Lecture 12: Ecosystem + Biomes

Question 1

Ecosystem

Answer 1

All of the organisms in a given area and the abiotic factors they interact with.
One or more communities and physical environment around them.
Biotic and Abiotic factors of an ecosystem interact by nutrient cycles and energy flows.

Question 2

Ecosystem Ecology

Answer 2

Study of energy flow and the cycling of chemicals among the various biotic and abiotic components in an ecosystem.
Cycling of nutrients and energy are regulated by physical laws.

Question 3

Energy

Answer 3

Ability to do work.

Defined by the Laws of Thermodynamics

Question 4

First Law of Thermodynamics

Answer 4

Energy can be changed from one form to another, but cannot be created or destroyed. Total energy of a system remains constant.
You can’t win.
You can’t get something for nothing.

Question 5

Second Law of Thermodynamics

Answer 5

In all energy conversions, the potential energy of the final state will always be less than the potential energy of the initial state.
You can’t break even.
There is always an increase in entropy (disorder) when energy is transferred.
As you go up the trophic level, most of the energy is lost as heat.

Question 6

Trophic Structure & Trophic Level

Answer 6

The different feeding relationship within an ecosystem which determine the route of energy flow and the pattern of chemical cycling.
Trophic Level of an organism is its position in a food web.

Question 7

How Organisms Get Food

Answer 7

Producers: reduce carbon. Autotrophs.
Consumers: eat reduced carbon in the form of living organisms. Heterotrophs.
Decomposers: eat reduced carbon in the form of dead organisms. Heterotrophs.

Question 8

Food Web

Answer 8

Food web demonstrates feeding relationship in an ecosystem.
Includes a feeding hierarchy with trophic levels. Energy is lost each time you go up a level due to the 2nd Law of Thermodynamics.

Question 9

Biomagnification

Answer 9

In the food web, predators consume many prey animals.
Predators of predators consume many predators.
Top predators then represent an accumulation of material from many lower animals.
If there are molecules in the environment that are not readily broken down or metabolized, they can reach high concentrations in top predators through biomagnification.

Question 10

Nutrient Cycles

Answer 10

AKA Biogeochemical Cycles

Pathway by which an element moves through biology and the environment.
Water Cycle
Carbon Cycle
Nitrogen Cycle
Sulfur Cycle

Question 11

Biome:

____ biomes are classified by ____?

Answer 11

One of the world’s major ecosystem types.
Terrestrial biomes are classified by predominant vegetation and weather
Aquatic biomes are classified by physical environment.

Question 12

Lumpers vs. Splitters

Answer 12

Lumpers: holistic view and define groups broadly.
Splitters: precise and create new categories to further subdivide groups.
The more you care about a field, the more of a Splitter you are likely to be within that field.

Question 13

Terrestrial Biomes

Answer 13

• Deserts and Xeric Shrublands
• Tropical and Subtropical Moist Broadleaf Forests
• Tropical and Subtropical Dry Broadleaf Forests
• Tropical and Subtropical Coniferous Forests
• Temperate Broadleaf and Mixed Forests
• Temperate Coniferous Forests
• Boreal Forests/Taiga
• Tropical and Subtropical Grasslands, Savannas, and Shrublands
• Temperate Grasslands, Savannas, and Shrublands
• Flooded Grasslands and Savannas
• Montane Grasslands and Shrublands
• Tundra
• Mediterranean Forests, Woodlands, and Scrub or Sclerophyll Forests
• Mangroves

Question 14

Deserts and Xeric Shrublands

Answer 14

Xeric: characterized by or adapted to an extremely dry habitat.
Varies by amount of rainfall but dry conditions and evaporations rule.
Varies by temperature.
Created by man in some regions by the process of Desertification.
Have unique adapted flora and diverse reptile fauna.

Question 15

Tropical and Subtropical Moist Broadleaf Forests

Answer 15

Includes: Tropical rainforest, Moist deciduous forest, Montane rainforest, Flooded forest.
Characterized by low temperature variability and high rainfall.
Dominated by semi-evergreen and evergreen deciduous tree species.
High species diversity- half the world’s terrestrial species live here.
17,000 species disappear due to deforestation annually.

Question 16

Rainforest Layers

Answer 16

Top to bottom: Emergent trees, Canopy, Under-Canopy, Shrub layer, Ground level.

Question 17

Tropical and Subtropical Dry Broadleaf Forests

Answer 17

Characterized by moderate temperatures but long dry seasons.
Dominated by deciduous trees, many lose their leaves during the dry season.
Loss of leaves in canopy allows under canopy & shrub layers to receive more light.
Less diversity than rainforests.
Higher mammalian biomass than rainforest.

Question 18

Tropical and Subtropical Coniferous Forest

Answer 18

Characterized by low rainfall and moderate variability in temperature.
Populated by diverse groups of conifers, needles are adapted to low rainfall and variable temperatures.
Thick canopy often leaves only ferns and fungi capable of living on the ground.

Question 19

Temperate Broadleaf and Mixed Forests

Answer 19

Characterized by variable temperature and variable rainfall.

Conifers in canopy layer.

Question 20

Temperate Coniferous Forest

Answer 20

Characterized by warm summers and cool winters and enough rainfall to sustain a forest.
Dominated by evergreen conifers.
Have the highest levels of biomass of any terrestrial biome.
Include temperate rainforests.

Question 21

Boreal Forests/ Taiga

Answer 21

Characterized by low rainfall and cold temperature. Located in Northern latitudes.
Dominated by conifers.
World’s largest land biome.
Relatively undisturbed large animal migration.
Under threat due to climate change.

Question 22

Tropical and Subtropical Grasslands, Savannas and Shrublands

Answer 22

Characterized by low rainfall (not enough to sustain a forest) and moderate to warm temperatures.
Dominated by grasses with some trees.
Home to large mammals.
Soon to only exist in natural parks.

Question 23

Temperate Grasslands, Savannas and Shrublands

Answer 23

Characterized by low rainfall (not enough to sustain a forest) and moderate temperatures.
Dominated by grasses with few trees.
Home to large mammals.
AKA prairie, which doesn’t exist anymore in the US.

Question 24

Flooded Grasslands and Savannas

Answer 24

AKA Swamps.
Located tropically or subtropically and flooded seasonally or year round.
High avian diversity with both resident and migratory birds.

Question 25

Montane Grasslands and Shrublands

Answer 25

Located at high altitude (alpine or subalpine) and above/ below the treeline.
Plants adapted to cool temp and high light.

Question 26

Tundra

Answer 26

Treeless cold climate.
Arctic- polar desert
Antarctic- polar desert
Alpine- above the treeline
Dwarf vegetation and lichen.

Question 27

Mediterranean Forests, Woodlands and Scrub

Answer 27

AKA Chaparral, Maquis.
Characterized by dry summers & rainy winter.
Moist plants, fire adapted.
Highly distinctive fauna with many endemic plants.
Only 5 places in the world are part of this biome.
10% of all plant species in the world are here.
40% of all plant species in the US and Canada are here, in an area the size of Maine.

Question 28

Mangroves

Answer 28

Waterlogged salty coastal soils in the tropics and subtropics are home to a forest of various mangrove trees.
Plants uniquely adapted to temporally flooded, brackish, low oxygen conditions.
Protect against storms & tsunamis.
50% of biome gone compares to 100 years.

Question 29

Aquatic Biomes

Answer 29

Lakes
Wetlands
Streams & Rivers
Littoral Zone
Pelagic Zone
Coral Reef
Benthic Zone

Question 30

Lakes

Answer 30

Standing body of water, large or small.
Surrounded by land, localized in basin.
Weak tidal forces.
More temporary than an ocean in geologic time scales.
Caspian Sea is a lake.
Sensitive to pollution.

Question 31

Wetlands

Answer 31

AKA Marshes, Swamps, Bogs & Fens.
A habitat flooded with water at least some of the time and supports plants adapted to water-saturated soil.
Includes mangroves and flooded grasslands and savannas.
half the worlds wetlands drained by 1993.

Question 32

Streams and Rivers

Answer 32

Characterized by flowing water.
Upland headwaters tend to be faster, cooler, clearer, turbulent.
Lowland downstream water tend to be slower, warmer, turbid and less turbulent.

Question 33

Littoral Zone

Answer 33

Contains intertidal zone and estuary zone

Question 34

Littoral Zone: Intertidal Zone

Answer 34

Flooded with water twice a day.
Sub-zones depending on amount of flooding, compressed into narrow bands.
Biologically productive though harsh condition

Question 35

Littoral Zone: Estuaries

Answer 35

Where freshwater stream or river merges with the ocean.
Transition zone with temporal variation in salinity and temperature.
Very productive, very impacted.
60% of worlds population lives here.

Question 36

Coral Reef

Answer 36

Warm water tropical ecosystem dominated by hard skeletal structure secreted by corals. Some also exist in cold/ deep waters.
Disappearing faster than rain forests. Could be gone in 100 years.

Question 37

Pelagic Zone

Answer 37

AKA Water Column.
Open water component of aquatic biomes.
Not near the shore or bottom.
Primary producers are phytoplankton.

Question 38

Benthic Zone

Answer 38

Bottom surface of any aquatic environment.
Begins at shoreline, extends down the continental shelf.
Deeper regions are dark, nutrients come from detritus raining down from above or thermal vents below.

Question 39

6th Great Extinction

Answer 39

Man made occurring right now.
It’s your fault.
Stop it.