BIO 320 exam 3
Which community in the above graph has the highest species richness?
1
What log scale are these graphs using?
2
You collect the following data in this table on all the beetle species found in 3 communities in the desert. Shown below is the proportional or relative abundance of each beetle species in the 3 communities. A rank abundance curve of the data in the beetle Table would show that the absolute slope of the "curve" would be the lowest for which community?
3
You collect the following data in this table on all the beetle species found in 3 communities in the desert. Shown below is the proportional or relative abundance of each beetle species in the 3 communities. Which community has the greatest beetle species diversity, based on the Shannon-Wiener Index of diversity?
3
You collect the following data in this table on all the beetle species found in 3 communities in the desert. Shown below is the proportional or relative abundance of each beetle species in the 3 communities.Which community has the greatest species evenness of beetles?
3
What is the Aboveground NPP in Gt of C/year based on the above estimates?
60 Gt of C/year
The graph (Figure 18.3 in your textbook) shows Net primary production as a function of average annual total precipitation across sites in the Great Plains of the USA. Technically, the vertical axis shows:
Aboveground net primary productivity
What would likely happen if the snail preferred to eat a competitively inferior algal species such as Chondrus?
Algal richness would decrease as snail densities increased from low to high.
How could the system shown at right support the most humans?
Change human diet to phytoplankton
Which community has the greater bird species evenness (smaller slope)?
Community 1
You collect the following data in this table on all the beetle species found in 3 communities in the desert. Shown below is the proportional or relative abundance of each beetle species in the 3 communities. Which community has the highest beetle species richness?
Community 3
Community A and Community B are pools in a stream in which we are studying zooplankton (plankton that feed on photosynthetic plankton or phytoplankton) and the predator species that feed on these zooplankton. We observe that the number of predator species, as a proportion of all zooplankton and predator species, is higher in Community A. Based on this observation, which community would you predict to have higher species diversity of zooplankton and their predators?
Community A
Ecosystems have a pyramid shaped trophic distribution of:
ET and soil nutrient levels
Why would earlier snowmelt lead to more frost-killed flower buds?
Earlier snowmelt means earlier sunflower growth. Hence, sunflowers are producing flower buds earlier in the growing season, and they will be exposed to frosts (some frosts still occur each late spring)
Ecosystems with > 5 trophic levels would have
High NPP
Your text uses this study in support of the intermediate disturbance hypothesis. In technical sense, the graph does not do this because this hypothesis concerns the influence of disturbance on species diversity , and:
It does not provide information on species relative abundance.
What is the strongest or most important limiting factor to NPP during the growing season in grasslands of the Great Plains?
Moisture availability
A chamber is sealed to ground surface to measure the change in CO2. The ground surface inside the chamber includes both plants and soil. What is he measuring (over seconds to minutes time span)?
Net CO2 uptake or loss (flux) of the ecosystem (NEE- Net ecosystem exchange)
How common are obligate plant-animal pollination mutualisms involving one plant species relying solely on one animal species for pollination in nature.
Rare
Annual Actual ET would be highest in which biome?
Temperate deciduous forest
A graph of the day of year when snowpack has melted by 50% vs year for monitoring site at Vail, CO, near Inouye's study sites . What does this graph tell us?
The date that 1/2 the snowpack has melted each year comes earlier in the year
Why are ecosystems with >5 trophic levels uncommon in nature?
There's not enough energy in the lower trophic levels to support high trophic level species.
Both keystone species in the trophic cascade concepts involve -------- control of trophic levels
Top down
Any support for the ideas that mycorrhizae from low nutrient soil benefited plants more than mycorrhizae from high nutrient soil?
Yes
You remove coyotes from your ranch in Arizona. After nearly all the coyotes are gone, you notice that the rabbit population increases dramatically (rabbits are the main food source of the coyotes). Along with this, you notice that the rabbits have consumed much of the plant biomass, and the standing biomass, NPP, and species diversity of the plant community drops dramatically. A few years later, you stop removing coyotes, and within a few years the coyote population recovers, the rabbit population declines, and the standing biomass, NPP and species diversity of the plant community are back up to what they used to be. The coyotes can be described as:
a keystone species and secondary consumers
Ecosystems that have low NPP typically have _____ of trophic levels.
a relatively small number
You remove coyotes from your ranch in Arizona. After nearly all the coyotes are gone, you notice that the rabbit population increases dramatically (rabbits are the main food source of the coyotes). Along with this, you notice that the rabbits have consumed much of the plant biomass, and the standing biomass, NPP, and species diversity of the plant community drops dramatically. A few years later, you stop removing coyotes, and within a few years the coyote population recovers, the rabbit population declines, and the standing biomass, NPP and species diversity of the plant community are back up to what they used to be. The increase in NPP brought about by the increase in coyote densities after you stopped removing them from your ranch illustrates a:
a strong top-down control on NPP
Which biome has relatively high annual precipitation, but relatively low NPP?
alpine tundra
Algal biomass is usually low in aquatic systems that have a high density of top predator (highest trophic level) that is a keystone species and:
an even number of trophic level in the system
Respiration by the following releases carbon dioxide into the atmosphere.
animals, microbes, and plants
The above graph illustrates that most tree species ____ in nature.
are moderately abundant
Primary producers accumulate:
biomass, carbon and energy
For many of the past 25 years, severe drought has dramatically lowered or limited NPP in many ecosystems in Arizona. This type of limitation on NPP would be an example of a ______ control of NPP.
bottom up
Which community has the greater bird species richness (number)
community 3
The conversion of nitrate (NO3-) to N2 is called:
denitrification
Ecosystems have a pyramid shaped trophic distribution of:
energy
Plant species diversity generally increases as:
environmental heterogeneity increases
The authors attempted to test the influence of extreme precipitation regimes. What are these?
fewer number of individual precip events, but larger events (more intense rainfall in less occurrences, doesn't change annual rainfall)
In order for N to be taken up and incorporated by green plants or terrestrial primary producers, N2 gas must be ____ into ________.
fixed, an available form of N
The treatment of the study involved
frequency or number of precip events
The mechanism responsible for the higher species diversity you predicted in the previous question would be:
higher predation pressure would increase the number of prey species or zooplankton through lower competition among zooplankton species
In general, decomposition rates of plant litter ____ as the average annual precipitation of biomes increase.
increase
The model (from the mycorrhizae root study) predicts that as soil nutrients availability declines, the roots : shoot ratio of plants will
increase
The pool size of C in the atmosphere has ________ over the past 150 years.
increased
In the aspen sunflower/ant mutualism studied by David Inouye, he found that rising temperatures associated with global warming have:
increased the prevalence of flower bud deaths by late-spring frosts
Mycorrhizae fungi can improve the water relations of plants by:
increasing the effective absorbing surface area of a plant's root system
Jane Heisler-White article: How does the average total annual precipitation change across the Great Plains with longitude (from west to east)?
it increases from west to east
After a plant leaf dies, it decays and can lose most of its mass over the next few years. Where does the leaf's mass (or matter) go?
it is converted to molecules in microbes, soil and the atmosphere
If the global gross photosynthetic rate increased (by global, I mean the rate of the entire ecosphere), while the rates of all other pathways or fluxes in the global carbon cycle remained the same, how would the size of carbon pool in the atmosphere change?
it would decrease
Species diversity is generally highest at _____ levels of disturbance.
moderate or intermediate
At low densities (or absence) of steelhead trout, what would the river look like?
more algae
According to Paine, how would a greater proportion of predators promote higher total species richness?
more predator spp would lower the population size of prey species, reducing competition for resources and competitive exclusion among prey species.
In general, plant/animal mutualisms are _____ flexible in temperate than tropical climates because _____ a greater likelihood of disrupting mutualisms in temperate climates.
more, the physical environment has
Most plant pollination/animal mutualisms involve a plant species relying on:
multiple animal species for pollination
You place a large air-tight chamber over a patch of prairie to monitor CO2 exchange from the community during daylight hours. The chamber covers plants and also bare soil between the plants. The plants are not water stresses and are photosynthesizing at high rates during the day. During the day, your measurements would show a:
net decline in CO2 concentrations in the chamber (there is a net uptake of CO2 by the community)
If you combined your daytime and nighttime measurements of CO2 and summed up how much CO2 the system is taking in or releasing over the 24 period, it would give you an estimate of ______ of the community over that period.
net ecosystem exchange of the community
You place a large air-tight chamber over a patch of prairie to monitor CO2 exchange from the community during daylight hours. The chamber covers plants and also bare soil between the plants. The plants are not water stresses and are photosynthesizing at high rates during the day. You continue your measurements during the night (it is dark). Your measurements during the night would show a:
net increase in CO2 concentrations in the chamber (there is a net release of CO2 by the community)
There is a strong positive correlation between primary production and precipitation across sites in the Great Plains, as illustrated in the above figure from your textbook. Would there also be strong positive correlation if we plotted primary production of a diverse group of terrestrial biomes (including hot deserts and cold tundras)?
no
saguaro cacti are commonly referred to as a keystone species of the Sonora Desert. Based on our criteria for keystone species, should saguaro cacti be considered a keystone species in the community picture in the foreground?
no
If we harvested all the aboveground biomass in the forest in fall just before the leaves senesced and fell off, would the weight of that (dried) biomass provide an estimate of Annual Aboveground NPP of the forest?
no - the trees are representatives of many years of accumulated biomass (it's perennial
Which is a sedimentary biogeochemical cycle?
phosphorus
C is taken up by organisms in ecosystems via this process;
photosynthesis
Most plant pollination/animal mutualisms involve animal pollinators that:
pollinate multiple plant species or have alternate food sources
You remove coyotes from your ranch in Arizona. After nearly all the coyotes are gone, you notice that the rabbit population increases dramatically (rabbits are the main food source of the coyotes). Along with this, you notice that the rabbits have consumed much of the plant biomass, and the standing biomass, NPP, and species diversity of the plant community drops dramatically. A few years later, you stop removing coyotes, and within a few years the coyote population recovers, the rabbit population declines, and the standing biomass, NPP and species diversity of the plant community are back up to what they used to be. The rabbits could be described as:
primary consumers
In the aspen sunflower/ant mutualism studied by David Inouye, the sunflower receives _______ while the ant receives _______.
protection from seed predators, nectar
Preston's findings concerning lognormal distributions showed that:
relatively few species occur in very low or very high densities in nature; rather, most species occur in moderate or medium densities
The functional equilibrium model proposed by Mooney (1972) predicts that a plant's
root:shoot ratio will be higher under water or nutrient limitations
Species A and B both exert a strong influence on the makeup and functioning of an ecosystem - removal experiments show that removal of either one of these species leads to large changes in the species diversity of the community. Species A, a plant, makes up a relatively large proportion of the total biomass the community, while species B, an animal, makes up a relatively small proportion of the biomass. Which statement is true?
species A is a dominant species and species B is a keystone species
You are studying the leaf litter decomposition rates of 3 tree species at a site in a mesic temperate deciduous forest. Leaves of tree species A have a nitrogen concentration of 1% and a lignin concentration of 10%. Leaves of tree species B have a nitrogen concentration of 2% and a lignin concentration of 15%. Leaves of tree species C have a nitrogen concentration of 2.5% and a lignin concentration of 25%. Leaves of which species would decay fastest at the site?
species B
Trophic cascades involve:
strong top-down controls of NPP
Comparing the swollen thorn acacia/ant mutualism to the aspen sunflower/ant mutualism, which mutualism is more obligate?
swollen thorn acacia/ant
Figure 16.19 in your textbook (above) shows evidence for the Intermediate Disturbance Hypothesis using data on marine species in the intertidal zone. However, in a technical sense, the graphs don't show us the influence of disturbance on species diversity because:
the graphs don't incorporate data on the relative abundance of species
The above graph summarizes the abundance of all tree species in 2 different communities. The graph shows:
the lognormal distribution of tree species abundance for the 2 communities
Plant pollination/animals mutualisms played a substantial role in the rapid diversification of flowering plants (i.e. speciation) over the past 100 million years.
true
The hydrologic cycle is a ----- cycle
volatile
Did Nancy Johnson (1993) find that mycorrhizae improved the shoot or aboveground growth of the grass she studied?
yes - within each nutrient level she grew the grass, mycorrhizae led to greater shoot growth or shoot mass.
Was the long term average (ambient/natural) aboveground NPP of the 3 sites correlated with the ambient precip by the 3 sites
yes, there was a positive correlation.
If community A has a higher species richness, while community B has more even species abundance, what can you conclude with respect to species diversity?
you can't definitively tell which community has higher species diversity without further information (the actual data and a specific species diversity equation to use)