3.1 Organisms and their Physical Environment
1. Identify abiotic factors affecting organisms in their environment.
2. Describe the range of an abiotic factor locally.
3. Describe habitat requirements of local species.
Readings: 15: 393-412: 4: 81-86, 101-103
Reminders: Digital Collection and Classification (Assignment #1), Due Wednesday Sept 23rd
Reading Quiz 3 and Attitudes about Biology Survey Due today Sept 21st
Welcome Survey due Wednesday Sept 23rd
Physical Characteristics of an Environment = Abiotic (non-living) Conditions
temperate forest grassland kelp forest (underwater) coral reef
1. Sunlight –light intensity
- light wavelength
- duration of light
2. pH of soil
3. pressure (particularly in ocean)
5. inorganic compounds –could be harmful to some organisms
-some needed for organisms’ growth
6. tectonic plate movement
QUESTION: 1. Can you think of some other abiotic factors that could affect organisms?
Variation in Abiotic Conditions Within One Location
Daily – light intensity
- temperature (cooler at night)
QUESTION: 2. Can you think of others which vary daily?
Seasonally –precipitation (eg rainy season eg Dec., Jan., Feb., in Brazil)
-precipitation type (eg snow vs. rain)
-duration of light due to angle sunlight hits the earth
An example of the abiotic conditions in Kamloops, BC:
Kamloops Climatic Data (monthy averages for a 30 year period)
Statistic Units Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average
C -4.8 -0.6 4.5 9.4 14.0 18.3 20.8 20.3 14.9 8.5 1.7 -3.3 8.64
C -1.3 3.4 10.2 16.2 21.1 25.4 28.3 27.8 21.7 14.0 5.3 0.0 14.34
C -8.4 -4.8 -1.3 2.5 6.9 11.1 13.2 12.8 8.1 3.0 -2.0 -6.6 2.88
Mean Monthly mm 26.1 13.8 9.6 14.8 21.8 28.6 27.9 30.2 27.6 14.4 22.0 32.6 22.45
Mean Monthly cm 27.5 11.9 3.1 0.3 0.0 0.0 0.0 0.0 0.0 0.2 12.1 31.0 7.17
QUESTIONS: 3. What is the range of temperatures that an organism living in Kamloops must be able to
tolerate to survive?
4. How do you think an amphibian like Spea intermontana tolerates this temperature range as well as the low
amount of precipitation?
5. What is the maximum amount of precipitation at any time in Kamloops?
6. In what month do organisms receive the maximum hours of daylight?
(other data will be provided) When are we likely to see the greatest growth of
a weedy flowering plant such as Hieracium aurantiacum which grows in
7. What other favourable abiotic conditions are important for plant growth
Tolerance of Abiotic Conditions
Many abiotic factors vary over time meaning that organisms living in a particular environment will be exposed
to a wide range of abiotic factors. Each species are able to tolerate a particular range of each factor
Organisms usually thrive and reproduce in their optimum range for a factor but become stressed at the
extremes of the tolerance. Few individuals survive the extremes and if a factor occurs beyond their range of
tolerance they will die.
QUESTION: 8. Which factor or combination of abiotic factors could be limiting the growth and survival of
vegetation in Kamloops?
The mountain pine beetle (Dendroctonus ponderosae) lay their eggs under the bark of coniferous trees,
particularly lodgepole pines (Pinus contorta) which are found in Kamloops. The larvae chew tunnels in the
wood and leave behind a bluish fungus (Ophiostoma spp ) which kills the tree.
QUESTION: 9. What is lowest temperature that mountain pine beetle can survive?
10. Why have their populations increased in British Columbia forests in the last 10 years? (FYI: the infestation
in and around Kamloops is classified as “severe” to completely “overrun” which you can observe on this map.)
Defining a Habitat:
Habitat is generally determined by the abiotic characteristics of a
location. These characteristics then also determine the other species
that live in the same area and the possible interactions among them.
All species within the same location, with same abiotic environment,
form a community of organisms
Burrowing owl (Athene cunicularia), found in dry interior of BC (Kamloops)
Niche: –the abiotic and biotic conditions tolerated by a population of one species
-the role of the organism in the community
Ecosystem: -the community of organisms (biotic) and the physical environment (abiotic)
What strategies do organisms have for dealing with changing environmental conditions?
-migration or dispersal to a more favourable location eg. geese
QUESTION: 8. Can you think of any organisms which randomly disperse their offspring to increase the
chances that at least some will survive?
-adjust metabolic functions or physiology –hibernation in cold winter (decrease activity and lower body temp.)
-estivation in warm weather, hide from extreme abiotic factor and
Within the lifecycle of a species one stage is more tolerant of extreme conditions (cold of winter)
QUESTION: 11. What tends to be the tolerant stage of plants? What strategies do they employ to protect
QUESTION 12: What tends to be the tolerant stage of animals? What strategies do they employ to protect