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Lab 6

Ecological footprint Data analysis

What is an ecological footprint?

• The ecological footprint estimates the area of land and ocean required to support your consumption of food, goods, services, housing, and energy and assimilate your wastes.

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Ecological footprints are measured in global hectares

• A global hectare is one hectare of biologically productive space with world-average productivity.

• In 2002 the biosphere had 11.4 billion hectares of biologically productive space corresponding to roughly one quarter of the planet's surface. This includes 2.0 billion hectares of ocean and 9.4 billion hectares of land. 1 global hectare is a hectare representing the average capacity of one of these 11.4 billion hectares.

We are overshooting the Earth's biological capacity by nearly 50%. To sustain present levels of consumption,

we would need 1.5 Earths!

http://www.myfootprint.org/en/

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Share your ecological footprint

My ecological footprint

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If everyone on the planet lived my lifestyle, we would need 2.99 Earths!

Specific things I can do to reduce my ecological footprint

• Eat vegetarian

• Join Tucson Community Supported Agriculture (CSA)

• Turn off & unplug electronics

• Fly less

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How much money does your family spend each week on food?

Germany: The Melander family of Bargteheide

Food expenditure for one week: 375.39 Euros or $500.07

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United States: The Revis family of North Carolina

Food expenditure for one week $341.98

Italy: The Manzo family of Sicily

Food expenditure for one week: 214.36 Euros or $260.11

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Mexico: The Casales family of Cuernavaca

Food expenditure for one week: 1,862.78 Mexican Pesos or $189.09

Poland: The Sobczynscy family of Konstancin-Jeziorna

Food expenditure for one week: 582.48 Zlotys or $151.27

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Egypt: The Ahmed family of Cairo

Food expenditure for one week: 387.85 Egyptian Pounds or $68.53

Ecuador: The Ayme family of Tingo

Food expenditure for one week: $31.55

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Bhutan: The Namgay family of Shingkhey Village

Food expenditure for one week: 224.93 ngultrum or $5.03

Chad: The Aboubakar family of Breidjing Camp

Food expenditure for one week: 685 CFA Francs or $1.23

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United States: The Revis family of North Carolina

Food expenditure for one week $341.98

How much food do you throw away?

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Same for the USA

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Data analysis

What is data analysis?

• Data analysis is the use of different analytical methods to summarize, describe, and compare data. In science, data analysis is a necessary step in hypothesis testing.

Statistical tests

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•Descriptive statistics

•Inferential statistics

Descriptive statistics

• Frequency distribution

• Mean

• Median

• Mode

• Variance

Describe the data!

(Describe the data!)(Describe the data!)(Describe the data!)(Describe the data!)

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Inferential statistics

• IQ decreases with increasing exposure to PCBs

• Is there a biological explanation?

• Is this a result of chance events?

• Results indicated significant linearity between PCB exposure and full scale IQ (linear F = 5.43, p = 0.022)

Make conclusions about the data

Stewart et al. 2008

Not random chance!Not random chance!Not random chance!Not random chance!

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Examples of inferential statistics

• t-test

• To compare the means of two groups

Sun vs. Shade

Examples of inferential statistics

• Chi-square test (compare observed to expected frequencies)

5059

5041ExpectedObserved

Chi-square = 3.24P = 0.072

Not significantly different!

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Examples of inferential statistics

• ANOVA

• To compare between 3 or moreindependent groups (or factors)

1000 m 2000 m 3000 m Does elevation has Does elevation has Does elevation has Does elevation has an effect on leaf size?an effect on leaf size?an effect on leaf size?an effect on leaf size?

Time to get to work!