Ecology Chapter 5

dryas flowers example

temperarure in middle of the flower warmer than the air; lures insects in

microclimate

climatic variation on a small scale

list of things that microclimate is influenced by

altitude, aspect, vegetation, ground color, boulders

altitude

temps lower at high elevations

why are temps lower at high elevations

lower atmospheric pressure

aspect

hills, mountains, and valleys create microclimates

how do hills, mountains, and valleys create microclimates

shades parts of the land

vegetation

plants create microclimates

how do plants create microclimates

trees, shrubs, plant litter; important in deserts

color of the ground

black beaches heat much faster and are hotter than white beaches

presence of boulders and burrows

under sides of stones create distinctive microclimates

burrows

soil temperature more moderate than at surface

aquatic temperatures

water temp more stable than air

adapting to one set of environmental conditions

reduces a population’s fitness in other environments

all organisms are adapted to a

limited range of environmental conditions

the principle of allocation

energy allocated by reproduction, growth, etc. reduces energy available for other functions

bennett and lenski experiment question

does adaptation to a low temperature decrease fitness at high temperatures

bennett and lenski experiment

lineages of E. coli grown at 20 degrees for 2,000 gens. lower fitness at 40 degrees

biological heat balance equation

Hs= Hm ± Hcd ± Hcv ± Hr - He

Hs

heat storage

Hm

metabolic heat

Hcd

conduction

Hcv

convection

Hr

radiation

He

evaporation

ectotherm

an animal that relies on its external environment to regulate its body temperature

endotherm

animals that generate their own internal body heat to maintain a stable temperature

homeotherm

animals that maintain a stable internal body temperature

plant in desert example

reduces conduction by keeping foliage off ground; high convective heat loss to wind; reflective leaves reduce radiation

majority of organisms are

ectotherms (insects)

grasshoppers reared at low temps develop

dark pigmentation highly absorbent to light

grasshoppers reared at high temps develop

light and reflective pigmentations

clear-winged grasshopper experiment

one exposed to light and one kept in dark; light raised body temp 10 degrees above air temp

why does the clear-winged grasshopper maintain a higher body temp

fungi can’t live above 35 degrees celcius

endotherms use metabolism to

gain or lose heat

thermal neutral zone

range of environmental temps which an endotherm’s metabolic rate does not change

tropical species have a more … thermal neutral zone because…

narrow; don’t need to adapt because no seasons

arctic species have a … thermal neutral zone because…

large; adapted to large range because of temp seasonality

many organisms … to avoid extreme temps

migrate

what do beetles do on hot sand

lift there bodies off and eventually move to shade

torpor

state of low body temp and metabolic rate

torpor example

broad-tailed hummingbird

broad-tailed hummingbird example

caught birds before and after night; torpor same weight, non torpor lower weight

reasons for the broad-tailed hummingbird to go into torpor

finite number of plante during winter and rainy days where they can’t fly

estivation

state of dormancy involving reduced metabolic rate in summer

arctic and alpine plants

increased radiative heating and decreased convective cooling; leaves perp to sun; cushion plants hug warm ground

tropical alpine plants

retain dead leaves for insulation; water retention

example of something that endotherms do to regulate temp

shivering, sweating