spatial ecology Flashcards
geladas
live in clumps with dominant males
Distribution types
Random: uniform resourse distribution and absense of strong repulsion or attraction among individuals
Uniform: exclussive use of areas. individuals avoid each other. territorality
Clumped: most common–> mutual attraction and patchy resourse availability–> mating behavior and group defense
seastar distribution type
clumped
penguin distribution type
uniform
dandelion distribution type
random
index of dispersion
used to determine distribution type mean count per quadrant / variance >1 are clumped =1 are random <1 are uniform
desert shrubs
begin clumped, but members of the population die as they age due to competition. Eventually become random and then uniform
reasons for desert shrub clumping
- seed germination in a safe place
- seed dispersal
- asexual reproduction
relationship between bodymass/biomass and species density
negative
plant size vs density
- seedlings can live at high densities
- trees live at lower densities
- example: sequoia and lemma
Christmas bird count
Chapman said we should count them rather than hunt them –> can learn about their distributions
Audobon bubble plots
tell liklihood of detecting a species in a particular place
cardinal disperal type
uniform
fish crow dispersion type
clumped
Sort these from highest to lowest elevation: Red maple, hemlock, table mountain pine
table mountain pine, red maple, hemlock
moisture gradient
trees showed clumping along moisture gradient
-dry at top, wet at bottom
Ehleringer and Clark
- encelia californica = cool moist and cool dry
- encelia actoni = dry warm
- encelia farinosa = hot
kangaroos
climate impacts their distribution
climate change
organisms retreat northward in response to melting glaciers –> evidence in pollen
Tree dispersal rate
100-400 meters per year
range expansion
dispersal involving the movement of small seeds or larvae over large geographical area
Tree of heaven (A. altisima)
- example of range expansion
- grew rapidly and produced many seeds and became invasive because it didn’t have its control species like it did in china
- moth spread rapidly with it
Honey bees from Africa
- hybridized in Brazil
- aggressive
- range expansion all the way to north america
collared doves
invasive species from turkey
-introduced to Jamaca, so it spread throughout US
difference between dispersal and migration
- dispersal is usually individaul
- they don’t return
- can be small or large scale
methods of seed dispersal
gravity, wind, water, pressure, animals
Lesser Kestrals
- young emigrate (disperse)
- 30% young females
- 22% young males
- 4% adults
how do stream dwellers maintain their position?
- streamlined bodies
- bottom dwellers
- adhesion to surfaces
spate
flooding of stream that causes downstream dispersal
downstream vs upstream dispersal
passive vs wind or animals
monarch dispersion
-migrate north throughout generations and then return to Mexico
metapopulations
network of subpopulations living in patches of habitat and exchanging individuals
sub populations
- high connectivity and frequent movement of populations
- relatively reproductively isolated
Alpine butterfly
- has subpopulations
- only 5.8-15.2% were recaptured in different meadows
- the ones in small meadows were more likely to disperse
