Abiotic Factors that Affect Diversity

Question 1

What are abiotic factors that affect terrestrial diversity? (8)

Answer 1

Sunlight, Temperature, Precipitation, Nutrients, Wind, Latitude, Attitude, Soil Type.

Question 2

What are abiotic factors that affect aquatic diversity? (7)

Answer 2

Light (penetration), Water Temperature, Nutrients, Water Currents, Salinity, Water Chemistry.

Question 3

What is the most important factor is the distribution of organisms?

Answer 3

Temperature.

Question 4

Why is temperature that most important factor in the distribution of organisms?

Answer 4

Because many animals (ectotherms) are unable to regulate temperatures precisely, and even endothermic animals (who can control their body temperature) are still affected.

Question 5

What is the relationship of the size of animals and the temperature?

Answer 5

Smaller animals must spend more energy to maintain their body temperature, while larger animals body temperature is slower to change.

Question 6

What is an example of a terrestrial animal that is heavily affected by temperature?

Answer 6

Vampire bats (limited to habitats where the average minimum temperature is January is above 10 degrees).

Question 7

What is an example of an aquatic organism that is heavily affected by temperature?

Answer 7

Reef-building corals (require warm water conditions to survive). Different corals can withstand different temperature fluctuations, but generally the ideal temperature is 20-32 degrees. Coral reefs may have the greatest biodiversity (30-40% of all fish species), and are the most productive habitats on Earth. Many corals consist of a symbiotic association made up of an invertebrates animal and algae.

Question 8

What affect does light have on corals?

Answer 8

The symbiotic association of corals and invertebrate animal/algae is light dependent and part of the reason we see coral declines in warming waters is the impact of turbidity on the algae.

Question 9

What is the photic zone?

Answer 9

The level at which light cannot help life in water, due to turbidity and biological activity. This value is not static and fluctuates with turbidity and biological activity.

Question 10

What happens to light in most aquatic environments?

Answer 10

Water absorbs light, preventing photosynthesis at depths greater than 100m (photic level). As light penetrates water, different wavelengths are lost before others.

Question 11

What is an advantage of Red algae?

Answer 11

They can occur at greater depths because they posses pigments enabling them to use blue-green light, which allows them to be below the average photic level.

Question 12

What must aquatic organisms maintain, and what affects this?

Answer 12

Aquatic organisms must maintain osmotic balance (i.e. keep internal salt levels constant), and this is affected by salinity.

Question 13

What is the relationship of Freshwater fish and salinity?

Answer 13

Freshwater fish are hypertonic and tend to gain water, having to constantly eliminate water.

Question 14

What is the relationship of Marine fish and salinity?

Answer 14

Marine fish are hypotonic, and lose water to the environment and must drink water to compensate.

Question 15

What happens with low precipitation and low temperature?

Answer 15

Tundra.

Question 16

What happens with low precipitation and high temperature?

Answer 16

Deserts.

Question 17

What happens with high precipitation and high temperature?

Answer 17

Rain Forests.

Question 18

What happens with high precipitation and cold temperature?

Answer 18

No such niche exists.

Question 19

What happens when environmental variables come together?

Answer 19

They form Biomes, regions of homogenous structures.

Question 20

What is a Tropical Forest?

Answer 20

A biome where light and nutrients are in high demand. There is a thick canopy blocking light to the bottom strata, so many trees are covered by epiphytes that mooch off the tree’s height to gain access to the sun.
The rain forest soil is very low in nutrients because the nutrients are locked in long-lived trees.

Question 21

How species-rich are Tropical Forests?

Answer 21

Extremely high, with the Tree species greater than 100 per square kilometre. Large mammals are less common, but there are plenty of birds and ectotherms.

Question 22

What is the Taiga?

Answer 22

Boreal Forest, one of the largest terrestrial biomes on earth. It has moderate moisture and long, cold winters.

Question 23

How species-rich is the Taiga?

Answer 23

Relatively low, but varies season to season. Ectotherms such as amphibians and reptiles are low.

Question 24

What are the Grasslands?

Answer 24

Areas where the moisture is too low to support forests and have inter-continental climate (cold winters, hot summers). Marked by seasonal droughts and fires, and grazing by large animals. Considered the most endangered biome worldwide (1% of NA prairie left).

Question 25

How species-rich are the Grasslands?

Answer 25

Fairly high in plants, but fairly low in animals. The soil is very rich in nutrients.

Question 26

What is the Tundra?

Answer 26

Permafrost (permanent frozen ground), bitterly cold, have high winds, low moisture, no trees, short growing season. Covers 20% of land surface on earth.

Question 27

How species-rich is the Tundra?

Answer 27

Low in animals and plants. Fauna is much richer in the summer, due to increased energy and migratory birds.

Question 28

What is the Desert?

Answer 28

Defined by lack of moisture, plants and animals have adapted for water storage and conservation. They can either be very hot or very cold.

Question 29

How species-rich is the Desert?

Answer 29

Moderate to low.

Question 30

How much of Earth is covered in aquatic biomes?

Answer 30

Aquatic biomes cover 75% of the earth’s surface and contain the majority of living space (>90%).

Question 31

What is important about freshwater in northern climates?

Answer 31

They go through annual cycles of temperature fluctuations, starting at 4 degrees and uniform oxygen distribution. In the summer, thermal stratification sets in and the temperature and oxygen distribution is no longer uniform (colder, less oxygen at bottom). As fall sets in, heat declines and returns to 4 degree levels. As ice sets in, an inverted temperature profile is established and water column again becomes thermally stratified.

Question 32

What is an Oligotrophic lake?

Answer 32

A freshwater lake that is nutrient poor, the water is clear, cool, and oxygen rich: little productivity by algae, often have high diversity of fish.

Question 33

What is an Eutrophic lake?

Answer 33

A freshwater lake that is nutrient rich, with lots of algal productivity but oxygen poor at times - high algal diversity, but low diversity of fish (winter kill likely).

Question 34

What is important about Rivers?

Answer 34

They are heavily affected by human activities, most large rivers are now dammed at multiple points. Benthic (bottom dwelling) algae and aquatic insects are a highly diverse group in rivers but are sensitive to changes in turbidity, temperature, and nutrient loading.

Question 35

What are Wetlands?

Answer 35

Includes marshes, bogs, swamps, and seasonal ponds. Habitats of high biodiversity and productivity but many wetlands have been lost (>70% on Plains). The result of lost wetlands is increased flooding because wetlands act as a natural reservoir, capturing heavy rains and snow melt.

Question 36

What is an Estuary?

Answer 36

Where freshwater streams or rivers merge with the ocean. It’s a highly productive biome, with many euryhaline species. They depend on a dynamic but predictable salt cycle, which is easily disrupted by human activities.

Question 37

What is the pelagic zone at risk from?

Answer 37

Overfishing and pollution.

Question 38

What zone is likely unaffected by human activity?

Answer 38

Abyssal zones, which are out of human reach.

Question 39

What do oceans offer?

Answer 39

The most stable conditions for life, unfortunately this has resulted in life forms that have minimal abilities to adapt and even small changed in temperature can change distributions and disrupt communities.

Question 40

What are Mangroves?

Answer 40

Biomes that are very frost sensitive, and only found between specific latitudes (25N and 25N) where wave action in minor. They cover 60-75% of tropical coastlines, and support a rich fauna of birds and snails, barnacles, oysters, and crabs. The sheltered waters around roots provide nursery habitat for organisms.