Sci11 2nd LE

• Ecological Complexity


  Emerging multidisciplinary field of study that makes use of tools and concepts developed from the essential disciplines of complex systems science, namely physics, mathematics, and computer science
• Ecological Complexity


  • Characterized by local interaction between individual ecosystem components, feedbacks between processes occurring at different scales, implications of minor variations in initial conditions and the emergence of patterns in the absence of a global controller
• Community


  Assemblage of populations that occupy a given area, interacting either directly or indirectly
• Biosystems


  Biotic + Abiotic
• Structure of ecosystems


  • Population - community
  • Ecosystems as networks of interacting populations
  • Abiotic environment as backdrop where biotic interactions occur
• Function of ecosystems


  • Process - function
  • Ecosystems = pathways of matter or energy
  • Functions of processes are more important and more fundamental than organisms performing them
• Components of an ecosystem

  • Population - community (food chain/web)
  • Process - function (carbon flow)
• Ecosystem


  • UNIT including all the organisms interacting with each other (Biotic Community) in a given area interacting with the physical environment
  • First unit in the ecological hierarchy that is complete
  • Cycling of Materials - Flow of Energy - Community
• Ecosystems as networks of interacting populations
• Abiotic environment where biotic interactions occur
• Fails to see the bigger picture
• Ecosystems as pathways of matter and energy
• Misses out important and more fundamental than the organisms performing them
• Hypothetical Food Web

  • Basal species
  • Intermediate species
  • Top predators
• Keystone species


  Roles: create/modify habitats, influence interactions among species
• Ecosystem engineers


  • Allogenic engineers - modify the environment by modifying materials from one form to another (e.g. beaver, earthworm)
  • Autogenic engineers - modify the environment by modifying themselves (e.g. Coral, trees)
• Landscape


  Heterogenous area composed of several systems
• Landscape ecology


  Landscape structure and processes
• Elements of a landscape

  • Landscape matrix - "primary cover type" in the landscape, greater control over fauna and flora, makes up larger coverage in an area, has several patches
  • Landscape patch - homogenous area that differs from the surrounding matrix
  • Landscape corridor - a strip of environment connecting 2 or more landscape patches of similar habitat
• By convention, systems are described only at one level of organization (population or community, but not both simultaneously)
• Complexity theory


  Differs from other analytical approaches in that it is based upon a conceptual model in which entities exist in a hierarchy of interrelated organizational levels
• Parameters that make up a Complex System


  • Numerosity - number of elements in different levels to the hierarchy within our system
  • Non-linearity - interactions and feedback loops over time, it is cyclic
  • Connectivity - degree of how things flow in the networks
  • Autonomy and Adaptation - enables self organization and the process of evolution that shapes complex systems on macro scale (ecological memory)
• Dimensions in Ecological Complexity


  • Spatial - distribution defines spatial extent of a population/ecosystem, patterns in nature or how they are organized, limits the distribution of species, tolerance on physical factors/environment
  • Temporal - time series of different variables describing the dynamics of a system, changes in population, effects of changes in climate & weather, extinction rate, invasion rate, succession, predator-prey cycles, seasonalities, population oscillation, primary succession, secondary succession
  • Structural - relationships within the ecosystems (food web), measuring connectants
• Graph Theory


  Kinds of connectivity networks/matrices: Plannar, Random, Scale free, Small world
• Node 12 is regarded as a high-degree node or high quality patch warranting conservation and monitoring efforts
• Node 12 is designated as a hub because it is connected to many other nodes
• The number of its connections is higher compared to those of other hubs, so NODE 12 is regarded as a high-degree node or high quality patch
• Implications of Clustering and Compartmentalization

  • Clustering - Disadvantage: facilitate fast spread of disturbances, Advantage: facilitate fast dispersal, resilient to patch removal due to many redundant pathways
  • Compartmentalization - Disadvantage: connectivity would break apart if hubs were taken away, Advantage: may isolate the potentially cascading effects of disturbance
• Stability of a system


  Measured through resistance & resilience, Perturbation - disturbances, A forest developed for many years can resist disturbance
• Vanishing Ecosystem


  Global Warming
• Restoration


  To accelerate the recovery of partially damaged habitats back to as close as possible to its former state
• Rehabilitation


  To partially substitute alternatively lost components of a completely damaged ecosystem that existed in the former state
• Restoration > Rehabilitation
• Biodiversity


  Variety and extent of difference among and within living things
• Types of Biodiversity


  • Genetic Diversity - sum total of information contained in genes, variation in genetic makeup, plays a vital role in survival and adaptability
  • Species Diversity - variety of species, their abundance, distribution and functions in a spatial context, richness and evenness
  • Ecosystem Diversity - distribution and abundance of habitats, biotic communities, and ecological processes in the biosphere, every ecosystem has a unique variation of species and genetic variation
• The diversity of genetic diversity will be transferred to species diversity then to ecosystem diversity
• Biodiversity Attributes and Ecosystems Processes

  • Compositional biodiversity - variety of components present at each level (genes, species, ecosystem) in an area
  • Structural biodiversity - variety of ways in which components (genes, species, ecosystems) are arranged over space and/or time
  • Functional biodiversity - variety of biological processes (climatic, geologic, hydrologic, ecological, evolutionary), due to species interaction with each other and their environment that generate biodiversity
• Anthropocentric benefits


  Potentials for different lifeforms to provide information necessary for science, materials that are useful to humans, and all other recreational, medical, or consumptive benefits
• Ecocentric benefits


  Based on the intrinsic value of biodiversity which is beyond any potential use, e.g. healthy corals and forests can be fulfilling
• Surrogate species


  Subsets of species which are "representative" of multiple species or aspects of the environment