Chapter 16 Flashcards
A(n) __________ is a group of species that occupy an area and may interact directly or indirectly.
community
the species ranking based on relative abundance, ranked from the most to the least abundant
rank abundance
dividing the total number of individuals of the species of interest by the total number of individuals of all species present in the community
Relative abundance is calculated by __________.
Simpson’s index of diversity ranges between __________ and __________, with __________ values indicating greater diversity.
0, 1, higher
The Shannon index is a widely used index of biological diversity. The lowest possible value for this index is __________, and the highest possible value is __________.
0, the natural log of the species richness
You find a forest with a few different tree species: maple, oak, hickory, and tulip polar. You determine that the maples are abundant in the understory, and the hickories have the largest biomass. Which of the following statements can you make about this forest?
The maples and the hickories are possible dominant species, depending on how you are analyzing the structure of the forest
The removal of a keystone species from a community will initiate changes in that community’s structure and typically results in __________.
a significant loss of diversity
In a food web, an example of an intermediate species is __________.
an herbivore
In a food web, organisms can be grouped based on how they obtain their energy. These groupings are called __________.
trophic levels
In community structure, coastal marine communities are defined based on their plant life. T/F
False
In physical structure of communities, most photosynthesis in a temperate lake occurs in the hypolimnion of the lake. T/F
False
In sandy beach, Almost no species moves between the zones of sandy beaches.
t/F
False
The spatial scale at which sampling occurs can influence what is considered a unique community.
T/F
True
The __________ concept of communities suggests that communities are simply assemblages of species that have similar environmental requirements.
Continuum
In restoration ecology, an important aspect of restoration ecology is to eliminate all disturbances and keep the natural communities as stable as possible.
T/F
false
In order to reconstruct natural communities as part of restoration, many critical ecological questions must be answered. All of the following are important questions involved in restoration of ecological communities with one exception. Choose the exception.
How can invasive species be integrated into the natural community?
In a rank-abundance curve comparing two communities, the community with the greater species richness is characterized by a
greater length of the curve and a more gradual slope.
Communities with low evenness will have rank-abundance curves
they are very steep
The relative abundance of a tree with 100 individuals in a community of 1000 would be
0.1
When an ecologist compares the diversity of different communities by counting the number of species within each community, the measure of diversity being used is called
species richness
Which of the following has the highest species richness? A community with
36 species with very low evenness.
Most communities have many common species and a few rare species.
False
Which is the most dominant species? most relative biomass largest in number highest in relative abundance All of the above can indicate dominance
All of the above
The removal of a keystone species from a community typically results in an increase of diversity.
false
a rare or uncommon species that has a strong effect on its community
keystone species
A species that has massive effects on an ecosystem but in proportion to its abundance is a
dominant species
What might be a result of hunting sea otters to extinction for their fur?
loss of kelp beds
In the following community, which serves as the keystone species?
sea otters
A food web is more complicated than a food chain
true
The species within a guild are unlikely to interact with one another.
False
Which of the following groups of species represents a guild?
species of birds that feed on nectar
Which of the following is considered a guild?
insect feeding birds
The form and structure of terrestrial communities are defined more by the plants than the animals present.
true
In a well-stratified lake, the thermocline refers to a steep and rapid decline in temperature relative to the waters above and below
True
he aphotic zone of a lake is inhabited primarily by phytoplankton
False
In a forest community, the layer in which most photosynthesis occurs is the
canopy
The layer of a forest in which decomposition takes place and mineral nutrients are released for reuse by plants is called the
forest floor
Zonation within a community is typically the result of differences in the
physical characteristics of the environment across a spatial gradient.
In a sandy beach community, ghost crabs and beach flies occur within
supra tidal zone
n which of the following zones would you most likely expect to find flounders (a type of fish)?
subtidal
T/F The boundaries between communities are usually sharply defined and easily discerned.
false
T/F The organismic concept views communities as clusters of species associating together as an interacting, integrated component.
true
An ecologist samples the abundance of various species along an environmental gradient and fails to find clusters of species. Instead, peaks of abundance of dominant species are merely randomly spaced segments along a continuum. This distribution of species supports the
individualistic or continuum concept of a community.
An organismic concept of communities was developed by
Clements
The goal of restoration ecology is to
return the community to its pre-disturbance condition
Who was Aldo Leopold?
conservationist
