ch. 52 Flashcards
ecology
scientific study of interactions between organisms and the living/nonliving components of their environment
levels of organization
- organisms
- populations
- communities
- ecosystems
- biomes
- biosphere
organismal ecology
studies how an organism’s structure, physiology, and behavior meet environmental challenges
what does organismal ecology include
physiological and behavioral ecology
population ecology
focuses on factors affecting population size over time
population
group of individuals of the same species living in an area
community ecology
examines effect of interspecific interactions of community structure and organization
community
group of populations of different species in an area
ecosystem ecology
emphasizes energy flow and chemical cycling between organisms and the environment
ecosystem
entire community of organisms in an area and the physical factors with which they interact
landscape (or seascape)
mosaic of connected ecosystems
landscape ecology
focuses on exchanges of energy, materials, and organisms across multiple ecosystems
biosphere
global ecosystem, sum of all the planet’s ecosystems and landscapes
global ecology
examines influence of energy and materials on organisms across the biosphere
what constitutes a climate
long-term prevailing weather conditions in an area
what does climate consist of
- temperature
- precipitation
- sunlight
- wind
what are global climate patterns determined by
solar energy and earth’s movement in space
what does the warming effect of the sun establish
- temperature variations
- circulation of air and water
- evaporation of water
what causes latitudinal variations in climate
warming effects of sun
what affects sunlight intensity
angle at which sunlight hits earth
intensity
amount of heat and light per unit of surface area
where is the intensity of sunlight the strongest
in the tropics - strikes earth most directly
wet air masses circulation and tropics
- water evaporates in tropics, and warm/wet air masses flow from tropics to poles
- rising air masses release water and cause high precipitation
what do dry air masses create
arid climates
what creates predictable global wind patterns
air flowing close to earth’s surface
where do cooling trade winds blow
from east to west in the tropics
where do prevailing westerlies blow
from west to east in temperate zones
what seasonal variations increase steadily toward the poles
- day length
- solar radiation
- temperature increase
what is seasonality at high latitudes caused by
- tilt of earth’s axis of rotation
- annual passage around the sun
what do regions at 20 N and 20 S latitudes have
wet and dry seasons due to the changing angle of the sun
what are ocean currents altered by
seasonal changes in wind patterns
what do altered ocean currents cause
upwelling of cold, nutrient-rich water from deep ocean layers
- stimulates population growth of phytoplankton and organisms that feed on them
what do ocean currents influence
the climate of nearby terrestrial environments
how do large bodies of water moderate the climate of nearby land
- day: air rises over warm land and draws a breeze from the cooler water
- night: air rises over warmer water and draws cooler air from land back over water, which is replaced by warm air from offshore
how do mountains influence air flow over land and affect climate
- warm air cools as it rises up a mountain and releases moisture on the windward side
- cool, dry air absorbs moisture from the land as it descends and creates a “rain shadow” on the leeward side
what is the temperature drop for each 1,000 m increase
6 degrees celsius
microclimate
very fine, localized patterns in climate
what is every environment characterized by differences in
abiotic and biotic factors
abiotic factors
nonliving attributes such as temperature, light, water, and nutrients
biotic factors
other organisms that are part of an individual’s environment
climate change
directional change to the global climate lasting 3 decades or more
what have increased the concentration of greenhouse gases in the atmosphere
- burning of fossil fuels
- deforestation
what does climate change effect
- wind and precipitation patterns
- global temperature
- frequency of extreme weather events
how to predict effects of future global climate change
study how species responded to changes in the past
what have geographic ranges of many species have shifted in response to what?
climate change
what happens to species that have trouble dispersing or face a shortage of suitable habitat?
could have smaller ranges or become extinct
biomes
major life zones characterized by vegetation type (terrestrial biomes) or physical environment (aquatic biomes)
how are terrestrial biomes separated
usually grade into each other without sharp boundaries
ecotone
area of intergradation of terrestrial biomes - may be wide or narrow
what is an important feature of terrestrial biomes
vertical layering
vertical layering in forest
- upper canopy
- low-tree layer
- shrub understory
- ground layer of herbaceous plants
- forest floor
- root layer
disturbance
event such as a storm, fire, or human activity that changes a community
intermediate disturbance hypothesis
need just right amount of disturbance to have high biodiversity
what are terrestrial biomes characterized by
- distribution
- precipitation
- temperature
- plants
- animals
tropical forest
- distribution is in equatorial and subequatorial regions
- temperature high year-round with little seasonal variation
tropical rain forest precipitation
rainfall relatively constant
tropical dry forest precipitation
precipitation highly seasonal
desert
- occur in bands near 30 north and south of equator and in interior of continents
- may be hot or cold
desert plant adaptations
heat and desiccation tolerance, water storage, reduced leaf surface area
desert animals
many nocturnal and have adaptations for water conservation
savanna
- huge ecotone
- grassland dotted with trees
- less precipitation than a forest, and more than on a grassland
dominant plant species of savanna
- fire-adapted
- tolerant of seasonal drought
- grasses and forbs make up most of ground cover
animal species in savanna
- large herbivores common
- insects dominant herbivores
forb
herbaceous plant that’s not a grass or grass-like plant
herbaceous plant
one that doesn’t develop a toddy stem and so dies back to the ground after one growing season
- annual or perennial
what are grasses
graminoids
chaparral
- precipitation highly seasonal with rainy winters and dry summers
- summer hot, fall/winter/spring cool
plants in chaparral
shrubs, small trees, grasses, and herbs
- many adapted to fire/drought
animals in chaparral
amphibians, birds, reptiles, insects, browsing mammals, diversity of small mammals
temperate grassland
- found on many continents
- precipitation highly seasonal
- winters cold and dry
- summers hot
dominant plants of temperature grassland
- grasses and forbs
- adapted to droughts and fire
animals in temperate grasslands
- large grazers such as bison/wild horses
- small burrowers such as prairie dogs
northern coniferous forest (taiga)
- North America and Eurasia
largest terrestrial biome on earth
northern coniferous forest
plants in northern coniferous forest
pine, spruce, fir, hemlock
temperate broadleaf forest
vertical layers (closed canopy, understory trees, shrub layer, herb layer)
dominant plants of temperate broadleaf forest
- deciduous trees in the northern hemisphere
- evergreen eucalyptus australia
tundra
- covers expansive areas of the arctic
- annual precipitation lower in arctic tundra than in alpine tundra
- winters cold
- summers cool
where does alpine tundra exist
on high mountaintops at all latitudes
vegetation of tundra
herbaceous (mosses, grasses, forbs, drawf shrubs, trees, lichen)
permafrost
permanently frozen layer of soil, restricts the growth of plant roots
mammals in tundra
musk, oxen, caribou, reindeer, bears, wolves, and foxes, migratory bird species
largest marine biome
oceans - 75% of earth’s surface
how are many aquatic biomes are stratified into zones defined?
- light penetration
- temperature
- depth
upper photic zone of aquatic biomes
sufficient life for photosynthesis
aphonic zone of aquatic biomes
receives little light
pelagic zone
photic and aphotic zones
abyssal zone
located in aphasic zone with a depth of 2-6,000 m
benthic zone
organic and inorganic sediment at bottom of all aquatic zones
benthos
communities of organisms in the benthic zone
detritus
dead organic matter that falls from the productive surface water and is an important sources of food
thermocline
temperature boundary that separates the warm upper layer from the cold deeper water
turnover
semiannual mixing of water of lakes
- mixes oxygenated water from surface with nutrient-rich water from bottom
