3.2 Communities of Species and their DistributionLearning Outcomes:4. Define the composition of biological communities5. Describe the effect of changing abiotic factors on the regional or geographic distribution of species.

Reminders: Assignment #1 Digital Collection Due Now. Deadline to do the Welcome Survey Due before class today

Natural Communities:

Marsh alpine forestmeadow desertCommunity = all populations of organisms living close enough together in a particular environment to potentially interact

Plants give communities their structure but animals, fungi, protists, bacteria are also members of a community(Communities are often named after dominating plants)

What affects community structure?

Global gradients of abiotic factors: (Fig 15.8)

Late assignments policy: -10% per day including weekends. Eg. -10% if the assignment comes in between the time that class has started (12pm) today until 12pm Thursday. -20% if the assignment comes in between 12:01pm Thursday and 12pm Friday…..etc…..

“Our weather comes from the west”. Your textbook explains that this is partially due to the direction of the rotation of the earth. We can observe that moisture-laden air tends to come off the Pacific towards Vancouver.

THOUGHT EXPERIMENT: Imagine Dr. Evil came up with a way to reverse the rotation of the Earth. The sun would now rise in the West and set in the East. 1. In the long term, with the earth’s rotation changed, what region might come to resemble Vancouver in terms of weather and climate? And what might be the new climatic conditions of

Climatic regions of the world (biomes) (Fig 15.9):

Climatic regions of British Columbia:

Taken from the Tree Book:http://www.for.gov.bc.ca/hfd/library/documents/treebook/biogeo/biogeo.htm

Biological communities correlate with substratum (types of soils) and climate.

Recognizable differences in plant communities were used to classify communities according to dominant tree species.QUESTION: 3. What biogeoclimatic zone to you suspect Kamloops to be in based on what you learned last class? (Hint: What type of trees are affected severely by mountain pine beetle, Dendroctonus ponderosae?)

Climate change in British Columbia: http://www.geog.ubc.ca/courses/geog376/students/class05/skcurtis/

Vancouver lies within temperate forest according to the map. To be more specific it is temperate rainforest. There are only 7 other regions of temperate rainforest in the world:-beside the Caspian sea (Iran), -beside the Black sea (Turkey and Georgia), southwestern S. America, a region of coastal South Africa, New Zealand and Tasmania, SW Japan, small regions of NW Europe. QUESTION: 2. What is common to all regions

The Boreal Forest Community:

Covers 17% of earth’s land surface (300 million ha in Canada, 1.43 billion ha global-carbon sink 714 billion tonnes of carbon (37% of carbon stored in terrestrial biosphere)QUESTIONS: 4. How can the carbon stored in trees be returned to the atmosphere? There are several important ways.

5. This community depends on disturbance for renewal. What are two types of disturbances you can think of which usually occur every 50-100 yrs?

Climate change will cause changes in precipitation, species composition, disturbanceThe boreal forest will be more severely affected than tropical or temperate forests.It has been predicted by IPCC that the frequency and pattern of disturbance may be more important than increased temperature and CO2

Due to warmer temperatures the boreal forest is moving northward encroaching on the tundra biome but due to the magnitude of climate change the overall prediction is this biome will decrease in area, biomass, and amount of carbon stored.

Local Communities reflect gradients of abiotic factors:Elevation:

Differences in precipitation and wind: (similar to Fig. 15.1)

Question: 6. What are some other local examples of abiotic gradients causing variation in communities?

QUESTIONS: 7. If all other chipmunks were gone where would the lodgepole pine chipmunk live?

8. What do you need to know in order to determine where the alpine chipmunk would live if the lodgepole pine chipmunk were gone?

-aggressive, determines the upper limit of the least chipmunk (ie if yellow pine chipmunk is gone then least chipmunk will move in)-if least chipmunk gone it does not move into Sagebrush

-can tolerate all environments and better than others at handling heat stress such as in the Sagebrush

-most aggressive, determines the upper limit of the yellow pine chipmunk and the lower limit of the alpine chipmunk-requires shaded forest because it is vulnerable to heat stress

9. In addition to tolerating the abiotic conditions in a particular environment, what biotic conditions must be met besides outcompeting other species? (Biotic interactions involve an organism interacting in some way with other living organisms)

10. Considering what the abiotic conditions must be like in the alpine zone in the winter, what do you predict the alpine chipmunk does to survive?

TOUGH QUESTION TO CONSIDER:The ambitious 10 year long Manahatta project http://themannahattaproject.org/ (on the cover of this month’s National Geographic magazine) reconstructs what the natural habitat of Manhattan (New York City) was like before the arrival of man. There were once 55 different ecosystems there. How do you think they determined what organisms used to live there?