ch 9 Flashcards
population
group of individuals of single app in specific area
characterize population
number of individuals and density
distribution limit
physical environment limits geographic distribution of spp.
distribution limit can be
geographic range or home range
geographic range
geographic area where you find spp.
home range
where individuals organism spends its time
case study: kangaroo distribution relate to climate
hypothesis
climate and distribution of 3 largest kangaroos in Australia
case study: kangaroo distribution relate to climate
result
limited overlap of 3 kangaroos.
limited distribution may be indirectly determined by climate.
limited distribution do to climate affects
food production.
water supply.
habitat.
parasites, pathogens, and competitors.
case study: tiger beetle of cold climates
hypothesis
prefer low temps (boreal or temporal forest).
compared physiological characteristics of populations
measured water loss
metabolic rate
body temp preferences
case study: tiger beetle of cold climates
results
same preferred temp all through locations.
no different physiological measurements btwn population.
high metabolic rates.
low preferred temp
support generalization physical environments limit species distribution .
case study: plant distributor along moisture -temp gradients
hypothesis
Encilia spp distribution corresponds with variation in temp and precipitation
California - costal with least pubescent
actoni - inland with less pubescent
other - further inland, hotter, overlap
case study: plant distributor along moisture -temp gradients
result
E. frutescens pubescents < E. farinosa even at same temp.
E. frutescens: evaporatively cool and lie in deep soil
spp in intertidal zone
exposed to wide variation in temp, light intensity, wave acton, etc.
case study: distribution of barnacle along intertidal exposure gradient **
hypothesis
see if zonation off muscle spp leads to drying
chthalamus stellatus usually lives on the upper level
balanus balanodes usually on mid-low level
case study: distribution of barnacle along intertidal exposure gradient **
result
balanus are vulnerable to dessication and excluded from upper level
chthalamus cannot be in lower level due to high competition
random distribution
equal chance of being anywhere.
uniform resource distribution
regular distribution
uniformly spaced .
territoriality
avoid one another
territoriality
exclusive use of the area
clumped distribution
unequal chance o being anywhere,
mutual attraction btwn individualizing.
patchy resource distribution
case study: bees
prediction
aggressive will be regularly distributed
non aggressive will be random or clumped.
nest trees will be randomly distributed and abundant and not limited in colonies
case study: bees
result
supported hypothesis
case study: desert shrubs
hypothesis
competition lead to regular distribution
case study: desert shrubs
result
young shrubs were clumped.
as clumps grow shrubs die reducing clumping and lead to regular distribution
competition influenced distribution in roots; few overlapping
small scale distribution
few 100 m
little environmental change
large scale
substantial environmental change
like entire continent or mountain slope
Christmas bird count
continental scale of clumped and widespread distribution of bird population
case study: bird population in NA by Root
prediction
looked at 346 spp of birds that showed showed clumped distribution at a continental scale
case study: bird population in NA by Root
observations
abundance and distribution of crows are limited to hot spots
hot spots
areas of high density
case study: bird population in NA by brown
looked at distribution during breeding season
saw small proportion of sites had most records for each spp. in breeding bird survey
case study plant availability and moisture gradient in Arizona
observation
moist canyon bottoms and dry SW facing slopes
tree spp were clumped along gradients
case study plant availability and moisture gradient in Arizona
result
densities decrease toward edge of distribution
case study plant availability and moisture gradient in NE U.S.
clumped distribution because they aggregate where conditions are favorable
