Biology 211 Final Exam (5- Ecology)

What is the difference between scientist versus advocate? (49-01)

What is the difference between scientist versus advocate? (49-01)

An environmental advocate works for changes in policy or human behavior to benefit the environment.

A scientist studies the interactions among organisms and their interactions with the environment.

How does science inform policy? (49-01)

Ecological Society of America: An organization of professional scientists strives to ensure the appropriate use of ecological science in environmental decision-making.

What is the difference basic versus applied science? (49-01)

Basic Ecology: Research on the distribution and abundance of species and how species interact with each other and the environment.

Applied Ecology: Develop conservation and management plans to limit or repair damage to the ecosystem from human actions.

How are they interconnected? Information can help us solve practical problems (applied ecology) only if we understand why these problems first occurred (basic ecology).

What are the fundamental questions of ecology? (49-02)

What factors determine the abundance of a species?

What factors limit the distribution of a species?

What is the definition of a population? (51-01)

A group of organisms of the same species occupying a particular place (often arbitrary) at a particular time.

What are the different population attributes? (51-02)

Size (N)

Density (N per unit area)

Dispersion

Demography

Genetic characteristics

What are the three different forms of dispersion? (51-04)

Random dispersion: The position of each individual is independent of other individuals.

Clumped dispersion: Individuals aggregate in patches.

Uniform dispersion: Individuals are evenly spaced. Influenced by social interactions such as territoriality.

What are the properties of demography? (51-05)

Age structure

Generation time (The average age a female gives birth)

Number of individuals of different ages likely to survive to the

following year

Number of offspring produced by females of each age

Net immigration/emigration rate

What is the Type I survivorship curve? (51-06)

High survivorship for juveniles (low death rate)

Low survivorship for older individuals

Example: Humans (with access to health care)

What is the Type II survivorship curve? (51-06)

Uniform survivorship for each age group

Example: Beavers, squirrels

What is the Type III survivorship curve? (51-06)

Low survivorship for juveniles (high death rate)

High survivorship for older individuals

Example: Most plants (seeds), fungi (spores), Insects

What are fitness trade offs? (51-07)

Individuals have a restricted amount of time and energy, and they cannot maximize all physiological aspects. Includes growth, defense, maintenance, or offspring production

What are life history trade offs? (51-07)

Organisms with high fecundity (lots of offspring) tend to grow quickly, reach sexual maturity at a young age, and produce many small eggs or seeds.

Organisms with high survivorship tend to grow slowly, invest their energy and time in traits that reduce damage from enemies, and increase their own ability to compete for resources.

What does r mean in population growth rate? (51-08)

r = birth rate - death rate

r > 0, population growth

r < 0, population is declining

r(max) = maximum growth rate for a population

What is exponential growth, a density independent and J-shaped

curve? (51-09)

A few individuals colonize a new habitat with plentiful resources. A population has been devastated by a storm or some other type of catastrophe and then begins to recover, starting with a few surviving individuals.

Exponential model assumes infinite resources. Resources are finite and will run out.

What is carrying capacity? (51-09)

There is a limit to the number of individuals that can occupy a habitat.

What is logistic growth, a density dependent and S- shaped curve? (51-09)

Begins exponentially (r = rmax)

But, in the logistic model the value of r is dependent on population density. As N (the number of individuals) approach K (carrying capacity), r (the growth rate) approaches zero (i.e., births = deaths)

The model does not always fit, as organisms’ reproduction does not respond instantly and environmental conditions are not constant.

What are density independent factors? (51-10)

Does not depend on population size. Disasters, Climate change.

What are density dependent factors? (51-10)

Depends on population size. Competition for resources, disease, parasitism, predation, toxic waste accumulation, behaviors.

Includes inter and intraspecific behaviors. Intra-specific interactions are those that occur between individuals of the same species, while interactions that occur between two or more species are called inter-specific interactions.

What are human population dynamics? (51-12)

Human population growth began to slow in the 1960’s. Deviation from true exponential growth. Results from conscious population control, like the “pill” which was introduced in 1960.

Dynamics include: human carrying capacity, Zero Population Growth and ecological footprints.

What is the extinction vortex? (54-03)

Inbreeding and genetic drift reduce variation. Amplifies as population size decreases, and the population does not have genetic resources to adapt to environmental change.

It is called an Extinction vortex.

What is commensalism? (52-02)

Defined as (+/0)

One species benefits but the other species is unaffected.

What is consumption? (52-02)

Defined as (+/-)

May only harm - Typical of herbivores, parasites, and pathogens

May result in death -Typical of carnivores and parasitoids

Herbivory is also an example - Has led to the evolution of plant mechanical and chemical defenses and consequent adaptations by herbivores.

What is parasitism? (52-02)

Defined as (+/-)

Organism that live on or in another organism and harms it, or kills it.

What is mutualism? (52-02)

Defined as (+/+)

Both species benefit. Mutual benefits are a by-product of each individual pursuing their own self interest. Maximizing survival and reproduction.

What is competition? (52-02)

Defined as (-/-)

Intraspecific – within species

Interspecific – between different species

Exploitation competition – organisms compete indirectly through the consumption of a limited resource

Interference competition – individuals interact directly with one another by physical force or intimidation

What is an ecological niche? (52-03)

The sum of a species use of the biotic and abiotic resources in its environment.

– Where it lives

– What it eats (or what resources it uses)

– When it eats (or when it uptakes resources)

What is niche exclusion? (52-03)

If two species utilize:

1. The exact same resources

2. At the exact same time

3. At the exact same place

Two species cannot occupy the same niche. One species will go extinct or will be restricted to areas of non-overlap

What is a fundamental niche? (52-03)

The total range of environmental conditions that a species can tolerate

What is a realized niche? (52-03)

The portion of the fundamental niche that a species

actually occupies – Limiting factors include competition with other

species.

What are passive defenses in prey? (52-04)

Cryptic coloration, camouflage within their environment.

What is escape behavior in prey? (52-04)

Out run (or fly away from) your predator

What is schooling behavior in prey? (52-04)

Individuals that stay in a group or “school” to avoid predation.

What are mechanical defenses in prey? (52-04)

Hard shell on turtles, thorns on roses.

What are intimidation strategies in prey? (52-04)

Having horns or appearing dangerous

What are faking death strategies in prey? (52-04)

Opossums faking death to avoid being killed

What are chemical defenses in prey? (52-04)

Skunks spraying, usually have aposematic (warning) coloration

What is batesian mimicry? (52-05)

A palatable or harmless species mimics an unpalatable or harmful species.

What is müllerian mimicry? (52-05)

Two or more unpalatable species resemble each other. Advantageous to both species since predators learn more quickly.

What is a keystone species? (52-06)

Play a unique role in the way ecosystems function. This effect is GREATER than their biomass would suggest.

What are trophic cascades? (52-06)

Also called top-down control

1. Apex predator lost

2. Herbivore populations increase exponentially

3. Vegetation is over-consumed

4. Major ecosystem effects due to loss and/or change in vegetation

What is disturbance? (52-07)

The disruption of community structure, and this varies in type, frequency, and severity. Sometimes necessary to maintain diversity. Includes things like fire & severe storms.

What is succession? (52-07)

Recovery from disturbance. Predictable turnover of species.

What is primary succession? (52-07)

A disturbance that removes all life, including the soil.

Examples include: Glacier retreat, Massive wildfires, Volcanos, Major human activities

What is secondary succession? (52-07)

A disturbance that significantly alters biological community, but does NOT remove the soil.

Examples include: Prairie fire, Windthrow

What is species richness? (52-08)

The number of species present in an area.

What is species evenness? (52-08)

Measure of relative species abundance in an area.

What is low species evenness? (52-08)

A few abundant species and many rare ones

What is high species evenness? (52-08)

The same number of individuals in each species

What is the Shannon Index? (52-08)

A weighted index of richness and evenness. The Shannon diversity index tells you how diverse the species in a given community are. It rises with the number of species and the evenness of their abundance.

What is island biogeography? (52-10)

Study of species richness on islands. An equilibrium number which is a balance between immigration and extinction

How does immigration relate to island biogeography? (52-10)

Controlled by distance to mainland (source).

Closer islands have more immigration, far away islands have less immigration.

How does extinction relate to island biogeography? (52-10)

Controlled by species-area effect. Larger islands have more habitats, thus more species.

Does consumption always result in death of the prey? (52-11)

No! Parasitism is an example of consumption, and the prey does not always die.

What is genetic diversity in biodiversity? (54-02)

Genetic variation within populations and between populations, important for microevolution.

– Reduction in genetic diversity

– Possibility for adaptation in a changing environment

– Implications for plant breeding and crop production

What is species diversity in biodiversity? (54-02)

Species diversity consists of species richness, the number of species, and species evenness, the relative abundance of species.

What is ecosystem diversity in biodiversity? (54-02)

Ecosystem diversity is the variety of habitats, the communities found in a geographic location, the beneficial services they provide, and the processes that support the ecosystem.

What is the current best estimate of extant biodiversity? (54-04)

~30 million species

What is an endemic species? (54-05)

Species that are found in a very limited area, compared with a wide-spread relative species

What are biodiversity hot spots? (54-05)

Biodiversity hotspots are regions that contain a high level of species diversity, many endemic species (species not found anywhere else in the world) and a significant number of threatened or endangered species. Targets for conservation – high return on investment.

What are the global patterns of biodiversity? (54-05)

Generally higher at the equator (low latitudes)

Higher in terrestrial systems compared to marine

Generally higher in larger habitats

Generally higher in old growth habitats

Higher in topographically diverse areas

What are the abiotic constraints on organisms? (49-03)

Temperature, precipitation, sunlight, wind soil, and site history.

Which two constraints are the most important? (49-03)

Temperature and precipitation

How does temperature vary? (49-04)

Depends on latitude and season, which determine solar input. Seasons occur from the Earth tilting on the axis.

Where does precipitation originate? (49-05)

Warm air picks up and holds water vapor

Warm air rises

As it rises, the air cools

Cooler air loses its water vapor

How do Hadley Cells influence precipitation? (49-05)

Hadley cells influence precipitation by creating bands of rising and falling air that cause high precipitation in the tropics and low precipitation at higher latitudes.

How do rain shadows influence precipitation? (49-05)

The mountains block most precipitation from falling in the valley, creating a dry climate where few plants grow. A rain shadow is a patch of land that has been forced to become a desert because mountain ranges blocked all plant-growing, rainy weather.

How do ocean currents influence precipitation? (49-05)

Ocean currents act much like a conveyor belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics.

Example: This warm water in the western Pacific Ocean causes low air pressure and high rainfall. Warmer water causes the air above the ocean's surface to warm and rise, leaving an area of lower pressure. More rainfall is associated with lower air pressure.

How are terrestrial biomes determined? (49-06)

They are mainly determined by temperature and precipitation. Biomes are characterized by dominant vegetation.

What percent do terrestrial biomes make up? (49-07)

22% of the Earth’s surface area.

What percent do aquatic biomes make up? (49-07)

78% of the Earth’s surface area.

What qualities determine aquatic biomes? (49-08)

Salinity, depth, flow, and nutrient content (upwellings, turn over).

What are the characteristics of the Iowa biome, tall grass prairies? (49-10)

Hot summers, cold winters, and moderate precipitation.

This biome is grass dominant with 50% or more of the biomass below ground, and this created the fertility of Iowa’s soils.

Why is the tall grass prairie endangered? (49-11)

99% of tallgrass prairies converted to agriculture and the problem of woody encroachment, which results from a lack of fire and large herbivores.

What is specific about ecosystem size? (53-01)

Ecosystem size is variable, and it is defined by researcher.

What do ecosystems do? (53-02)

Energy flows

- Solar to chemical energy

- Lost as heat

- Cannot be recycled

Nutrients cycle

- Nutrients get absorbed, transferred, released and reabsorbed

What is the conversion from solar energy to gross primary productivity? (53-03)

Total chemical energy produced, 0.8% of solar energy (1%)

What is the conversion from solar energy to gross primary productivity to net primary productivity? (53-03)

New tissue produced, 45% of GPP. Net primary productivity does not include respiration by plants.

What is a food chain? (53-04)

A food chain outlines who eats whom.

What is a food web? (53-04)

A food web is all of the food chains in an ecosystem.

Aboveground vs decomposer food chain? (53-04)

In above ground food webs, energy moves from producers (plants) to primary consumers (herbivores) and then to secondary consumers (predators).

Decomposers, like fungi and bacteria, complete the food chain. Decomposers turn organic wastes, such as decaying plants, into inorganic materials, such as nutrient-rich soil.

How does Net Primary Productivity vary? (53-06)

Varies by ecosystem

How does the ranking of Net Primary Productivity vary? (53-06)

Measurement technique (by area or time) can influence the ranking of NPP

Why are food chains short? (53-07)

Consumers are very inefficient energy transformers.

Production efficiency – the percentage of energy consumed by an organism that becomes new biomass. Usually between 5 – 20%

10% of biomass makes it to the next trophic level.

How does energy efficiency vary? (53-08)

Age, metabolism, and organism type. For example, younger organisms and ectotherms have higher energy efficiency, more of their food is converted to organism biomass. More of food goes into maintaining body temperature instead of growth. Endothermy is expensive.

What is biomagnification? (53-15)

Some materials do not breakdown and become stored in the tissues of the organism, usually in fat.

Overtime these chemicals become concentrated within food chains

Examples: DDT, Mercury, PCBs, Lead

What are the nitrogen cycle reservoirs? (53-10)

95% is in the earth’s crust, mantle and core (not biologically available).

Of the remaining 5%: 49% organic matter in soil, dissolved in water, 49% in atmosphere as N2, and 1% in biomass

How are materials moved through the nitrogen cycle? (53-10)

Nitrogen fixation: Converting atmospheric N2 to the biologically

available forms of nitrate and ammonium. Only certain bacteria do this: diazatrophs, Frankia, and rhizobia. Breaking N2 requires LOTS of energy.

What are the human impacts on the nitrogen cycle? (53-10)

Humans have DOUBLED nitrogen in the biosphere.

Too many nutrients (N and P) in a system leads to eutrophication.

Fertilizer increases plant biomass (or algae) production. In terrestrial systems this reduces diversity, in water excessive algae growth causes hypoxia (lack of oxygen in water) and this kills fish.

What are dead zones? (53-11)

Dead zones are areas of water bodies where aquatic life cannot survive because of low oxygen levels. Dead zones are generally caused by significant nutrient pollution, and are primarily a problem for bays, lakes and coastal waters since they receive excess nutrients from upstream sources.

Caused from nitrogen and phosphorous

Consequences of nutrient loading (nitrogen)? (53-11)

Nitrates can cause many health problems: Increased heart rate, nausea, headache, abdominal cramps, low birth weight, and birth defects.

What are solutions for dead zones? (53-11)

Dead zones can be reversed by eliminating or reducing the factors that caused them. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands slow down and filter runoff before it reaches bodies of water.

What are the phosphorus cycle reservoirs? (53-12)

Lithosphere, Water, and ~1% of the human body is P (ATP, DNA)

How are materials moved through the phosphorus cycle? (53-12)

No gaseous form – cannot cycle globally, only cycles LOCALLY

What are the human impacts on the phosphorus cycle? (53-12)

Some phosphorus is mined (fossilized poop) and we are running out of resources.

Phosphorus acts similarly in ecosystems: Decreases terrestrial diversity, and causes eutrophication in aquatic systems.

What is “peak phosphorus”? (53-12)

Peak phosphorus is a concept to describe the point in time when humanity reaches the maximum global production rate of phosphorus as an industrial and commercial raw material.

The idea that phosphorus production could level off within a few decades, at which point the world might face skyrocketing prices and widespread shortages

What are the carbon cycle reservoirs? (53-13)

Ocean, soil, and the atmosphere is a small pool, but it is very important.

How are materials moved through the carbon cycle? (53-13)

Photosynthesis, respiration, decomposition

What are the human impacts on the carbon cycle? (53-13)

We are mining sequestered carbon and burning to fuel activities

We are cultivating soil, which releases carbon when soil is exposed

We are cutting down forests, a large plant reservoir of carbon

What are climate change consequences? (53-13)

Increases in greenhouse gasses cause increases in GLOBAL temperature, which is not consistent over space and time.

Changes in temperature alter precipitation patterns, jet streams, etc.

Storms and other abnormal weather increasing in frequency.