Ecology Quiz - Science

Intro to ecology, species interactions, biodiversity, food chains, web, energy flow, bioaccumulation and bioamplification

What is ecology?

study of the relationship between living things and their environments

Biotic factors

• living components

  • all organisms

  • their remains

  • their products and wastes

Abiotic factors

• nonliving, physical, and chemical components

  • temperature, wind, water, minerals, air

Sustainable ecosystem

can meet their current needs without depletion of natural resources or compromising future needs

Ecological niche

An organisms ecological role in an ecosystem

• what it eats, what eats it, how it behaves

• spot in food web (diet)

• habitat (where it lives)

• interactions with others (relationships)

• time of day it’s active (behavior)

Competitive exclusion (-/-)

• two similar species occupying the same niche at the same time

• will compete for the same resources

• less competitive species will be eliminated eventually

• e.g. hawk and owl

Predation / parasitism (+/-)

• predation: one feeds on another

• parasitism: one lives on or in and feeds on host organism

• parasite: organism whose ecological niche is closely linked to its host, causing discomfort and possibly death to host

• e.g. lynx preying on snowshoe hares, tapeworms are parasites of cats and dogs

Mutualism (+/+)

• two individuals benefiting each other

• e.g. bees pollinate plants, plants provide food for bees

Commensalism

• one benefits, other neither benefits nor is harmed

• e.g. birds nesting in particular trees

Native species

• species that naturally occur in a specified area

• e.g. koalas are native to australia

Invasive species (“killer” bees in South America)

• animals new to the area create an imbalance in the ecosystem, compete for an ecological niche

  • may cause extinction or extirpation (no longer exists in particular region)

  • may thrive due to lack of natural predators in area

Impact of invasive species

• ecological

  • compete with or feed on native species, leading to population decline or extinction

• economic

  • damage to forests, crops, causes financial losses

  • diseases and pests may destroy livestock and crops

• tourism

  • species lost, reduced water quality have negative impacts on wildlife viewing, fishing, etc.

• health

  • disease-causing organisms

  • pesticides used to control invasive species because pollution and health are at risk

Species diversity

• greater diversity = greater stability

• more food resources, habitats, ability to adapt to change

Agricultural “monoculture” (Irish potato famine [1845 - 1852])

• only growing single crop species over large area of land

• reduced biodiversity leads to pests, diseases, soil degradation

“Old field”

• piece of abandoned farmland slowly returning back to its original state

• reduced biodiversity weakens ability to recover, support wildlife, and function

Ecological succession

• gradual changes in the ecosystem after a disturbance

• allows ecosystem to recover after a natural or human-caused disturbance

Primary succession (volcanic eruptions)

occurs on soil or bare rock where no previous life existed

Secondary succession (forest fire)

follows disturbance that disrupts but does not destroy the community

Dominant species (American Chestnut Tree)

• most abundant species / biggest biomass (total mass of all living things in an ecosystem)

• removal can cause decrease in biodiversity

• almost always producers (plants)

Keystone species (sea otters, prairie dogs)

• greatly affect population and health of an ecosystem

• not most abundant (non-dominant)

• can be plants or animals

Indicator species (amphibians)

• sensitive to changes in the environment, indicates a problem exists

• changes in population can signal pollution, climate change, habitat loss, etc.

• frogs are sensitive to water and air pollution because they breathe through their skin

Ecosystem engineers (beavers)

• physically change the environment in ways that affect other species

• can create, modify, maintain habitats

Ecosystem services (insects pollinating crops, controlling pests, supporting soil health, decomposing organic material)

• benefits experienced by organisms (including us) provided by sustainable ecosystems

• natural result of all activities that occur in the biosphere

Ecological connectivity

links between ecosystems that are separated geographically

Ecological ladder

• biosphere

  • all life on earth

• biome (tundra, rainforest, desert)

  • large region with specific climate and types of plants and animals

• ecosystem (forest + soil, sunlight, air)

  • community plus abiotic things

• community (deer + rabbits, trees, wolves)

  • all different species living together in an area

• population (herd of deer)

  • group of the same organism living in the same area

• organism (one deer)

  • one single living thing

Ecotone

• transition area between two ecosystems

• contains members of both ecosystems

• greater biodiversity

Biodiversity

• number and variety of species in an ecosystem

• high biodiversity usually = more sustainable ecosystem

producer / autotroph - 1st trophic level (plants, algae)

an organism that makes its own food using sunlight (photosynthesis)

consumer / heterotroph

an organism that eats others to get energy

• herbivores: 2nd trophic level, eats plants (e.g. rabbit)

• carnivores: 3rd trophic level, eats animals (e.g. wolf)

• omnivores: 3rd trophic level, eats both (e.g. human)

Decomposer (fungi, bacteria, earthworms)

an organism that breaks down dead plants and animals and recycles nutrients into the environment

Food chain

path showing how energy moves from one organism to another

food web

many connected food chains (complex feeding relationships in an ecosystem)

Trophic levels

categorizes level in a food chain/web

Bioaccumulation

• build up of pesticides (toxins) inside one organism

• e.g. plants absorbing pesticides from soil and water over time

Bioamplification

• increase of toxin levels as they move up the food chain

• e.g. grasshopper comes and eats a bunch of these pesticide-covered plants, pesticide builds up in their bodies. they now have more pesticides than the original plants

Pesticides

• designed to kill pest organisms (kill = -cide) and do not break down

• useful for reducing pests but have environmental and health risks

• some pests become resistant when the pesticides are used for too long

How do we fix pesticide resistance?

• organic farming

• integrated pest management (IPM)