LANDSCAPE ECOLOGY
SREM 3011
LECTURE 10
Dr Brendan Mackey
Department of Geography
The Australian National University
Communities criterion:
- Integration of complex behaviour of biota in a given
area
- Integration results in cohesion and a degree of
self-regulation
,changes physical environment
- eg,rainforest?closed canopy
- +ve and -ve population interactions
Ecosystem criterion:
- Biota are explicitly linked to the abiotic world of their
physical environment
- Cycles and pathways of energy and matter
,water,nutrients,carbon
- Organisms,populations,communities are viewed in
terms of their ecosystem function
- process rates are critical
Nested vs Non-nested Hierarchies
The human body is a nested hierarchy.
The Soviet Union was a non-nested hierarchy.
- it was a hierarchy because of the ‘chain-of-
command’
- it is structured by the flow of information
- the President is a low frequency,large-scale
phenomena
- the foot soldier is a high frequency,small-scaled
phenomena
Conventional levels of biological/ecological organization
Planet
Region
Subcatchment
Patch
Site
Types of ecological entity and their inter-relationships at different scales of observation
O = organism; P = population; C = community; E = ecosystem; L = landscape; B = biome
Types of ecological entities are really criteria for defining ecological
phenomena
All criteria can be applied at any scale
Criteria distinguish foreground from background
Small scale
Large scale
Example of organism providing context for ecosystem:
Organism Cow
Ecosystem Cow’s rumen
Example of organism providing context for population:
Organism Dog
Population Fleas
Example of organism appearing to have characteristics
of a population
Population
or Banyan tree
Organism?
A cross-section of banana tree identifies that the,trunk” is almost entirely
fleshy sheathing leaf bases,not woody stem
What is a tree?
The army of Alexander the Great camped under a single banyan tree.
Both banyans and aspen clones have stems connected,banyans above
the ground,aspen below ground.
What is an organism?
What is a population?
In a detailed study of the environmental impact
of a dam on the Kickapoo River,the
Center for Biotic Systems,University of
Wisconsin-Madison,collected,A,maps of the
fine detail of the stream patterns in the entire
watershed of approximately 15 by 25 miles
and then aggregated these small rivulets into
successively larger watersheds within the
entire Kickapoo watershed system,B Fifth order
watershed,C Sixth order watersheds,
What is a landscape?
For a mineral nutrient to pass once around a nutrient cycle,it must pass in and
out of the biotic component of the ecosystem several times in one year,Accordingly,
biota are not often a simple subsystem of process/functional ecosystems.
When is biota part of an ecosystem process?
Characteristics of hierarchical systems
Assumptions:
- Ecological systems are hierarchically structured
- Some are nested,some non-nested
- Hierarchies have levels; levels consist of entities
- Higher levels contain large scale entities;
lower levels contain small scale entities
Characteristics:
1,Frequency
2,Context
3,Containment
4,Constraint
5,Emergent properties
6,Holon
1,Frequency
- Frequency of return time for the critical behaviour of
the entity
- ie,phenomena viewed as cyclical rather than
directional
,human breathing
seasonal pulse of plant growth
death and recruitment in a population
- Higher levels in hierarchy have a lower return time
ie,behave at a lower frequency
- Lower levels behave at a higher frequency
,maintenance of forest structure through individual spp
come and go
forest structure - high level,low frequency
individual trees - low level,high frequency
,the whole turns over more slowly than the parts
SREM 3011
LECTURE 10
Dr Brendan Mackey
Department of Geography
The Australian National University
Communities criterion:
- Integration of complex behaviour of biota in a given
area
- Integration results in cohesion and a degree of
self-regulation
,changes physical environment
- eg,rainforest?closed canopy
- +ve and -ve population interactions
Ecosystem criterion:
- Biota are explicitly linked to the abiotic world of their
physical environment
- Cycles and pathways of energy and matter
,water,nutrients,carbon
- Organisms,populations,communities are viewed in
terms of their ecosystem function
- process rates are critical
Nested vs Non-nested Hierarchies
The human body is a nested hierarchy.
The Soviet Union was a non-nested hierarchy.
- it was a hierarchy because of the ‘chain-of-
command’
- it is structured by the flow of information
- the President is a low frequency,large-scale
phenomena
- the foot soldier is a high frequency,small-scaled
phenomena
Conventional levels of biological/ecological organization
Planet
Region
Subcatchment
Patch
Site
Types of ecological entity and their inter-relationships at different scales of observation
O = organism; P = population; C = community; E = ecosystem; L = landscape; B = biome
Types of ecological entities are really criteria for defining ecological
phenomena
All criteria can be applied at any scale
Criteria distinguish foreground from background
Small scale
Large scale
Example of organism providing context for ecosystem:
Organism Cow
Ecosystem Cow’s rumen
Example of organism providing context for population:
Organism Dog
Population Fleas
Example of organism appearing to have characteristics
of a population
Population
or Banyan tree
Organism?
A cross-section of banana tree identifies that the,trunk” is almost entirely
fleshy sheathing leaf bases,not woody stem
What is a tree?
The army of Alexander the Great camped under a single banyan tree.
Both banyans and aspen clones have stems connected,banyans above
the ground,aspen below ground.
What is an organism?
What is a population?
In a detailed study of the environmental impact
of a dam on the Kickapoo River,the
Center for Biotic Systems,University of
Wisconsin-Madison,collected,A,maps of the
fine detail of the stream patterns in the entire
watershed of approximately 15 by 25 miles
and then aggregated these small rivulets into
successively larger watersheds within the
entire Kickapoo watershed system,B Fifth order
watershed,C Sixth order watersheds,
What is a landscape?
For a mineral nutrient to pass once around a nutrient cycle,it must pass in and
out of the biotic component of the ecosystem several times in one year,Accordingly,
biota are not often a simple subsystem of process/functional ecosystems.
When is biota part of an ecosystem process?
Characteristics of hierarchical systems
Assumptions:
- Ecological systems are hierarchically structured
- Some are nested,some non-nested
- Hierarchies have levels; levels consist of entities
- Higher levels contain large scale entities;
lower levels contain small scale entities
Characteristics:
1,Frequency
2,Context
3,Containment
4,Constraint
5,Emergent properties
6,Holon
1,Frequency
- Frequency of return time for the critical behaviour of
the entity
- ie,phenomena viewed as cyclical rather than
directional
,human breathing
seasonal pulse of plant growth
death and recruitment in a population
- Higher levels in hierarchy have a lower return time
ie,behave at a lower frequency
- Lower levels behave at a higher frequency
,maintenance of forest structure through individual spp
come and go
forest structure - high level,low frequency
individual trees - low level,high frequency
,the whole turns over more slowly than the parts
