QUIZ: Succession, Population Biology, Biodiversity Flashcards
succession definition
succession is the orderly replacement of one community by another (generally we refer to plant communities) until a stable community (one that is not replaced by another) is reached.
types of succession - primary definition
succesion in a place that…
succession in a place life never existed before (such as bare rock or an island emerging from the sea as a result of volcanic activity)
during primary succession, what do plants do?
plants modify the enviornment, making it available to more complex plants
as the plant life changes, what else does as well?
the animal life changes as well
(primary succession) this replacement of one community by another will continue until..
until the stable community is established
pioneer organisms are../ what do they do
the first organisms to occupy an area
these organisms start breaking down the rock, forming soil. they also add nutrients into the soil.
examples of pioneer organisms include
moss and lichens (combination of fungus and algae)
climax community is the
the stable community formed after succession
this community will not be replaced by another. As long as there are no natural disasters and people do not disturb it, it will continue indefinitely.
the type of climax community is determined by what
the climate.
(Examples - Desert - climax community is made up of cactus
Temperate forest - is made up of beech, maple, oak, and hickory trees)
secondary succession is
succession in a place life once existed before
(population biology) exponential growth
- population doubles in a specific time
- can result in overpopulation
-human population goes through this in shorter periods of time
-demonstrated by a “J curve”
secondary succession could take place at…
an abandoned farm, an area in which fire of flood killed the members of the community, or in a place devastated by a volcano (Mt. St. Helens)
increase in population results in..
- crowding and stress
- increased competition and stress on organisms
stressed animals may start to exhibit..
unusual behaviors
(human population growth) As the human population has grown, it has resulted in
overcrowding, hunger, extinction of species, and pollution
density dependent factors are
factors that have a big influence on high density populations rather than low density populations
- usually biotic factors
density independent factors are
factors that have equal influence on both high and low density populations
-usually abiotic factors
biodiversity is
the variety of life in an ecosystem
3 reasons why biodiversity is important
-stability of eco system
-medical implications
-variety of food
(importance of biodiversity) stability of ecosystem
the greater the biodiversity the more stable the ecosystem. if species numbers within an ecosystem decreases, it could result in the loss of the ecosystem
(importance of biodiversity) medical implications
many drugs have been formed from extracts from plants and animals. the extinction of a species could mean the loss of a possible cure for disease.
(importance of biodiversity) variety of food
most living things have more than one food source
(threats to biodiversity)
habitat loss
- This is the number one threat to biodiversity
Human activities such as farming, building of roads, malls, and housing, along with pollution have resulted in habitat loss
(threats to biodiversity) habitat fragmentation
breaking up large habitats into smaller habitats by building roads. Bridges, housing developments ect
Smaller habitats can not support as much life/biodiversity as larger habitats can
habitat degradation definition
the lowering of the quality of a habitat through pollution
- this degradation can be so severe that life can no longer exist in the polluted enviornment
(air pollution) acid precipitation is
rain, snow, sleet, hail, or fog that has a PH less than 7
Sulfur dioxides and nitrogen oxides are released when
we burn fossil fuels (coal,oil)
acid precipitation is also responsible for
erosion of buildings, statues and the damaging of art work in areas that have climate control systems
(air pollution - depletion of the ozone layer) what is the ozone layer?
The ozone layer sometimes called the ozone shield, is a layer of our atmosphere that reduces the amount of harmful radiation in the form of ultraviolet light, from reaching the Earth
overtime, the ozone layer has been
The ozone layer has been thinned, and in some areas around the poles, there are holes, the presence of CFCs (chlorofluorocarbons) being released into the atmosphere has caused this problem
humans have used CFC’s in
fire extinguishers, and to assist with cooling in air conditioners and refrigerators
UV light is/can cause
a mutagen, and can cause genetic mutations within organisms
Excessive UV light can cause
cause skin problems within animals and humans, disrupt plant growth, and cause marine life to die (which could lead to the collapse of the marine biome and life on this planet)
Using a tanning bed before the age of 35 increases your chances of developing skin cancer by 75%
climate change (global warming) global warming is the result of
the excessive release of greenhouse gasses
There are several different greenhouse gasses but, the one that is most associated with the warming of the planet is
carbon dioxide
carbon dioxide in the atmosphere prevents…
heat energy from escaping the Earth
the major cause of increased carbon dioxide in the atmosphere is
the burning of fossil fuels
An increase of the earth’s temperature will cause…
a change in biomes and ecosystems
This increasing temperature will result in:
-the extinction of some species
-shifts in where some species will inhabit
-change in plant life
-will cause the ice at the poles to melt
if the ice at the poles melt…
sea levels will rise, and there will be less land for people to farm and live
water pollution
All water on the earth today is polluted. To get clear water today you need to either create the water or filter it
The effect of pollution are now affecting the stability of the largest biome on earth, the marine biome
Oil reduces the rate of
evaporation, is toxic to marine organisms
Radioactive material can cause
mutations and at high levels, create dead zones
Plastic takes a long time to…
decompose, plastic nets can trap organisms resulting in starvation or drowning, if ingested it can block the digestive system resulting in starvation, can travel through the food again
when fertilizers enter the marine biome, it can result in an increase of
algae and bacteria populations. these organisms use up the available oxygen, resulting in fish kills
Pesticides and toxins
will also enter marine and freshwater areas
These toxins will be absorbed by the plants and microorganisms
As these toxins and pesticides move through the food chains the concentration with the organism will increase. This is known as biological magnification
As the pesticide/toxin concentration increases. This may result in mutation, disease, or death of the organism
Pesticides - including herbicides, can produce
toxic environments
These pesticides could kill unintended victims and can be transmitted through the food chain
radioactive material from the military, hospitals, and power plants have been/can lead to
buried in the soil
this can lead to radioactive dead zones
landfills are
large areas that trash is stored
- destroy local habitats
- we are running out of room to store our garbage
(threats to biodiversity) invasive/ exotic species are organisms that have been
imported, either on purpose or accidentally from their native area to an area they have never existed before
frequently, invasive species will increase their
their population quickly, replacing native speices
- reasons why invasive species replace native species include, the invasive species is a better competitor than the native species and the invasive species has no predator to control the population size
to counter habitat loss,
people and organizations have been purchasing large areas to conserve species habitat
There have also been requests to governments to declare wildlife areas and sanctuaries or national parks
Preserving habitats saves species and has led to a new business, ecotourism
acid precipitation results from
from water vapor in the air combining with sulfur dioxides or nitrogen oxides
