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ENVIRONMENTAL

CONDITIONSAND

RESOURCESConcepts to be covered in class:

Ecological Niche

Self study:

Effects of temperature

Biogeochemical cycles

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Oikos(Home) >>>> Ecology (Ernest Haeckel, 1869)

the scientific study of the distribution and

abundance of organisms and the interactionsthat determine the distribution and abundance.

(Begon, Harper and Townsend)

So what is ecology all about? The formal definition

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So what are the factors that you expect to

be important in determining where you willfind a particular organism?

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Who is this?

Movie

http://localhost/var/www/apps/conversion/tmp/BIO201_Pune2012/02_Conditions%20and%20resources/Barnacles_Feeding.flvhttp://localhost/var/www/apps/conversion/tmp/BIO201_Pune2012/02_Conditions%20and%20resources/Barnacles_Feeding.flv

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Many species of barnacles often found together

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Stratification in barnacles observed

What might be the reason? How will you test?

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Connells experiment on

barnacles (1961)

Molles, Page 311

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A condition is an abiotic environmental factor that influences

the functioning of living organisms.

e.g. temperature, relative humidity, pH, salinity, concentration

of pollutants

Resources are entities required by an organism, the quantities ofwhich can be reduced by the activity of the organism.

e.g. Solar radiation, carbon dioxide, oxygen, water, mineral

nutrients, space, etc.

Lim i t ing resources of ten lead to compet it ion which plays a major ro le in

determining th e growth and dis t r ibut ion of o rganisms.

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Response to conditions

Response curves illustrating the effects of a range of environmental conditions

on individual survival (S), growth (G) and reproduction (R).(a) Extreme conditions are lethal; less extreme conditions prevent growth; only

optimal conditions allow reproduction.

(b) The condition is lethal only at high intensities; the reproductiongrowth

survival sequence still applies.

(c) Similar to (b), but the condition is required by organisms, as a resource, at

low concentrations. Begon, Harper, Townsend

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Ecological Niche: n-dimensional hypervolume

1-D 2-D 3-D

(a) A niche in one dimension. The range of temperatures at which a variety of plant

species from the European Alps can achieve net photosynthesis of low intensities ofradiation (70Wm2).

(b) A niche in two dimensions for the sand shrimp (Crangon septemspinosa) showing

the fate of egg-bearing females in aerated water at a range of temperatures and

salinities.

(c) A diagrammatic niche in three dimensions for an aquatic organism showing a volume

defined by the temperature, pH and availability of food.

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Population-Persistence Nicheecological niche is a quantitative description of the

range of environmental conditions that allow a

population to persist* in some location.

*persist = positive growth rate

GE Hutchinson

From Ecological Niche by TW Schoener

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Fundamental and realized

niche

Connells experiment on

barnacles

The fundamental niche of an organism

is that portion of its niche that it can

potentially use. Realized niche refers to

that part of the niche that it actually

ends up using.

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Resource-Utilization Nichefocuses entirely on what members of a species population in

some locality actually doin particular, how they use resources.

From Ecological Niche by TW Schoener

Robert McArthur Richard Levins

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Kinds of niche axes typically used for

utilizationsHabitat

microhabitat (e.g., height in

vegetation)

macrohabitat (e.g., vegetation zone

such as tropical rainforest or desert)

Food type

food size

hardness

Timedaily activity

seasonal activity

From Ecological Niche by TW Schoener

Resource-Utilization Niche

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Niche Theory: Present Status

Ecologys love-hate relationship with the niche

concept has been long and not especially pretty.

N. G. Hairston Jr. (1995)

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R f

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References

Detailed Reading

Rest of Chapter 2 from Ecology: Individuals to Ecosystems by Begon and Townsend

(This is a detailed description of other kinds of conditions and how they might affect the distribution

of organisms)

Mandatory Reading:

Ecological Niche:

Section 2.1-2.2 from Ecology: Individuals to Ecosystems by Begon and Townsend.

Effects of temperature:

Section 2.3.1 -2.3.4 (page 32-37) from Ecology: Individuals to Ecosystems by Begon and

Townsend.

Biogeochemical cycles:

Ch 2 from Spellman, FR (2008) Ecology for non-ecologists.

Advanced Reading /PaperEcological Niche by Thomas W. Schoener in Princeton Guide to Ecology by Simon A Levin (Editor)

Fun:

http://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-

alzheimer%E2%80%99s

I looove the beginning and the ending!!! The author sounds like an aspiring Hollywood screenplay writer. Good example of how to

take a simple scientific experiment and put a nice spin on it for consumption by the non-technical public.

http://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99shttp://www.popsci.com/science/article/2013-01/sad-science-fiction-plot-becomes-reality-space-radiation-could-cause-alzheimer%E2%80%99s