What are Biomes?
Collections of ecosystems sharing similar climatic conditions.
What are the 5 main biomes?
Aquatic, forest, grassland, desert, tundra.
What are the three abiotic factors affecting biome structure, function and location?
- Rate of photosynthesis and productivity
What is the tricellular model?
- Explains differences in atmosphere pressure belts, temperature and precipitation.
- 0 to 30 is hadley
- 30 to 60 is ferrel
- 60 to 90 is polar cell
- 30 is desert
- 60 degree is temperate forest
- 0 is tropical rainforest
What are the qualities of a tropical rainforest biome?
- Constant high temperature
- High rainfall
- Near the equator, little seasonal variation between the tropic of capricorn and cancer
- High levels of biodiversity and NPP
- Soil is low in nutrients
What are the qualities of temperate forests?
- Between 40-60 N
- Cold winters and warm summers
- Evergreen (needles or waxy) trees or deciduous trees (sheds its leaves)
- NPP is lower than tropical but the second highest
- Less biodiversity due to the forests being made one species tops 6 species
- But the rainforests have very high dense canopies, there’s grass and ferns
What are the qualities of deserts?
- 30 N
- Water is limiting factor , NPP is very low
- Xerophytic adaptations, low decomposition due to low water, high salinity, low leeching
- Roots either deep or extended on surface
What are the qualities of tundra?
- High latitude, low insolation
- Water is ice, sunlight is low, NPP low
- Decomposition is slow, nutrition is low, biodiversity is low
- Larger animals for energy efficiency
- formed due to the retreat of glaciers
What is zonation?
- Changes in community along an environmental gradient due to factors such as changes in latitude, altitude, tidal level, distance from shore or coverage by water
- Biome distribution
- Patterns in an ecosystem (bands of vegetation)
- Distance from the sea on a rocky shore
- Changes in ecosystems up a mountain
What is succession?
- Is the process of change over time in an ecosystem involving
- pioneer, intermediate, climax communities
What is primary succession?
Occurs on a previously uncolonized substrate
What is secondary succession?
- Occurs in places where a previous community has been destroyed
- Due to soil bank
Zonation on a rocky shore?
- Stress of dehydration increases as we get away from the shore
- Stress of temperature increases as we get away from shore
- Stress from wave action increases as we get towards the shore
Zonation on a mountain?
- As temperature decreases, decomposition is slower and the release of nutrients is less overall
- Temperature is colder
- Atmospheric pressure is less
- Precipitation is more
- Insolation is more
What is Sere?
- The change in communities from the earliest community to the final community
- A natural succession of plant or animal communities, especially series from uncolonized habitat to the appropriate climax vegetation.
What is Seral Stage?
- The series of relatively transitional plant communities that develop during ecological succession from base ground to climax community.
- What is a pioneer community?
- The first stage of ecological succession, species that can live in difficult conditions
- Lichen, moss
What is intermediate community?
- Several stages between pioneer and climax communities
- (herbaceous plants, grasses, dandelions)
What is a climax community?
Final stage of succession, more stable and in equilibrium
What does an ecosystem in equilibrium look like?
- High biodiversity
- Complex food chains
- P/R is close to 1
- NPP is balances
- Steady state equilibrium
- Rich soil
What are the 2 types of succession depending on the type of environment?
- Xerosere: dry habitat
- Lithosere: bare rock
- Hydrosere: freshwater habitat
List Succession pls
- Colonization: lichen and moss weather rock and produce dead material
- Establishment: growth of moss, further weathering, beginning of soil formation, growth of small plants such as grasses and plants,
- Competition: growth of small plants, larger herbaceous plants grow, shrubs, small trees
- Stabilization + Climax
List succession with examples:
- Lichen, Moss (creates shallow soil, photosynthesis)
- Intermediate: Grass (reduces erosion, increases photosynthesis, reduce wind, effective in absorbing water)
- Intermediate: Herbaceous plants (dandelions) wind dispersed seeds, more growth, competitions
- Intermediate: Shrubs (gorse)
- Climax: Trees (kills shrubs and everything, generate organic matter, soil traps water and allows for plants in later stages of succession)
Explain Climax Communities:
- There is no one climax communities but rather a set of alternative stable states for an ecosystem
- Nutrient cycles are closed
- Greater biomass
- More favorable soil conditions
- Better sou structure (greater water retention and aeration, deeper soil with more nutrients)
- Plants are taller and live longer
- Greater community complexity
- Greater habitat diversity
Which is faster, secondary or primary succession?
What is a tipping point?
- Least amount of change needed to change the equilibrium point
- It is affected by
- Size of storages in systems
- Variety of nutrients and energy pathways
NPP and GPP in early and late succession?
- GPP increases
- NPP decreases
What happens to P/R throughout succession?
Nutrient conversion in early and late succession?
- Closed systems in late succession
- Open systems in early succession
Niches in early and late succession?
Realized niches get smaller throughout succession due to less competition
Human Influence on Succession?
- Introduction of species that are not native to the environment
What is Plagiosere or Plagioclimax: arrested stage of succession
What does it mean if P/R is more than 1?
What does it mean if P/R is less than 1?
Depletion of biomass
J curve or S curve curve?
- J curve is for r strategists
- S curve for K strategists
What are k strategists?
- Few progeny
- Stable environment
- Energy efficient
- Investment in progeny
- More intelligent
- More evolved
- Live for longer
- Larger litter
- Age of reproduction is higher
- Maturation speed is low
What are r strategist?
- Small animals
- Unstable environments
- More progeny
- Little investment
What are the properties of Grasslands?
- Not enough precipitation for forests, not little enough for deserts
- Temperate grasslands: great plains, russian steppes
- Tropical grasslands: savannas of east africa
- High diversity, low productivity (grass)
- With low humidity comes fluctuating temperature
- Decomposition rate is low
What are the properties of tropical coral reefs?
- High biodiversity, near the equator, warm water all year long
- Polyps take CO2 from the water Ca from seawater and from CaCO2 skeletons to live with symbiotic algae
What are the properties of Hydrothermal vents?
- Super heated metal laden fluids
- Chemosynthetic bacteria and polychaete worms can live
- Hydrogen sulfide is used for chemosynthesis
- Biodiversity is low
- K strategists high
- R strategist low
- Depends on competition
- Depends on reproductive strategy and
- Predatory relationships
What are the impacts of climate change?
- Relocation due to flooding or storms
- Shortage or oversupply of water
- Shift of agriculture to the poles, desertification
- Increase of flooding, sea levels, oceans becoming warmer