Welcome to
Principles of Ecology

What questions come to your mind?

How many bats live in this group?

Course Introduction

About me

Quantitative plant ecologist and educator

Research focus: How are the above-ground dynamics of plant communities affected by below-ground microorganisms?

How to call me: Dr. Kandlikar (like “candy car”, but “candly-car”), or Dr. G, or Dr. K, or Gaurav

Photo by Gaurav, of Tejon Ranch in southern California

Photo by Gaurav, of a forest canopy in south India

Photo by Gaurav, of lab members in a longleaf pine savanna in Louisiana

Approaches to ecology

Find out more at gklab.org:

I want to get to know you!

• Please fill out the “Who’s in class” survey on Moodle!

• What does “Ecology” mean to you?

What is Ecology?

Ecology as a discipline is motivated by human efforts to
describe, understand, predict, and modify nature.

Contemporary ecology research aims to understand
  the factors that shape where organisms live,
  how their abundances change over time,
  how interactions shape communities and ecosystems,
  and how these are affected by global environmental change.

This course will introduce you to the questions that motivate the field of ecology, the approaches that ecologists take, and the implications of ecological research for societal challenges.

How many bats live in this group?

How many bats live in this group?

Why is this simple question not very simple to answer?

Some complicating factors:

• Our brains are bad at processing big (or small) numbers
• Population size changes over time – so, when do we want to know?
• The bats don’t exist in a vacuum – how do interactions (with other organisms, with human decisions, etc.) shape this population?

Photo by Matej Spulak on Unsplash

Common themes in ecology

• Ecological systems are dynamic, meaning that their properties can change over time.
• Ecological systems are structured by feedacks, meaning that the dynamics of one component often affects others.
• Understanding ecological systems requires us to confront uncertainty, which can arise for various reasons.
• The dynamics and wellbeing of ecological systems are tightly intertwined with the wellbeing of human societies.

Photo by Matej Spulak on Unsplash

Over the semester, you will develop skills to:

• Describe how the field of ecology tackles complexity
• Explain how mathematical thinking helps generate
  ecological insights
• Interpret figures and results from published ecological literature
• Discuss the role of ecology in addressing major societal challenges.

Photo by Matej Spulak on Unsplash

Over the semester, you will develop skills to:

• Describe how the field of ecology tackles complexity
• Explain how mathematical thinking helps generate ecological insights
• Interpret figures and results from published ecological literature
• Discuss the role of ecology in addressing major societal challenges.

How many bats live in this group?

• Mark-Recapture as a method to estimate of population size:

1. Capture and mark (tag) some number of individuals
2. Release tagged individuals and allow the population to re-equilibrate
3. Once population is settled (e.g. in the case of bats - on a different night), capture some number of individuals
4. The proportion of individuals that are marked in your second sample can give you a good estimate of the total population size

How many bats live in this group?

• Mark-Recapture as a method to estimate of population size:

• \(N_{Marked}\): number of individuals marked in first sample

• \(N_{Captured}\): number of individuals captured in second sample

• \(N_{Captured,\ Marked}\): number of individuals in the second sample that are marked

• \(N_{Total,\ Estimated}\): estimate of total population size

• \[N_{Total,\ Estimated} = \frac{N_{Marked}*N_{Captured}}{N_{Captured,\ Marked}}\]

Worked example

• On your first sampling day, you mark 200 bats with a metallic tag (\(N_{Marked} = 200\))

• You return to the bridge next week, and capture 1500 bats (\(N_{Captured} = 1500\))

• Of the 1500, only 17 bear the metallic tag mark (\(N_{Captured,\ Marked} = 17\))

• Intuition: Since you marked 200 bats initially and only recaptured 17 in a large sample of 1500, you were only able to mark a small fraction of the bats!

• \[N_{Total,\ Estimated} = \frac{N_{Marked}*N_{Captured}}{N_{Captured,\ Marked}} = \frac{200*1500}{17} \approx 17647 \mathrm{\ bats}\]

Principles of Ecology

Course structure
What are we here to learn?

Note about slides

You can download the slides as a PDF:

• Navigate to the slides webpage
• click the e button on your keyboard
• click ctrl+p to “print” the slides as a PDF file.

What is Ecology?

• Ecology as a discipline is motivated by human efforts to
  describe, understand, predict, and modify nature.

• Contemporary ecology research aims to understand
    the factors that shape where organisms live,
    how their abundances change over time,
    how interactions shape communities and ecosystems,
    and how these are affected by global environmental change.

• This course will introduce you to the questions that motivate the field of ecology, the approaches that ecologists take, and the implications of ecological research for societal challenges.

Photo by Matej Spulak on Unsplash

Common themes in ecology

• Ecological systems are dynamic, meaning that their properties can change over time.
• Ecological systems are structured by feedacks, meaning that the dynamics of one component often affects others.
• Understanding ecological systems requires us to confront uncertainty, which can arise for various reasons.
• The dynamics and wellbeing of ecological systems are tightly intertwined with the wellbeing of human societies.

Photo by Matej Spulak on Unsplash

Over the semester, you will develop skills to:

• Describe how the field of ecology tackles complexity
• Explain how mathematical thinking helps generate
  ecological insights
• Interpret figures and results from published ecological literature
• Discuss the role of ecology in addressing major societal challenges.

Course structure
What are the logistics of the course?

This course will be administered through Moodle and
https://ecology.gklab.org.

• Show calendar on Syllabus page
• Highlight readings
• As ecologists we think a lot about the history shaping the places we study – for example why is a forest the way it is, or an abandoned farm the way it is. And in that spirit I also want us to acknowledge the history of the land we’re on right now, which has a long indigenous history that is often erased, and that much of baton rouge and the ecological settings around us were built on the labor of enslaved people. So as studnets of ecology it’s important to remember how the history shapes our present systems around us.

Course rhythm

• In-class sessions will be a mix of lecture, hands-on activities, and discussions.
• You are responsible for engaging with the Readings and other Resources made available to you on Moodle before coming to class.
• Most submissions will be due on Sunday nights at 11.59pm via Moodle; in some weeks, you will be asked to bring in copies of your submission to class (hard copy or digital copy on laptop/tablet is fine)

Evaluation and grading

Grading philosophy

• As an instructor, my goal for this class is for each of you to achieve the core learning objectives for our course.
• A huge body of research by colleagues in education shows that grades are a poor motivator for learning, and a poor predictor of future success.
• This shapes how the course is structured:
  • No high-stakes, “one size fits all” exams
  • Low-stakes assignments throughout the semester
  • Considerable opportunity for each student to earn the grade they aspire to

Evaluation and grading

Your grade in this class will reflect your performance in three areas:

• Self reflections (biweekly)
• Biweekly activities
  mostly completed in-class
  
• Semester project
  more on this next week

Self reflections

• The goal is to help you take a step back and reflect more generally on your growth as a scientist over the semester
• I encourage you to think about how the material we are learning in-class relates (or doesn’t relate) to your life more generally
• I will include a list of potential reflection topics, but I encourage you to think broadly about what matters to you.
• First self reflection due next Sunday night (Sept 7), and then every other Sunday night.

Why self reflections?

• Learning happens not only through doing, but by reflecting on what we are doing (metacognition)

Dr. Saundra McGuire - Director Emerita of LSU Center for Academic Success

Why self reflections?

• Make space for deliberately thinking about how lessons from basic ecology apply to our increasingly complex and “weird” environment

• Reflect on what topics you find especially engaging and/or especially challenging

Evaluations of self reflections

• You are in charge of re-reading and evaluating your own self-reflections
• On every “off” week, you will be asked to return the previous week’s self reflection, reread your submission, and assign yourself a grade out of 10 points.
• Also explain why you are giving yourself this grade (2-3 sentences).

Evaluations of self reflections

Schematic for grading self-reflections

Category	Grade and justification	Grade and justification	Grade and justification
Response addresses relevant themes in the prompt, or new themes identified by the student	No submission: 0 points	Response is answering only a narrow subset of the potential ideas that could have been explored in the reflection, or addresses numerous themes but only at surface-level: 4 points	Response addresses various themes, and does so in depth: 7 points
Response reflects the students’ own thoughts and written in their own words	No submission: 0 points	Responses quotes heavily on material not generated by the student: 1 point	Response fully reflects the student’s own thinking and words: 3 points

Self reflections

Themes for first self reflection:

Reflections on ecology

• What does the word “ecology” mean to you? How do you think it is relevant to your life?
• What is your relationship with “nature”? In your mind, how can humans have a healthy relationship with nature?
• Is there a particular place that comes to your mind when you think of “being out in nature”? What kinds of characteristics define that space for you?

Reflections on the semester

• What are some things you are excited about for this semester? What are some things you are nervous about?
• Looking at your semester schedule, are there going to be particular weeks that are looking busier (multiple exams/assignments due, etc.)? If so, how are you planning to prepare for these weeks?
• Two weeks into the semester, how do you see this course relating to the other courses you are taking, or to other activities in your life outside of this class?

Evaluation of self reflections

• Over the semester, you will have the opportunity to submit seven self reflections, each worth 10 points
• Only six of these will be counted towards the final grade, meaning that you have one “free pass”.
• Each self reflection comes with a 24-hour grace period for submission.
• I will read self-reflections to get a sense of how the class is going.

In-class activities

• Approximately every other week starting in Week 3, you will be asked to complete an activity related to the material covered in the past two weeks
• The exact format will vary across the semester (e.g. reading primary ecological literature in some weeks; completing quantitative worksheet in another, etc.)
• These will be completed in-class, usually on Wednesdays or Fridays.

Evaluation of in-class activities

• Graded by Dr. Kandlikar, following an exemplar that will be made available on Moodle.
• You will have an opportunity to earn back any lost points by completing an alternative version of the activity.
• There will be 7 biweekly activities assigned through the semester, each worth 10 points
• Only six of these will be counted towards the final grade, meaning that you have one “free pass”.

Weekly readings and other resources

• Each week, I will post resources on the course website and moodle, which I expect you to complete before coming to class
• These will include a range of formats, including textbook chapters, primary ecological literature, podcast episodes, and material from the news.

This week’s resource

Co-Working sessions

• Each week, I will be available for two co-working sessions
• Please indicate your time preferences on the Moodle poll.
• Available for discussions regarding course content, professional development, etc.

Course structure
How is the material organized?

Levels of ecological organization

• Organism
• Population
• Community
• Landscape
• Ecosystem

Levels of ecological organization

• Organism
• Population
• Community
• Landscape
• Ecosystem

Photo by Jeffrey Hamilton on Unsplash

Population ecology:

• How do individuals of a given species (“conspecific individuals”) interact with one another?

• Does the nature of interactions vary across environments?

• How do these interactions affect population dynamics?

• Under what conditions do populations grow, shrink, or stabilize?

Photo by Mason Field on Unsplash

Community ecology:

• How do individuals of different species (“heterospecific individuals”) interact with one another?

• Does the nature of interactions vary across environments?

• Why are some species able to coexist with one another over long timescales, while other sets of species cannot persist with one another?

• What regulates the dynamics of species interactions across trophic levels (e.g. predator–prey interactions)?

Photo by Courtney Kenady on Unsplash

Landscape ecology:

• What are the patterns of diversity across ecological gradients?

• What processes give rise to variation in biodiversity across space and time?

• How does human land use change restructure ecological communities?

Latitudinal patterns of biodiversity

Diversity of vertebrate species, from Mannion et al. 2014

Diversity of amphibian species, from Anton-Pardo, 2019

Diversity of mammal species, from Davies et al. 2008

Photo by NASA on NASA Earth Observatory

Ecosystems ecology:

• How do energy and nutrients flow across ecosystems, for example at the scale of entire continents?

• What are the consequences of disruptions to ecosystems cycles?

• How do feedback loops shape the dynamics of ecosystems?

Direct link

Photo by Matej Spulak on Unsplash

Common themes at all scales

• Ecological systems are dynamic, meaning that their properties can change over time.
• Ecological systems are structured by feedacks, meaning that the dynamics of one component often affects others.
• Understanding ecological systems requires us to confront uncertainty, which can arise for various reasons.
• The dynamics and wellbeing of ecological systems are tightly intertwined with the wellbeing of human societies.

Population ecology

What defines a population?

• Individuals of the same species living together

• Individuals interact with one-another
  e.g. mating, facilitating, competing

How does a population grow or shrink?

• Birth (+)
• Death (-)
• Immigration (individuals coming in, +)
• Emigration (individuals leaving, -)

If we know a few of these rates, how can we predict population size time in the future?

How does a population grow or shrink?

• Consider a ‘closed’ population
  no movement in or out of a population:
  immigration = emigration = 0

• Change in population size (\(N\)) only driven by births and deaths

• There is some per-capita birth rate (\(b\)), and some per-capita death rate (\(d\))

• Total number of births = \(b*N\)
  Total number of deaths = \(d*N\)

Estimating population sizes