Interactions and Community Ecology

Question 1

Competition

Answer 1

organisms that see the same resource have a relation

Question 2

infraspecific competition

Answer 2

members of the same species, population level

Question 3

interspecific competition

Answer 3

members of different species

Question 4

competitive exclusion

Answer 4

one species is a stronger competitor, it may exclude other species from the resource

Question 5

species coexistence

Answer 5

no single competitor excludes other, coexisting species will alter their behavior to minimize competition, alerting their niche

Question 6

Fundamental niche

Answer 6

the full niche of a species

Question 7

realized niche

Answer 7

the portion of the fundamental niche that is actually filled (due to competition or other species’ interaction)

Question 8

Resource partitioning

Answer 8

the process by which species use different resources or use shared resources in different ways

Question 9

character displacement

Answer 9

competing species diverge in their physical characteristic

Question 10

Exploitation

Answer 10

process by which one member exploits another for its own gain (predation, parasitism, herbivory )

Question 11

Predation

Answer 11

the process by which individuals of one species (predators) capture, kill, and consume individuals of another species(prey)

Question 12

Parasitism

Answer 12

a relation in which on organism (parasite) depends on another (host) for nourishment or some other benefit, doesn’t kill host

Question 13

Herbivory

Answer 13

when animals feed on the tissues of plants, may not kill the plant, but affects its growth and survival

Question 14

Mutualism

Answer 14

a relationship where two or more species benefit each other

Question 15

symbiosis

Answer 15

mutualism in which the organisms live in close physical contact

Question 16

pollination

Answer 16

interaction in which bees, bats, birds, and other transfer pollen from one flower to another, fertilizing its eggs

Question 17

Community

Answer 17

an assemblage of populations of organisms living in the same place at the same time

Question 18

Trophic level

Answer 18

rank in the feeding hierarchy, producers, consumers, detrivores

Question 19

Biomass

Answer 19

the collective mass of living matter in a given place and time

Question 20

Food chain

Answer 20

a linear series of feeding relationships

Question 21

Food webs

Answer 21

all of the interlinking food chains within an entire community

Question 22

Keystone species

Answer 22

have a strong or wide-reaching impact far out of proportion to their abundance

Question 23

Ecosystem engineers

Answer 23

physically modifying the environment

Question 24

Trophic cascade

Answer 24

a phenomenon in which predators at high trophic levels indirectly affect populations at low trophic levels

Question 25

Disturbance

Answer 25

an event that causes rapid changes in the environment that alters the community or ecosystem

Question 26

Communities have different ways of maintaining themselves when disturbed called _ and _

Answer 26

resistance and resilience

Question 27

Succession

Answer 27

the predictable series of changes in a community following a disturbance

Question 28

Primary Succession

Answer 28

disturbance removes all vegetation and soil life. - community is built from scratch - glaciers, drying lakes, volcanic lava

Question 29

Pioneer species

Answer 29

the first species to arrive in a primary succession area (lichens, mosses)

Question 30

Secondary succession

Answer 30

a disturbance dramatically alters but does not destroy, all local organisms - fires, hurricanes, farming, logging

Question 31

Climax Community

Answer 31

a community that remains in place with few changes until another disturbance restarts the succession

Question 32

Phase(regime) shift

Answer 32

occurs when the overall character of the community fundamentally changes - some crucial threshold is passed, a keystone species is lost, or an exotic species invades

Question 33

Novel or nonanalog communities

Answer 33

new mixtures of species that have not been seen before in nature

Question 34

Introduced species

Answer 34

non-native arrivals to a community brought by people, most fail to establish populations, but the ones that thrive are called invasive species

Question 35

How should we respond to invasive species?

Answer 35

- removal - applying toxic chemicals - introducing native predators or disease - stressing them with heat, sound, electricity, carbon dioxide, or ultraviolet light - Prevention, rather than control is the best policy

Question 36

Ecological restoration

Answer 36

- restore the functionality of an ecosystem - return a community to its ‘pre-settlement’ condition

Question 37

Earth’s Biomes

Answer 37

- a regional complex of similar communities is called a **biome** - biomes are classified primarily by **dominant plant type and vegetation structure**, which in turn is the result of climate - temperature and precipitation exert the greatest influence over all other climatic factors

Question 38

Climates also vary with elevation

Answer 38

high altitudes - temperature, atmospheric pressure, and oxygen decline - ultraviolet radiation increases Mountains also affect climate through the rainshadow effect

Question 39

Tropical rainforest

Answer 39

- Southeast Asia, west Africa, central and south America - year-round rain and warm temperatures - the forest floor is dark and damp - lush vegetation - diverse species - but species in low densities - very poor soils

Question 40

Temperature deciduous forest

Answer 40

- deciduous trees lose their leaves each fall - they remain dormant during winter - mid-latitude forests in Europe, Eastern China Eastern North America - even, year-round precipitation - fertile soils - dominant forest trees are often oak, beech, maple

Question 41

Temperature grasslands

Answer 41

- more extreme temperature difference between winter and summer than temperature deciduous forest - less precipitation - also called steppe or prairie - once widespread, but has been converted to agriculture - bison, prairie dogs, ground-nesting birds, pronghorn

Question 42

Temperature rainforest

Answer 42

- coastal pacific northwest - a great deal of precipitation - coniferous trees: cedar, spruce, hemlock, fir - moisture-loving animals - banana slug - erosion and landslides affect the fertile soil - logged for lumber and paper - most old growth is gone

Question 43

Tropical dry forest

Answer 43

Also called tropical deciduous forest - Plants drop leaves during the dry season - India, Africa, South America, north Australia - Wet and dry seasons - Warm, but seasonal rainfall and less overall than rainforest - Converted to agriculture - Severe soil erosion

Question 44

Savanna

Answer 44

- Grassland interspersed with trees - Africa, South America, Australia, India - Precipitation is only during the rainy season - Animals gather near water holes - Zebras, gazelles, giraffes, lions, hyenas

Question 45

Desert

Answer 45

- Minimal precipitation - Some are bare, with sand dunes (Sahara) - Some are vegetated (Sonoran) - They are not always hot - Temperatures vary widely during the day - Saline soils - Animals are often nocturnal, nomadic - Plants may have defenses

Question 46

Tundra

Answer 46

- Russia, Canada, Scandinavia - Minimal precipitation - Extremely cold winters - Extreme variation in day length - Permafrost = permanently frozen soil - Melting due to climate change - Few animals: polar bears, muskoxen, caribou, migratory birds - Lichens, low vegetation, few trees

Question 47

Boreal forest

Answer 47

- Also called taiga - Canada, Alaska, Russia, Scandinavia - Extends for large continuous areas - A few evergreen tree species - Cool and dry climate - Long, cold winters - Short, cool summers - Nutrient-poor, acidic soil - Moose, wolves, bears, lynx, migratory birds

Question 48

Chaparral

Answer 48

- Occurs in small patches around the globe - Mediterranean Sea, coastal Chile, California, southern Australia - Highly seasonal biome - Mild, wet winters - Warm, dry summers - Frequent fires - Densely thicketed, evergreen shrubs