Using ecological dynamics to move toward an adaptive architecture

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Using ecological dynamics to move toward an
adaptive architecture

• Garry Peterson

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What is ecology?

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

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Ecological Processes

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

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Ecological Pattern

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

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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.

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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.

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Four Theories of Ecological Dynamics

• Scale
• Resilience
• Adaptive cycle
• Ecological change

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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

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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

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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

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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.

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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

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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

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Figure 5.2
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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.

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Survival Strategies

• K-phase
• R-phase
• Alpha or reorganization phase
• Omega phase

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K-Phase

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

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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.

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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.

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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.

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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

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Learning

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

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Insurance

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

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Resistance

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

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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.

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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.

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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)

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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.

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Adaptive Management

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

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Dynamics of construction

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

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Design phase

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

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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

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Operation and maintenance phase

• Requires energy and materials
• Similar to ecosystems processes of adaptation
  and self-organization

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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

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Deconstruction Phase

• Design for Disassembly
• Design for Reuse
• Design for Decay

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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.

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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.

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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.

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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

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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.

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Temporal Scales of Buildings
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Scale Matching

• Short building life with low impact would be
  equal to long building life with higher impact.

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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.

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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.

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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.

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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.

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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