ecology 4

Question 1

The greatest constraint imposed by terrestrial environments, referring to the loss of water from living cells to the air through diffusion.

Answer 1

Desiccation

Question 2

The balance of water between organisms and their surrounding environment, crucial for hydration and continued function.

Answer 2

Water Balance

Question 3

A waxy surface on the aerial parts of plants, such as stems and leaves, that prevents water loss but also restricts gas exchange.

Answer 3

Waxy Cuticle

Question 4

Pores on the leaf surface that allow gases like carbon dioxide and oxygen to diffuse into the interior of the leaf.

Answer 4

Stomata

Question 5

Specialized cells joined into tubes that transport water and nutrients throughout the plant body, evolved in land plants to maintain water balance.

Answer 5

Vascular Tissues

Question 6

On land, organisms must overcome gravitational forces without the buoyancy provided by water, leading to adaptations like skeletons in animals and cellulose in plants.

Answer 6

Gravity Constraint

Question 7

The upward force resulting from the displacement of water that helps aquatic organisms overcome gravitational constraints.

Answer 7

Buoyancy

Question 8

Structural materials in plants that help provide support against gravity, especially in terrestrial plants like trees.

Answer 8

Cellulose and Lignin

Question 9

The timing and quantity of rainfall in terrestrial environments, which constrain water availability for plants and animals.

Answer 9

Precipitation

Question 10

The dominant factor influencing the vertical gradient of light in terrestrial environments is the absorption and reflection of solar radiation by plants.

Answer 10

Vertical Gradient of Light in Terrestrial Environments

Question 11

The surface area of one or both sides of a leaf, used to express foliage density.

Answer 11

Leaf Area

Question 12

The area of leaves per unit ground area (m² leaf area/m² ground area).

Answer 12

Leaf Area Index (LAI)

Question 13

Describes the relationship between available light and Leaf Area Index (LAI), where light decreases as LAI increases.

Answer 13

Beer’s Law

Question 14

A pigment that allows plants to perceive shading by other plants, affected by the shift in spectral quality of light.

Answer 14

Phytochrome

Question 15

The angle at which a leaf is oriented relative to the Sun influences the amount of light it absorbs, with angled leaves absorbing less light than perpendicular ones.

Answer 15

Leaf Orientation

Question 16

a natural product formed and synthesized by the weathering of rocks and the action of living organisms.

Answer 16

soil

Question 17

is a collection of natural bodies of earth, composed of mineral and organic matter, capable of supporting plant growth.

Answer 17

soil

Question 18

a pioneer of modern soil studies, expressed difficulty in defining soil precisely, acknowledging the complexity of soil’s nature and functions.

Answer 18

Hans Jenny,

Question 19

not just an abiotic environment for plants; it is teeming with life, including billions of minute animals, bacteria, and fungi.

Answer 19

soil

Question 20

The unconsolidated layer of debris that overlies hard, unweathered rock, varying in depth from nonexistent to tens of meters, where soil is formed.

Answer 20

regolith

Question 21

results from the interaction of forces like water, wind, and temperature, causing rock surfaces to flake and peel away. It breaks down rock and minerals into smaller particles without significantly altering their composition.

Answer 21

mechanical weathering

Question 22

Causes of Mechanical Weathering

Answer 22

1. Water seeps into crevices, freezes, expands, and cracks the rock.
2. Wind-borne particles, such as dust and sand, wear away the rock surface.
   3.Growing roots of trees split rock apart.

Question 23

involves the alteration and breakdown of rock particles due to the presence of water, oxygen, and acids from soil organisms, as well as organic matter.

Answer 23

Chemical Weathering

Question 24

Five Factors of Soil Formation

Answer 24

parent material, climate, biotic factors, topography, and time.

Question 25

the material from which soil develops. It can originate from bedrock, glacial deposits (till), wind-carried sand and silt (eolian), gravity-driven material (colluvium), or sediments from flowing water (fluvial).

Answer 25

parent material

Question 26

Plants, animals, bacteria, and fungi contribute to soil formation by breaking up parent material, stabilizing the soil surface, and adding organic matter.

Answer 26

Biotic Factors

Question 27

or land contour, affects how climate influences weathering. Steeper slopes have more runoff and less soil infiltration, while flatter land accumulates more water.

Answer 27

topography

Question 28

allows the factors of soil formation—weathering, organic material decomposition, mineral loss, and material movement through soil—to take effect, requiring 2,000 to 20,000 years for well-developed soils to form.

Answer 28

time

Question 29

Physical Properties of Soil

Answer 29

color, texture, structure, moisture, and depth, which are highly variable from one soil to another.

Question 30

influenced by organic matter and chemical composition. Dark or black soil is rich in organic matter, while oxides of iron give yellowish-brown to red colors, and manganese oxides give a purplish to black color.

Answer 30

soil color

Question 31

Soil color is classified using standardized color charts, such as the __.

Answer 31

Munsell Soil Color Charts

Question 32

refers to the proportion of different-sized soil particles, including gravel, sand, silt, and clay. It affects soil's physical properties, including water-holding capacity and ion exchange.

Answer 32

soil texture

Question 33

spaces within and between soil particles, essential for air and water movement, and root penetration.

Answer 33

pore space

Question 34

have large pore spaces, favoring rapid water infiltration, percolation, and drainage.

Answer 34

Coarse-Textured Soils

Question 35

have smaller pores, greater water adhesion, and chemical activity. Heavy soils like clays can become compacted, poorly aerated, and hard for roots to penetrate.

Answer 35

Fine-textured soils

Question 36

varies based on slope, weathering, parent materials, and vegetation

Answer 36

soil depth

Question 37

A sequence of horizontal layers in the soil, differentiated by physical, chemical, and biological characteristics, which together constitute a soil profile.

Answer 37

Soil Profile

Question 38

The horizontal layers of soil, including the O, A, B, and C horizons, each with distinct characteristics.

Answer 38

Horizons

Question 39

layer dominated by organic material, consisting of partially decomposed plant materials such as leaves, needles, twigs, mosses, and lichens. (organic layer)

Answer 39

O Horizon

Question 40

sublayer of O horizon (undecomposed leaves and twigs)

Answer 40

Oi

Question 41

sublayer of O horizon (partially decomposed tissues)

Answer 41

Oe

Question 42

sublayer of O horizon (humus)

Answer 42

Oa

Question 43

composed of material derived from parent materials and enriched with organic matter (humus) from above. It often has a darker color due to organic accumulation. (topsoil)

Answer 43

A horizon

Question 44

zone of maximum leaching (eluviation), where minerals and finer soil particles such as clay are washed out from the A horizon. Common in soils developed under forests.

Answer 44

E horizon

Question 45

The process of washing out minerals and finer soil particles from the upper soil layers to lower portions of the soil profile

Answer 45

eluvation

Question 46

Contains accumulations of mineral particles, such as clay and salts, leached from the topsoil. It is denser and contains less organic matter than the A horizon, making it harder for roots to penetrate. (Subsoil)

Answer 46

B Horizon

Question 47

The process of accumulation of minerals and particles from upper soil layers in the B horizon

Answer 47

Illuviation

Question 48

The unconsolidated material beneath the subsoil, largely unaltered by soil-forming processes and retaining characteristics of the parent material. Below it lies the bedrock.

Answer 48

C horizon

Question 49

The process by which water moves into the soil by gravity into the open pore spaces, with the size of soil particles and their spacing determining how much water can flow in.

Answer 49

Infiltration

Question 50

When the pore space in the soil is fully filled with water, and excess water drains freely from the soil.

Answer 50

Saturated Soil

Question 51

The amount of water a soil holds when all pore spaces are filled and water is held by internal capillary forces

Answer 51

field capacity

Question 52

Water held between soil particles by capillary forces after infiltration.

Answer 52

Capillary Water

Question 53

The point at which soil moisture decreases to a level where plants can no longer extract water

Answer 53

Wilting Point

Question 54

The amount of water retained by the soil between field capacity and wilting point, representing the water available for plant uptake.

Answer 54

Available Water Capacity (AWC)

Question 55

have low field capacity and low wilting points

Answer 55

Coarse-textured soils

Question 56

have higher values for field capacity and wilting points.

Answer 56

fine-textured soils

Question 57

AWC is highest in

Answer 57

intermediate clay loam soils.

Question 58

Chemical nutrients dissolved in soil water that are most readily available for uptake and use by plants.

Answer 58

exchangeable nutrients

Question 59

A charged particle, with cations carrying a positive charge and anions carrying a negative charge.

Answer 59

ion

Question 60

The total number of negatively charged sites on soil particles (clay and humus) that bind and prevent the leaching of positively charged nutrient cations.

Answer 60

Cation Exchange Capacity (CEC)

Question 61

Anions, such as nitrate (NO3=) and phosphate (PO43=), are not retained on exchange sites in soils and tend to leach away if not taken up by plants.

Answer 61

Anions and Leaching

Question 62

The order of cations based on their strength of bonding to cation

Answer 62

Lyotropic Series

Question 63

The process that gives rise to different classes of soils, involving five main processes: laterization, calcification, salinization, podzolization, and gleization.

Answer 63

Soil Formation (Pedogenesis)

Question 64

A soil formation process common in humid tropical and subtropical regions, involving rapid weathering, heavy leaching, and the retention of iron and aluminum compounds, giving the soil a reddish color.

Answer 64

Laterization

Question 65

Occurs when evaporation and plant water uptake exceed precipitation, leading to the upward movement of alkaline salts (typically calcium carbonate) and their deposition in the B horizon, sometimes forming a hard layer called caliche.

Answer 65

Calcification

Question 66

Similar to calcification, but in drier climates, resulting in the accumulation of salt deposits at or near the soil surface, common in deserts and coastal regions.

Answer 66

Salinization

Question 67

Occurs in cool, moist mid-latitude climates with coniferous vegetation, leading to acidic soil conditions, leaching of cations and compounds of iron and aluminum, and the creation of a white- to gray-colored sand layer in the A horizon.

Answer 67

Podzolization

Question 68

A process in waterlogged, poorly drained areas where organic matter accumulates due to slow decomposition, releasing acids that react with iron and give the soil a black to bluish-gray color.

Answer 68

Gleization

Question 69

An environmental disaster in the 1930s caused by wind erosion, leading to the loss of topsoil, destruction of farmland, and mass migration. It prompted the establishment of the Soil Conservation Service and the Prairie States Forestry Project.

Answer 69

Dust Bowl

Question 70

The removal of soil, particularly topsoil, by wind or water, which destabilizes soil surfaces and reduces agricultural productivity.

Answer 70

soil erosion

Question 71

A farming practice where crops are planted directly into the soil without plowing, dramatically reducing soil erosion to as low as 0.14 tons per hectare per year.

Answer 71

No-Till Techniques

Question 72

A soil conservation technique that involves planting different crops in the same area in sequential seasons to reduce soil erosion, with rates as low as 3 tons per hectare per year compared to 44 tons per hectare per year with continuous cropping.

Answer 72

Crop Rotation