chapter 18 Flashcards
what is ecology
everything is related to something else, everything is going someplace, there is no such thing as a free lunch, nature knows best
what is a population
group of interbreeding individuals of the same species, living in the same geographic area
what is a community
two or more populations of different species, living in the same geographic area and interacting with one another
what is an ecosystem
a community of living organisms plus their non-living environment through which energy flows and minerals cycle
what is a biome
group of ecosystems with common patterns of climate and distinctive vegetation distributed over a wide area
what is the biosphere
all of the ecosystems of the world – the portion of the earth that supports life, including the atmosphere [air], hydrosphere [water] and lithosphere [land]
what are the two main climatic factors which determine the distribution of biomes
temperature and precipitation
which biome is characterized by permafrost
—tundra–
>arctic regions of North America & Eurasia
> long cold winters, summers only few weeks
> permafrost—permanently frozen subsoil; preventing water & plant roots
> lichens, mosses sedges, grasses, low growing shrubs
soil builds slowly
> food chains are simple and limited
in which biome is Memphis located
—-taiga—
[northern coniferous forest]
> summers cool, winters cold
> rainfall moderate, soil thin & nutrient-poor
> pine, spruce, fir plants
> squirrels, beaver, porcupine
what are the four most abundant tree species in west Tennessee
beech, maple, basswood, oak
which biome has the best agricultural land
—grassland—
[all continents except Antarctica; places where its too dry to support a forest but too wet to be a desert ]
> light rainfall; nutrients aren’t leached from soil; very fertile
> grasslands both tall and short
> antelope, prairie dog, coyote, badger, prairie chicken
which is the only major biome not found in North America
—tropical savanna—
[tropical grassland]
> only major biome not represented in north America
–warm regions with prolonged dry seasons and recurrent fires [Africa]
> grasses with few small scattered shrubs or trees
> hoofed grazed mammals; giraffe, antelope, wildebeest, zebra, and their predators lion and cheetah
which biome is the richest in species diversity
—–tropical rain forest—-
[equatorial central and south America, Africa and southeast Asia where rainfall and temperatures are high throughout the year]
> richest biome in species diversity
> rapid growth due to excellent growing conditions year-round[temperature, rainfall, light] also organic decomposition is rapid, minerals recycled quickly
> tall trees with slender tree trunks, branching near top forming dense canopy over thick understory of vines, ferns, orchids
> diverse animals and colorful; birds, amphibians, mammals, reptiles, insects
what is the effect on vegetation of increasing latitude and increasing altitude
going north from the equator to the pole or going from base to the top of a mountain—you would see similar changes in the vegetation which result from decreasing temperatures and decreasing amounts of available moisture
what are the zones in a lake
photic zone—>the upper zone where there is sufficient light for photosynthesis—plants produce more oxygen than they use so extra is available for respiration of other organisms
aphotic zone—>below the photic zone where there is not enough light for photosynthesis—where the available light is just enough for photosynthesis and respiration to balance each other
littoral zone—> the shallow, well-lighted water around the edge of the lake—here there are rooted aquatic plants such as water lilies, willows and rushes
limnetic zone–>well-lighted open surface of the lake — here there are floating plants, algae and animals such as fish, small arthropods and zooplankton
what factors are important in determining distribution of organisms
in aquatic ecosystems
dissolved oxygen–>this affects many aspects of life in the lake, including what can live where and the solubility of many nutrients
what are the spring overturn and the fall overturn in a lake
temperature
what peculiar property of water allows for these overturns to occur
winter—>at 0 degrees C the surface freezes, while under the ice the water remains between 0 and 4 degrees C and the lakes organisms survive without freezing
spring—>ice melts –when the surface reaches 4 degrees C it sinks; forcing the colder water below to rice to the surface—[this is spring overturn which is important because it brings nutrients up and oxygen down]
summer—>another temperature stratification occurs as the colder 4 degree denser water gets trapped below the warmer water on the surface
fall—>[fall overturn] occurs as the surface cools, when it reaches 4 degrees it sinks bellow the warmer water just below the surface—[this is important to the life in the lake because it brings the nutrients up and carries oxygen down]
what is a eutrophic lake, what is an oligotrophic lake
eutrophic—>relatively shallow, rich in organic matter and nutrients, very productive, but contains little oxygen because decomposers use it up rapidly
oligotrophic–>deeper, poor in nutrients and therefore little productivity, little organic material, but contains more dissolved oxygen because there are fewer decomposers to use it up —generally very clear water as lakes age
what are the zones in the ocean
intertidal zone –> area between low and high tides—this area supports a variety of plants and animals depending on type of shore
subtidal zone –>area extending from low tide out to edge of continental shelf – less temperature fluctuations and less violent wave movement than intertidal zone
oceanic zone–>open ocean—from edge of one continental shelf to another—organisms in the open ocean include plankton, nekton, benthos
