Ecology Exam 1

Why is Earth great? What are 2-3 things that make earth unique to support life?

It is the “Goldilocks” planet

The habitable zone for many forms of life.

Climate dictated by temperature and precipitation.

The Earth is an active planet, the rock cycle, ring of fire… there is a constant recycling of material .

Space weather and auroras

Who coined the term "ecology”?

Ernst Haeckel

Define ecology

the scientific study of the relationships between living organisms (including humans) and their physical environment

What does ecology seek to understand?

it seeks to understand vital connections between living organisms and the environment.

• cause and effect

Who is recognized as the father of modern ecology? hint: UGA

Eugene Odum - founder of the Eugene P. Odum School of Ecology

List the Biological Level of Organization

Atoms

Cells

Tissues

Organs

Organ Systems

Organisms

List the Ecological Levels of Organization

Individual

Population

Community

Ecosystem

Landscape

Biome

Ecosphere/Biosphere

Define ecosystem

a functional unit comprising all living organisms (plants, animals, microbes) and their non-living environment in a specific area.

self contained system of interactions

Define Landscape

a mosaic of diverse interacting ecosystems and land types (forests, grasslands, rivers, farms) across a broad area.

larger than a single ecosystem, often encompassing many

What is a green space in ecology?

a functioning forest, the way nature intended.

What are the components of an ecosystem?

• biota

• abiota

• interactions

What is the difference between biota and abiota?

Biotic factors are the living parts of an ecosystem, while abiotic factors are the non-living physical and chemical elements.

List some biotic factors.

• Bacteria

• Protists

• Fungi

• Plants

• Animals

• “Waste” dead leaves, exoskeletons, dropped fur, excrement, decaying animals

List some abiotic factors

• Weather/Climate

• Soil

• Geology

• Topography - exposure, aspect, hydrology

• Water - salinity, chemistry, pH, turbidity

• Rocks

• Nutrients

Briefly define population.

Same species, that are breeding

Somewhat isolated

Define community

biotic components - all populations within an area

Define landscape

multiple ecosystems over a landscape.

Define biome, what are they classified by?

broad geographic areas, classified by temperature and precipitation.

What are the three broad categories of biomes?

• Terrestrial

• Marine

• Freshwater

What differentiates weather and climate?

Weather describes the state of conditions from a day-to-day perspective including temperature, atmospheric pressure, wind speed and direction, and precipitation.

Climate establishes the variety of long term conditions that influence the types of organisms that can survive or thrive in a given area.

• determines the various growing seasons, hardiness zones for plants and farming, and the biomes and ecosystems that occur on Earth

What is Earth always headed to in long term climatic changes?

Ice age or a more tropical Earth

Define niche

• role/job/function

• ecological space occupied by an organism

• evolves (natural selection) as a means of avoiding competition

Define fecundity

a population or individuals’ reproductive potential.

ability to produce offspring

Define keystone species

species with disproportionately large effect on its environment.

Give an example of a keystone species

The dam-building activity of beavers creates and maintains entire wetland habitats that support a high diversity of other plants and animals.

Dams filter water, manage floods and drought, and play a role in preventing wildfires.

What are the 3 types of biodiversity?

• Ecosystem diversity

• Genetic diversity

• Species diversity

Define flagship species

a species chosen to raise support for biodiversity conservation in a given place or social context.

What is biosphere 1?

Earth

What is biosphere 2?

A case study that focused in ecosystems and nutrient cycling.

What were the two goals of Biosphere 2?

1. to prove that an entirely self contained, human-made ecosystem could sustain life.

2. to better understand our own planet’s delicate balance and how to best protect it

What are some things we learned from biosphere 2 ?

• More than 1/3 of the flora and fauna became extinct, including most of the vertebrates and all of the pollinating insects.

• Cockroaches and “crazy ants” thrived

• Plant diseases killed most of the crops, and sweet potatoes were the only thing researchers could eat, and they turned orange.

• Oxygen levels plummeted from 21% to 14% forcing the researchers to pump in outside air.

• Nitrous oxide became so concentrated that brain damage became a significant concern.

Define matter cycles

movement of life’s essential chemicals or nutrients through an ecosystem.

ex: carbon, nitrogen, phosphorus

Define energy flow

the one way passage of energy through an ecosystem.

Earth is a _______ system for matter but not for _____.

closed; energy

Earth is materially closed but energetically open.

Define photosynthesis, what is the opposite reaction?

the chemical reaction performed by producers that uses the energy of the Sun to convert carbon dioxide and water into sugar and oxygen.

Cellular respiration is the opposite reaction.

Define cellular respiration

cellular respiration is a metabolic pathway that breaks down glucose and produces ATP.

What is the first law of thermodynamics?

Energy cannot be created or destroyed but it can change forms.

What is the second law of thermodynamics?

Every time energy changes form some energy is lost as heat energy (entropy)

Define entropy

lack of order or predictability; gradual decline into disorder

How does time affect entropy?

Entropy always increases with time

Define limiting factor

the critical resource whose supply determines the population size of a given species in a given ecosystem.

• the critical resource in least supply determines the survival, growth, and reproduction of a given species in a given biome

Define range of tolerance

the range within upper and lower limits of a limiting factor that allows a species to survive and reproduce.

Briefly describe the range of tolerance of humans.

Humans have a large range of tolerance because they are constantly changing their environments.

Define sinks

abiotic or biotic components of the environment that serve as storage places for cycling nutrients, can be called reservoirs.

What is residence time?

the amount of time a nutrient spends in the sink.

What is the carbon cycle?

movement of carbon through biotic and abiotic parts of an ecosystem.

What is the input of the carbon cycle?

Photosynthesis

What is the output of the carbon cycle?

• Cellular respiration

• Burning fossil fuels

• Forest fires

• Deforestation

What is the most important sink for terrestrial plants?

The atmosphere where carbon is stored as CO₂

What are examples of human activity that adds extra CO₂ into the atmosphere?

Burn swarths of forests

Deforestation

Burning fossil fuels

Define producer

organisms that converts solar energy to chemical energy via photosynthesis

Define consumers

organisms that obtain energy and nutrients by feeding on another organism

Define anthropogenic

caused, produced, or influenced by human activity rather than by natural processes.

What is the nitrogen cycle?

a continuous series of natural processes by which nitrogen passes from the air to the soil, to organisms, and then returns back to the air or soil.

How is human impact playing a role in nitrogen and microbiota?

Increasing the amount of usable nitrogen in the environment, and decreasing the microbiota in soils.

What element is the most abundant element in the Earth’s atmosphere?

Nitrogen

Can plants use atmospheric nitrogen? How do they overcome this?

Plants cannot utilize nitrogen in its atmospheric form N₂, all plant life depend on bacteria to convert atmospheric nitrogen into usable forms.

How does nitrogen enter an ecosystem?

nitrogen fixation

What is nitrogen fixation?

Bacteria convert atmospheric nitrogen into ammonia which is a form of nitrogen that is biologically available to plants.

How do humans impact the nitrogen cycle?

fertilizers and vehicle emissions are doubling the availability of nitrogen, this additional nitrogen can disrupt the ecosystem.

What is the phosphorus cycle?

a series of natural processes by which phosphorus moves from rock to soil to water, to living organisms, and back to soil.

mechanical weathering of plants.

How is the phosphorus cycle disrupted?

the release of more phosphorus into the environment by mining and the use of fertilizer.

Define eutrophication

the process where a body of water becomes overly enriched with nutrients, leading to explosive plants and algae growth that can suffocate aquatic life.

What is the green line? the blue shaded area?

green line = fall line

blue area = coastal plane

Define species

a group of organisms that can successfully breed to produce fertile offspring.

interbreeding natural populations which are reproductively isolated from other such groups.

Define speciation

the formation of new and distinct species in the courses of evolution (genetic changes over time)

How does speciation occur?

occurs when a group within a species becomes isolated from other members and genetic recombination results in unique characteristics that prevent genetic recombination with the ancestorial species.

What are the three species concepts?

Biological

Morphological

Phylogenetic

Give an example of speciation.

The Galapagos Island finches, the finches evolved different kinds fo beaks based on the food sources available to them.

• large blunt beaks that can crack the hard shells of nuts and seeds.

• long, thin beaks that can probe into cactus flowers

• medium size beaks that can catch and grasp insects

Define allopatric speciation

reproductive isolation occurs because of geographic separation or physical barrier that prevents organisms from interacting.

Define sympatric speciation

reproductive isolation that occurs without geographic separation, genetic changes prevent populations from successfully mating.

Give an example of sympatric speciation.

• Kokanee and anadromous sockeye salmon

• European whitefish

• African cichlids

Identify and define the mode of speciation.

Allopatric - new species formed from geographically isolated populations.

Identify and define the mode of speciation.

Peripatric - new species formed form a small population near a larger population.

Identify and define the mode of speciation.

Parapatric - new species formed from a continuously distributed population.

Identify and define the mode of speciation.

Sympatric - new species formed from within the range of the ancestral population

Define artificial selection

the intentional breeding of plants and animals by humans to highlight and pass on specific, desirable traits

Give an example of artificial selection/

Carolina dog - medium sized, erect, long ears, moderately slender, tapering point tip.

What are the prezygotic isolation mechanisms?

• Habitat Isolation

• Temporal

• Behavior

• Mechanical

• Gametic Isolations

Define habitat isolation in context of prezygotic isolation.

Species prefer different habits so it is unlikely they will interact.

Define temporal isolation in context of prezygotic isolation.

Species mate at different times of the year.

Define mechanical isolation in context of prezygotic isolation.

Physical differences prevent reproduction, for example, size or appendages are different and highly specialized.

Define gametic isolation in context of prezygotic isolation.

Species gametes are incompatible.

the giant red urchin and the purple urchin both live off the west cost of the US and although their eggs and sperm come into contact through broadcast spawning, no fertilization can occur.

Define hydrid in-fertility

a biological condition where the offspring resulting from the mating of two different species grow into healthy adults but cannot reproduce

Define hybrid in-viability

post-zygotic reproductive barrier where offspring (hybrids) resulting from the mating of two different species fail to develop properly or survive to reproductive age.

Define bottleneck effect

a drop in a population's size that randomly destroys most of the group, leaving only a few survivors to rebuild the next generation.

What is a watershed?

A watershed is an area of land where precipitation drains to a common outlet, such as a reservoir, river, or stream.

What is Corbicula?

An invasive freshwater bivalve 

• Hermaphroditic → can self-fertilize 

• High reproductive rate; about  35,000 larvae per breeding season 

• Mature in about  3–8 months 

• Can survive a wide range of temperatures and even periods out of water.

• Dispersed by water currents and human activities 

• Competes with native mussels for food and habitat. 

List a few ecosystem services provided by dams

• Hydropower 

• Flood-risk management 

• Recreation 

• Fish and wildlife management 

• Water quality 

• Water supply 

• Downstream navigation 

Natural resource impacts from a dam/reservoir 

Dams can: 

• Eliminate aquatic habitat 

• Change water flow 

• Change water temperature 

• Change water chemistry 

• Affect freshwater mussel habitat 

• Flood existing land/historical sites 

• Alter downstream river conditions. 

Differentiate osprey and eagle

Ospreys are smaller, specialized fish-eaters with dark eye stripes and bent wings in flight, while Eagles are much larger predators with broad, flat wings and solid white heads

How do non-native mussels become so invasive?

• Reproduce rapidly 

• Can attach to different surfaces 

• Are easily dispersed by water currents and human activities 

• Compete with native mussels for food 

• Reduce/displace native mussel habitat 

• Can alter water chemistry 

• Have high filtration rates. 

Describe the life cycle of the freshwater mussel.

Male releases sperm → female downstream takes in sperm → eggs develop into glochidia inside female's gills → glochidia are released → attach to a specific fish → develop on/in the fish → juvenile mussel drops off → lives on stream bottom → grows into adult. 

What is AVM? How is it related to hydrilla? 

AVM = avian vacuolar myelinopathy. 

• Hydrilla is an invasive aquatic plant. 

• Toxic cyanobacteria grow on hydrilla. 

• Coots eat the material on the hydrilla. 

• The toxin causes AVM in birds. 

• Bald eagles eat infected birds such as coots and can die from the disease. 

Why were grass carp introduced into Lake Thurmond?

Sterile triploid grass carp were introduced to reduce hydrilla. 

The goal was to reduce hydrilla abundance by about 50%. 

How can fluctuating water levels impact native fish/wildlife? 

Fluctuating water levels can alter habitat and water conditions for aquatic organisms. 

At Thurmond: 

• Weekend water levels can decline because of dam releases and pumpback. 

• Temporary weekend drawdown can be 3.5–13 inches. 

• Downstream river levels can fluctuate 3–5 feet daily because of peaking power generation. 

• Fish spawning can be affected; pumpback is restricted during spring spawning because of increased risk of fish entrainment.