Env science

• What is succession in ecology?

  The sequence of changes in species types
• What are the two types of seral stages mentioned?

  Xerosera and Hydrosera
• What limits xerosera?

  Limited by water availability
• What initiates hydrosera?

  Starts in water environments
• What is psamosere associated with?

  Coastal regions and sand dunes
• What drives succession?

  Organisms altering environmental conditions
• What factors are altered during succession?

  Soil pH, nutrients, salinity, stability
• What is primary succession?

  Colonization of a new site after total removal
• What events can cause primary succession?

  Lava flows and glaciation
• What are pioneer species?

  Plants that adapt to new soil conditions
• What happens to organic material in primary succession?

  It enters the soil after decomposition
• How do new species establish in primary succession?

  By outcompeting existing species
• What is a climax community?

  The final stable community in succession
• What changes occur in soil during succession?

  Changes in pH, nutrients, and moisture
• What is secondary succession?

  Succession in an environment with existing soil
• What can cause secondary succession?

  Disturbances like forest fires or droughts
• Why is secondary succession faster than primary succession?

  Soil already contains nutrients
• What are primary colonisers in secondary succession?

  Weeds that grow on pre-existing soil
• What characterizes a climax community?

  It is balanced and self-sustaining
• What are the features of climax communities?

  High biodiversity and complex food webs
• What influences succession?

  Climate, edaphic, and biotic factors
• What are abiotic factors in succession?

  Non-living environmental factors like soil type
• What are biotic factors in succession?

  Living factors like competition and predation
• What is a food web?

  A diagram showing energy relationships among organisms
• What is the original source of energy in food webs?

  The Sun
• What do arrows in a food web represent?

  The direction of energy flow
• What is the decay process in a food web?

  Recycling nutrients from dead material
• What are the two main types of decomposers?

  Fungi and bacteria
• What is the role of detritivores?

  They consume dead organic matter
• What are autotrophs?

  Organisms that produce their own food
• What are heterotrophs?

  Organisms that must consume others for energy
• What are the stages of primary succession?

  1. Coloniser/Pioneer species
  2. Intermediate Community
  3. Climax Community
• What are the stages of secondary succession?

  1. Primary colonisers (weeds)
  2. Intermediate communities
  3. Climax community forms
• What are the differences between primary and secondary succession?

  • Primary: starts on bare rock, no soil
  • Secondary: starts with existing soil and nutrients
  • Primary: slower process
  • Secondary: faster due to pre-existing conditions
• What does primary productivity measure?

  Rate of new organic matter development
• What are the two key types of primary productivity?

  Gross primary productivity and net primary productivity
• What does gross primary productivity (GPP) measure?

  Rate of biomass production by autotrophs
• How is net primary productivity (NPP) calculated?

  NPP = GPP - energy used in respiration
• What fraction of GPP do plants typically use for respiration?

  About half of their GPP
• What happens to the rest of the GPP after respiration?

  It is stored or used for biomass production