Lecture 3: Land Ecosystems and Ecological Succession Flashcards
- The __ is the part of the Earth that supports life.
- Spread around this are __ ; land-based ecosystems with unique biotic and abiotic factors.
- biosphere
- biomes
Nonliving conditions that influence the type of biome found in a geographic area
Abiotic Factors
The two most significant abiotic
factors in biomes are __ and __ which are influenced by: __, __, __, __
- temperature and precipitation
○ Latitude
○ Altitude
○ Prevailing winds
○ Nearby mountains
the distance from the equator, measured in degrees north or south.
Latitude
Day length is __ near the equator, then becomes __ towards the poles.
- highly consistent
- more seasonal
As latitude increases, __ and __ tends to decrease due to the __.
- temperature
- primary productivity
- hanging sun angle
the elevation above sea level.
altitude
As altitude increases, average temperature and primary productivity __
decrease
Hot air at the equator rises, moves across the
atmosphere, cools, then sinks at about __, creating __
- 30°N or S
- prevailing winds
Prevailing wind: From the tropics southwest or northwest towards the equator are __
From the subtropics west towards the midlatitudes.
- Trade winds
- Westerlies
a moving system of deep ocean currents that circulate warmth across the globe.
ocean conveyor
Biomes located near bodies of water have __.
○ __ from the water fuels storm systems.
- greater precipitation levels
- Evaporation
a periodic warming and cooling of the central/eastern Pacific Ocean caused by shifts in trade winds.
El-Niño-Southern Oscillation (ENSO) cycle
- During a normal year, the warmest waters gather in the __, fueling rainfall throughout __.
- During an El Niño year, warm waters shift to the coast of __, fueling more rainfall in the __.
- western Pacific
- southeast Asia
- South America
- Western U.S
- a decrease in precipitation on the side of a mountain facing away from prevailing winds.
○ __: Faces winds and receives more precipitation.
○ __: Reduced precipitation.
rainshadow effect
- Windward slope
- Leeward slope
The distribution of biomes is the result of
- latitude
- altitude
- prevailing winds
- ocean currents
- landforms
__ are combination line/bar graphs that show trends in temperature and precipitation over a typical year in a biome.
Average monthly __ : Bar graph
○ Average monthly __: Line graph
- climatographs
- precipitation
- temperature
Climatographs tell you:
○ If temperatures are seasonal or consistent.
○ If precipitation is seasonal or consistent.
○ If the climate is below freezing for part of the year.
Climatographs can infer:
○ Latitude and geography of the ecosystem.
○ Northern or southern hemisphere.
○ What type of ecosystem is present.
Low precipitation, high temperatures.
Lowest net primary productivity of all
ecosystems
Desert
Kinds of desert:
- subtropical desert
- rainshadow desert
- Coastal desert
- Temperate desert
- Polar desert
Type of desert
- form between the tropics and temperate latitudes.
○ Convection cells deliver __ down from the atmosphere at __ and __.
- subtropical desert
- dry air
- 30°N and 30°S
are found on the leeward side of mountain ranges.
rainshadow desert
- the result of wind currents that run parallel to a coastline.
○ May bring __, but __.
- coastal desert
- fog
- no measurable precipitation
A type of dessert that have seasonal temperature variations
Temperate deserts
Type of desert
consistently cold and dry
polar deserts
Adaptations of desert organisms:
○ Ability to store water (e.g. succulents) or fat (e.g. camels).
○ Reduced growth rate and/or herd size.
○ Spikes and camouflage for defense.
○ Energy conservation (dormancy, cold-blooded)
○ Deep taproots
What kind of biome
Moderate or seasonal precipitation.
Warm or seasonal temperatures.
Moderate net primary productivity.
Grasslands
Kinds of grasslands:
- savanna (tropical grasslands)
- Prairies (temperate grasslands)
- tundra (polar grasslands)
Type of grassland
located near the equator between tropical forests and subtropical deserts.
○ Temperature: __
○ Precipitation: __
- savanna (tropical grasslands)
- Consistent
- Seasonal
Type of grassland
found in midlatitudes
○ Temperature: __
○ Precipitation: __
- prairies (temperate grasslands)
- Seasonal
- Moderate
Type of grassland
have short growing seasons and permanently frozen soil called __.
○ Temperature: __
○ Precipitation: __
- tundra (polar grasslands)
- permafrost
- Consistently cold
- Moderate
Adaptations of Grassland Plants: Prairie
- have deep and complex root structures that allow them to recover from drought, wildfire, cold winters, and grazing animals.
Adaptations of Grassland Plants: Tundra
- low lying due to permafrost and mature rapidly in the short growing season.
What kind of biome
- Consistent moderate-to-high precipitation that
supports tree growth.
- Warm or seasonal temperatures.
- High net primary productivity across multiple layers.
Forests
- the uppermost layer in a forest.
○ Receives the most direct sunlight. Few plants reach this high.
emergent layer
the highest layer that most trees reach, and contains most of the plant and animal life.
○ Highest net primary productivity area of any forest.
canopy
the layer of vegetation below the canopy, where only 5% of the sunlight reaches.
understory
the bottommost layer of the forest, and has a community centered around decomposition
forest floor
characteristics of Broadleaf Trees
- Wide, flat leaves that maximize sun absorption.
- Prone to moisture loss via transpiration.
- Shed in winters or prolonged dry seasons.
characteristics of Coniferous Trees
- Narrow, wax-coated leaves.
- Absorb less sunlight but transpire less water.
- Not shed during cold or dry seasons.
receive high rainfall and are consistently warm.
○ Broadleaf trees only.
○ Highest net primary productivity of all land based ecosystems.
Tropical rainforests
receive high rainfall but have seasonal temperature changes.
○ Broadleaf or coniferous trees
Temperate rainforests
have moderate precipitation and significant seasonal temperature changes.
○ Mostly broadleaf trees that shed their leaves each winter.
Deciduous forests
are the coldest and driest of all the forest biomes.
○ Coniferous trees only.
boreal forest (taiga)
have highly seasonal rainfall that mostly falls during the winter months.
○ Small coniferous trees and shrubs.
Mediterranean forests (chaparral)
Subcontinental land masses surrounded by water
island
__ have many species that are __, or not found anywhere else in the world.
○ Evolved due to the __.
- Islands
- endemic
- founder effect
Islands are __ due to the number of endemic species present.
biodiversity hotspots
predicts that the species richness or biodiversity of an island depends on two factors:
○ As island size increases, species richness also
increases. (Positive correlation)
○ As distance from the mainland increases, species richness decreases. (Inverse correlation)
theory of island biogeography
- Many small or distant islands lack __ due to the limited food.
- Increases risk of extinction from introduced species.
- apex predators
Land converted for human development.
Urban Ecosystems
Urban development causes __ by dividing natural areas up into smaller pieces.
habitat fragmentation
Large buildings block wind flow, causing
updrafts and downdrafts.
downdraught effect
The __ causes cities to be warmer due to the absorptive properties of asphalt and pavement and reduced airflow due to blocked winds.
urban heat island effect
connect fragmented ecosystems, restoring gene flow
land bridges
Classifying organisms based on their niche
Specialists and Generalists
characteristics of a generalist:
◍ Variety of food sources.
◍ Wide range of environmental conditions.
◍ Highly adaptable to many niches.
◍ Tend to be an invasive species.
◍ Dominate edge habitats and urban areas
characteristics of specialists:
◍ Specific food source.
◍ Narrow range of environmental conditions.
◍ Highly adapted to one niche.
◍ Tend to be an endangered species.
◍ Dominate islands and interior habitats.
Process of change in the abiotic and biotic factors of an ecosystem over time.
succession
occurs when a new ecosystem is created
– no prior life exists.
○ Example:
primary succession
- Volcanic island
◍ The first stage of primary succession requires __.
○ Wind and water
○ Acidic rainfall
○ Growth of lichens and mosses
◍ Lichens and mosses are __ because they are the first to appear in the new ecosystem.
- rock to be weathered into the soil
- pioneer species
