Ecology assigned reading notes Flashcards
what are biomes?
major life zones characterized by vegetation type (in terrestrial biomes) or by physical environment (in aquatic biomes)
what are the 10 major terrestrial biomes?
- tropical forest
- savanna
- desert
- chaparral
- temperate grassland
- temperate broadleaf forest
- northern coniferous forest
- tundra
- high mountains
- polar ice
what is a climograph?
a plot of the annual mean temperature and precipitation in a particular region
what factors determine where a biome exists?
mean temperature and precipitation
how are terrestrial biomes named?
most terrestrial biomes are named for major physical or climatic features and for their predominant vegetation
what is an ecotone?
terrestrial biomes usually grade into each other without sharp boundaries . The area of intergradation is called an ecotone
what is a disturbance in ecological terms?
is an event such as a storm, fire or human activity that changes a community, removing organisms from it and altering resource availability
In the Terrestrial biome: Tropical Forest, what are the distributions?
equatorial and subequatorial regions
In the Terrestrial biome: Tropical Forest, what is the relative temperature?
high year-round is about 25 - 29 degree celsius with little seasonal varaiation
In the Terrestrial biome: Tropical Forest, the plants available there are?
- very layered and competition for light is intense
- emergent trees grow above a closed canopy, the canopy, one or two sublayers of sub-canopy trees, and layers of shrubs and herbs
In the Terrestrial biome: Tropical Forest, what is the precipitation?
- In tropical rain forests, rainfall is relatively constant about 200-400cm annually
- in dry forests, precipitation is seasonal about 150-200cm annually
In the Terrestrial biome: Tropical Forest, what animals exist here?
5-30 million still undescribed insects
animals including amphibians, birds, and other reptiles, mammals, and arthropods
- very diverse
In the Terrestrial biome: Desert, what is the distribution pattern?
deserts occur in bands 30degrees north and south latitude
In the Terrestrial biome: Desert, what is the precipitation like?
precipitation is low, generally 30cm per year
In the Terrestrial biome: Desert, what is the temperature like?
temperature is not really seasonal and daily
maximum temperature of 50degrees celsius
in cold deserts temperature may fall below -30degrees celsius
In the Terrestrial biome: Desert, what are the plants found here?
cacti or euphorbs and deeply rooted shrubs and herbs that grow during infrequent moist periods
In the Terrestrial biome: Desert, what are the animals found here?
-snakes, lizards, scorpions, ants, beetles, migratory and resident birds and seed-eating rodents
In the Terrestrial biome: Desert, what is the human impact in these areas?
long distance transport of water, have allowed humans to have populations in the desert
In the Terrestrial biome: Tropical Forest, what is the human impact in these areas?
humans established thriving communities in tropical forests
rapid population growth leading to agriculture and development is now destroying many tropical forests
In the Terrestrial biome: Savanna, what is the distribution like?
equatorial and subequatorial regions
In the Terrestrial biome: Savanna, what is the precipitation like?
rainfall is seasonal 30-50cm per year
dry season can last 8-9 months
In the Terrestrial biome: Savanna, what are the plants found in this area?
the scattered trees, have thorny and small leaves
and grass
fires are common in these areas
In the Terrestrial biome: Savanna, what animals are found here?
large plant-eating mammals
- wildebeests
- zebras
- and predators like lions and hyenas
In the Terrestrial biome: Savanna, what is the temperature like in these areas?
24-29degrees celsius with more seasonal variation than in tropical forests
In the Terrestrial biome: Savanna, what is the human impact in these areas?
since the olden days humans have been living in Savannas
fires set by humans help maintain this biome
cattle ranching and overhunting have led to declines in large mammal populations
In the Terrestrial biome: Chaparral, what is the distribution like?
midlatitude coastal regions on several continents
In the Terrestrial biome: Chaparral, what is the precipitation there like?
highly seasonal, with rainy winters and dry summers about 30-50cm a year
In the Terrestrial biome: Chaparral, what is the temperature there like?
fall, winter, and spring are cool with average temperatures between 10-12degrees celsius
summer temp can reach up to 30-40degrees celsius
In the Terrestrial biome: Chaparral, what are the plants within this area?
shrubs, and small trees along with many kinds of grasses and herbs
plant diversity high
In the Terrestrial biome: Chaparral, what are the animals available in this area?
native mammals include browsers, such as deer and goats, that feed on twigs and bugs
high diversity of small mammals
In the Terrestrial biome: Chaparral, what is the human impact in this area?
these areas have been heavily settled and reduced through conversion to agriculture
humans contribute to fires in this area
In the Terrestrial biome: Temperate Grassland, what is the distribution like?
the veldts of south Africa, the puszta of Hungary, the pampas of Argentina and Uruguay, and the Steppes of Russia
In the Terrestrial biome: Temperate Grassland, what is the precipitation like in this area?
precipitation is often highly seasonal
average of about 30-100cm a year
In the Terrestrial biome: Temperate Grassland, what is the temperature like here?
winters falling below -10degrees celsius
summers average temperatures approaching 30degrees celsius
In the Terrestrial biome: Temperate Grassland, what kind of plants are in this area?
grasses and forbs, which vary in height from a few cm to 2m
many grassland plants
In the Terrestrial biome: Temperate Grassland, what are the types of animals in this area?
native mammals include large grazers such as bison and wild horses
In the Terrestrial biome: Temperate Grassland, what is the human impact in this area?
deep fertile soils make this area and ideal place for agriculture
essential for growing grains
In the Terrestrial biome: Northern Coniferous Forest, what is the distribution like in this area?
extending in broad band across northern North America and Eurasia to the edge of the Arctic tundra or taiga
THIS IS THE LARGEST TERRESTRIAL BIOME ON EARTH
In the Terrestrial biome: Northern Coniferous Forest, what is the temperature like in this area?
winters are cold, in Siberia areas around -50degrees celsius
summers are hot, in Siberia areas around 20degrees celsius
In the Terrestrial biome: Northern Coniferous Forest, what is the precipitation like in this area?
annual precipitation is around 30-70cm
U.S Pacific Northwest are temperate rain forests receive over 300cm a year
In the Terrestrial biome: Northern Coniferous Forest, what are the plants and animals found in this area
trees: pine, spruce, fir, abd hemlock
Animals: birds, other species reside there year round
In the Terrestrial biome: Northern Coniferous Forest, what is the human impact in this area?
human populations are being logged at an alarming rate and the old growth stands of these trees may soon disappear
In the Terrestrial biome: Tundra, what is the distribution like in this area?
covers expansive areas of the Arctic amounting to 20% of Earth’s surface
In the Terrestrial biome: Tundra, what is the precipitation like in this area?
averages from 20-60cm annually in Arctic Tundra
may exceed 100cm in Alpine Tundra
In the Terrestrial biome: Tundra, what is the temperature like in this area?
winters are cold, about -30degrees celsius
summer temperatures generally average about less than 10degrees celsius
In the Terrestrial biome: Tundra, what are the plants and animals that exist in this area
vegetation is herbaceous, mosses, grasses and forbs along with dwarf shrubs, trees and lichen
Animals: musk oxen, bears, wolves and foxes, many birds migrate for summer nesting
In the Terrestrial biome: Tundra, what is the human impact in this area?
Tundra is sparsely settled, but has become the focus of significant mineral and oil extraction
what does dispersal mean?
one factor that contributes greatly to the global distribution of organisms
what are some factors that affect species dispersal?
- biotic factors (like predators or herbivores prevent species from surviving and reproducing)
2 abiotic factors (like temperature, water, salinity, oxygen, soil, and sunlight)
what does the abiotic factor temperature do for species dispersal?
temperature affects biological processes
cells may rupture if the water they contain freezes
proteins of most organisms denature at temperature above 45degrees celsius
MOST ORGANISMS FUNCTION BEST WITHIN S SPECIFIC RANGE OF ENVIRONMENTAL TEMPERATURE
what does the abiotic factor of water and oxygen do for species dispersal?
the dramatic variation of water availability among habitats is another important factor in species distribution
The distribution of terrestrial species reflects their ability to obtain and conserve water
water affects oxygen availability in aquatic environments and in flooded soils
what does the abiotic factor of salinity do for species dispersal?
the salt concentration of water in the environment affects the water balance of organisms through osmosis
most aquatic organisms are restricted to freshwater or saltwater habitats by their ability to osmoregulate
what does the abiotic factor of sunlight do for species dispersal?
sunlight absorbed by photosynthetic organisms provides energy and drives most ecosystems, and too little sunlight can limit the distribution of photosynthetic species(ie. rain forests and canopy’s, fight for light is intense)
what does the abiotic factor of rocks and soil do for species dispersal?
in terrestrial environments, the pH, mineral composition and physical structure of rocks and soil limit the distribution of plants therefore of the animals that feed on them.
what is resource partitioning?
the differentiation of niches that enables similar species to coexist in a community is called RESOURCE PARTITIONING
what is interspecific competition?
is an interaction that occurs when individuals of different species compete for a resource that limits their growth and survival.
ie. grasshoppers and Bison in the Great Plains compete for the grass they both eat
what is character displacement?
This tendency for characteristics to diverge more in sympatric then in allopatric populations of two species is called CHARACTER DISPLACEMENT
what is cryptic coloration?
aka camouflage, makes prey difficult to see
mechanical or chemical defenses protect species from predation
what is predation?
refers to an interaction between species in which one species, the predator kills and eats the other, the prey.
what is aposematic coloration?
animals with effective chemical defenses often exhibit bright aposematic coloration or warning coloration
this seems to be adaptive because predators often avoid prey that have bright colour patters
what is Batesian Mimicry?
a palatable(plesant to eat) or harmless species mimics an unpalatable(unpleasant to eat) or harmful one
what is Mullerian mimicry?
two or more unpalatable(unpleasant to eat) species, such as the cuckoo bee and yellow jacket, resemble each other.
The more unpalatable prey there are, the more quickly predators learn to avoid prey with that particular appearance
what does herbivory mean?
refers to an interaction in which an organism eats parts of a plant or alga (ie. grasshoppers, and beetles)
what is facilitation?
species can have positive effects on the survival and reproduction of other species without necessarily living in the direct and intimate contact of symbiosis this type of interaction is called FACILITATION
what is species diversity of a community?
the variety of different kinds of organisms that make up the community has two components
what are the two components of species diversity in a community?
- species richness (the number of different species in the community)
2, Relative abundance (of different species, the proportion each represents of all individuals in the community
what are invasive species?
organisms that become more established outside their native range
what does sympatric mean?
a speciation in which new species evolve from a single ancestral species, while inhabiting the same geographical region
what does allopatric mean?
a speciation in which biological populations are physically isolated by an external barrier and evolve internally (genetic reproductive isolation) such that if the barrier of the population breaks down, individuals within it can no longer interbreed
