IB Biology Topic B4.1.3 Abiotic Variables Affecting Species Distribution Revision Notes (SL/HL)

IB Biology Topic B4.1.3 Abiotic Variables Affecting Species Distribution Revision Notes (SL/HL) | RevisionDojo

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Abiotic Variables: The Non-Living Conditions That Decide Where Species Live

Definition

Abiotic factors

Abiotic factors are non-living components like temperature, water availability, salinity, and soil type.

Note

Abiotic variables are the non-living physical and chemical features of a habitat.
They set the conditions a species must cope with to survive and reproduce in a place.
The combined effect of several abiotic variables, not any single one, explains where a species is found.

Definition

Range of Tolerance

Each species has an optimal range of abiotic factors within which it can thrive.
Conditions outside this range lead to stress or intolerance, making survival or reproduction impossible.

Terrestrial Habitats: Six Abiotic Variables Shape Land Distribution

Temperature sets the rate of metabolism and enzyme activity, so it limits which species can live in a region.
Soil moisture and water availability control the risk of drought stress and decide where plants can take up water.
Light intensity supplies the energy for photosynthesis, so it shapes which plants grow in open ground versus deep shade.
Soil pH affects how easily plant roots can absorb dissolved minerals from the soil.
Mineral nutrients such as nitrate and phosphate limit growth where the soil is poor.
Wind increases water loss and physical stress, which limits distribution on exposed sites such as mountain ridges and coasts.

Note

No single variable acts alone.
A hot, dry, nutrient-poor site suits very different plants from a cool, damp, fertile one.

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Note

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Tip

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Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Abiotic Variables: The Non-Living Conditions That Decide Where Species Live

Definition

Abiotic factors

Abiotic factors are non-living components like temperature, water availability, salinity, and soil type.

Note

Abiotic variables are the non-living physical and chemical features of a habitat.
They set the conditions a species must cope with to survive and reproduce in a place.
The combined effect of several abiotic variables, not any single one, explains where a species is found.

Definition

Range of Tolerance

Each species has an optimal range of abiotic factors within which it can thrive.
Conditions outside this range lead to stress or intolerance, making survival or reproduction impossible.

Terrestrial Habitats: Six Abiotic Variables Shape Land Distribution

Temperature sets the rate of metabolism and enzyme activity, so it limits which species can live in a region.
Soil moisture and water availability control the risk of drought stress and decide where plants can take up water.
Light intensity supplies the energy for photosynthesis, so it shapes which plants grow in open ground versus deep shade.
Soil pH affects how easily plant roots can absorb dissolved minerals from the soil.
Mineral nutrients such as nitrate and phosphate limit growth where the soil is poor.
Wind increases water loss and physical stress, which limits distribution on exposed sites such as mountain ridges and coasts.

Note

No single variable acts alone.
A hot, dry, nutrient-poor site suits very different plants from a cool, damp, fertile one.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic B4.1.3: Abiotic Variables Affecting Species Distribution Notes

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

Abiotic Variables: The Non-Living Conditions That Decide Where Species Live

Terrestrial Habitats: Six Abiotic Variables Shape Land Distribution

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Abiotic Variables: The Non-Living Conditions That Decide Where Species Live

Terrestrial Habitats: Six Abiotic Variables Shape Land Distribution

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account