Chapter 4: The Terrestrial Environment

what are some functions of soil? (4)

1) medium for plant growth 2) main determinant of water availability 3) recycling system (breaks down waste products) 4) habitat for small mammals, invertebrates, and microbes (bacteria, fungi)

what is the wavelength range comprising visible light?

400-700 nm

What percentage of land surface is agricultural lands? Of this, 1/3 of land is planted in crops and 2/3 is used for grazing domesticated livestock.

50%

___ ___ = topsoil; a mixture of ___ soil from parent material and ___ from the O horizon -it is ___ in color than lower soil layers -water flows down through this layer, leaching minerals and fine soil particles to lower layers -can lead to an ___ ___ (eluviation), which is common in forest soils, rare in grasslands (low precipitation)

A horizon, mineral, humus, darker, e horizon

____ ___ = subsoil; contains less organic matter than layers above -accumulation of __ and ___ ___ --> clays and salts leached from the A horizon -usually ___ dense than the A horizon -___ for plant roots to penetrate

B horizon, soil, mineral particles, more, harder

____ ___ = unconsolidated material; mainly composed of ___ ___ from which soil developed -relatively little alteration by soil-forming processes (little biological activity, little weathering) -____ is just below the C horizon

C horizon, parent material, bedrock

___ ___ = organic layer, containing undecomposed or partially decomposed organic material - can be subdivided into: 1) ___ --> surface --> undecomposed leaves and twigs 2) __ --> middle --> partly decomposed 3)__ --> bottom --> dark humus layer -In temperate zones, thickness varies ___. It is thickest in the ___, and thinnest in the ___.

O horizon, Oi, Oe, Oa, seasonally, fall, summer

True or False: Clay soils have smaller pores and hold considerably less water than sandy soils.

false

In temperate regions dominated by deciduous forests, seasonal changes result in __________. -a larger leaf area index during summer months -one-half the leaf area index during winter months -a larger leaf area index during winter months -no change in leaf area index -a smaller leaf area index during summer months

a larger leaf index during summer months

The regolith is _____

all the unconsolidated layers of soil

How do terrestrial species obtain water? (animals, plants)

animals --> drinking and eating/plants --> diffusion, roots/vascular tissue

How do terrestrial species deal with gravity? (animal, fungi, plants?

animals --> internal or external skeletons/fungi --> cell walls of chitin/ plants --> cell walls of cellulose

__ __ __ = field capacity - wilting point. Of the three components of soil, which has the highest available water capacity?

available water capacity (AWC), loam

Each of the following is a challenge faced by a terrestrial plant EXCEPT: -cells and tissues to maintain structure. -buoyancy. -variability in air -temperature. -desiccation.

buoyancy

_____ is a result of evaporation and water uptake by plants exceeding input by precipitation Dissolved alkaline salts such as ____ move up from the groundwater. There is also some downward transport of these salts by ___ ___. (calcium carbonate precipitates out of water moving downward or upward) It leads to an accumulation of salts in the ___ horizon. It can form a hard layer called a ____.

calcification, CaCO3, surface water, B, caliche

___ ___ are the chemicals within the soil that dissolved in soil water that are available for uptake and use by plants.

exchangeable nutrients

___ ___ ___ = total number of negatively charged sites, located on leading edges of ___ particles and in ___ (organic matter)

cation exchange capacity (CEC), clay, soil

___ are positively charged ions (calcium, magnesium, ammonium cation(NH4+)). ___ are negatively charged ions (nitrate (NO3-), sulfate (SO42-)). Because of this information, soil particles are ____ ____.

cations, anions, charged surfaces

____ weathering alters the internal structure of rock materials. Potassium feldspar weathers in the presence of water containing ___ ___. Iron weathers through the process of ___. A greenhouse gas called ___ ___ influences the rate of chemical weathering.

chemical, carbonic acid, oxidation, carbon dioxide

The smallest particles occurring in soil are referred to as ___

clay

basic soil formation processes produce different soils. ____, ___, and ___ give rise to different soil types. There are __ orders of soil, each with distinct features and distribution.

climate, geology, vegetation, 12

___ are negatively charged particles that are prevalent in ___ zone soils; cation exchange predominates b/c they are attracted to them.

colloids, temperate

soils have certain distinguishing physical characteristics. The ___ of soil is useful and easy to distinguish; dark soil indicates high concentration of ___ ___. Oxides of iron tend to impart a __ color. ___ affects pore space and plays a major role in movement of water and air. Write highest soil texture component to lowest soil texture component. (3) Soil texture class is determined by the ratio of those 3 components ^^

color, organic matter, red, texture, sand/silt/clay

Soil can be conserved by: 1. ___ ___ - a series of different crops planted in the same area over sequential growing seasons 2.___ ___ ____ - plant crops directly in the soil without plowing 3. ____ ___ - planting crops on a contour rather than up or down a hill These steps can counter degradation of agricultural lands that are needed to feed a growing human population.

crop rotation, no till techniques, contour planting

What happens to the LAI as you move from the top of the tree canopy to the ground?

cumulative leaf area and LAI increase, light decreases

A waxy layer coating the aerial parts of most plants, such as stems and leaves, which reduces water loss is referred to as the ____.

cuticle

Soils developing from sand and silt carried by the wind are referred to as ___.

eolian

Soils lose moisture (capillary water) through __ and __ by plants

evaporation, extraction

____ positively charged particles means that anions are not retained in soils but leach away quickly if not taken up by plants

few

___ ___ - water fills all of the pore spaces and is held within the soil by internal capillary forces; it is the % of the soil (weight or volume) occupied by water when saturated compared to oven-dried weight of that soil -it is the amount of soil moisture or water content held in the soil after excess water has drained away -it varies with TEXTURE: coarse soils have ____ field capacity and fine soils have ___ field capacity

field capacity, lower, high

The soil's ability to retain water is strongly related to particle size; water molecules hold more tightly to the ___particles of a clay soil than to ___particles of a sandy soil, so clays generally retain ___ water.

fine, coarser, more

____ ____ can be expressed as leaf area. Leaves are flat so they can be measured as ___ __ ___, or the area of leaves per unit ground area (m^2 leaf area/m^2 ground area). The percentage of PAR (photosynthetically active radiation) that reaches the ground is a function of ___ and orientation of __ ___ in the canopy. The greater the LAI, the __ PAR reaching the surface of ground, defined by ___ Law (this law quantifies the relationship between available light and LAI)

foliage density, leaf area index (LAI), PAR, leaf surfaces, lower, Beer's

_____ occurs in areas with high rainfall or poor drainage (low-lying). Constantly wet conditions __ decomposition of organic material. Organic material accumulates and releases ___ ___, which react with ___ in the soil

gleization, slow, organic acids, iron

On land, we most likely visualize the vegetation in terms of characterizing the type of ____ and its features. Vegetation composition constrains the ___ and ___ of animal life in the terrestrial environment.

habitat, distribution, abundance

The soil body has horizontal or vertical layers/horizons?

horizontal

Which of the following statements is FALSE? -Humidity is a cause of mechanical weathering of rock. -Freezing is a cause of the mechanical weathering of rock. -Wind erosion is a cause of the mechanical weathering of rock. -Heating is a cause of the mechanical weathering of rock. -Liquid erosion is a cause of the mechanical weathering of rock.

humidity is a cause of mechanical weathering of rock

Three types of chemical weathering processes are particularly important for transforming minerals within rocks into weathered products. These are:... (3) Through hydrolysis reactions, minerals are weathered in the presence of ____, often rainwater. Through oxidation reactions, ___-rich materials transform in the presence of oxygen in air. And through dissolution, minerals dissolve in water, making their chemical products ___ within water.

hydrolysis, oxidation, dissolution, water, iron, ions

Sort into example of chemical weathering process: ______ --> feldspar in granite rocks weathering to clay _____ --> red color of rocks in arches national park ____ --> yellow-stained rocks that used to contain pyrite before it is weathered ____ --> salty taste of ocean water ___ --> caves formed in limestone

hydrolysis, oxidation, oxidation, dissolution, dissolution

Which of the following creates a FALSE statement? The amount of light that reaches the soil surface in a stand of trees is __________. -affected by the angle at which leaves are displayed on the trees -influenced by the season -influenced by the albedo of the ground -a function of the leaf area index -influenced by the types of plants forming the canopy

influenced by the albedo of the ground

As a general relationship, the amount of light available at a given height in a forest canopy is __________ related to the leaf area index above that height.

inversely

___ exchange capacity is important to soil fertility. Ions interact with soil particles and exchange important parts to plants

ion

___ ___ ___ - total number of charged sites on soil particles within a volume of soil

ion exchange capacity

_____ is a result of hot and rainy conditions that cause rapid weathering of rocks and minerals. Large amounts of tropical rain cause heavy ___ in the soils. Compounds and nutrients made available by weathering are transported away if not taken up by plants; some exceptions are ___ and ___. Soils are ___ due to loss of cations except ___.

laterization, leaching, iron, aluminum, acidic, H+

____ = movement of solutes, nutrients, minerals, and pollutants through the soil. Role of climate: under warm conditions and abundant water, weathering/leaching/plant growth are ____. Role of time: well-developed soils require _____ - ____ years.

leaching, maximal, 2000-20000

____ __ is another important factor that influences solar radiation INTERCEPTION..

leaf orientation

soil particles are ____ charged (Attract positive ions), so ___ ___ make positively charged hydrogen ions that allow for binding to the soil particles without positive charges bound.

negatively, root hairs

diverse lineages of organisms colonized terrestrial environments, emerging from the ___ more than a billion years ago. This transition presented challenges to organisms that were adapted to an aquatic habitat.

ocean

soil formation involves 5 interrelated factors:...

parent material, climate, time, topography, biotic factors

____ = soil formation, which involves a wide variety of processes. There are 5 ___ processes: 1) _____ = tropical rainy conditions, rapid weathering, acidic 2) _____ = evaporation and uptake of water by plants, upward movement of CaCO3 3)____ = in dry climates, salt appears at the soil surface 4) ____ = cool moist coniferous forests, acidic removal of iron and aluminum cations from the topsoil 5) ____ = high rainfall, poor drainage, water delays organic breakdown, soil is blueish/black

pedogenesis, laterization, calcification, salinization, podzolization, gleization

_____ occurs in cool, moist climates where conifers dominate. Organic material from conifers creates strongly ___ conditions. Acidic soil solution enhances ____. Cations, iron, and aluminum compounds are removed from the ___ horizon

podzolization, acidic, leaching, A

Ability to hold moisture is an essential feature of soils. •Soils gain moisture through ___ •Water infiltrates the soil •Flows as a result of ___ into the open pore spaces in the soil •Larger pore size, ___ infiltration rate •coarse soils have ___ infiltration rate than fine soils •___ ___- there is more water than the pore space can hold; excess drains away

precipitation, gravity, faster, higher, saturated soil

Soil is formed from the layer of unconsolidated debris overlaying hard, unweathered rock referred to as ____

regolith

____ is the unconsolidated debris of varying depths (0-10's of m), covering the un-weathered rock below, forms an interface between rock and the air, water and living organisms. What are some things regolith includes?

regolith, dust/soil/broken rock

____ is similar to calcification in regards to evaporation and water uptake by plants exceeding input by precipitation, but in drier climates. It leads to an accumulation of salts at or near the soil surface. It is most common in __ and, ____ regions (sea spray).

salinization, deserts, coastal

Soil Erosion is a threat to agricultural sustainability. Tilling land removed the___, the grass-covered ___ __, and the mat of fibrous grass ___holding the soil together. This led to years of severe ___, high winds the 1930s. The topsoil was dry and easily eroded by the wind Resulted in massive dust storms, region became known as the __ ___. These storms resulted in: buried homes and farm equipment, killed livestock, 500,000 americans being homeless, mass migration. This disaster also led to the establishment of the ___ ___ ___ (natural resources conservation service). It also led to the Prairie States Forestry Project, which plant trees and create miles of windbreaks.

sod, surface soil, roots, drought, dust bowl, soil erosion service

___ __ = sequence of horizontal layers visible in the soil What are these layers called? (also each of the ANSWER have different physical, chemical and biological characteristics) What are each of the specific layers?

soil profile, horizons, O/A/B/C

Cations on soil particles are in dynamic equilibrium with cations in ___ ___; cations in soil solution are continuously being ____ or ___ with cations on clay and humus particles. Cations in soil solution are also taken up by __ and leached to ground and surface waters. Abundance of ions on exchange sites is determined by the __ for sites and their ___ in soil solution. In general, ___ ions and/or those with a greater ___ charge are more tightly held

soil solution, replaced, exchanged, plants, affinity, concentration, smaller, positive

___ is the foundation upon which all terrestrial life depends. It is composed of ___ and ___ material capable of supporting plant growth. Soil scientists consider soil a living entity due to interaction of ___ and ___ components.

soil, organic, mineral, biotic, abiotic

in ____ forests, most trees are ____, meaning they often shed leaves in winter. Seasons drastically affect the ___ levels reaching the ground in temperate regions. In regions with distinct wet/dry seasons, there are similar patterns seen of __ levels of light at the ground level during the dry season.

temperate, deciduous, PAR, high

Angled leaf orientation functions in the ____ regions to reduce desiccation, in ___ regions to maximize PAR absorption. ___ account for up to 80% of light reaching the ground in forests.

tropical, polar, sunflecks

True or False: Leaves vary in size and shape so the # of leaves is not a good measure of the effect leaves have on light levels below

true

True or False: The greater the leaf area index (LAI) above the forest floor, the lower the quantity of light reaching the forest floor.

true

Plant Cover Influences the ___ __ of Light. Light striking vegetation can be ___ or ___. A forest absorbs far more light than a ___.

vertical distribution, reflected, absorbed, meadow

Unlike in the ocean where solar radiation has a strong ___ gradient, on land solar radiation is controlled by ___ and ___ of solar radiation by plants

vertical, absorption, reflection

The biggest challenge being desiccation, plant and animal cells are 75%-95% ___. Water evaporates from cell surfaces, so plants tend to be coated with a ___ ___. Animals replace evaporated water by drinking and eating.

water, waxy cuticle

How do terrestrial species deal with desiccation? Plants reduce water loss through: -A ___ ___ covering the above ground parts of the plant, but this waxy surface prevents ___ exchange -_____, which are the pores on the surface of the plant, allow O2 to leave and CO2 to enter the leaf

waxy cuticle, gas, stomata

Soil formation begins with ___. __ __ - when exposed to water, wind and temperature fluctuation rock flakes and crumbles, wind-borne sand and dust scour rock surfaces, WITHOUT altering composition ___ __ - occurs in presence of water, O2, acids and continual accumulation of dead plant material. Mineral and organic components mix and undergo chemical reactions that change/transform the composition relative to the original rock material.

weathering, mechanical weathering, chemical weathering, chemical weathering

___ ___ - soil moisture level below which plants can no longer extract water -minimum amount of water in the soil that the plant requires not to wilt--> amount taken away -water remains in the soil, but up to a point, the water is held too tightly by the soil that the plant can't take it up

wilting point