variation in temperature and precipitation that identities several ecologically important climatic factors such as relatively moist periods and periods of drought

Question 8

Coriolis effect

Answer 8

phenomenon caused by rotation of earth, which produces a deflection of winds and water currents to the right of their direction of travel in the N. Hemisphere and to the left in the S. Hemisphere

Question 9

desert

Answer 9

arid biome occupying ~ 20% of land surface of earth in which water loss due to evaporation and transpiration by plants exceeds precipitation during most of year

Question 10

drought

Answer 10

extended period of dry weather during which precipitation is reduced sufficiently to damage crops, impair functioning of natural ecosystems, or cause water shortages for human pops.

Question 11

lithosol

Answer 11

soils very low in OM and composed of rock frags

Question 12

Mediterranean woodland/shrubland

Answer 12

biome associated with mild, moist winters, dry summers, between 30 and 40 degrees latitude.

• vegetation; small, tough leaves and adaptations to periodic fire
• found in Mediterranean sea, chile, S. Australia, s. Africa

Question 13

mycorrhizae

Answer 13

mutualistic association between fungi and roots of plants

Question 14

natural history

Answer 14

study of how organisms in a particular area are influenced by factors such as climate, soils, predators, competitors, and evolutionary history

Question 15

O horizon

Answer 15

most superficial soil layer containing substantial amounts of OM, including whole leaves, twigs, other plants parts, highly fragmented OM

Question 16

palmer drought severity index

Answer 16

index of drought that uses temperature and precipitation to represent moisture conditions in a region relative to long term average temp and precip within the region

Question 17

sample mean

Answer 17

average of a sample of measurements or observations; an estimate of true pop mean

Question 18

solifluction

Answer 18

slow movement of tundra soils down slopes as a result of annual freezing and thawing of surface soil and the actions of water and gravity

Question 19

temperate forest

Answer 19

deciduous or coniferous forests generally found between 40 and 50 degrees latitude, where annual precip is 650 to 3000 mm
-this biome receives more winter precip than temp. grasslands

Question 20

temperate grasslands

Answer 20

grasslands growing in middle latitudes that receive 300 and 1000 mm annual precip with max precip in summer

Question 21

tropical dry forest

Answer 21

broadleaf deciduous forest growing in tropical regions having pronounced wet and dry season; trees drop their leaves during dry season

Question 22

tropical rain forest

Answer 22

broadleaf evergreen forest growing in tropical regions where conditions are warm and wet year round

Question 23

tropical savanna

Answer 23

tropical grassland dotted with scattered trees; characterized by pronounced wet and dry season and periodic fires

Question 24

tundra

Answer 24

northern biome dominated by mosses, lichens and dwarf willows, receiving low to moderate precip and having very short growing season