Fundamentals of Ecology: A Preface

Dann Sklarew, Ph.D.Spring 2010

A New Year Greeting by WH Auden (1969)

On this day tradition allotsto taking stock of our lives,my greetings to all of you,

Yeasts,Bacteria, Viruses,Aerobics and Anaerobics:A Very Happy New Yearto all for whom my

ectodermis as Middle-Earth to me.

For creatures your size I offera free choice of habitat,so settle yourselves in the zonethat suits you best, in the poolsof my pores or the tropicalforests of arm-pit and crotch,in the deserts of my fore-arms,or the cool woods of my scalp.

A New Year Greeting by WH Auden (1969)

Build colonies: I will supplyadequate warmth and moisture,the sebum and lipids you need,on condition you neverdo me annoy with your

presence,but behave as good guests

should,not rioting into acneor athlete's-foot or a boil.

Does my inner weather affectthe surfaces where you live?Do unpredictable changesrecord my rocketing plungefrom fairs when the mind is

in tiftand relevant thoughts occurto fouls when nothing will

happenand no one calls and it rains.

A New Year Greeting by WH Auden (1969)

I should like to think that I make

a not impossible world,but an Eden it cannot be:my games, my purposive acts,may turn to catastrophes there.If you were religious folk,how would your dramas justifyunmerited suffering?.

By what myths would your priests account

for the hurricanes that cometwice every twenty-four hours,each time I dress or undress,when, clinging to keratin rafts,whole cities are swept awayto perish in space, or the Floodthat scalds to death when I

bathe?

A New Year Greeting by WH Auden (1969)

Then, sooner or later, will dawna Day of Apocalypse,when my mantle suddenly

turnstoo cold, too rancid, for you,appetising to predatorsof a fiercer sort, and Iam stripped of excuse and

nimbus,a Past, subject to Judgement.

Lesson learned?Auden shows ecology is as close

as our nose (if not closer)…

but what exactly IS ecology?

And how can you become wise to its ways in our few short weeks together?

(Hint: Go check out http://biol607001sp10.pbworks.com and the syllabus link from there too, then come back.)

Elements of Ecology, 7th Ed. Overview

1 for each of these 8 units:I. THE PHYSICAL ENVIRONMENTII. THE ORGANISM AND ITS ENVIRONMENTIII. POPULATIONSIV. SPECIES INTERACTIONSV. COMMUNITY ECOLOGYVI. ECOSYSTEM ECOLOGYVII. BIOGEOGRAPHICAL ECOLOGYVIII. HUMAN ECOLOGY

+ 1 session ea. for mid-term and final showcase

How will learning be assessed?

• CO-OP: Collaborative problem-solving environment, where you construct your own knowledge; prof serves as facilitator and guide

• METRICS: Explicit scorecards (rubrics) in syllabus• EVALUATION: Rating and feedback on activities

provided by professor -- and often by peers too• CHANGE: Pre- and post-tests assess personal

and collective learning• IMPACT: Complete course with useful skills and

products meaningful to you and your lives.

Case-in-Point: Pre-test Results

Note: These are actual questions from prior mid-term and final exams, along with my scores [and parentheticals] for your answers.

Now, about you…

• Ecological interests?• Confident about ecological knowledge?• Knowledgeable about ecology?• Ecological footprint of graduate study?

Now, about you...

Microbiomes and endophytic habitats

Aquatic ecology

Coral reef threats/indicators

Marine ecology framework

Fundamental understanding (x2)

Basic understanding (x2)

Understand interactions

Interactions, resilience, restoration

Human-nature interactions

Inform green engineering

Eco-wise policy-adminEco-wise politics

Natural resources, land-use

Now, about you…

Of 15 students to respond to the pre-test:

Confidence in understanding of Ecology?

ExtremelyVerySomewhatNot at all

I. The Physical EnvironmentQ1. Describe four abiotic factors affecting diversity of

aquatic ecosystems.

• Ave. score: 3.0/4.0 (Well done!)

• Best answer in class:* “salinity, temperature, wave action, bottom type”

• Dr. Dann asks:• 4 items identified, but how affecting was not described.• What do we call the bottom of a body of water? • Is that substrate ever alive?• What else is a critical abiotic factor for aquatic life?

II. The Organism and its Environment

Q2. Illustrate 2 potential ecological tradeoffs and how a dog's adaptations have allowed it survive in the context of these tradeoffs.

• Ave. score: 1.5/4.0

• Best answer in class:* – “Length of parental care and age of sexual maturity are two potential ecological

tradeoffs.”– [Parental investment vs. puppy survival:] “Dogs care for their puppies for a period of

time after birth. This costs time and energy but makes the pups more likely to survive once they are on their own.”

– [Sexual maturity/reproduction rate vs. longevity:] “Dogs reach sexual maturity around one year of age. While this may seem relatively early, it suggests that mortality rates are highest for older animals, compared to juveniles. Therefore, it is advantageous for dogs to reproduce earlier rather than later in their lives.”

* Good, but note: make tradeoff (X vs. Y) & “spot” for dogs’ adaptation explicit.

X Y

III. Populations• Q3. Describe the equation for the exponential model of population

growth, defining the variables and constants used, and stating the shape of the resulting curve of population size over-time.

• Ave. score: 1.2/4

• Best answer in class:* “N = No. e(to the power)rt

• No is the initial population• N Population at a time t• e base of natural log• r is the rate of increase.

• It is some what like a 'J' shape or a tick mark shape: ✓ (no negative slope)”

* Dr. Dann adds: e is an irrational constant [like extremism], approx. 2.718281828.

IV Species InteractionsQ4. State 2 possible outcomes of competition between 2

species and conditions under which each is obtained.

• Ave. score: 2.7/4.0

• Best answer in class:* 1. “One possible outcome of competition between two species is the ability to live

in the same ecosystem while adapting to take advantage of slightly different niches so they are no longer in direct competition with each other.

2. “Another possible outcome is for one species to out-compete the other and force the other species out of the habitat all together which occurs when one of the species is more strongly adapted to the ecosystem and the second species is unable to adapt quickly enough to compete. One species prevails and the other becomes extinct.”

* Dr. Dann adds: So, either co-existence (win-win) or elimination (win-lose). Note that one species can migrate, adapt to a new niche or – like coral, beavers, astronauts and other “ecosystem engineers” – create their own!

V. Community EcologyQ5. In your own words, explain each of the following [4] ecological

terms…

• Ave. score: 1.4/4.0

• Best answer in class:*

1. “Allometry: relating an organism's individual traits or characters with its size.

2. Secondary succession: The establishment of a new ecological community in a place that once had life on it but has been destroyed.

3. Ecotone: A transition zone between two separate or distinct ecosystems

4. Climax: The last stage in ecological succession where the stability of the ecosystem is achieved.”

* Dr. Dann adds: “One of these things is not like the others…” which term is unrelated to community ecology?

VI. Ecosystem EcologyQ6. Describe how consumption efficiency relates to energy flow

in an ecosystem, as well as how it varies in detrital vs. grazing food chains.

• Ave. score: 0.7/4.0 (Y’all bombed this one.)

• Best Answer in class:*

“Efficient consumers use a larger amount of the energy available in their food supply so more energy is conserved from one consumption level to the next in the ecosystem. Detrital food chains are more efficient than grazing food chains because they use the energy that would otherwise go unused by organisms solely feeding on primary producers.”

Dr. Dann adds: This description of consumption efficiency is as close as any came to correct… (make sure you know correct one!)

So, to which food chain do we humans belong? (And why?)

VII. Biogeographical EcologyQ7. Explain the meaning and significance of “compensation

point” and the role it plays in structuring aquatic ecosystems. For which of {lakes, streams, rivers, oceans} is it most & is it least important?

• Ave. score: 0.5/4.0 (Ugh. Even worse than Q6…)

• Best answer in class:*

“The compensation point is the depth at which a plant can grow in water.

It is least important in streams and most important in oceans.”

* Dr. Dann notes: Good definition. For assessment, be sure to consider respiration, photosynthesis, and covey why you think it’s most/least important for your choice of water bodies. (No room to give all that on pre-test, though, I know…)

Q8. Discuss at least 2 expected impacts that human-induced climate change may have on one of the following ecosystem services: food from coral reef OR food from domesticated crops. Clarify whether increased CO2 &/or air temperature is the primary factor contributing to each impact.

• Ave. score: 2.5/4.0

• Most succinct of several great answers students provided:* – “Food from domesticated crops can be damaged by floods and strong

storms, which occur more regularly with higher air temperatures in certain regions.

– Increased air temperatures could also result in decreased rainfall within a region, which would result in insufficient water resources available to grow crops. ”

Dr. Dann asks: Well done on this one folks! (Should I make final Q harder?)

VIII. Human Ecology

Re-capI. THE PHYSICAL ENVIRONMENTII. THE ORGANISM AND ITS ENVIRONMENTIII. POPULATIONSIV. SPECIES INTERACTIONSV. COMMUNITY ECOLOGYVI. ECOSYSTEM ECOLOGYVII. BIOGEOGRAPHICAL ECOLOGYVIII. HUMAN ECOLOGY

For each unit, we’ll have explicit learning objectives

upon which to focus, instead of digesting every word.

About you…

Of 15 students to respond to the pre-test:

2

10

3

Confidence in understanding of Ecology?

4 Extremely3 Very2 Somewhat1 Not at all

An eco-knowledgeable Irony…• 2 of 2 students with lowest ave. pre-test scores (<1) rated

themselves “somewhat confident” (2)• Confidence varied (1-3) for 3 students with

highest ave. scores (2.0-2.9)• No one got more than 3 of 8 pre-test questions completely

correct:– The 2 “very confident” students ea. had 1-2 questions completely

correct (4/4).– The 10 “somewhat confident” students had 0-3 completely correct– All 3 “not at all confident” students had 1-3 questions completely

correct.THUS:

Your confidence does not match your competence - yet!

More about you…

12 of 15 responding students drive to campus:

0 5 10 15 20 25 3005

10152025303540

MPG

1-way Distance Commute to Mason (miles)

MIA: 1 walker, 1 transit, & 1 out-of-region student

Human ecology meets economics:• Ave. 1-way trip to Mason (miles): 13*• Ave. MPG: 26*• Thus, gallons of gas per 2–way trip: 1

– In dollars, about (50% of subway ride?): $2.50– In greenhouse gas emissions (kg CO2e**): 9.25

Across 15 weeks x 15 students (gallons): 225– In dollars: $563– In GHG emissions (kg CO2e): 2,081

vs. est. Dist. Ed. electricity, in dollars: $14 (2.5%)– in kg CO2e** 562 (27%)

* Exact same as face-to-face 607 section in fall 2009! ** Electricity usage estimates and CO2 equivalent (CO2e) conversion factors

courtesy of Erik Tucker, BIOL/EVPP607 semester project, Summer 2009 (If you want to re-assess electricity use for our class, please let Dr. Dann know!)

SO WHAT???

Human ecology of hydrocarbons• Each driver’s semester-long commute produces on average 138.7 kg CO2e.

• Average human respiration produces about 145.6 kg CO2e per year.*

• So, for a weekly face-to-face section this semester, our car exhaust alone emits almost as much CO2e as we each exhale in an entire year!

• This exemplifies the disproportionate impact of each of our individual activities on local through global ecological scales.

• Without ecologically-conscientious decisions and actions, we collectively threaten individual organisms, populations, species, ecological communities, ecosystems and potentially our entire planet’s life support system.

(That’s a key sub-text for our semester together…)

* Source: http://www.abovetopsecret.com/forum/thread278647/pg1

So, don’t hold your breath…… because here we go!

What is ecology? Web site and syllabus preview Review of Pre-Test / Overview of Course

The rest of the Session 01 Plan:

☐Self-introductions and nature journal Q&A☐Review our learning objectives (LOs) for this session☐Focusing on LOs, read text (Smith & Smith 2008) Chapters 1-4 and Levin (1992)☐A. SCORED: Do one or more session 01 activities (ID which you want scored), explicitly citing

any external sources you use (4 pts.)☐B. Post 2-3 potential course project ideas or questions which might interest yo☐C. N/A (No exam related assignments this week.)☐D. SCORED: Submit your first annotated bibliography entry to our Zotero groups library (1

pt.)

Please do before next Monday the tasks that Iwill score!

Questions? dsklarew@gmu.edu

or skype jendann GOOD LUCK!!!

Session 01 Learning Objectives• 01-1. Distinguish environmentalism and ecology. [EoE Ch. 1] (Dr. Dann)

• 01-2. Apply the scientific method to explain an ecological curiosity or pattern observed in nature. [Ch. 1] (Everyone)

• 01-3. Characterize the spatial, temporal and organizational range and resolution of ecology's focus (Individual study)

• 01-4. Examine how ecological patterns and variability change with the scale of description. [Levin 1992] (LEAD?)

• 01-5. Discriminate how mechanisms operating at different scales of time, space and organization affect a pattern we observe in nature. [Levin 1992] (LEAD?)

• 01-6. Recognize key climatic factors affecting organisms and ecosystems, and illustrate these factors’ natural variability (periodic, episodic, aperiodic and sustained) vs. what is "normal.” [Ch. 2] (LEAD?)

• 01-7. Explain the key abiotic factors & constraints affecting diversity of patterns observed in aquatic ecosystems. [Ch. 3] (LEAD?)

• 01-8. Explain the key abiotic factors & constraints affecting diversity of patterns observed in terrestrial ecosystems. [Ch. 4 ] (LEAD?)