Chapter 8 Flashcards
What do population suggest?
potential for interbreeding
What do populations serve as?
serves as a genetic unit
What do populations define?
gene pool
What do populationsr equire?
spatial boundary
What are modular organisms?
a unit of construction producing further, similar modules
What is a stolon?
specialized plant stems growing above surface of the substrate (rhizomes are below)
What are suckers?
new stems from surface roots
What is a genet?
a genetic individual
What is a ramet (2), and what is it referred as?
- modules produced asexually
- group referred as clonal colonies
- may be physically linked or separate
How can ramets reproduce?
sexually or asexually
What is distribution, and what is it influenced by?
- spatial location over which it occurs
- ## influenced by habitat suitability
What is geographic range?
defined area encompassing all individuals of a species
What are ubiquitous species?
- ## species with a geographically widespread distribution
What is an endemic species?
species with a restricted localized habitat
What may limit distribution?
geographic barriers like water, microclimates and mountain ranges
What is a subpopulation?
small groups of populations as a result of environmental heterogeneity
What is a metapopulation?
spatially separated populations connected through movement of individuals
What is abundance?
number of individuals in a population
What is population density?
- number of individuals per unit area
What are three types population distribution?
random, uniform, or clumped
How do uniform and clumped distributions differ, and what kind of animals exhibit them?
- uniform- negative interactions like competition
- common in territorial or competitive plants
- clumped- suitable habitat causes patches of population
- social animals
What is ecological denisty?
number of individuals per unit of available living space
What is population size?
density x area
How would you sample density for sessile units?
quadrats
What is the mark recapture formula?
population= (marked*second capture)/ recaptured
What is the Lincoln-peterson index, and what does it assume (3)?
- single mark-single recapture
- assumes population is random
- marked individuals must distribute themselves randomly
- ratio of marked and unmarked must not change between sampling periods
What are indices of population?
- presence of organism instead of count
- recording number of grouse heard along a trail, count of scat, tracks
- if observation is a constant relation with population size, it can be used
- recording number of grouse heard along a trail, count of scat, tracks
What shows population growth?
relative proportion of each age groups (prereproductive, reproductive, and postreproductive )
How do short-lived populations grow?
short-lived populations increase rapidly with short span between populations
How can you obtain age data? (4)
mark young individuals and follow them
examine carcasses to determine age at death
(growth rings) dendrochronology
marking individual seedlings
drawback of marking young individuals and follow their survival through time
- difficult but most accurate
- requires large sample and time
What is dendrochronology?
- approximating tree age based on annual growth rings
- some use dbh to age, but it is not valid for smaller trees
What is seedling marking used for?
nonwoody plants
what is an age pyramid?
- snapshot of age structure of a population at some period in time
-
What is the distribution of an age pyramid in plants?
- distribution is often skewed
- older trees inhibit seedlings from growing
What is the age distribution and gender mortality in mammals?
- in mammals, older age shifts to female dominance
- men have lower due to physiological and behavioral factors
- ex- rivalries for dominance
- men have lower due to physiological and behavioral factors
What is the gender mortality in birds? (2)
- in birds, males tend to outnumber
- nesting female mortality
What is dispersal?
movement of individuals in space
What are three examples of migration?
- zooplankton moving to lower depths in the day and surface at night
- seasonal migrations like earthworm going into deeper soil during winter
- some have only one return trip, where salmon spawn in freshwater but return to the sea
How do sessile organisms disperse?
gravity, wind, water, and animals
What determines plant dispersal? (3)
- distance of organisms travel depends on agents of dispersal
- plants often seed near parent, with density falling off quickly with distance
- ## heavy seeds have short dispersals
How do aquatic animals disperse passively?
- larvae being dispersed by moving water
Why might animals disperse?
- dispersal can be due to crowding, temeprature change, quality and abundance of food, and photoperiods
- often to seek vacant habitat
Why is dispersal important?
to establish metapopulation
What can dispersal do?
shift or expand species’ geographic range
How do animals become introduced (3)?
- initial population becomes established
- individuals disperse into suitable habitat
- expand distribution as it grows
Why might cause range expansion?
temporal changes in environment
