APES Unit 1

Primary productivity, trophic levels, food chain, community ecology, terrestrial and aquatic biomes, and nutrient cycling

Biotic

Living things

Abiotic

Nonliving things

Biosphere

Region of planet where life resides; combination of all Earth’s ecosystems

Producer/autotroph

An organism that uses solar energy to produce usable forms of energy

Photosynthesis

Using solar energy to convert carbon dioxide and water into glucose (organic material)

Cellular respiration

Consuming plants for energy

Consumer/heterotroph

Organism that is incapable of photosynthesis and gets energy by consuming other organisms

Aerobic respiration

Respiration w/ oxygen

Anaerobic respiration

Respiration w/o oxygen

Produces less energy than aerobic

Primary consumers

Eat primary producers

Secondary consumers

Eat primary consumers

Tertiary consumers

Consumers that eat secondary consumers

Trophic levels

Successive levels of organisms consuming each other

Food chain

Sequence of consumption from producers to consumers

Food web

Complex model of how energy and matter move between trophic levels

Scavenger

Organism that consumes dead animals

Ex. Vultures and hyenas

Detritivore

Organism that specializes in breaking down dead tissues and waste into smaller particles

Ex. Earthworms and dung beetles

Decomposers

Fungi and bacteria that convert organic matter into small elements and molecules to be recycled back into ecosystem

Gross primary productivity (GPP)

Total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time

Net primary productivity

Energy captured by producers in an ecosystem minus energy producers respire

(GPP - producers’ respiration)

Biomass

Total mass of all living matter in specific area

Standing crop

Amount of biomass present at a particular time

Ecological efficiency

Proportion of consumed energy that can be passed from one trophic level to another

10% Rule

Only 10% of biomass can be converted into usable energy at next trophic level

Trophic pyramid

Representation of distribution of biomass, numbers, or energy among trophic levels

Community ecology

Study of interactions between species

Symbiotic relationship

Relationship between two species that live in close association w/ each other

Competition

Struggle of individuals to obtain a shared limiting resource

Neg/Neg interaction

Competitive exclusion

Two species competing for same limiting resource cannot coexist

If two species have same niche - one species will perform better and drive the other to extinction

Resource partitioning

Caused by competition for a limited resource

Two species divide a resource based on differences in behavior or morphology

Can be split temporally, spatially, or morphologically

Predation

One animal typically kills/consumes another animal

Population control

Neg/Pos interaction

Parasitism

One organism lives on/in another organism (host)

Rarely causes death of host

Neg/Pos interaction

Pathogen

Parasite that causes disease in host

Neg/Pos interaction

Herbivory

Animal consumes a producer

Neg/Pos interaction

Mutualism

Increases chances of survival for reproduction for both species

Ex. plants and pollinators; algae and coral reefs

Pos/Pos interaction

Commensalism

One species benefits and other species is unaffected

Ex. bird in a tree; fish hiding in corals

Pos/Null interaction

Keystone species

Species that is not very abundant but has large effects on ecological community

Ex. Beavers create dams that turn narrow streams to large ponds; pollinators

Ecosystem engineer

Keystone species that creates/maintains habitat for other species

Ex. Beaver create dams, alligators create pools

Climate

Avg weather that occurs in a given region over a long period of time

Weather

Short-term conditions of atmosphere in local area (temp, humidity, clouds, precipitation, wind speed)

Terrestrial biome

Geographic region categorized by combination of avg annual temperature, annual precipitation, and distinctive plants

Habitat

Area where particular species lives in nature

Climate diagrams

Display monthly temperature and precipitation values; determine productivity of biome

Tundra

Cold, dry

Major threats: warming air temperatures/melting permafrost

Indicator plants:

• Woody shrubs

• Mosses

• Heaths

• Lichens

Subsoil is permafrost

Permafrost

Impermeable, permanently frozen layer of soil

Found in tundra

Melting releases greenhouse gases into atmosphere

Boreal forest

Cold, moderate precipitation

Major threats: logging, mining and extraction of oil and gas

Indicator plants:

• Coniferous trees - spruce, pine, fir

• Deciduous trees - birch, maple, aspen

Temperate rainforest

Mild temp, humid

Major threats: logging

Indicator plants:

• Coniferous trees - fir, spruce, cedar, hemlock, redwood

Temperate seasonal forest

Moderate temp, moderate precipitation

Major threats: agriculture, development

Indicator plants:

• Deciduous trees - oak, maple, beech, hickory

• Some coniferous trees

Woodland/shrubland (chaparral)

Hot, dry summers + mild, rainy winters

Major threats: irrigation

Indicator plants:

• Drought-resistant shrubs - yucca, sagebrush, scrub oak

Temperate grassland/cold desert

Cold winters + hot summers; dry

Indicator plants:

• Grasses

• Nonwoody flowering plants

Tropical rainforest

Hot, humid

Major threats: deforestation

Indicator plants:

• Lush vegetation (2/3rds of terrestrial species)

• Cocoa

• Coffee

• Cassava

• Bamboo

• Strangler figs

Tropical seasonal forest/savanna

Hot; distinct wet and dry seasons

Major threats: development, habitat destruction

Indicator plants

• Dense stands of shrubs and trees - broadleaf grasses, acacia, baobab

Subtropical desert

Hot; dry

Major threats: drilling for oil and water

Indicator plants:

• Drought-resistant plants - cacti, euphorbs, succulents

Aquatic biome

Aquatic region characterized by combination of salinity, depth, and water flow

Streams and rivers

Flowing fresh water

Streams

Narrow, carry little water, rapid flow

Rivers

Wider, carry more water, slow water flow

Lakes and ponds

Standing water; some too deep to support emergent vegetation

Littoral zone

Shallow zone of soil and water

Where most algae and emergent plants grow

Limnetic zone

Open water

No plants break surface, no rooted plants

Phytoplankton are primary producers

Phytoplankton

Floating algae; producers

Profundal zone

Deepest water

Limited oxygen

Benthic zone

Muddy bottom of lake, pond, or ocean

Oligotrophic

Low level of productivity

Mesotrophic

Moderate level of productivity

Eutrophic

High level of productivity

Freshwater wetland

Submerged/saturated by water for at least part of year

Swamps, marshes, fens, bogs/mires

Shallow enough to support emergent vegetation

Very productive

Take in rainfall - limits severity of floods/droughts

Major threats: drainage for agriculture, development, removal of pest breeding grounds

Salt marsh

Marine

Marsh w/ nonwoody emergent vegetation

Found along coast in temperate climates

Very productive

Found in estuaries

Major threats: development and pollution

Estuaries

Coastal area where freshwater from rivers mixes w/ salt water from ocean

Mangrove swamp

Marine

Tropical and subtropical coasts

Contains salt tolerant trees w/ roots submerged in water

Trees protect coastlines from erosion and storm damage

Major threats: development and agriculture

Coral reef

Marine

Warm, shallow waters beyond shoreline

Very diverse

Relatively poor in nutrients/food

Coral bleaching

Algae inside coral die/leave → coral turn white

Caused by disease, warming oceans (algae die/leave), ocean acidification (less structural support)

Intertidal zone

Coastline between high tide and low tide

Waves make it hard for organisms to hold on

Stable at high tide

Sunlight + high temp in low tide → desiccation

Open ocean

Deep ocean water away from shoreline

Sunlight cannot reach bottom

Photic zone

Upper layer

Receives enough sunlight for photosynthesis

Aphotic zone

Deeper layer

No sunlight, no photosynthesis

Relies on chemosynthesis for energy

Chemosynthesis

Used by some ocean bacteria to generate energy w/ methane and hydrogen sulfide

Biogeochemical cycles

When matter cycles via biological, geological, and chemical processes

Hydrologic cycle

Movement of water

• Evaporation

• Transpiration

• Evapotranspiration

• Precipitation

• Plant uptake

• Infiltration

• Percolation

• Surface runoff

Transpiration

Plants release water into atmosphere during photosynthesis

Evapotranspiration

Combined amount of evaporation and transpiration

Carbon cycle

• Photosynthesis

• Respiration

• Exchange

• Sedimentation

• Burial

• Extraction

  • Combustion

Photosynthesis and respiration

CO2 from atmosphere → producer tissue

Respirate CO2 → atmosphere

Decomposers break down biomass: CO2 → atmosphere and water

Exchange

Carbon equally exchanged between ocean and atmosphere

Sedimentation

Carbon settles to bottom of water, create carbon-rich sediment

Burial

Dead biomass buried into ocean sediment - fossilized and turned to fossil fuels

Extraction

Carbon removed from carbon reservoir to surface

Combustion

Releases CO2 into atmosphere by burning organic material

Macronutrients

Elements needed in large amounts by organisms

• Nitrogen

• Phosphorus

• Potassium

• Calcium

• Magnesium

• Sulfur

Limiting nutrients

Nutrient required for organism growth, available in low quantity

Include macronutrients

Nitrogen cycle

• Nitrogen fixation

• Nitrification

• Assimilation

• Mineralization

  • Denitrification

Nitrogen fixation

Converting gaseous nitrogen into usable form

N2 → ammonia → ammonium

Nitrification

Via bacteria

Ammonium → nitrite → nitrate

Assimilation

Ammonia, ammonium, nitrate, nitrite → producer tissues

Consumers assimilate nitrogen from producers

Mineralization/Ammonification

Decomposers break down organic matter into inorganic components

Organic matter → ammonium

Denitrification

Nitrate → nitrous oxide → nitrogen gas

Via bacteria in anaerobic conditions

Leaching

Excess nitrogen dissolved and transported via groundwater

Increase nitrogen levels cause atmosphere to adapt

• High-nitrogen condition species survive better than low-nitrogen condition species; biodiversity decreases

Phosphorus cycle

• Assimilation

• Mineralization

• Sedimentation

• Geologic uplift

• Weathering

Assimilation

Producers take up inorganic phosphate, assimilate as organic phosphorus

Mineralization

Decomposers break down dead organic material: organic phosphorus → inorganic phosphate