SCI 11

• System


  Interconnected set of elements that is coherently organized to achieve a certain function/purpose
• Community


  Assemblage of populations that occupy a given area, interacting directly or indirectly
• 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 (because you have now a source of habitat)
• Levels of understanding ecosystem

  • Cycling of Materials (Biogeochemical Energy)
  • Community
  • Flow of Energy
• Population-community approach


  • Ecosystems as networks interacting populations (structure and components)
  • Abiotic environment as backdrops where biotic interactions occur
  • Disadvantage: Fails to see the bigger picture
• Process-function approach


  • Ecosystems as pathways of matter and energy
  • Functions and processes are more important and more fundamental than the organisms performing in them
  • Disadvantage: Calcification process- corals convert carbonate ions dissolved the seawater into usable forms (calcium carbonate minerals) that form their skeleton
• Types of species in a hypothetical food web

  • Basal species
  • Intermediate species
  • Keystone species
  • Top Predators /Apex predators
  • Ecosystem Engineers
• Keystone species


  Create or modify habitats an influence interact among species and impact is disproportionally large relative to its abundance
• Ecosystem Engineers


  • Any organism that modifies a habitat
  • Allogenic engineers- modify the environment by modifying materials for one form to another
  • Autogenic engineers - modify the environment by modifying themselves
• Landscape


  Heterogeneous area composed of several ecosystems
• Elements of a landscape

  • Landscape matrix
  • Landscape patch
  • Landscape corridor
• Landscape matrix


  The primary cover type in the landscape, greater control over the flora and fauna
• Landscape patch


  Homogeneous area that differs from the surrounding matrix
• Landscape corridor


  A strip of environment connecting 2 or more landscape patches of similar habitat
• Ecological Complexity


  • 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 of a Complex System

  • Numerosity - number of elements in different levels to the hierarchy within our system
  • Non-linearity- interactions and feedback loops over time
  • Connectivity- indicates the 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 of Ecological Complexity

  • Spatial
  • Temporal
  • Structural
• Spatial dimension


  Distribution defines the spatial extent of a population/ecosystems
• Spatial elements


  • Edge - marks the perimeter of each patch
  • Border - place where the edge of one patch meets the edge of another
  • Ecotone- wide border
• Edge Effect


  More biodiversity at the borders or boundary of 2 or more habitats
• Temporal dimension


  The time series of different variables describing the dynamics of a system
• Examples of temporal dynamics


  • Changes in population
  • Effects in change in climate and weather
  • Extinction Rate
  • Invasion Rate
  • Succession
  • Predator-prey cycles
• Structural dimension


  Relationships within the ecosystem (food web)
• Connectivity


  • Black dots are nodes representing individual organisms situated in a habitat patch
  • Hubs: most number connections/edges. Regarded as a high-quality patch
  • Lines are edges representing relations between two nodes
• Types of connectivity networks

  • Planar
  • Random
  • Scale-free
  • Small world
• Among the four kinds of networks, the more complex and ideal habitat may resemble a scale-free network with several large hubs connected to multiple smaller patches
• Healthy Biodiversity leads to a stable economy, weather conditions, food security, and health and wellness
• Biodiversity


  Variety and extent of differences among and within living things
• Types of biodiversity


  • Genetic diversity
  • Species diversity
  • Ecosystems diversity
• Genetic diversity


  Any variation in chromosomes, genes, alleles, or nucleic acid within the cells of organism/ diversity of genes within the same species
• Species diversity


  Refers to vast number of species within an area
• Measures of species diversity

  • Species Richness - Number of different kinds of organisms present in a particular area
  • Species Evenness - Compares the similarity of the population size of each of the species' present
• Ecosystems diversity


  The variety of habitats which could support different populations of species
• Biodiversity attributes


  • Compositional biodiversity - variety of components present at each level (genes, species, ecosystem)
  • Structural biodiversity - variety of ways in which components (genes, species, ecosystem) are arranged over space and time
  • Functional biodiversity - variety of biological processes due to species interaction that generate biodiversity/variety of roles
• Surrogate species


  • Keystone Species
  • Umbrella Species
  • Indicator species
  • Flagship species
• Keystone species


  Impact on the community or ecosystem are much larger relative to its abundance, and more influential than expected
• Umbrella species


  One with large habitat area and exerts a major ecological influence on the community
• Indicator species


  Species that are sensitive to certain environmental factors change thus only found in environments where these factors are optimal
• Flagship species


  Popular, charismatic species that serve as symbols and rallying points to stimulate conservation awareness and action
• Biodiversity hotspots


  Places on Earth that are both rich in endemic species living in a deeply threatened habitat mainly due to human activity