


Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
Abiotic factors such as temperature, light, and soil can influence a species' ability to survive. Every species is able to survive within a range of each of.
Typology: Lecture notes
1 / 4
This page cannot be seen from the preview
Don't miss anything!
limiting factor any factor that restricts the size of a population
tolerance range the abiotic conditions within which a species can survive
Population size
optimum range
tolerance range
no population
no population
high populationlow population populationlow
low high
high
low
Abiotic factor
0
Figure 1 Species can be successful over a range of abiotic conditions. However, they will become stressed and will die out if conditions exceed their tolerance limits.
52 Chapter 2 • Understanding Ecosystems (^) NEL
Figure 3 The distribution of black spruce
Crowle Art Group Deborah Crowle 1st pass
Ontario Science 10 SB 0-17-635528- FN CO
Pass Approved Not Approved
Table 1 Key Abiotic Factors of Terrestrial and Aquatic Ecosystems and the Effects Human Activities Can Have on Them^ C02-F19-UAOS9SB.ai
Ecosystem Key abiotic factors Human action and result terrestrial ecosystems
light availability Clear-cutting and fire remove shade and expose the remaining organisms to much more light.
water availability Damming rivers and draining swamps and marshes change water availability. Irrigation increases water availability. nutrient availability Farming practices may increase or decrease nutrient levels in the soil.
temperature Global warming is decreasing suitable habitat for many cool-adapted species.
aquatic ecosystems
light availability Activities that increase erosion or stir up the bottom cloud the water and reduce light penetration.
nutrient availability Nutrient runoff from agriculture and urban environments increases the nutrient content of surface water and groundwater, causing algal blooms. acidity Acidic air pollution results in acid precipitation. Carbon dioxide emissions produced by the burning of fossil fuels are increasing the acidity of the oceans. temperature Industries and power plants release heated waste water into lakes and rivers, killing fish and other organisms. salinity Salting highways and long-term irrigation practices can cause salt to accumulate.
Figure 2 (a) Cacti can withstand long periods of drought. If overwatered, they may die because their roots cannot survive consistently damp conditions. (b) Aquatic plants, such as water lilies, will perish quickly if the water level drops and the roots are exposed to air. (c) While both cacti and water lilies prefer exposure to full sun, bunchberries are adapted to shade.
(a) (b) (c)
NEL^ 2.7 Biotic and Abiotic Influences on Ecosystems^53
You can apply what you learned in this section about how biotic and abiotic factors limit population size to the Unit Task described on page 156.
Carrying Capacity
carrying capacity the maximum population size of a particular species that a given ecosystem can sustain
CHECKCHECK YOUR LEARNING
IN SUMMARY
Figure 5 These green circles, visible from the International Space Station, are formed by an irrigation project in Libya. Irrigation increases the carrying capacity of the desert ecosystem.
NEL^ 2.7 Biotic and Abiotic Infl uences on Ecosystems^55