Lecture 3: Ecosystems on Land Flashcards
is the part of the Earth that supports life
Biosphere
Spread around the biosphere are ___.
Biomes
land-based ecosystems with unique biotic and abiotic factors.
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 _______.
Temperature and Precipitation
The Temperature and Precipitation are influenced by:
Latitude, altitude, prevailing winds, nearby mountains
is the distance from the equator, measured in
degrees north or south.
Latitude
As latitude ______, temperature and primary productivity tend to _____ __ __ __ _____ ___ ___.
- Increase
- decrease due to the changing sun angle
is the elevation above sea level.
Altitude
As altitude _____, average temperature and primary productivity ______.
increases, decrease
is a moving system of deep ocean currents that circulate warmth across the globe.
ocean conveyor
Biomes located near bodies of water have ____ precipitation______.
greater, levels
is a periodic warming and cooling of the central/eastern Pacific Ocean caused by shifts in trade winds
El-Niño-Southern Oscillation (ENSO) cycle
ENSO cycle: Normal Year
The warmest waters gather in the western Pacific, fueling rainfall throughout southeast Asia.
ENSO cycle: during an El Niño year
warm waters shift to the coast of South America, fueling more rainfall in the Western U.S.
is a decrease in precipitation on the side of a mountain facing away from prevailing winds.
Rainshadow Effect
Faces winds, receives more precipitation.
Windward slope
Reduced precipitation. Opposite of Windward slop
Leeward slope
are combination line/bar graphs that show trends in temperature and precipitation over a typical year in a biome
Climatographs
What does climatographs show?
Precipiation and Temperature
-Low precipitation, high temperatures.
- Lowest net primary productivity of all
ecosystems
Deserts
Types of deserts
- Subtropical deserts
- Rainshadow deserts
- Coastal desserst
- Temperate deserts
- Polar deserts
-form between the tropics and temperate latitudes.
- Convection cells deliver dry air
down from the atmosphere at
30°N and 30°S.
Subtropical deserts
deserts that are found on the leeward side of mountain ranges
Rainshadow deserts
desert that are the result of wind currents that run parallel a coastline.
coastal deserts
deserts that have seasonal temperature variations.
Temperate deserts
deserts that are consistently cold and dry.
Polar deserts
Adaptations of deserts organism:
○ 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
Moderate or seasonal precipitation.
Warm or seasonal temperatures.
Moderate net primary productivity.
Grasslands
Types of grasslands
- Savannas or tropical grasslands
- Prairies or temperate grasslands
- Tundras or polar grasslands
are located near the equator between tropical forests and subtropical deserts
○ Temperature: Consistent
○ Precipitation: Seasonal
Savannas or tropical grasslands
are found in midlatitudes.
○ Temperature: Seasonal
○ Precipitation: Moderate
Prairies or temperate grasslands
short growing seasons and permanently frozen soil called permafrost.
○ Temperature: Consistently cold
○ Precipitation: Moderate
Tundras or polar grasslands
permanently frozen soil
Permafrost
Adaptations of grassland plants
◍Prairie plants have deep and complex root structures that allow them to recover from drought, wildfire, cold winters, and grazing animals.
◍Tundra plants are lowlying due to permafrost and mature rapidly in the short growing season
- Consistent moderate-to-high precipitation that supports tree growth.
-Warm or seasonal temperatures.
-High net primary productivity across multiple layers.
Forests
Layers of forest (from top to bottom)
- Emergent layer
- Canopy
- Understory
- Forest floor
- is the uppermost layer in a forest
- Receives the most direct sunlight. Few plants reach this high.
Emergent layer
- is 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
is the layer of vegetation below the canopy, where only 5% of the sunlight reaches.
Understory
is the bottommost layer of the forest, and has a community centered around decomposition
Forest Floor
- Wide, flat leaves that
maximize sun absorption. - Prone to moisture loss via
transpiration. - Shed in winters or prolonged
dry seasons.
Broadleaf trees
- Narrow, wax-coated leaves.
- Absorb less sunlight but
transpire less water. - Not shed during cold or dry
seasons
Coniferous Trees
Types of forest
- Tropical rainforests
- Temperate rainforests
- Deciduos forests
- Boreal forest (also called taiga)
- Mediterrannean forests (also called chaparral)
- receive high rainfall and are consistently warm.
○ Broadleaf trees only.
○ Highest net primary productivity of all land-based ecosystems.
Tropical Rainforests
- also 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.
Deciduos forests
are the coldest and driest of all the forest biomes.
○ Coniferous trees only.
- Also called taiga
Boreal forests
have highly seasonal rainfall that mostly falls during the winter months.
○ Small coniferous trees and shrubs.
- Also called chaparral
Mediterrannean forests
Subcontinental land masses surrounded
by water.
Islands
Islands have many species that are ____, or not found anywhere else in the world.
Evolved due to the ________ effect
-Endemic
-Founder effect
the reduced genetic diversity which results when a population is descended from a small number of colonizing ancestors.
-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: Island size and Distance from mainland
-Theory of island biogeography
What are the two factors that depends on theory of biogeography?
-Island size
-Distance from mainland.
As island size ____, species richness also _____ (____ ___).
-Increase, increase (positive correlation)
As distance from the mainland ____, species richness ____. (___ ___ )
-Increase, decrease (Inverse correlation)
Land converted for human development
-Urban ecosystems
Urban development causes ___ ___ by dividing natural areas up into smaller pieces
- Habitat fragmentation
- Cause when an individual building redirects the wind head on spreading in all direction.
- Large Buildings block wind flow, causing updrafts and downdrafts
- The Downdraught Effect
causes cities to be warmer due to the absorptive properties of asphalt and pavement, and reduced air flow due to blocked winds.
- The urban heat island effect
connect fragmented ecosystems, restoring gene flow
- Land bridges
Classifying organisms based on their
niche
- Specialist and Generalists
Properties of Generalists
◍Variety of food sources.
◍Wide range of environmental conditions.
◍Highly adaptable to many niches. ◍Tend to be invasive species. ◍Dominate edge habitats and urban areas
Properties of Specialists
◍Specific food source.
◍Narrow range of environmental conditions.
◍Highly adapted to one niche.
◍Tend to be 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.
- Primary succession
Example of primary succession
- Volcanic Island
The first stage of primary succession requires rock to be ___ __ __.
- weathered into soil.
Pioneer species of primary succession are __, __ because they are first to appear in the new ecosystem.
- Lichens and Mosses
The middle stages of primary succession are dominated by ___ ___ like grasses and wildflowers.
- Intermediate species
Late stages result in the formation of a ___ ___ that is highly stable and will remain until a disruption occurs.
- Climax community
Dominated by niche specialists that are slow-growing but long-lived.
- Late stages
Primary succession process
- First Stage (weathering of soil, mosses, and lichens)
- Intermediate stage (grass and wildflowers
- Late stages (formation of climax community)
occurs when an existing ecosystem undergoes a disruption –fire, flood, volcanic eruption, etc.
- Secondary succession
Occurs faster than primary succession because soil is already present.
- Secondary succession
Secondary succession process
- Disruption to existing ecosystem – Soil is intact - Rapid transition to intermediate species – Climax community takes decades.
