ecosystems

• What does an ecosystem include?

  All organisms living in a particular area and all non-living elements of that environment
• What factors control the distribution and abundance of organisms in a habitat?

  Both biotic factors like predators and abiotic factors like light levels
• What is a niche in an ecosystem?

  A particular role of a species in its habitat, including its interactions
• What is succession in an ecosystem?

  • Change of one community of organisms into another
  • Primary succession: occurs in lifeless areas (e.g., after a volcano)
  • Secondary succession: occurs in previously colonized areas after disturbances
• What are pioneer species in primary succession?

  Species like lichens that colonize harsh environments first
• How does humus contribute to soil formation during succession?

  It is formed from decomposed organisms, enriching the soil
• What is a climax community?

  The final stable and self-sustaining community in succession
• What is net primary productivity (NPP)?

  The rate at which energy is stored in plant biomass after respiratory losses
• What is the formula for calculating net primary productivity (NPP)?

  NPP = GPP - R
• What does gross primary productivity (GPP) measure?

  The rate at which energy is incorporated into organic molecules during photosynthesis
• How can the net production of consumers (N) be calculated?

  N = I - (F + R)
• Why is nitrogen important for plants?

  It is essential for the synthesis of proteins and nucleic acids
• What are the steps in the nitrogen cycle?

  1. Nitrogen fixation by bacteria (e.g., Rhizobium)
  2. Ammonium ions released from decomposed organic matter
  3. Oxidation of ammonium to nitrites by Nitrosomonas
  4. Oxidation of nitrites to nitrates by Nitrobacter
  5. Absorption of nitrates by plants
  6. Denitrification by bacteria to return nitrogen gas to the atmosphere
• What is the role of chemotrophic bacteria in the nitrogen cycle?

  They oxidize ammonium ions to nitrites
• How is carbon recycled in the environment?

  Through photosynthesis, feeding, respiration, and decomposition
• What methods can be used to measure the abundance of organisms?

  • Line transect: recording species along a line
  • Quadrat: counting species in a square frame
  • Belt transect: sampling between two tape measures at intervals
• What are limiting factors in an ecosystem?

  Factors that determine the carrying capacity of an environment
• What is the relationship between predator and prey populations?

  They fluctuate based on each other's population sizes
• What are the two types of competition in ecosystems?

  • Interspecific competition: between different species
  • Intraspecific competition: between the same species
• What is the difference between conservation and preservation?

  • Conservation: sustainable use of resources to maintain biodiversity
  • Preservation: maintaining biodiversity by minimizing human impact
• What are some reasons for conservation?

  Economic, social, and ethical reasons, including food and medicine sources
• What are some sustainable management practices for ecosystems?

  • Coppicing: cutting trees to encourage new growth
  • Selective felling: removing mature or diseased trees
  • Pollarding: cutting trees higher to prevent deer damage
• What impact has tourism had on the Galapagos Islands?

  Increased demand for resources leading to waste and pollution
• What conservation efforts are being made in the Galapagos Islands?

  • Goat culling to eliminate non-native species
  • Breeding giant tortoises in captivity to increase their population
• What are some management strategies for protecting ecosystems?

  • Controlling tourist numbers
  • Involving local communities
  • Educating local communities
  • Active vegetation management
  • Controlling species introductions