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AP Bio Notes on Conservation Biology – Ch. 56
Most of the species of organisms in the world are found in the ____________.
However, human activities have been changing ____________structure, ______cycling and energy flow.
There is a ____________ crisis in which there is a rapid decrease in the
____________ of organisms on Earth as many become ____________ due to the activities of humans.
There are 3 levels of the destruction of biodiversity occurring:
1. ____________ - The genes of individuals are different and
members of the same species in different ____________ also differ in their genes.
If one local population becomes __________, this decreases the genetic diversity of the species as a whole.
2. ___________ diversity – Can mean the number of different kinds of species within a particular ecosystem or the biosphere as a whole.
If a species is ____________it means that it could become ______in one or more of its ranges.
If a species is ____________ it means that a species is on its way to becoming extinct, but is in less immediate danger.
At the current rate of destruction, as many as ___________ of the current species may be extinct in another 100 years.
3. __________ diversity – certain ecosystems are being destroyed. Ex. Tropical rain forests.
Biodiversity matters because:
A. Species that are threatened could some day provide valuable materials such as
________,______ or fibers. A certain species might be the only one in
the world with a certain ______ that could be valuable to us for medicines, foods, chemicals, etc.
B. It is morally right to preserve the Earth and its ______.
C. Ecosystems that are threatened may be important in many ways including ____________
of chemicals, ____________ of air and water, reducing ______and droughts,
_________ control, pollination, etc.
4 major threats to biodiversity:
1. The biggest threat is ____________ due to
______, mining, urban development and pollution. Many natural
habitats have not been totally destroyed, but they have been ____________ in
ways that make reproduction difficult.
2. The second most important threat to biodiversity is _________
______. When humans move a species to a new location,that new species can cause
serious and often ____________ problems. Frequently the new species has taken
________, and caused the original species to become extinct in that area.
3. ____________ is when humans harvest organisms at a rate that is greater than the organism’s ability to reproduce. Ex. Overfishing or overhunting
4. Disruption of ________ - extinction of one species can interfere with the
survival of other species that feed on it or cause ______(which can lead to a population drop) of a species it eats.
Population Decline
An ______ is the downward spiral in size of a
population that is already small. Having a small population leads to _________
between its members. This and occasional disasters (called ________) will
reduce the ____________ within the population. Less genetic
variation causes the population to be less ____________ to changes in its environment
and this causes more individuals to _________ or be unable to ____________.
This reduces the population __________ even more and the downward spiral continues. Diagram:
Lack of genetic variation is not always a __problem______, but often it is.
Some declining populations have been saved by ___________ with members of the same
species from another area to increase the ________ in the population.
Ex. ______chickens were declining in North America and they also had
reduced genetic ______when their DNA was compared with museum
specimens. When the population was bred with prairie chickens imported from ______,
their genetic diversity increased and the ______rate of eggs increased with it.
A ____________approach such as this also looks to determine how small a population needs to be before an extinction vortex begins.
The ____________size is the smallest number
of individuals needed to prevent the vortex. ____________ calculations can also be
used to determine the ____________ population size which deals with the number of
individuals who can actually __________ in a population and population
________ analysis which seeks to predict the chances of the survival of a certain population.
Another approach to endangered populations is the ____________ population
approach which uses ____________ method to try to list and _________ possible causes
for the decline of the population. These may include reasons such as a toxic ____________
which is poisoning a species, _________ reduction, etc.
Ex. The Red Cockaded ______population was declining. They nest in
mature red pine trees and live in social groups in which an older bird must ______to open
up a nesting site for a younger bird because nest construction can take several years. To increase
the population, scientists found that if they put ______in pines for the young birds, they would nest there and produce more young.
There are often many ____________ interests at stake when it comes to helping endangered species.
Ex. Resources needed by humans vs. habitat for an animal
Of particular interest to be saved are ____________ species which have large impacts despite their small population numbers.
Landscape conservation
____________ ecology considers human land use patterns. Certain species live on
the ____________ of a particular ecosystem.
Ex. ______live on the edge of the woods where it connects to open fields.
Human land divisions have often ______ the amount of edges, which increases some populations, but decreases others.
In fragmented land areas,____________ for animals have been created to help them move safely between the fragmented ecosystems.
There are many problems to be solved for ______ trying to set up areas of protected land:
1. Much of the current focus has been on ________
such as the rainforest or chaparrals where there are many different ________ (found
only there in the world) species. However, a hot spot for one species may ______ be a hot spot for another species. Also vertebrates and plants are ____________ likely to be considered than invertebrates and microorganisms.
2. The areas that are preserved are often too ______ to provide enough habitat to support the minimum viable population size needed to keep a species alive.
3. However, a single large area may contribute more to the spread of ___________ in the population than if the preserves were more fragmented.
4. Management of a preserve where some organisms need ________ or other disasters to maintain their ecosystem can be difficult to justify to some who upset by the dead and ugliness it creates at first.
A ______ has large areas that are undisturbed by humans
scattered in other areas in which humans can _________ the land for economic gain in a way that protects the long term viability of the reserve region.
Ex. This is becoming very successful in ______.
Restoration ecology
________ ecology works to restore areas that have been used and damaged
by humans to their original natural state. The larger the area, the _______ it will take to restore it.
One method of restoration is ____________ is the use of living organisms such as fungi, prokaryotes and plants to detoxify a polluted ecosystem.
Ex. ______will take in toxic zinc, nickel and lead from old mining sites
Ex. The bacterium ______will take in oil from oil spills.
Another method is biological ____________ in which needed materials are added to an area to help it recover.
Ex. Adding chemical nutrients to soil so plants will be able to grow there.