ZOL3702 Summaries
Ecology
Chapter 2–5
Chapter 8- 10
Chapter 16
, THE NATURE OF ECOLOGY
The word ecology was first used by Ernest Haeckel in 1869, describing ecology as the scientific study
of the interactions between organisms and their environment
Krebs definition: ecology is the scientific study of the interactions that determine the distribution and
abundance of organisms
The environment of an organisms consists of all the factors and phenomena outside the organisms
that have an influence (can be biotic or abiotic)
Ecology deals with:
• Individual organism, at this level ecology deals with how individuals are affected and how
the effect their environment
• Population, at this level ecology is concerned with the presence/ absence of particular
species (abundance/ rarity) and the trends/ fluctuations in their numbers
• Community, ecology deals with composition and organisation of ecological communities
Ecologists focus on the pathways energy and matter move among living and non-living elements in
the ecosystem
EXPLANATION, DESCRIPTION, PREDICTION AND CONTROL
Explain/ understand, search for knowledge but it is necessary to first describe. Most valuable
descriptions are those carried out with a particular problem or need for understanding in mind
• All descriptions are selective
On the basis of prediction on what will happen due to a set of circumstances we can try and control
the situation
• Some may be carried out without explanation/ understanding
• Confident predictions, precise predictions can be made only when we explain what is
happening
• Mathematical modelling
Proximal explanations are those focused on physical environment. Ultimate explanations are
focused on the ecological experiences.
, CONDITIONS
A condition is an abiotic environmental factor that influences the functioning of living organisms, e.g:
- Temperature
- Relative humjidity
- pH
- Salinity
- Concentration of pollutatns
Condition may be modified by the presence of other organism, conditions are not consumed or used
up by organisms
Optimal conditions are those under which individuals leave most descendants (are fittest), measures
of fitness should be made over several generations
Often measure the effect of conditions on some key property like:
- Activity of enzyme
- Respiration rate of a tissue
- Growth rate of individuals
- Rate of reproduction
Organisms can usually survive over a wider range of conditions than permit them to grow/
reproduce
, ECOLOGICAL NICHES
A niche is a summary of the organism’s tolerances and requirements
- Considered n-dimensional hypervolume
- N is the number of dimensions that make up the niche
Temperature limits the growth and reproduction of all organisms but different organisms tolerate
different ranges of temperature (Range is one dimension of an organisms ecological niche)
Provided hat a location is characterised by conditions within acceptable limits for a given species and
that it contains all the necessary resources then the species can potentially occur and persist there.
Dependent on two factors
1. Must be able to reach the location (depends on powers of colonisation and remoteness of
the site)
2. Occurrence may be precluded by the action of individuals of other species that compete/
prey on it
A species has a larger ecological niche in the absence of competitors and predators
Fundamental nice describes the overall potentialities of a species
Realised niche described the more limited spectrum of conditions and resources that allow it to
persist
RESPONSES OF INDIVIDUALS TO TEMPERATURE
METABOLISM, GROWTH, DEVELOPMENT AND SIZE
Individuals respond to temperature in the manner of impaired function and ultimately death at the
upper and lower extremes with a functional range between these two extremes within which there
is an optimum
- Accounted for by changes in metabolic effectiveness
- Each 10°C rise (Q10) in temperature the rate of biological enzymatic processes often roughly
doubles (appears as an exponential curve against temperature)
- High temperature increases speed of molecular movements and chemical reactions
The rates of growth and development determine the final size of an organism, development usually
increases more rapidly with temperature (final size tends to decrease with rearing temperature)
- Temperature-size rule
Ecology
Chapter 2–5
Chapter 8- 10
Chapter 16
, THE NATURE OF ECOLOGY
The word ecology was first used by Ernest Haeckel in 1869, describing ecology as the scientific study
of the interactions between organisms and their environment
Krebs definition: ecology is the scientific study of the interactions that determine the distribution and
abundance of organisms
The environment of an organisms consists of all the factors and phenomena outside the organisms
that have an influence (can be biotic or abiotic)
Ecology deals with:
• Individual organism, at this level ecology deals with how individuals are affected and how
the effect their environment
• Population, at this level ecology is concerned with the presence/ absence of particular
species (abundance/ rarity) and the trends/ fluctuations in their numbers
• Community, ecology deals with composition and organisation of ecological communities
Ecologists focus on the pathways energy and matter move among living and non-living elements in
the ecosystem
EXPLANATION, DESCRIPTION, PREDICTION AND CONTROL
Explain/ understand, search for knowledge but it is necessary to first describe. Most valuable
descriptions are those carried out with a particular problem or need for understanding in mind
• All descriptions are selective
On the basis of prediction on what will happen due to a set of circumstances we can try and control
the situation
• Some may be carried out without explanation/ understanding
• Confident predictions, precise predictions can be made only when we explain what is
happening
• Mathematical modelling
Proximal explanations are those focused on physical environment. Ultimate explanations are
focused on the ecological experiences.
, CONDITIONS
A condition is an abiotic environmental factor that influences the functioning of living organisms, e.g:
- Temperature
- Relative humjidity
- pH
- Salinity
- Concentration of pollutatns
Condition may be modified by the presence of other organism, conditions are not consumed or used
up by organisms
Optimal conditions are those under which individuals leave most descendants (are fittest), measures
of fitness should be made over several generations
Often measure the effect of conditions on some key property like:
- Activity of enzyme
- Respiration rate of a tissue
- Growth rate of individuals
- Rate of reproduction
Organisms can usually survive over a wider range of conditions than permit them to grow/
reproduce
, ECOLOGICAL NICHES
A niche is a summary of the organism’s tolerances and requirements
- Considered n-dimensional hypervolume
- N is the number of dimensions that make up the niche
Temperature limits the growth and reproduction of all organisms but different organisms tolerate
different ranges of temperature (Range is one dimension of an organisms ecological niche)
Provided hat a location is characterised by conditions within acceptable limits for a given species and
that it contains all the necessary resources then the species can potentially occur and persist there.
Dependent on two factors
1. Must be able to reach the location (depends on powers of colonisation and remoteness of
the site)
2. Occurrence may be precluded by the action of individuals of other species that compete/
prey on it
A species has a larger ecological niche in the absence of competitors and predators
Fundamental nice describes the overall potentialities of a species
Realised niche described the more limited spectrum of conditions and resources that allow it to
persist
RESPONSES OF INDIVIDUALS TO TEMPERATURE
METABOLISM, GROWTH, DEVELOPMENT AND SIZE
Individuals respond to temperature in the manner of impaired function and ultimately death at the
upper and lower extremes with a functional range between these two extremes within which there
is an optimum
- Accounted for by changes in metabolic effectiveness
- Each 10°C rise (Q10) in temperature the rate of biological enzymatic processes often roughly
doubles (appears as an exponential curve against temperature)
- High temperature increases speed of molecular movements and chemical reactions
The rates of growth and development determine the final size of an organism, development usually
increases more rapidly with temperature (final size tends to decrease with rearing temperature)
- Temperature-size rule
