Introductory ecology key terms

Question 1

Define ecology

Answer 1

The study of the distribution and abundance of organisms, the interaction between organisms, the interaction between organisms and their environments, and structure and function of ecosystems.

Question 2

Define ecosystem

Answer 2

A dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.

Question 3

Define communities

Answer 3

An assemblage of populations of different species, interacting with one another

Question 4

Define carrying capacity

Answer 4

The maximum population of a species an environment can sustain

Question 5

Define biosphere

Answer 5

The global sum of all ecosystems

Question 6

Define habitat

Answer 6

A place where an organism or community lives, including biotic and abiotic factors

Question 7

Define microhabitat

Answer 7

The smallest part of the environment, which supports flora and fauna e.g. a hole in a tree

Question 8

Define population

Answer 8

The summation of all organisms within a species

Question 9

Define ephemeral

Answer 9

Temporary habitats, e.g. puddles

Question 10

Define ecotones

Answer 10

The transition between habitats

Question 11

Define ecocline

Answer 11

The gradient of abiotic factors in ecotones

Question 12

Define succession

Answer 12

The process of change in the structure of an ecological community, beginning with pioneer plants

Question 13

Define plagioclimax community

Answer 13

A community which arises in succession due to human intervention

Question 14

Define populations

Answer 14

The summation of organisms within a specis

Question 15

Define autotrophs

Answer 15

Self-nourishing organisms

Question 16

Define photoautotrophs

Answer 16

Organisms that use sunlight as energy

Question 17

Define chemoautotroph

Answer 17

Organisms that obtain energy from chemical reactions

Question 18

Define heterotrophs

Answer 18

Organisms that cannot make their own food

Question 19

Define photoheterotrophs

Answer 19

Organisms use light energy as well as other food sources

Question 20

Define chemoheterotrophs

Answer 20

Organisms that use organic sources for energy

Question 21

Define granivores

Answer 21

Organisms that eat grains

Question 22

Define frugivores

Answer 22

Organisms that eat fruit

Question 23

Define foliovores

Answer 23

Organisms that eat leaves

Question 24

Define saprotrophic nutrition

Answer 24

Organisms that feed on dead organic matter, e.g. fungi

Question 25

Define commensalism

Answer 25

Ecological interactions where one organism benefits, whilst the other neither gains or loses

Question 26

Define competition

Answer 26

Ecological interactions where both species suffer

Question 27

Define mutualism

Answer 27

Ecological interactions where both species benefit

Question 28

Define parasitism

Answer 28

Ecological interactions where one species benefits whilst the other is disadvantaged

Question 29

Define amensalism

Answer 29

Ecological interaction where one species is disadvantaged, but there is no effect on the other

Question 30

Define interference competition

Answer 30

Direct competition for common resources, e.g. 2 birds fighting for food

Question 31

Define exploitation competition

Answer 31

Indirect competition for common resources e.g. plants shading out each other

Question 32

Define apparent competition

Answer 32

There isn't competition for resources but it appears there is e.g. buzzards eating mice, which leads to a decrease in mice populations and an increase in vole populations.

Question 33

Define intraspecific competition

Answer 33

Competition within the same species

Question 34

Define interspecific competition

Answer 34

Competition between species

Question 35

Define obligate mutualism

Answer 35

Interaction where one species can not live without the other e.g. acacia ants defend acacia trees from herbivores and in return provide shelter for the ants

Question 36

Define facultative mutualism

Answer 36

Intereaction where both species benefit but could survive without each other. E.g. mycorrhizal fungi

Question 37

Define fundamental niche

Answer 37

The entire set of conditions under which an animal can survive and reproduce

Question 38

Define realised niche

Answer 38

The actual set of condition under which an animal lives

Question 39

What is Gause's competitive exclusion principle?

Answer 39

Two species cannot inhabit the same niche, competition for limited resources will lead to decline and extinction of a species

Question 40

Define niche packing

Answer 40

The umber of species along a resource gradient, species have niches which overlap

Question 41

Define resource partitioning

Answer 41

Animals can divide up resources to live on. E.g. zebras eat low quality grass as they have a low metabolic rate compared to their body mass and don't have a rumen. The smallest ruminant, Thomson Gazelle, had a high protein and high energy diet as it has a higher metabolism and has a ruminant strategy to obtain maximum nourishment by thorough digestion. Bees have different proboscis lengths and choose different plants with different proboscis lengths to feed on. Plants have different root lengths to reach water at different levels.

Question 42

Define r strategies

Answer 42

Animals have many offspring, care less for individual young, are short lived, high juvenile mortality, begin breeding early in life and have short gestation periods. There are boom and bust cycles and populations are effected by major environmental catastrophes.

Question 43

Define k strategies

Answer 43

Animals have few offspring, care more for individual young, mature slowly, long-lived, low juvenile mortality, begin breeding later on in life, long gestation periods. They have more stable habitats but can be vulnerable due to the few offspring.

Question 44

What are examples of density dependent factors which effect populations?

Answer 44

The amount of food or water available, number of predators, pests, diseases, competition for food or space, availability of nest sites.

Question 45

What are examples of density independent factors which effect populations?

Answer 45

Drought, flood, fire, storms, human interference

Question 46

What is type I survivorship

Answer 46

There are larger young populations and smaller old populations, e.g. humans

Question 47

What is type II survivorship?

Answer 47

There are equal populations of all age groups e.g. water voles and golden eagles

Question 48

What is type III survivorship?

Answer 48

More older populations survive than younger populations e.g. frogs and mayflies

Question 49

Define species richness

Answer 49

A measure of the variety of species based on a count of the number of species

Question 50

Define species abundance

Answer 50

The number of individuals of a particular species

Question 51

What are generalist species?

Answer 51

They have broad niches, can tolerate a broad set of environmental conditions, use a wide range of resources, widespread species

Question 52

What are specialist species?

Answer 52

Narrow niches, tolerate narrow set of environmental conditions, use a narrow range of resources, species are usually restricted and locally scarce

Question 53

What is the MacArthur-Wilson theory of biogeography?

Answer 53

As new species immigrate, the rate of immigration slows and extinction of current species rises

Question 54

What did Ciais et al. find?

Answer 54

Estimated 30% reduction in primary production during the 2003 heatwave. Could be explained by the reduction in evapotranspiration and reduced water uptake by plants. Leaf area index also reduces with temperature rise, meaning that energy isn't captured. However, this was only data from 1 year.

Question 55

Define chronosequence

Answer 55

Sites showing different stages of succession since abandonment

Question 56

Define sere

Answer 56

The sequence of succession

Question 57

Define secondary succession

Answer 57

The second stage, which occurs when disturbance such as fires does not kill all life in an environment.

Question 58

What are examples of autogenic succession

Answer 58

Soil development and vegetation structure

Question 59

What are examples of allogenic succession

Answer 59

External influences e.g. climatic changes, animal influence, pathogens

Question 60

Define keystone species

Answer 60

Species which act as ecosystem engineers and are able to control dominanat species e.g. otters, elephants and humingbirds

Question 61

What did Payne et al find?

Answer 61

Removing pisaster, a keystone species, led to species reducing from 15 to 8 as mussels took over.

Question 62

What are flagship species?

Answer 62

Species chosen to represent charities and organisations

Question 63

What are umbrella species?

Answer 63

Species with a focus on their conservation, which then benefits others.