Download chapter 8 wiki questions and answers 2014

Chapter 8 questions and answers
Mina Puig
1) Physicl Appearance - the relative sizes, stratification, and distribution of its populations and species
Species Diversity - a combination of its species richness (the number of types of species) and the
abundance of individuals within each of the species (species evenness)
Niche Structure - the number of ecological niches, their resemblences and difference, and how species
interact with one another
2) Species Equilibrium Model (theory of island bioigeography) - a balance between two factors
determines the number of different species found on an island: the rate at which new species immigrate
to the island and the rate at which existing species become extinct on the island. Two factors affect these
two rates: size and distance from the mainland.
Of the two imaginary islands, the one further away from the mainland would attract fewer new species but
this does not account for how fast the existant species will go extinct so the island closer to the mainland
has the potential to have the most diversity.
3)
Name
Native
Species
Nonnative
Speices
Indicator
Species
Keystone
Species
Effect on ecosystem
They are the species normallly found in
an ecosystem
Example of how interacts with environment
lives and flourishes amoung the other native
species in a balanced or consistently fluctuating
state
Sometimes displace native species
overtakes native species place and causes
extincton - killer bees in Brazil
serve as an early warning of damage or birds are good indicator species because they
danger to an to a community
are easily affected by environmental changes
such as loss of habitat and introduction of
chemicals
effect the types and abundance of many pollination - insects and birds for flowers and
other species in a community more so
flowering plants
than their numbers would suggest they
top predators regulating animals with rapid or
could
numeral reproductions
4) Interspecific Competition - competition for shared space and food due to an overlap in certain species
fundamental niches. one of them must alter their lifestyle in order to continue surviving
Predation - when one species feeds directly on another species (prey). The predators benefit and the
prey are harmed... well killed. Lions and zebras.
Symbiosis Interference competition
Chapter 8 questions and answers
Exploitation competition
Competitive exclusion principle
Strategies for reducing competition
5) Strategies Predators use to catch their prey: pursuit and ambush - big cats, camoflauge - spiders,
chemical warfare - snakes and scorpions
Five ways prey defend themselves: protective outer coverings like shells or thorns, camoflauge,
chemicals on ther skin or saliva, sharp claws or teeth, showy frills or designs on their skins such as
butterflies and certain types of lizards
Example of predator prey relationship: lions and elephants - lions use pursuit and ambush strategies
while elephants defend themselves with their tusks
Olivia Gehrke
10/16/14
Chapter 8 Q's 6-9
6. Parasitism is when one organism (the parasite) is benefitting while its host organism is suffering. An
example, tapeworms, which are disease-causing organisms, feed in the intestines of organisms,
weakening them. Mutualism is when both organisms are benefitting from an interaction. For example,
oxpeckers eat parasites off rhinos, which provides them with food, while benefitting the rhino by removing
harmful parasites. Commensalism is when one organism benefits from an interaction, while the other is
not affected at all. An example would be epiphytes which grow on tall trees in order to have a greater
access to sunlight, but the host tree isn't affected.
7. Succession is the gradual change in species composition of a given area. Primary succession is
succession with a fairly lifeless foundation to grow from. Secondary succession occurs where biotic
Chapter 8 questions and answers
communities are already present. Four categories of successional species are pioneer species (i.e.
lichens or mosses), early successional plant species (i.e. low-growing vegetation), midsuccessional plant
species (i.e. herbs, grasses, & low shrubs), and late successional plant species (i.e. trees). Three factors
that affect how succession occurs are facilitation, inhibition, and tolerance.
8. Disturbances can affect succession by reverting it back to an earlier stage, should a disturbance occur.
a. The intermediate disturbance hypothesis states that there is greater species diversity in communities
where disturbances occur fairly frequently.
b. Succession at Hubbard Brook Experimental Forest was disturbed by harsh winters and acid rain.
Eventually, succession lead to an increase in nutrient retention in the ecosystem.
9. Inertia is the ability of a living system to resist being altered or disturbed. An ecosystem that has high
inertia is a tropical rainforest. Constancy is the ability of a living system such as a population to keep its
numbers within the limits imposed by available resources. A rainforest is a good example of an
ecosystem with constancy because even when there are disturbances, the ecosystem is not “thrown off”
very much. Resilience is the ability of a living system to repair damage after an external disturbance that
is not too drastic. Grasslands have high resilience because most of their roots are underground, so when
they're disturbed, they are still able to recuperate and survive because of the grasses' underground root
systems. Originally it was thought that systems with more diversity had more stability because if a
disturbance took place, the ecosystem's “eggs weren't all in one basket.” However, there is research
showing that some systems with a lesser amount of diversity are actually very stable. In the ecosystems
with lots of diversity, it's difficult to tell just what species are contributing to the overall stability, which is
why it's difficult to find a definitive tie between stability and diversity.
EMILY GRIFFIN Chapter 8 community ecology homework questions
Chapter 8 questions and answers
1. Three forms of symbiotic ways species interact that increases their ability to survive are
parasitism, mutualism, and commensalism. Parasitism is a relationship where one organism
benefits off the other, and is worsened. An example is a tick and a dog or human. A
mutualistic interaction is when two organisms of different species "work together," each
benefiting from the relationship.An example is a flower and a bee. Commensalism an
interaction between two organisms in which one benefits and the other derives neither
benefit nor harm. An example is barnacles of a whale.
1. Succession can be primary or secondary. Primary succession is the graduated
establishment of biotic community on near lifeless ground. Secondary succession is a biotic
community that is established where some already existed. The four categories of
successional species are pioneer species like lichen, early successional plant species like
annuls that flower and then give way to seeds, mid successional plant species like small
perennial grasses that last around 2 years, lastly late successional plant species like herbs
and ferns. The three factors are: soil, nutrients, and temperature.
1. a). Communities that experience fairly frequent, but moderate disturbances have the
greatest species diversity, big enough to develop new species, but small enough to allow
some survival.
b).Hubbard Brook experimental Forest is a small watershed that scientists used to
manipulate factors to see the changes it would create in the system. The results were that
communities that had more species were more resilient.
Chapter 8 questions and answers
1. Inertia is persistence. it is the ability of organisms to resist being altered. An example is
temperate forests are generally more diverse than grasslands, so both their inertia would be
greater. Constancy is the ability of a population to keep its numbers within the limits set by
its resources. Resilience is the ability of a system to repair the damage after an external
disturbance that is not drastic. Using the grassland example grasslands have high resilience
because they will grow back quickly. The difference between these concepts seems to be
their scale.