Primary Productivity Ecosystem

Unit 1: Ecosystems

Topic 1: Species
interactions

Definitions

● Ecosystem: A particular

location on Earth with
interacting biotic and
abiotic components

● Biotic: living
● Abiotic: non-living

Competitive exclusion principle

Competitive exclusion
principle: two species
competing for the same
limited resource cannot
coexist

Resource partitioning

● Resource partitioning: When

two species evolve to divide a
resource based on differences
in behavior or morphology
○ Temporal- time
○ Spatial- space
○ Morphological- size/shape

Types of species interactions

● Predation: one organism consumes another
● Parasitism: one organism feeds on a host
● Herbivory: organism consumes plants or algae
● Mutualism: both organisms benefit
● Commensalism: one organism benefits, while

the other is unharmed

Invasive species

Invasive species: A
species that
spreads rapidly
across large areas
and causes harm

Multiple Choice

What type of species interaction is shown?

• predation

• parasitism

• mutualism

• commensalism

Multiple Choice

What type of species interaction is shown?

• predation

• parasitism

• mutualism

• commensalism

Topic 2: Terrestrial
biomes

Terrestrial biomes

●

Tundra

●

Taiga

●

Temperate rainforest

●

Temperate seasonal
forest

●

Shrubland

● Temperate

grassland

● Tropical rainforest
● Savanna
● Hot desert

Tundra

Cold and treeless with low-growing vegetation

Taiga (boreal forest)

● Cold winters

and short, cool
summers

● Coniferous

(cone-bearing)
evergreen trees

Temperate rainforest

Coastal biome
typified by
moderate
temperatures
and high
precipitation

Temperate seasonal forest

Biome with warm
summers and
cold winters with
moderate
precipitation

Shrubland (woodland)

Biome with hot, dry
summers and mild,
rainy winters

Temperate grassland (cold desert)

Cold, harsh
winters and hot,
dry summers

Tropical rainforest

Warm and wet, little
seasonal temperature
variation, high
precipitation

Savanna

Warm
temperatures and
distinct wet and
dry seasons

Hot desert

Hot
temperatures,
extremely dry
conditions,
sparse
vegetation

Multiple Choice

Which biome is represented by this graph?

• tundra

• desert

• tropical rainforest

• temperate rainforest

Multiple Choice

Which biome is represented by this graph?

• tundra

• desert

• tropical rainforest

• temperate rainforest

Topic 3: Aquatic biomes

Freshwater aquatic biomes

● Streams and rivers: flowing freshwater
● Lakes and ponds: standing water
● Freshwater wetlands: standing, shallow

water (supports emergent vegetation)

Littoral: shallow
Limnetic: deep as sunlight
Profundal: no sunlight

Marine aquatic biomes

Estuary: coastal,
where fresh and
saltwater mix

Marine aquatic biomes

Salt marsh: along the coast in temperate climate,
non-woody vegetation

Marine aquatic biomes

Mangrove swamp:
along (sub)tropical
coasts, salt-tolerant
trees with
submerged roots

Marine aquatic biomes

Intertidal zones: band
of coastline that exists
between levels of high
and low tide

Marine aquatic biomes

Coral reefs:
warm, shallow
waters beyond
shoreline in
tropical regions
(highly diverse)

Marine aquatic biomes

Open ocean:
deep-ocean
water

Multiple Choice

Most of the photosynthesis in lakes and ponds occurs in the...

• benthic zone

• littoral zone

• limnetic zone

• profundal żonę

Multiple Choice

Which ecosystem experience harsh conditions due to fluctuation from tides?

• coral reef

• open ocean

• intertidal zone

• ponds and lakes

Topic 4: Carbon cycle

Multiple Choice

By which process do plants take carbon out of the atmosphere?

• respiration

• exchange

• photosynthesis

• combustion

Open Ended

Explain one way that humans impact the carbon cycle.

Topic 5: Nitrogen cycle

Human impacts: Agriculture

● Synthetic fertilizers

can runoff into water
supply (algal blooms)
and vaporize into
atmosphere

● Can also disrupt soil

balance and reduce
biodiversity

Human impacts: Fossil fuels

● Fossil fuels release

nitrogen oxides (NOx)

● Pollute the air,

contribute to smog,
result in acid rain

● Disrupt soil and plant

health

Multiple Choice

By which process do bacteria convert atmospheric nitrogen to ammonia?

• fixation

• nitrification

• denitrification

• assimilation

Open Ended

Explain one way that humans impact the nitrogen cycle.

Topic 6: Phosphorus
cycle

Human impacts

1. Fertilizers: Phosphorus leaches into

waterways, result is algal blooms and dead
zones

2. Detergents: Discharge into streams from

washing machines, pollute waterways

Multiple Choice

What must occur in order for phosphorus to become available for plants to uptake?

• uplift

• weathering

• sedimentation

• runoff

Open Ended

Explain one way that humans impact the phosphorus cycle.

Topic 7: Water cycle

Human impacts: Deforestation

Harvesting trees: reduce
evapotranspiration

● Increases runoff
● Increases erosion and

flooding

Human impacts: Construction

Construction: pavement
reduces percolation,
increases runoff and
evaporation

Multiple Choice

What is the process by which water is released into the atmosphere by plants?

• photosynthesis

• evaporation

• transpiration

• precipitation

Open Ended

Explain one way that humans impact the water cycle.

Topic 8: Primary
productivity

Photosynthesis

●

The Sun is the ultimate source
of energy for ecosystems

●

Photosynthesis: producers
transform solar energy to
carbohydrates for building
tissue

Respiration

● Herbivores consume

plants and gain their
energy

● Respiration: organisms

use sugars for growth

Primary productivity

●Primary productivity (PP): the rate of converting solar energy
into organic compounds over a period of time

●Gross primary productivity (GPP):the total amount of solar
energy that producers in an ecosystem capture via
photosynthesis over a given amount of time

●Net primary productivity (NPP): the energy captured by
producers in an ecosystem minus the energy producers respire

Primary
productivity
is not an
efficient
process

99% of solar
energy is
reflected or
passes through
producers
without being
absorbed

Some ecosystems
are much more
productive than
others

●

Highest productivity:
plenty of sunlight,
water, nutrients, and
temperature

●

Higher productivity
→ more herbivores
supported

Multiple Choice

The net primary productivity of an ecosystem is 1 kg C/m2/year, and the energy needed by the producers for their own respiration is 1.5 kg C/m2/year. The gross primary productivity of such an ecosystem would be

• 1 kg C/m2/year

• 1.5 kg C/m2/year

• 2.0 kg C/m2/year

• 2.5 kg C/m2/year

Topic 9: Trophic levels

Trophic levels

●

Producers: make their own energy (photosynthesis)

●

Consumers: obtain their energy by consuming other
organisms
○

Primary consumers: Herbivores

○

Secondary consumers: Carnivores

○

Tertiary consumers: Carnivores that eat
carnivores

Not all organisms fit neatly into a single
trophic level

●

Omnivores: eat producers and consumers, e.g. bears

●

Scavengers: consume dead animals, e.g. vultures

●

Detritivores: break down waste, e.g. dung beetles

●

Decomposers: break down organic matter into
molecules to be recycled, e.g. fungi

Nothing gets wasted!

Energy is lost between trophic levels

Why?

1.

Some of the lower level energy is not usable (not
digestible)

2.

Some of the usable energy is used for maintenance

The 10% rule: only about 10% of energy gets passed to the
next trophic level

(Determines population size at each trophic level)

Food webs

● All species are

connected!

● Food webs model how

energy and matter
move through 2+
interconnected food
chains

Multiple Choice

At which trophic level are eagles that consume fish that consume zooplankton that eat algae?

• producer

• primary consumer

• secondary consumer

• tertiary consumer

Multiple Choice

How much energy transfers to secondary consumers if producers receive 10,000 J of energy from the Sun?

• 10,000 J

• 1,000 J

• 100 J

• 10 J