Lecture 12: Ecosystem + Biomes Flashcards
Ecosystem
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.
Ecosystem Ecology
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.
Energy
Ability to do work.
Defined by the Laws of Thermodynamics
First Law of Thermodynamics
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.
Second Law of Thermodynamics
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.
Trophic Structure & Trophic Level
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.
How Organisms Get Food
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.
Food Web
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.
Biomagnification
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.
Nutrient Cycles
AKA Biogeochemical Cycles
Pathway by which an element moves through biology and the environment. Water Cycle Carbon Cycle Nitrogen Cycle Sulfur Cycle
Biome:
____ biomes are classified by ____?
One of the world’s major ecosystem types.
Terrestrial biomes are classified by predominant vegetation and weather
Aquatic biomes are classified by physical environment.
Lumpers vs. Splitters
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.
Terrestrial Biomes
- 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
Deserts and Xeric Shrublands
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.
Tropical and Subtropical Moist Broadleaf Forests
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.
Rainforest Layers
Top to bottom: Emergent trees, Canopy, Under-Canopy, Shrub layer, Ground level.
Tropical and Subtropical Dry Broadleaf Forests
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.
Tropical and Subtropical Coniferous Forest
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.
Temperate Broadleaf and Mixed Forests
Characterized by variable temperature and variable rainfall.
Conifers in canopy layer.
Temperate Coniferous Forest
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.
Boreal Forests/ Taiga
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.
Tropical and Subtropical Grasslands, Savannas and Shrublands
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.
Temperate Grasslands, Savannas and Shrublands
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.
Flooded Grasslands and Savannas
AKA Swamps.
Located tropically or subtropically and flooded seasonally or year round.
High avian diversity with both resident and migratory birds.
Montane Grasslands and Shrublands
Located at high altitude (alpine or subalpine) and above/ below the treeline.
Plants adapted to cool temp and high light.
Tundra
Treeless cold climate. Arctic- polar desert Antarctic- polar desert Alpine- above the treeline Dwarf vegetation and lichen.
Mediterranean Forests, Woodlands and Scrub
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.
Mangroves
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.
Aquatic Biomes
Lakes Wetlands Streams & Rivers Littoral Zone Pelagic Zone Coral Reef Benthic Zone
Lakes
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.
Wetlands
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.
Streams and Rivers
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.
Littoral Zone
Contains intertidal zone and estuary zone
Littoral Zone: Intertidal Zone
Flooded with water twice a day.
Sub-zones depending on amount of flooding, compressed into narrow bands.
Biologically productive though harsh condition
Littoral Zone: Estuaries
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.
Coral Reef
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.
Pelagic Zone
AKA Water Column.
Open water component of aquatic biomes.
Not near the shore or bottom.
Primary producers are phytoplankton.
Benthic Zone
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.
6th Great Extinction
Man made occurring right now.
It’s your fault.
Stop it.
