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Using ecological dynamics to move toward an adaptive architecture

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Title: Using ecological dynamics to move toward an adaptive architecture


1
Using ecological dynamics to move toward an
adaptive architecture
  • Garry Peterson

2
What is ecology?
  • The study of how nature functions
  • Ecosystems can be described using the following
    terms
  • Ecological processes
  • Ecological pattern
  • Ecological organizations
  • Scale

3
Ecological Processes
  • The mechanisms that transform ecosystems over
    time
  • Ecological processes include the following
  • succession
  • nutrient cycling
  • seed dispersal

4
Ecological Pattern
  • Refers to the relative distribution of organisms
    and physical environment
  • Example The types of trees in the forest and
    their spatial organization

5
Ecological Organization
  • The connections among ecological pattern and
    processes
  • Example A tropical forest represents one type of
    ecological organization, while arctic tundra
    represents another, very different ecological
    organization.

6
Scale
  • Describes the domain of space and time over which
    a process, such as seed dispersal, organism, such
    as a mouse, operates
  • Example The domain of space and time over which
    a mouse forages, lives, and moves is smaller and
    faster than the domain in which people live.

7
Four Theories of Ecological Dynamics
  • Scale
  • Resilience
  • Adaptive cycle
  • Ecological change

8
Scale
  • A range of spatial and temporal frequencies
  • The range is defined by resolution, below which
    faster and smaller frequencies are noise and
    which slower and larger frequencies are
    background
  • The cross-scale organization of an ecosystem is
    described by defining the following spatial
    organization, temporal organization, and
    self-organization

9
Scale (cont.)
  • Spatial Organization
  • Larger spatial scales incorporate smaller objects
  • Example Boreal Forest-the organization of
    scales incorporates changes across scales
  • Temporal Organization
  • Scales can be analyzed by observing the dynamics
    of a fixed area over different periods of time
  • Example Boreal Forest- the mix of species has
    changed over periods of time

10
Scale (cont.)
  • Self-organization
  • The spatial-temporal interaction of structures
    and processes produce an emergent pattern at a
    larger and slower scale than the scale of the
    processes and structures themselves, these
    patterns and processes interact with larger and
    slower processes to organize still larger and
    slower sets of pattern and processes
  • Example Boreal Forest- Processes organize the
    landscape and then are constrained by the pattern
    that they have organized

11
Resilience
  • The measure of the amount of change or disruption
    that causes an ecosystem to switch from being
    maintained by one set of mutually reinforcing
    processes and structures to an alternative set
    (Holling 1973)
  • Example A clear-nutrient-limited lake may shift
    to being a murky, nutrient-rich lake as a result
    of disturbances ,such as a flood.

12
Resilience (cont.)
  • Resilience emerges from both cross-scale and
    with-in interaction (Peterson et al. 1998)
  • Cross-scale Resilience is produced by the
    replication of ecological function at different
    scales
  • With-in Scale Resilience is produced by
    compensating overlap of ecological function
    between similar processes that occur at the same
    scales.
  • The concept of resilience allows ecologists to
    focus upon the likelihood of transition among
    different sets of organizing processes and
    structures

13
Adaptive Cycle
  • Holling (1986) has developed a general model of
    ecological change that proposes that the internal
    dynamics of ecosystems cycle through four phases
    rapid growth, conservation, collapse, and
    reorganization

14
Figure 5.2
15
Survival Strategies
  • The dynamic nature of ecosystems has important
    consequences for the species that inhabit them. A
    plant species that lives within a fire dominated
    forest ecosystem can adopt a number of strategies
    that favor its survival.

16
Survival Strategies
  • K-phase
  • R-phase
  • Alpha or reorganization phase
  • Omega phase

17
K-Phase
  • Accomplished by reducing the destructive effects
    by evolving resistance attributes.
  • Ex. Thick bark of a tree that resist combustion.

18
R-Phase
  • Ability to regenerate quickly following a
    destructive event.
  • Ex. Storing energy in the root system to ensure
    survivability following the loss of above ground
    biomass.

19
Alpha or Reorganization Phase
  • Ensures the continued existence of a species
    after a destructive event.
  • Ex. A species that adopts pinecones that open to
    release their seeds following the heat of a fire.

20
Omega Phase
  • Deals with the ability to modify the qualitative
    character of an event to benefit the species.
  • Ex. Longleaf pine sheds flammable needles that
    burn readily, encouraging frequent low intensity
    fires. Longleaf pine can survive these fires but
    oak, an ecological competitor cannot.

21
Active Response To Change
  • The response of plants to fire is a specific
    example of general strategies for dealing with
    change within a dynamic system.
  • 4 active responses to change
  • Learning
  • Insurance
  • Resistance
  • Management

22
Learning
  • Attempts to understand system dynamics so that
    knowledge can be used to reconfigure a future
    system.
  • Ex. Colonizing a newly burned area.

23
Insurance
  • Invests in alternative strategies for the quick
    regrowth of a system.
  • Ex. Regrow quickly after a disturbance

24
Resistance
  • Attempts to control systems dynamics to prevent a
    disturbance from happening.
  • Ex. Plant resistance such as thick bark.

25
Ecosystem Dynamics
  • Ecosystems containing species that embody a wide
    diversity of alternative strategies will be more
    resilient than those that contain less diverse
    group. A broader mix of strategies reduces the
    susceptibility to a broader range of
    environmental variation or disturbance.

26
Change Through Dynamic Hierarchies
  • Change at higher level alters a lower level as a
    result of the constraints that it places upon it.
  • Reorganization at a higher level can trigger
    reorganization at a lower level.
  • Small scale disturbance can trigger a larger
    scale collapse if the larger system is in a
    brittle stage in its adaptive cycle.
  • Following the collapse of a system, small scale
    and surrounding large scale systems provide the
    components and constraints out of which a system
    reorganizes.

27
Managing Ecosystems
  • People currently lack the skills, understanding,
    and data to manage ecosystems competently.
    Ecosystems are evolutionary and self-modifying,
    rather than stable and static.
  • Different processes dominate at different spatial
    and temporal scales, making it difficult to
    predict how processes will interact across
    scales, or how ecological understanding can be
    transferred from one scale to another.(Levin 1992)

28
Managing (cont)
  • Consequently, the arrangement and behavior of
    natural systems is based upon what happened in
    the past, rather than looking forward in
    anticipation toward the future.

29
Adaptive Management
  • Attempts to use a scientific approach,
    accompanied by collegial hypotheses testing to
    build understanding.

30
Dynamics of construction
  • Four phases of adaptive cycle
  • Design -Hypothesis
  • Construction -Experiment set up
  • Maintenance -Data collection
  • Deconstruction -Data analysis and
    reformulation

31
Design phase
  • Information intensive process
  • Similar to adaptive ecosystem management
  • Should be reduced for sustainable construction
  • Active and passive experimentations

32
Construction phase
  • Stage that locks in possibilities for future
    growth and adaptation
  • Will almost inevitably depart from original plans
  • Simple design allows simple changes
  • Unfinished building allows effective adaptation

33
Operation and maintenance phase
  • Requires energy and materials
  • Similar to ecosystems processes of adaptation
    and self-organization

34
Principles applied to operation and maintenance
phase
  • Flexibility maintaining a loose coupling among a
    systems components (Allen and Starr 1984)
  • Effectiveness rather than efficiency (Kay, ch. 3)
  • Structures that gracefully decay
  • Example copper roofs look beautiful as they age
  • Reduce cross-connections among subsystems

35
Deconstruction Phase
  • Design for Disassembly
  • Design for Reuse
  • Design for Decay

36
Design for Disassembly
  • Buildings are designed in such a way that they
    can be easily taken apart and reused.
  • Disassembly cost reduction requires the reduction
    of energetic and material cost of disassembly.
  • Disassembly is particularly valuable if the
    design accommodates the removal of segments of
    the structure without complete disassembly.

37
Design for Reuse
  • An extension of Design for Disassembly
  • Consideration of materials such as metals and of
    entire building components.
  • Mimicking ecosystems ability to take a disposed
    item and reorganize it into a useful component of
    another system.

38
Design for Decay
  • Alternative to Disassembly and Reuse
  • Strive for the exclusive use of biodegradable
    materials including adhesive systems.
  • Reduction of high coverage, low mass products
    like paint. These materials limit the reuse of
    the materials in which they are applied.

39
Scale
  • Stewart Brand, How Buildings Learn.
  • Site Building Location
  • Structure the Frame of the Building
  • Skin what separates inside from outside
  • Services water, HVAC, phone lines
  • Space Plan how the interior is arranged
  • Stuff furniture and other mobile objects

40
Sustainability at all Scales
  • While looking at dividing a building up in the
    hierarchy defined by Stewart Brand, a change in
    one would subsequently affect another. Keeping
    this in mind and coordinating the process yields
    the highest rate of success.
  • In addition an identification of the scales of
    time, the longevity of this hierarchy is
    invaluable.

41
Temporal Scales of Buildings
42
Scale Matching
  • Short building life with low impact would be
    equal to long building life with higher impact.

43
Managing Disturbance
  • Limit investment in high-risk areas.
  • Controlled burning around buildings.
  • Preservation of wetlands to mitigate severe
    flooding.
  • Rapid, controlled deconstruction to move building
    out of harms way (for reconstruction after
    disturbance).
  • Social change to adapt obsolete buildings.

44
Cross Scale Resilience
  • Resilience suggests that ecosystems, or in this
    case building hierarchies are resilient as a
    result of compensation among functions within
    scales and their replication across scales.
  • Two items working in tandem to achieve a goal,
    each having varying strengths and weaknesses,
    each compensating for the other.

45
Cross Scale Connections
  • The fact that different component subsystems
    within a system change at different rates means
    that the connections between these subsystems
    should be carefully considered.
  • A limitation to adaptation by a lower life-span
    system could in turn, limit the life-span of the
    entire building.

46
Surprise
  • The functions of a building throughout its
    life-span are nearly impossible to predict.
    Therefore over specializing the design runs the
    risk of limiting the buildings useful life-span
    by limiting its ability to adapt.
  • Optimization is recommended.

47
Conclusion and Summary
  • Integrate natural and constructed ecosystems.
  • Four distinct Phases
  • Design
  • Construction
  • Operation
  • Deconstruction
  • Adaptive Management
  • Opportunities for Learning
  • Hypothesis
  • Learning
  • Monitoring
  • Evaluation
  • Hierarchy and Scale
  • Building Adaptability
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