FOR 260 Quiz 3

lectures 14 - 18 Chapter 10

Relative illumination

percent of total solar illumination on the forest floor

Saturation point

light intensity above which there is no further increase in photosynthesis

Compensation point

amount of light required where photosynthesis = respiration

Sun leaves

more chlorophyll, 2+ layers of palisade mesophyll (where photosynthesis happens)

Shade leaves

only one layer of mesophyll for photosynthesis, have a lower rate of photosynthesis despite light intensity.

Spring ephemerals

a flower present only for a short period of time in the spring, have a high light requirement.

phytochrome pigment system

\
Pr (phytochrome red)

Pfr (phytochrome far red, physiologically __active__)

Pr → Pfr → Pr

night length

plants really measure this to tell time

Short-day organisms

(long night is a better term) complete some aspect of life history with fewer than some critical number of hours of daylight (like going into dormancy)

Ex: cotton, hemp

Long-day organisms

respond to more than some critical number of hours of daylight

Day-length indifferent

respond whenever environmental conditions are favorable (ex: in tropical wet forests where day-length doesn’t change much and there is no drought period)

Photoperiodism

growing in response to day length

radiation

Latitude (how much light and warmth is received by the plant over time), altitude, and proximity to large bodies of water (convection and conduction processes) are factors that affect what?

Daytime radiation budget

greatly influenced by the “view factor” – the proportion of its irradiating environment that is accounted for by the sky.

Strongly negative radiation budget

(day) rapidly increasing temperatures; great high temperature hazard.

Weakly negative radiation budget

(day) slowly increasing temperatures; little high temperature hazard.

Strongly negative radiation budget

(night) rapidly decreasing temp, great ground frost hazard

Weakly negative radiation budget

(night) slowly dropping temps, little ground frost hazard

Law of Q10

The increase of a rate of reaction as a function of temperature:

Q10 = rate at (x+10) degrees C / rate at X degrees C

\*As a general rule reaction rates double with every 10 C rise in temperature. Metabolism goes up 2-3 times with 10 C rise.

Growing season heat sum

the sum of temp above a base temp over the course of a growing season.

Growing degree days

one degree-day is one day (24hrs) with the temp above the lower development threshold by one degree.

\*One one day it is 65 degrees, the threshold for a plant is 50 degrees so: 65 - 50 = 15 growing degree days (really a heat sum of the day)

Soil growing season

portion of the year when soil temps are above biologic zero (5\*C) at 50cm (19.7”).

Physiography

the surface features, their form and substance, of a given regional or local area. Largely controls climate and soil conditions.

Landform

any physiographic feature on the Earth’s surface, such as a plain, valley, hill, etc. caused by erosion, sedimentation, or movement. Distinguished by the parent material that is characteristic of a given landform and in which characteristic soils also develop.

Sandy outwash plains

Outwash plains made up of outwash deposits are characteristically flat and consist of layers of sand and other fine sediments.

Slope aspect

direction a slope faces in regard to the sun’s position.

Slope inclination

slope percent or degree of slope, steeper = more surface per hectare.

Parent material

kind of substrate, including rock type, particle size, mineralogy of the feature or landform.

Natural Levee

were large coarse sediment is deposited next to a river

first bottom

where finer sediment like clay and silt are deposited behind a levee by a river/stream

back swamp

a more poorly drained area with finer texture soil, less fluctuations in water level than first bottom

Non Riverine wet hardwood forest

Ephemeral bodies of water nursery for frog tadpoles, salamanders, etc (puddles dry up before fish can get there).

mounds

Trees prefer to grow on this microtopography feature

pits

This micro-topographic feature accumulates water and organic material.

True

True/false: even a 1 inch mound/pit significantly improves

diversity, species richness, and biomass.

Peatland

landform with little oxygen in the soil due to a high water table, meaning plant material degrades slowly (anaerobically)

Geomorphology

the science dealing with the nature and origin of topographic features of the earth.

Parent material

base geologic material that affects site and soil of the site

Shape and parent material

The two major components of landforms are

frost pocket

Level terrain surrounded by higher land creates a “sink” for cold air at night creates a…

planar

a sloping terrain surface with zero curvature.

convex

a sloping terrain that curves outward. (repels soil water, nutrients, and organic matter)

concave

a sloping terrain that curves inward. (accumulates

soil water, nutrients, and organic matter)

Relative elevation

Ridge-top; upper, mid, lower-slope, and level are all…

gravity, guiding flows of wind/water, creating barriers to movement

Landforms influence the flow of materials through:

disturbances

Landforms influence the frequency, severity, and effects of:

climate, hydrology, movement of materials, and disturbances

The way one landform is spatially related to another influences:

Riparian zones

3D zones of direct interaction between terrestrial and aquatic ecosystems.

Firebreaks

rivers and streams, lakes, and rough topography. Disrupts fuel for the fire, creates erratic wind movement, slows air flow, and generally slows/stops fires.

pits and mounds

More of these are created in areas where shallow rooting is encouraged (high water table, severe windstorms, wet mineral/organic soil, rocky soil, root-restricting soils).

True

True/false: The dormant buds and twigs of every tree species contain chloroplast and woody plants can photosynthesize during the winter.