Germination and Emergence
What is quasi-simultaneous germination?
When seeds typically germinate within the same time period ex) Broadleaf plantain
Reproductive effort
What is the measurement of resource allocation to reproduction
What are two ways plants respond to increased density?
Increased mortality and increased plasticity
Give one advantage of chemical control.
What is highly developed, high degree of control, decreased labor.
What is niche differentiation?
functional differences in the way species acquire limiting resources and respond to gradients in environmental and biotic conditions
What is a hypogeal? What are examples?
A cotyledon below the soil surface, plants in the Poaceae or peas are an example
When seeds are produced repeatedly for an indefinite period it is ___
The opposite of this is ___
What is polycarpic
What is monocarpic, which is when production occurs once in life cycle and death follows
What is intraspecific competition?
Competition between individuals of the SAME species
Name one limitation of biological control.
What is only one weed species is controlled, limited research, off target effects on the ecosystem.
How might herbivory facilitate plant invasion?
what is adaptation to ground disturbances, adaptations such as endo/epizoochory, unpalatable which leads to a competitive advantage
What does a red to far light ratio indicate?
High germination which indicates lower probability of competition
What are the four factors affecting dispersal curves?
1. height and distance of seed source
2. concentration of seed source
3. dispersibility of seed (i.e., appendages)
4. dispersal agents
What is the R* theory?
The species with the lowest resource requirement (R*) is expected to be the best competitor when two or more species are limited by the same resource
During which time period was cultivation machinery introduced (tractors)?
What is 1920-1947
Name three biotic and three abiotic factors influencing weeds?
Abiotic: light, temperature, water, nutrients, disturbance, stress, CO2
Biotic: plant competition, plant interference (allelopathy), herbivores/disease- apparent conditions
What are the two forms of Phytochrome and what do they do?
Red light is the active form and promotes germination
Far-red light is the inactive form and inhibits germination
The terms for wind, water, and animal seed dispersal.
What is anemochory, hydrochory, and zoochory
What is the difference between competitive EFFECT and competitive RESPONSE?
Competitive effect is the ability of a plant to deplete resources and make them unavailable while competitive response which is the ability of a plant to grow despite the depletion of resources
List the 6 weed control methods.
What is preventative, physical, managerial/cultural, biological, chemical, integrated
What are two invasive species that are facilitated by white tailed deer? What makes areas more susceptible to invasion?
Alianthus altissma- tree of heaven
Alliaria petiolata- garlic mustard
Microstegium vimineum- Japanese stilt grass
Berberis thunbergii- Japanese barberry
Vincetoxicum rossicum- pale swallowwort
Landscape fragmentation and deer browsing pressure
What are the six factors affecting germination?
Depth of burial
Moisture
Temperature
Light
Oxygen Level
Presence/absence of inhibitors
What are rhizomes, stolons, and tubers?
How are they different?
A weed that has each
What is modified stems
Rhizome is a specialized horizontal stem that grows BELOW ground ex) Canada thistle
Stolon- s a specialized horizontal stem but grows ABOVE ground
Tuber- specialized structure resulting from swelling of subapical portion of underground stem ex) yellow nutsedge
How can two species coexist in competition?
Each one is limited by a different resource (differing resource allocation strategy) OR the species are limited by the same resource but do not share resource requirements
What was the first chemical herbicide introduced, and during which time period was it released?
what is 2,4-D from 1947-1970's
deer avoid barberry, which gives it an indirect advantage over more palatable species to deer via apparent competition, barberry is an ideal humid habitat for ticks, more ticks that transmit Lyme disease