Test 4 Review Flashcards
A boundary created by sharp changes in environmental conditions over a relatively short distance is termed _________.
Ecotone
Specialized fishes and shrimp remove parasites from various fish species in a ___________ mutualism.
defensive
The symbiotic relationship of coral and zooxanthellae is an example of __________ mutualism.
obligate
Communities can be categorized as interdependent or independent. The community of trees in the Great Smoky Mountains is classified as:
independent
Species diversity incorporates both
species richness and relative abundances
The Pisaster sea star is an example of ___________ as it substantially affects the structure of its community.
keystone species
The correlation between species richness and disturbance frequency can be explained by the
intermediate disturbance hypothesis
T/F
Within a pond community, the presence of fish has an indirectly negative effect on the presence of pollinating insects.
False
When the abundance of trophic groups is determined by the existence of predators at the top of the food web, this is termed:
top down control
Each stage of a community change during the process of succession is termed:
seral stage
The community succession after a category three hurricane would be classified as:
secondary
In the aquatic succession experiment, the presence of acorn barnacle’s later arrival to the intertidal is due to which mechanism?
inhibition
The presence of macroalgae which depends on the presence of acorn barnacles is an example of which succession mechanism?
facilitation
The difference between net primary productivity and gross primary productivity is the amount of energy lost to
respiration
Examine Fig 18.5. Which of the following species would you characterize as seemingly unresponsive to changes in soil conditions across the ecotone between serpentine and nonserpentine soils in southwestern Oregon?
hawkweed
You have been maintaining a list of the bird species that frequent your property. At the end of the year you have tallied eight seed eaters, one nectar sipper, three woodpeckers, six insectivores, two frugivores, four predators and one carrion feeder. Which term best describes each of the categories you have used in your tally?
community
True/False: Herbivores, large and small, are all referred to as secondary consumers.
False
Which of the following is not a typical attributes of an early-successional species?
rapid growth
large seed size
excellent dispersal ability
ability to colonize unexploited environments
large seed size
In both aquatic and terrestrial ecosystems, an increase in primary productivity is positively correlated with an increase in ____________.
secondary productivity
True/False: Some aquatic phytoplankton are limited by iron availability and aeolian dust can supply this limiting nutrient.
True
Mutualism is defined as?
positive interaction between two species in which each species receives benefits that only the other species can provide
Generalists (in mutualism) are defined as?
one species can interact with many other species
Specialists (in mutualism) are defined as?
one species that interacts with either one other species or a few closely related species
Two species provide benefits to each other and require each other to persist, they are?
obligate mutualists
What are two examples of obligate mutualists?
Tubeworms and chemosynthetic bacteria
coral and zooxanthellae
What is the benefits tubeworms bring the chemosynthetic bacteria?
Since they live near deep sea hydrothermic vents, the tubeworms provide a place for the bacteria to live, and the bacteria provide food for the tubeworms.
What is the benefits the coral and zooxanthellae bring to each other?
Corals provide a place for algae to live and emit CO2, that the algae use for photosynthesis. As the algae photosynthesis they provide sugars and O2 that corals consume
When two species provide fitness benefits to each other, but the interaction is not critical to the persistance of the other species it is called?
faculatative mutalism
What is an example of facultative mutualism?
Aphids, which suck the sap from plants and produce droplet rich in carbohydrates that is consumed by several species of ants.
The ants gain a source of food and in exchange provide protection from predators for the aphids
- Also defensive mutalisms
Defensive mutualism is?
one organism receives protection and the other receives nutrients/resources
Fungi that surround plant roots and help plants obtain water and minerals are known as?
mycorrhizal fungi
The network of fungal hyphae provide plants with minerals such as __________ and ____________.
nitrogen and phosphorus
What do plants provide the fungi?
sugars from photosynthesis
Besides nutrients, what else do fungi help plants with?
increasing the plants tolerance to to both drought and salt stress and help prevent infections from pathogens
What is an example of plant/bacterial mutualism?
Bacteria from the genus Rhizobium live in a mutualistic relationship with legumes.
The bacteria enter the legumes through the root, and the legumes form small nodules that surround them providing them with a place to live.
The legumes provide the Rhizobium with products of photosynthesis, and the bacteria convert atmospheric nitrogen into ammonia.
*Great in areas of low soil fertility
What is an example of animals and protozoan mutalism?
Termites eat wood, but can not digest it. To aid in this effort, species of protozoans live in termite guts and the termites receive the benefits of protozoan digestion.
The protozoans receive a home and constant food source.
What is an example of mutualism among animals?
*human and animals
Humans and the honeyguide bird.
Humans use the bird to locate the honey, and then once the honey is scooped out of the hive, the bird is able to eat the bee larvae and beeswax
What is another example of mutualism among animals?
*hint animal and animal
Alpheid shrimp and gobie fish.
The aplheid shrimp has poor vision, but are able to burrow under the sand. The shrimp allow the gobie fish to share their burrows. If leaving the burrow, the shrimp places on of their antenae on the gobie, and if a predator shows up, the gobie alerts the shrimp and the shrimp s able to run back to burrow for protection.
What are two examples of plant defense?
ants and acacia trees and mutualism between fungi and plants
How does the ant/acacia relationship work?
The acacia tree provides large thorns with pulpy centers which the ants burrow out into nests, and in addition, the trees contain nectaries which provide the ant with food.
In return, the ants bite any herboviores that attempt to consume the leaves.
In Dan Janzen’s study, what did he find?
Trees with ants had low percentages of herbivorous insects than trees with the ants removed and had much higher survival rates than trees with no ants.
What was the difference between ants of the P. ferrurgineus species and P. gracilis?
When the P. ferrurgineus species was present, the leaves of the tree were nearly bacteria free, but when P. gracilis was present, there was no reduction in bacteria.
What is the type of fungi that plants use to defend themselves from herbivory?
endophytic fungi
What does the endophytic fungi do to protect the plant?
What does the plant do?
produces chemicals that can repel insects herbivores and provide drought resistance by increasing the concentration of minerals in plant tissues.
The plant provides the fungi with the products of photosynthesis
What do cleaner wrasse do?
These small fish spend their life consuming ectoparasites on much larger fish.The cleaner wrasse can consume more than 1,200 parasites per day
Explain how the relationship between cleaner wrasse and larger fish works and the benefits to both parties.
The cleaner wrasse approaches and the larger fish opens it’s mouth and flares it’s gills to permit access. The cleaner wrath has a large source of food and the larger fish benefit by having fewer parasites.
What is the relationship between the oxpecker bird and grazing animals such as rhinos and antelopes.
The oxpecker birds eat the ticks off of the grazing animals.
*Charts in book show that the oxpecker birds prefer animals with higher tick abundace
Explain the relationship between the yucca plant and yucca moth.
The female yucca moth lays eggs within the ovaries of the flower, and to ensure her offspring have food to eat, she purposely pollenates the yucca stigma.
When her eggs hatch, the catapillars feed on the seeds.
The yucca plant gains a very effective pollenator at the cost of a few seeds
How does the yucca plant stop the moth from consuming too many seeds?
If the moth lays more than 6 eggs, the flower spontaeously aborts, killing all the eggs with it.
What is an example of mutualism involving seed dispersal?
The African tree Omphalocarpum procerum which produces fruit as large as a person’s head and only the African elephant can break them. Also, the seeds can only germinate after passing through an elephants digestive system.
Give two example of Positive mutualism that turns negative under certain conditions/
Mycorrhizal fungi in fertile soil (made the citrus tree grow 17% slower)
Cleaner fish when ectoparasites are low (they eat the mucus and scales when parasites are low)
T/F
Plants are able to discriminate between fungi and send benefits to the most beneficial.
True
What is an example of an organism that interferes with a mutualistic reactions?
What does this result in?
Garlic mustard interferes with the growth of mycorrhizal fungi which in turn affects the tree growth of trees which need the fungi to grow.
This results in the potential to alter the species distribution
Researchers who removed cleaner fish from 9 small reefs found what?
lower populations of larger fish on the reefs
When a fence was placed around the acacia trees, what occured with the ant species?
The mimosa ant was no longer needed, but the sjostedi was found in more common occurance.
What did researchers do on the Republic of Mauritius in response to the extinction of natural predators?
They brought in a new species of tortoise to replace the extinct one, and it worked with great sucess
Social spiders have two personality types. What are they and what jobs are these personality types allocated for?
Docile-Build the large webs
Aggressive-capturing prey and defending the web against predators
Define-
Community
a assemblage of species living together in a particular area
How to ecologists generally cateorgorize communities
either by their dominate organisms or by physical conditions that affect the distribution of species
When an ecotone is present we expect to observe?
sharp changes in distribution of species as we leave one community and enter the adjacent community
What is an example of an ecotone?
Plant communities on serpentine soils
What are serpentine soils?
soils derived from underlying rock that that contains heavy metals such as nickle, chromium and magnesium and are toxic to many plants
Serpentine soil are normally low in _________ and ________.
nitrogen and phosphorus
What species could not survive in serpentine soils?
Black oak and poison oak
What species were found almost entirely in the ecotone where the soils come together?
Canyon live oak and ragwort
What species were found only in serpentine soils?
fireweed and knotweed
What species were found in the entire gradient of serpentine/non serpentine soils?
hawkweed and fescue
Communities that species depend on each other to exist are called?
Interdependent
Communities that do not depend on each other to exist are called?
Independent
What is an example of a interdependent community?
social spiders
What is an example of an Independent community?
tree communities in great smoky mountains
How is species diversity measured?
Species richness and number of relative abundances
What is relative abundance?
the proportion of individuals in a community represented by each species
What does species richness refer to?
number of species in community
On a species abundance chart, what is on the x axis?
What is on the y?
x axis-abundance category
y axis-Number of ____ species
Most ecologists find that only a ______ species have low or high abundances and most have _________________.
few; intermediate abundances
What is a rank abundance curve?
plots the relative abundances of each species in a community in rank order from the most abundant species to the least abundant species
What is species evenness?
comparison of the relative abundances of each species in a community
The number of species in a community can be greatly affected by the amount of _________________.
available resources
If you increase resources, what organisms are going to remain?
the most competitive
What is the most observed graph of relationship between productivity and species richness?
Hump shaped curve
On productivity and species richness charts, what is on the y axis, and what is on the x axis?
x axis-productivity
y axis-species richness
Species richness declines with?
habitat fertility
As the habitat opens up new niches, what occurs?
it increases species diversity
Robert and John MacArthur’s study on habitat diversity found what?
habitats with greater foliage height diversity supported higher diversity of bird species
What is a keystone species?
organisms that hold together the community and without them the community would not survive
What is an example of a keystone species?
The pisaster sea star, when present consume a larger number of mussels and many other types of prey. Without the sea star (or it’s removal) the mussels took over the community
What is an ecosystem engineer?
an organism which modifies the structure of habitat
An example of a ecosystem engineer is?
The beaver. Because they build damns in streams that block the flow of water and cause large ponds to develop
Another example of a ecosystem engineer that is not the beaver is?
the alligators who create numerous large depressions called gator holes which many other species use
What does the intermediate disturbance hypothesis tell us?
more species are present in a community that occasionally experiences disturbances than in a community that experiences frequent or rare disturbances
_______ disturbances results in low species diversity.
_______ disturbances results in high species diversity.
few disturbances=low species diversity
frequent disturbances=high species diversity
Maximum species diversity comes from?
varying levels of disturbances
What is on the x axis of the IDH?
What is on the y?
x axis=# of species (species diversity)
y axis=(from right to left)
few/slight–>Intermediate–>frequent
food chains are?
linear representations of how species in a community consume each other and therefor how they transfer nutrients and energy from one group to another in an ecosystem
Food webs are?
complex and realistic representations of how species food on each other and in a community including links among series of producers, consumers, detrivores, scavengers, and decomposers
What are trophic levels?
levels in a food chain or food web of an ecosystem
What are producers?
are the autotrophs, including algae such as phytoplankton and plants that convert light energy and CO2 into carbohydrates through photosynthesis
What are primary consumers?
Those species that consume producers
What are two examples of primary consumers?
zooplankton that eat algae and snails
What are secondary consumers?
Those species that eat primary consumers
What are two examples of secondary consumers?
Small fish that eat zooplankton and ducks that eat the snails
What are tertiary consumers?
Those which eat secondary consumers
What are two examples of tertiary consumers?
Large fish which eat smaller fish
Omnivores can cause issues in organizing things into food webs because?
Omnivores feed on multiple levels
Species that feed on similar items are grouped into?
guilds
Members of a guild feed on similar items but?
do not need to be related
What is a direct effect?
occurs when two species interact without involving another species
An indirect effect is?
When two species interact in a way that involves one or more intermediate species
What is an example of an indirect effect?
When scientist introduced the Myxoma virus to help reduce the rabbit population. When the rabbits died, the vegetation increased.
The virus had an INDIRECT effect on the vegitation
When indirect effects are caused by changes in the density of an intermediate species, we call them?
density mediated indirect effects
What are two examples of density mediated indirect effects?
Sea starts on the snail population because the sea starts decrease the density of the mussels.
Myxoma virus and vegitation because it decreased the density of rabbits
Indirect effects that are caused by changes in the traits of an intermediate species
trait-mediated indirect effects
What is an example of the trait mediated effects?
Grasshopper feeding amounts with the presence of spiders.
No spiders=higher percent herbivory
Lethal spiders & Non lethal=same lower amount of herbivory
What was the conclusion of the spider/grasshopper experiment?
non lethal spiders, which can alter the behavioral traits of the grasshopper but not grasshopper density had the same positive indirect effect on the grass as lethal spiders, which both alter the density and the traits of the grasshopper.
This indicates that the mere presence of spiders can alter the behavioral traits of grasshopper and can initiate a trait mediated indirect effect
What is bottom up control?
When the abundance of trophic groups is determined by the amount of of energy available from producers in a community
What is top down control?
When the abundance of trophic groups is determined by the existence of of predators at the top of the food web
What is community stability?
the ability of a community to maintain a particular structure
What is community resistance?
The amount that a community changes when acted upon by some disturbance such as the addition or removal of a species
What is community resilience?
the time it takes after a disturbance for a community to return to its original state
What is succession?
the process which the species composition of a community changes over time
What is a seral stage?
Each stage of community change during the process of succession
The earliest species to arrive at a site is called?
the pioneer species
Pioneer species have what characteristics?
they have the ability to disperse long distances and arrive quickly at the disturbed site
the final stage of in the process of succession is called?
climax community
What are the two methods of observation of succession?
direct and indirect
What is an example of direct observation?
researches at the volcanic erruption site of Krakatau.
They observed from 1883 to 1920 the full succession from no life to forest communities.
Indirect observation involves
looking back in time from the present day
what is chronosequence?
a sequence of communities that exist over time at a given location
How does chronosequence help ecologist?
it helps them to understand how succession has progressed over time in an area
The development of communities in habitats that are intially devoid of plants and organic soil, such as sand dunes, lava flows and bare rock is?
Primary succession
The developement of communitites in habitats that have been disturbed and contain no plants but still contain organic soil is?
Secondary succession
An example of secondary succession can be observed in?
the chronosequence of abandoned agricultural fields
Pioneer species are generally?
r selected organisms
Climax communities are generally?
k selected organisms
What are the steps in type A lake succession?
- The lake edge is colonized by plants
- The plants expand into the open water and begin accumulating plant matter known as peat
- The expantion continues and peat layer becomes thicker
- Lateral expansion eventually covers the lake surface and peat sediments fill the basin
What are the steps in type B lake succession?
- Open lake experiences a drought of one or more decades and the water level falls
- Plants colonize the newly exposed lake sediments
- As the drought ends and the water level rises, living plants detach from the loose lake and sediments and float, there by covering the lakes surface
- Peat sediments fill the basin
What are the characteristics of early succession plants?
*hint: 8 characteristics
Many seeds Small seed size Wind or stick seed dispersal Long seed viability Low root shoot ratio Fast growth rate Small size at maturity Low shade tolerance
What are the characteristics of Late succession plants?
*hint: 8 characteristics
Few seeds Large seed size Gravity or ingestion seed dispersal Short seed viability High root shoot ratio Slow growth rate High shade tolerance
What is facilitation?
a mechanism of succession in which the presence of one species increases the probability that a second species can become established
What is Inhibition?
A mechanism of succession in which one species decreases the probability that a second species will become established
What is tolerance?
A mechanism of succession in which the probability that a species can become established depends on it’s dispersal ability and its ability to persist under the physical conditions of the enviroment
What is the priority effect?
When the arrival of one species at a site affects the subsequent colonization of other species
What is an example of facilitation?
Nitrogen fixing bacteria and (alder shrubs)legumes.
The nitrogen fixing bacteria and legumes produces more nitrogen in the soil which faciliates the establishment of nitrogen limited plants such as spruce trees.
What is an example of Inhibition?
In the northeast United States adult maple and beech trees cast a deep shadow that prevents pioneer tree species from surviving
What is an example of the priority effect?
Bryozoans, which filter feed attached to rocks.
If they become established first, they prevent the establishment of tunicates and sponges.
Why does the priority effect occur?
Because the first species to arrive has grown to a competitively superior adult stage whereas the second species is in the competitively inferior immature stage
Explain what occured in the Facilitation, Toleration and inhbition experiment with macroalgae, little brown barnacle (Chthamalus) and acorn barnacle (Balanus) after rock was scraped clean.
The first species to dominate was the little brown barnacle, but after more time the larger acorn barnacle became established and slowly crushed the little brown barnacle. The little brown barnacle became more rare.
As the acorn barnacle became more abundant, numerous species of macroalgae colonized the site.
The little brown barnacle (Cthamalus) shows?
tolerance
The acorn barnacle (Balanus) shows?
Inhibition of the little brown barnacle
Facilitation of the macroalgae
A climax community that is not persistant is?
A transient climax community
What is an example of a transient climax community?
Small wet lands, sometimes called vernal pools, which fill with water each spring and dry up in summer or freeze in winter
A successional stage that persists as the final seral stage due to periodic fire is?
Fire-maintained climax community
When a successional stage persists as the final seral stage due to intense grazing is?
Grazer-maintained climax community
The rate at which solar or chemical energy is captured and converted into chemical bonds by photosynthesis or chemosynthesis is?
Primary productivity
The biomass of producers present in a given area of an ecosystem at a particular moment in time is?
standing crop
The rate at which energy is captured and assimilated by producers in an area is?
Gross primary productivity
The rate of energy that is assimilated by producers and converted into producer biomass in an area is?
Net primary productivity
What is gross primary productivity?
the rate at which energy is captured and assimilated by producers in an area
From the gross primary productivity total, producers use?
some of the assimilated energy for their own metabolism
What is the net primary productivity?
The rate of energy that is assimilated by producers and converted into producer biomass in an area
What is the formula for net primary productivity?
NPP=GPP-respiration
What is the equation for photosynthesis?
6CO2+6H2O—>C6H12O6+6O2
What is the equation for cellular respiration?
C6H12O6+6O2–>6CO2+6H2O
A technique that allows measurement of condition on earth from a distant distant location is?
remote sensing
____________ is the foundation of the food web because it represents a source of energy for herbivores.
Primary productivity
The portion of consumed energy that is excreted or regurgitated is?
egested energy
The portion of energy that a consumer digests or absorbs is?
Assimilated energy
The portion of assimilated energy that a consumer uses for respiration is?
Respired Energy
Respired Energy is?
The portion of assimilated energy that a consumer uses for respiration
Assimilated energy is?
The portion of assimilated energy that a consumer uses for respiration
egested energy is?
The portion of consumed energy that is excreted or regurgitated
The rate of consumer biomass accumulation in a given area is?
Net secondary productivity
Net secondary productivity is?
The rate of consumer biomass accumulation in a given area
In the Sahara desert, there is no ________ because there is no water.
Primary productivity
Even though there is no primary productivity in the Sahara desert, there is algal growth due to?
iron dust
Why is there algal growth along coast lines?
Nutrient run off from rivers causes this
What is an upwell zone?
a nutrient rich water flow that is off the coast of california and peru
A chart composed of stacked rectangles representing the amount of energy or biomass in each trophic group is called?
A trophic pyramid
A trophic pyramid is?
A chart composed of stacked rectangles representing the amount of energy or biomass in each trophic group
A trophic pyramid that displays the total energy existing at each trophic level is?
Pyramid energy
What is a trophic cascade?
Where predator controls it’s corresponding trophic levels (top down)
