Fundamentals of Environmental Biology: Exam 2

Ecological Succession

The process of vegetation changing over time until it meets that area

Primary Succession

We start with bare rock, then to soil as it takes thousands of years

Secondary Succession

Already soil there so things will grow more quickly (cornfields, yard)

Climax Vegetation

The final stable community in an ecological succession; where it will end up and stay in equilibrium (varies in different types of ecosystems)

What determines the extent of Vegetation?

Temperature and Precipitation

Biome

A large naturally occurring community that is home to similar plants and animals, defined by its climate and dominant vegetation

Desert

Major features: cool to mild winters, warm summers, dry all year round

Human Impacts: off-road vehicles, desertification

Plants: cactus, tumbleweed

Animals: reptiles, armadillo

Grassland

Major Features: warm summers, warm or cool winters, dry winters, moist summers

Human Impacts: overgrazing, poaching

Plants: grass, crops, trees, flowers

Animals: grazing animals, insects, rodents

Taiga

Major Features: cold, wet summers, cold, wet winters, short growing season

Human Impacts: logging

Plants: pine trees, shrubs, deciduous trees, wildflowers

Animals: Elk, moose, deer 

Temperature Decidious Forest

Major Features: cool winters, warm summers, moist all year round

Human Impacts: urbanization, logging, habitat destruction

Plants: oak trees, pine trees, mushrooms, grass, flowers

Animals: skunks, deer, coyotes, rabbits, raccoons, fox

Tropical Rain Forest

Major Features: warm all year, wet all year, low soil fertility

Human Impacts: logging/habitat destruction, loss of biodiversity

Plants: palm trees, citrus fruits, flowers, vines

Animals: snakes, sloths, monkey, frogs

Tundra

Major Features: cold all year, wet summers, dry winters

Human Impacts: localized habitat destruction around mines, drilling sites,
pipelines and military bases

Plants: small trees, shrubs, moss, lycans, wildflowers

Animals: moose, cariboo, penguins, orcas, walrus, seals, polar bears

Which terrestrial ecosystem is closer to the equator?

Desert

Which terrestrial ecosystem is known as a huge migration area?

Grasslands

What kind of soil do tropical rainforests have?

Non-fertile soil

Permafrost

Even when the top surface thaws, the inner layers of the soil are frozen all year

Ecosystem

Biotic and abiotic factors in a particular area that creates a community and climate

Where does the mass of a tree come from?

Photosynthesis (water vapor + carbon dioxide)

Freshwater Ecosystems

Major Features: Divided into zones

Littoral- edge of a pond

Lymnetic- as far down as light penetrates; plants reside/produce photosynthesis

Profundal- where light stops

Benthic- bottom; contains decomposers

Human Impacts: eutrophication, acid rain

Eutrophication

Ties to the nutrient cycles (Nitrogen + Phosphorus), leeching of fertilizers and nutrients into bodies of fresh water (fish die more)

Acid Rain

Continuing issue: when we burn fossil fuels or coal, sulfur is produced and mixes with moisture, causing sulfuric acid. This falls on living things, killing ecosystems, and more.

Marine Ecosystems

Major Features:

Light Zones:

Photic- how deep the sunlight goes

Aphotic- where there is no light

Life Zones:

Intertidal- land between high tide and low tide

Nertic- always underwater, but shallow

Oceanic- open ocean/ deep water

Human Impact: pollution (oil spills), global warming

Similarities between Freshwater and Marine Ecosystems

Fish, plants growth, shellfish, pollution, recreation

Differences between Freshwater and Marine Ecosystems

Size of water, coral reefs in marine ecosystems, bigger animals, complex food webs

Hydrothermal Vent Communities

One of the only places where photosynthesis is not the main source of energy (found on the crusts of the earth)

Chemosynthesis

Breaks down sulfar compounds

Niche

All the things that make an organism fit into specific ecosystem categories; where they fit in the food chain, climate, and where they live

How do organisms of the same species interact with each other?

Reproduction and Hierarchy

How do organisms of different species interact with each other?

Competition and Predation

Competition

No two species occupy exactly the same niche at the same time (they can overlap, but can’t be the same

Interspecific- members of different species

Intraspecific- members of the same species

Predation

Factor in coevolution; develop defenses by prey; overcoming defenses by predators

Predator

These acquire energy by taking energy from other organisms, but one predator eats multiple prey during the predator’s lifetime, predators tend to be bigger than their prey, and predators typically kill their prey

Key factor in coevolution

Development of defenses by prey

Overcoming the defenses of predators

Camouflage

EX) Camelion (prey/predator), Stinkbug (prey), Deer (prey)

Warning Coloration

Warning color to predators not to hunt them again

EX) Poisonous dart frog (prey)

Mimicry

Non-toxic animals/bugs copy something else in order not to be eaten. Looks like something the predator remembers to avoid

EX) Viceray butterfly, King snake/Coral snake

Chemical Warfare

Helps protect the prey from predators

EX) Skunk (prey), Octopus (prey), Beetles, Toads, Stinkbugs

Parasitism

One benefits, one is harmed (+ -)

EX) Tick

Commensalism

One benefits, one is not affected (+ 0)

EX) Barnacles

Mutualism

Both benefit (+ +)

EX) Pollenators

Parasitism (Definition)

A parasite is usually much smaller than its host, lives a shorter period of time, often reproduces within (or on) its host, and may or may not kill its host

Factualtive Mutualism

With or without partner species

EX) Large fish and cleaner fish

Obligate Mutualism

Requires partner species

EX) Lichen= fungus + algae

Plant Mutualism

Trees are able to communicate and share nutrients (Pollination and Mycorrhizae)

Animal Mutualism

Grazing animals, sea annemomea protects crab, cleaner birds

What is determined when ecosystems live together? 

Impacts how they interact with eachother; they require different resources, so more diveristy = successful ecosystem

How does predation help both prey and predators?

Prey: Natural selection, makes them stronger, controls groups

Predator: Gets nutrients

Biodiversity

Variety of living things in an ecosystem; the more diversity, the healthier the ecosystem will be 

Importance: For resources, creates a sense of balance

Direct Values

Nutrients (taking something)

Agriculture- GMO crops, genetic diversity, biological pest controls, pollination

Medicine- new drugs, new hosts for beneficial or harmful organisms

Consumptive Uses- wild fruits and vegetables, fibers, beeswax, seaweed, skins, cultivated crops, domesticated animals, lumber

Indirect Values

Observing something’s beauty

Nutrient Cycles- gives options and provides nutrients (Contains everything)

Waste Disposal- decomposition, sewage treatment, breakdown of toxic chemicals

Fresh Water- wetlands, swamps, marshes, forests (can help filter water)

Soil Erosion- forests, grasslands, stream banks (by having forests and plants, we’re able to prevent this)

Climate Regulation- shade, CO₂ absorption (helps moderate heat)

Ecotourism- sport fishing, hiking, birdwatching, boating (traveling to be in different ecosystems, going to protect it, helping to support programs that keep it healthy)

How does this diagram show competition and adaptation between these plant species?

• Really long roots in order to reach the nutrients and moisture at the bottom

• Really bushy fibrous roots

• Some grow in order to get sunlight before the other ones

What factors affect population growth?

Birthrate, death rate, migration (immigration and emigration)

Immigration- organisms come in

Emigration- organisms leave

Exponential Growth (J-curve)

Unrestricted growth of a population; nothing limiting the rate of reproduction

Logistic Growth (S-curve)

Population reaches equilibrium

• Most natural populations demonstrate logistic growth

Equilibrium

The state of balance

• When a population reaches equilibrium, it doesn’t exactly stay at 100. It stays around the carrying capacity.

What would cause Exponential Growth?

Resources, not a lot of predators, things aren’t reproducing faster than they can grow, physical space

Regulation of Population Growth on a S-curve Graph

Biotic Potential- max. growth rate under ideal conditions

Carrying Capacity- the maximum number that can be maintained over time

Environmental Resistance- limiting factors for the growth of a population (predation, weather, food availability, diseases, competition)

Equilibrium- population is stable

Exponential Growth- population is increasing

Density-dependent Factors

Disease, food and other resource shortages, production of toxic waste
products, predation, stress, emigration

Density-independent Factors

Natural disasters (drought, wildfires, flooding, blizzards,(drought, wildfires, flooding, blizzards, earthquakes, volcanic eruptions), human impacts, climate change

Boom and Bust Cycles (Predator + Prey Interaction)

Who is driving the ups and downs?

• They both drive it. While they go up and down together, it just may be that one is dying off or moving away from the other. There are too many factors involved to determine which goes up and which goes down.

(Similar Test Question) What does the graph tell you about this population?

They are at equilibrium. There is a natural fluctuation in their population. 

R Selection (strategy)

When a species has many offspring, but little parental involvement

EX) fish, turtles, frogs, insects

Benefits: safety in numbers, natural selection, does not require parental energy, and can reproduce quickly

Disadvantages: risk of laying eggs that none may survive

K Selection (strategy)

When a species does not have a lot of offspring, the parents stay to make sure they survive

EX) humans, deer, geese, kangaroos (mainly ALL mammals)

Benefits: most survive till adulthood, pass strategies for survival

Disadvantages: something big could wipe out the population easily (natural disasters), parental care energy is intensive

Which curve would represent r-selected species? K-selected species?

Line C represents r-selected species. Line A represents K-selected species.