URI BIO 102 Exam 3 Paim-Pinto Lopez
Example of mutualism
(+/+) bat and bees use the nectar from flowers as a food source and the flower uses the bees and bats as pollinators.
Commensalism
(+/0) least studied interaction because it is difficult to quantify the absence of a cost to the host. Orchids use trees to get closer to sun and rain, but tree isn't harmed. Not to be confused with parasitism in consumption
Net reproductive range
(R0) Indicates whether a population is increasing or decreasing (as long as immigration and emigration are insignificant).
Consumption
(including herbivory, predation, and parasitism) occurs when one organism eats or absorbs nutrients from another. The interaction increases the consumer's fitness but decreases the victim's fitness (+/ -)
The per-capita rate of increase or intrinsic rate of increase
(r) the difference between the birth rate and death rate per individual, r = b-d
2 Components of an ecosystem
1. Community of interacting species present in a region, 2. Abiotic components
Primary producers use this chemical energy in two ways
1. cellular respiration to produce ATP to fuel metabolic processes, 2. growth and reproduction- (NPP)
4 stages of secondary succession
1. pioneering species 2. early successional community 3. mid-successional community 4. climax community
3 stages of primary succession
1. solid rock —weather—> 2. gravel, sand, silt, and clay (also organisms enter this stage and contribute dead cells, tissues, and feces) —time—> 3. complex mixture of inorganic and organic particles and living organisms
Given that r = 0.22, how long will it take the population to double? Nt= N0e^rt
= 3.2 years Nt=2 No=1 r=0.22 t=3.15 2=1e^(0.22*t) --> ln2=0.22t
Natural selection involves energetic trade-offs between _____. A. high survival rates of offspring and the cost of parental care B. the emigration of individuals when they are no longer reproductively capable or committing suicide C. increasing the number of individuals produced during each reproductive episode and a corresponding decrease in parental care D. producing large numbers of gametes when employing internal fertilization versus fewer numbers of gametes when employing external fertilization E. choosing how many offspring to produce over the course of a lifetime and how long to live
A
In general, NPP in the oceans is greatest where? A. Open ocean B. Near coastlines C. Deep waters D. n the northern hemisphere oceans
B
Succesion in an ecological context refers to ____. A. The predictable series of changes in a community as species evolve and become extinct B. The sequence of changes in species composition over time within the community after a disturbance C. What happens to the evolution of species as a result of the co-evolutionary arms race D. The sequence of changes that a species goes through during its occupancy within a community
B
What makes species in late successional communities successful? A.They are short lived B. They are good competitors for resources C. They are able to disperse their seeds over long distances D. They are small
B
Processes that affect population size
Births Deaths Immigration Emigration
A population is growing exponentially and its instantaneous growth rate (r) is 0.02. Would the number of individuals added to the population (rN) be greatest at a population size (N) of 20, 500 or 1000? A. 20 B. All the populations would have the same number of individuals added to them since r is constant C. 1000 D. 500
C
What makes species in early successional communities successful? A. They are naturally selected for longevity B. They outcompete all other species C. They are able to disperse their seeds over long distances D. They are large
C
Which of the following disturbances would result in primary succession? A. Fire B. Hurricane C. Volcano D. Logging
C
Which two biomes is NPP the greatest in per unit area?
Coral reefs and tropical wet forests
If you are concerned about biomagnification, then what would be the worst choice to eat for lunch? A. garden salad B. veggie pizza C. shrimp cocktail D. yellow-fin tuna salad
D
The study of factors that determine the size and structure of populations through time is called _____. A. Community ecology B. Logistic growth C. Immigration biology D. Demography
D
When primary producers invest energy to build new tissue, this is _____________? A. Maintenance costs and the amount of energy available to consumers B. Net primary productivity C. Maintenance costs D. Net primary productivity and the amount of energy available to consumers E. The amount of energy available to consumers
D
Which of the following terms defines how the individual organism allocates resources to growth, reproduction, and activities or structures related to survival? A. Energy budget B. Demography C. Survivorship D. Life history
D
Which of these statements is true regarding biomagnification? A. Bioaccumulation is a concern for primary consumers but not secondary consumers. B. Primary producers have the highest concentrations of toxins. C. Bioaccumulation is not influenced by geography or eating habits. D. Bioaccumulation is a concern for secondary and tertiary consumers.
D
Why does net productivity diminish with increasing trophic levels? A. There are fewer plants at higher trophic levels. B. Energy is gained a each trophic level. C. Organisms at a higher trophic level have to work less to obtain food. D. There is poor trophic transfer efficiency at higher trophic levels.
D
Exponential growth is density dependent or independent
Density independent and occurs when per capita growth rate is constant
Logistic growth rate is density dependent or independent
Diversity dependent and occurs when the population size approaches the carrying capacity and growth rate decreases
5 Levels of Ecological Study
Global Community Population Ecosytem Organismal
Life History Fitness Trade-Offs. High/low fecundity vs high/low survivorship
High fecundity- low survivorship (small plant) Low fecundity- high survivorship (palm tree)
Graphing Exponential growth high r vs low r steepness
High r: steep Low r: not steep
Population
How and why does population size change over space and time
Organismal
How do individuals interact with each other and their physical environment
Community
How do species interact, and what are the consequences
Ecosystem level
How does energy flow and how do nutrients cycle through the local environment
Global level
How is the biosphere affected by global changes in nutrient and climate
Exponential growth curve shape
J
Primary productivity equation
NPP = GPP - CR
R₀
Net reproductive rate- indicates whether a population is increasing or decreasing (as long as immigration/emigration are insignificant)
Change in NPP for each hemisphere and why
Northern: increased in NPP (more CO2, higher temperature), Southern: decreased in NPP
How many years will it take the coral population to reach 20 individuals? (t)
Nt = 20 N0 = 2 r = 0.69 20 = 2e (0.69)(t) 10 = e (0.69)(t) ln10= 0.69(t) t =3.38
A pair of corals was introduces to new habitat in 2014. Assume these corals only breed once per year. In 2015 there were two pairs. What is the intrinsic rate of increase? (r)
Nt = 4 4 = 2 e r(1) 2 = e r(1) ln 2 = r(1) r = 0.69
Continuous growth equation
Nt = N₀e∧rt
Which two biomes have the highest % of the earth's NPP per unit area?
Oceans and tropical wet forest
Survivorship (Ix)
Proportion of the offspring produced that survive
Logistic growth curve shape
S
Three ways that niches change in response to competition between specie, Outcome 3
Species coexist when one or more changes its niche
Wolf and moose shows that
Species interactions can affect the distribution and abundance of a particular species
Three ways that niches change in response to competition between species, Outcome 1
The competitive exclusion principle states that it is not possible for species within the same niche to coexist
Three general types of survivorship curves
Type I Type II Type III
When does r reach a maximum value, rmax
When birthrates per individual are as high as possible and death rates per individual are low as possible
Three ways that niches change in response to competition between species, Outcome 2
When one species is more competitive and niches do not overlap completely, weaker competitors use non-overlapping resources
Does r have max?
Yes, r has a max
Quanitfying Population Growth
a populations growth rate is the change in the number of individuals in the population (delta N) per unit of time (delta t).
Niche differentiation or resource partitioning
an evolutionary change in resource use that occurs when species compete for many resources
Niche differentiation
an evolutionary change in resource use, caused by competition over generations
Density dependent
any characteristic that varies depending on population density or affects carrying capacity. Ex. colonization of a new habitat, recovery after disaster, predation, competition, toxic waste, disease, social behavior
b
birth rate per individual
Blue carbon
carbon stored by coastal and marine ecosystems
K stands for
carrying capacity- the maximum number of individuals in a population that can be supported in a particular habitat over a sustained period of time
Character displacement vs. disruptive selection differences
character displacement occurs as a result of interactions between 2 different species when disruptive selection occurs among only 1 species that form into 2
Defenses to consumption
constitutive and inducible
Herbivory
costuming plant and algal tissues
Why is change in NPP in the oceans potentially harmful
currents are less likely to bring nutrient-rich water to surface against the steep density gradient when water is much warmer
A population of animals in a specific environment with a carrying capacity of 2500 has an r of 1.0 per individual per year and exhibits logistic growth. Considering a population size of 750 individuals, by how many individuals is the population increasing per year?
dN= 525 K=2500 r=1 N=750 dN = ? dN/dt = 1*750 (2500-750)/2500 dN/dt = 525
Exponential growth equation
dN÷dt = rN
Logistic growth rate
dN÷dt= rN(k-N/K)
d
death rate per individual
Productivity declines/increases at higher trophic levels
declines
How does energy flow through ecosystems
decomposer <—> (sunlight~~>) primary producer —> primary consumer —> secondary consumer —> tertiary consumer (~~> heat)
NPP is increasing or decreasing on land? ; in the oceans?
decreasing; decreasing
Continuous Growth equations
delta N - ——— = rN delta t -N(subscript t) = N(subscript 0)e^rt
Population growth equation
delta n ------- = (b-d)N delta t
Logistic growth is density independent/dependent; which means its growth rate is
dependent; growth rate slows at high density, early growth is rapid, growth begins to slow, the growth falls to zero
Secondary succession
disturbance removes some or all of the organisms but leaves the soil intact. ex.- fire and logging
Primary succession
disturbance removes the soil and organisms. ex.- glaciers and volcanic eruptions
The outcome of interactions among species is _____
dynamic and conditional, interactions can change from mutualism to consumption or to other types
Net Primary Productivity (NPP)
energy invested in new tissue or offspring is called net primary productivity (45% of GPP, other 55% goes out in cellular respiration)
These two components are linked by the flow of ______ and the cycling of ______ needed to sustain life
energy; materials
Density independent
factors such as variation in weather or catastrophic events. Ex. hurricanes, tornados, wildfire
g stands for
generation time
dN/dt
growth rate of the population in a given instant
Is biomagnification beneficial or harmful to humans
harmful
Three types of consumption
herbivory, predation (can be herbivores that eat an entire plant or a seed, parastism
Type 3 curve
high death rates for larvae or seedlings but high survival rates later in life; insects and plants, sea turtles
For biomagnification, is there an increase or decrease in concentration of pollutants at higher levels in the food chain
increase
Inducible defense, def, pros, and cons
induced in the presence of a consumer. Pro- saves energy, Con- takes time to induce, ex.- mussels develop thicker shells in the presence of crabs
Late successional communities: adult size, growing speed, offspring size, dispersal, competitiveness
large adults, slow, few large offspring, low dispersal, are competitive
Does r ever reach maximum
most likely no, environment is not perfect. Hypothetical
N stands for
number of individuals
N₀ stands for
number of individuals at time 0 or initial generation size
Competition
occurs when individuals use the same resources— resulting in lower fitness for both (—/ —) Ex. lion and hyena
Commensalism
occurs when one species benefits but the other species is unaffected. (+/0) Ex. epiphytic orchids and their host trees
Mutualism
occurs when two species interact in a way that benefits both (+/+). Ex: bees and flowers
Which biome has the highest % of the earth's NPP?
open ocean
r stands for
per capita rate of increase- the difference between birthrate and death rate per individual
R0 < 1
population is decreasing
R0 > 1
population is increasing
R0 = 1
population is stable
N↓t stands for
population size at the end of time
Realized niche
portion of the fundamental niche that a species actually occupies, given limiting factors such as competition with other species (seats left after others are sitting
Constitutive defense, def, pros, and cons
present even in the absence of consumers. Pro- defense is always present, Con- costs a lot of energy, ex.- grasshopper resembles leaf
Which is slower to occur, primary or secondary succession
primary
An alternate way to calculate r
r= lnR(subscript 0) / generation time *g*
Which equation to calculate population growth
r=lnR₀/g
Community dynamics, Succession
recovery that follows a severe disturbance (natural disasters)
Type 2 curve
same probability of dying in each year of life; songbirds, lizards
Early successional communities: adult size, growing speed, offspring size, dispersal, competitiveness
small adults, fast growing, many small offspring, high dispersal, not competitive.
What does the life table do?
summarizes the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime
Type 1 curve
survivorship is high throughout life then drops in old age; humans, big mammals
Life Table, --> survivorship, fecundity, average births per year per female
survivorship: % that survived out of the original number (lx) fecundity: The number of female offspring produced by each female in the population (mx) average births per year per female = lxmx
Autotrophs
synthesize their own food from inorganic sources. ex. sunlight= photosythesis (not creating energy, just converting from solar to chemical)
Which marine ecosystems have the greatest NPP and why?
the coastlines because the rivers and upwellings carry nutrients to the ecosystems on the coastlines so there are more nutrients for primary producers
Character displacement
the evolutionary tendency for the traits of similar species that occupy overlapping ranges to change in a way that reduces interspecific competition
Is NPP higher on land or in the sea and why?
the land because there are primary producers because there is more light available on land than in the water
N
the number of individuals
Number of Survivors (Nx)
the number of individuals that survived to reach each age class
Niche
the range of resources that the species is able to use, or the range of conditions it can tolerate.
Demography
the study of factors that determine the size and structure of populations through time
Gross Primary Productivity (GPP)
the total amount of chemical energy produced in a given area and time period
Biomass
the total amount of chemical potential energy that is stored in organic material
How does energy enter an ecosystem
through primary producers
t stands for
time
Character displacement vs. disruptive selection, similarities
two bell shaped curves are moving away from each other
Where on land is NPP the greatest and why?
wet tropics because they get the highest availability of sunlight, increase in temperature, abundance of water
Parasitism
when a parasite consumes relatively small amount of tissue or nutrients from a host.
Predation
when a predator kills and consumes all or most of another individual. The consumed is the prey
Nectar cheaters
when a showy bright flower doesn't have nectar, becomes (+/—)
Exponential Growth (r doesn't change) axis labels
x axis: generations y axis: population size (N)