Chapter 44 - Ecology and Biosphere

Define ecology.

study of interaction between organisms and their environment

What are the 6 levels of ecology, from smallest to largest?

1. Individual

2. Population

3. Community

4. Ecosystem

5. Biome

6. Biosphere

If Charles Darwin considered himself an ecologist, which field of ecology would be fit best into?

Organismal ecology: Study of morphological, physiological, and behavioral

adaptations of individuals

What does a population ecologist study? Give an example.

Study of how numbers of individuals in a

population change over time

Example: the number of salmon in a stream and calculate their population change over time

what does a community ecologist study? give an example

Study interaction among species within an area

Example: Study the effects of crudatians bears on salmon,

How is community ecology different from population ecology?

population: Study of how numbers of individuals in a

population change over time

community: Study interaction among species within an area

What does an ecosystem ecologist study? Give an example

Study how nutrients and energy move b/n organisms

and the abiotic environment

Example: Study the nutrient load effected by the death of the spawning salmon

Which level of organisms ignores species?

Community organisms

What is the range of species defined as?

what geographical area of distribution of that particular species has

What is the primary determinant of a species range?

Abiotic factors such as temperature and precipitation.

Why are organisms limited to a specific range? Why don't cacti grow in Canada?

They are adapted to limit set of abiotic factors by fitness tradeoffs

How do biotic factors play a role in a species range?

competition, parasitism/disease

How does competition affect a species' range?

determines the species distribution

How does the sun's angle of incidence vary by latitude?

Northern latitude: earth is tilted closer towards the sun in summer months and further away from the sun in winter.

What causes the Earth's seasons?

By the earths natural tilt on its axis

What is the winter solstice? Summer solstice? Vernal equinox? Autumnal equinox?

The four terms refer to specific points in Earth's orbit around the sun, marking the start of the astronomical seasons: the vernal equinox (spring), summer solstice, autumnal equinox (fall), and winter solstice. The solstices mark the longest and shortest days of the year, while the equinoxes mark days with approximately equal daylight and nighttime hours.

What is the degree of tilt of the Earth?

23.5 degrees

Explain the Hadley cell: What happens at the equator? What happens at 30˚N? How does it affect precipitation?

tropical atmosphere circulation cell;

air hotter at the equator - expands & rises; warm air holds more moisture (as gas)

30˚N- Air masses descend back to the surface of the earth and are almost completely devoid of water. The air masses are gaining a water holding capacity. If there is any moisture in the air it gets quickly locked into the air mass and does not precipitate

Why do air masses rise? What happens when air masses rise?

Leaves a vacuum behind, as the warm air reaches the atmosphere, the mass moves equally in a northerly and southernly direction raining along the way.

Why do air masses fall?

dense dry air descends, warms and absorbs moisture

What happens to the water holding capacity as air masses rise and sink? What is the effect of this?

If there is any moisture in the air it gets quickly locked into the air mass and does not precipitate. This creates 30(degree) deserts.

How many global circulation patterns are their? What latitudes do they exist? What are their names?

3 cells in each hemisphere;

equator, 30 N/S, 60 N/S

What is the climate like at 0˚? 30˚N? 60˚S? 90˚N?

The climate at 0° latitude (the equator) is generally hot and wet with high precipitation, while 30°N (and S) latitude is characterized by warm, dry conditions and low precipitation, often referred to as the horse latitudes. At 60°S, the climate is typically cold and wet, often with a marine influence. At 90°N (the North Pole), the climate is extremely cold and dry, with little to no precipitation...

what are contrasting consequences of the rain shadow effect?

precipitates on one side, but not the other

creates high deserts

Give an example of where you might encounter a rain shadow effect.

Mojave Desert

Cascade mountains

How does the heat capacity of water create the ocean moderation effect?

High capacity for storing energy and moderates temperature

The ocean moderates temperature on land in the summer; ocean releases heat to the land in the winter.

27. Describe the temperature (mean & variability) and precipitation (mean & variability regimes for each of the following terrestrial biomes:

1. tropical rainforest

2. subtropical deserts

3. temperate forests

4. temperate grasslands

5. taiga

6. tundra

1. tropical rainforest: very hot temp, rainy, and dry seasons.

2. subtropical deserts: high avg temp, very low precipitation, very low biomass.

3. temperate forests: like grasslands, but higher precipitation, moderate productivity and diversity.

4. temperate grasslands: long warm summers, short cold winters, low precipitation and fire is common.

5. taiga: very cold winter, short cool summers, low annual precipitation, low productivity, and extreme temp variation.

6. tundra: very low temp and precipitation, permafrost, small woody shrubs, and low diversity, and biomass.

What is the difference between a biome's productivity and its biomass?

Biome productivity: biomes are defined by factors such as plant structures, leaf types, plant spacing, and climate.

Biomass: total mass of organisms in a given area or volume

Can a biome have high biomass and low productivity? If so, give an example.

yes, Taiga (boreal forests)

Can a biome have low biomass and high productivity? If so, give an example.

yes, grasslands

Explain the plant productivity and biomass regimes for each of the following terrestrial biomes:

1. tropical rainforest

2. subtropical deserts

3. temperate forests

4. temperate grasslands

5. taiga

6. tundra

1. tropical rainforest: very high biomass, and very high biodiversity

2. subtropical deserts: very low biomass, and low plant productivity.

3. temperate forests: moderate biomass, and moderate diversity

4. temperate grasslands: too dry for tress, and ow biomass with high productivity

5. taiga: low productivity but large biomass, and extremely low biodiversity

6. tundra: low diversity and low biomass

What is a multilayered canopy? Where is it most commonly found?

2-4 layers of trees

tropical rainforests

Do tropical rainforests have seasons? What are they?

yes, rainy season and dry season

where do tropical rain forests exists?

near equator

Give some examples of tropical rainforests (i.e. Congo).

Congo basin of Central Africa, amazon basin of south america, Malaysian tropical rainforest

Where are subtropical deserts located?

30 degrees north and 30 degrees south

Why don't trees grow in temperate grasslands?

because of low precipitation and too dry for trees

Why is fire common in temperate grasslands?

fire controls the growth of wood leaf plants;

because without it the grasses would eventually become shrub lands

what latitude are temperate forests found? give some examples.

25 and 50 degrees in both hemispheres

examples: Appalachian mountains from south carolina to maine & the rocky mountains

40. In taiga, there is low annual precipitation, but high biomass. How is this possible?

very little evaporation due to the cold temperatures as a result trees can grow

Where are tundra biomes found?

areas in arctic circle that are not covered by ice

What kind of plants live in a tundra?

small, woody shrubs, lichens, herbs

what is permafrost? where is it common?

The soils of the Arctic tundra may remain in a perennially frozen state. Arctic regions in the northern hemisphere.

how long is the growing season in the tundra

6-8 weeks

Be able to identify the following sections of a lake: littoral zone, limnetic zone, benthic zone, photic zone, aphotic zone.

littoral zone: edge of the lake, enough sunlight for plants

limnetic zone: offshore but enough sunlight so that photosynthetic organisms can make sugar to survive

benthic zone: bottom of the lake

photic zone: littoral zone and limnetic zone

aphotic zone: portion of lake where there is little or no sunlight

What types of organisms live in the littoral zone? The limnetic zone? The benthic zone?

Littoral zone: crab or starfish

Limnetic zone: fish or crustacean

Benthic zone: detritivores, coral or sponge

How are freshwater wetlands different from ponds?

Shallow-water habitats

Soil is saturated

Have emergent plants

What is the difference between a bog, a marsh, and a swamp?

bogs- stagnant and acidic

marsh- have non-woody plants

swamps- have trees and shrubs

How are rivers different from estuaries?

Rivers flow in one direction and estuaries flow in two directions based on the tides

estuaries- are where the river meets the ocean

What are the physical differences between the source and mouth of a river?

source: cold, narrow, and fast

mouth: warm, wide and slow

What are the biological differences between the source and mouth of a river?

source: fewer organisms- mostly animals

mouth: more organisms - plants and animals

How does salinity vary in estuaries?

varies with:

river flow (tides, storms)

proximity to oceans

How do changes in salinity levels affect biological organisms?

osmosis is changed because the water balanced in changed bc of salinity levels; some species adapt to salinity levels others have restrictions on salinity levels

What are intertidal zones? How are they different from estuaries? How are they different from coral reefs?

land meets sea. They are submerged, then exposed. Have huge variation in temperature and light intensity, plant life is limited, and animal life is abundant and diverse.

What are the physical characteristics of intertidal zones?

tides are submerged then exposed

huge variations in temperature and light intensity

plant life limited, animal life abundant and diverse

sand, muddy and rock shores

What organisms are most commonly found in intertidal zones?

small fishes, sea aneomes, herbit crabs, snails

mussels, seastars, sea urchins, sponges

Where are coral reefs restricted? Why?

warm water (20-30C), limited to photic zone sunlight is important bc they are symbiosis with dinoflagalletes

Why are coral colored?

warning predators of their toxic nature

Describe the symbiosis between coral and dinoflagellates?

they contribute nutrients to the animals and require light to live

What is the most diverse aquatic ecosystem in the world?

coral reef

What is the pelagic zone?

open ocean where water depth averages for 4000 meters

What are the physical characteristics of the pelagic zone?

Low nutrient concentration

Exception: upwellings

What organisms are common in the photic zone in the open ocean?

phytoplankton

zooplankton

nekton

What are nekton? Give some examples.

The collection of marine and freshwater organisms that can swim freely and are generally independent of currents, ranging in size from microscopic organisms to whales.

(to locate food)

examples: whales, sharks, fish

What is the benthic zone? What kind of organisms live there?

floor of the ocean; benthos

What are benthos? Give some examples.

Organisms

Mostly detritivores

examples: Starfish, oysters, clams, sea cucumbers, brittlestars and anemone