Objectives and Concepts

  • Icebreaker for the course
  • Sampling effort/species richness

Background

We frequently want to know how many species are present in a large area. It’s usually impractical or impossible to conduct an exhaustive search, so we need another approach.

One way to estimate the number of plant species is to choose manageable sub-areas and count the number of species present. It seems obvious that the larger area we survey, the more species we’ll find; this is the well-known species/area relationship.

How can we use this to our advantage if we can’t survey our entire area of interest?

A possible approach is to sample sub-areas of different size and record the total number of individuals, as well as the total number of species (present).
We can use these counts to estimate the total number of species present.

Instructions

In this exercise, you’ll be sorting and counting seeds sampled from hypothetical quadrats (a square or rectangular area) of different sizes.

You’ll also get a chance to get to know your classmates and ask any burning questions you have about the course!

1. Form groups of 5-6 students

You’ll work with your neighbors on this exercise.

Form a group of 5-6 of your neighbors and create a group using the group self-selection tool in Moodle. I’ll walk through how to do this in class.

Each group will get several bags of seeds. Each bag contains all the seeds found in a quadrat.

2. Sort and count seeds

Sort the seeds from one bag by species.

Many seeds look similar and we’re not all plant identification experts!

  • Do your best to sort seeds by species.
  • Don’t worry if you don’t get it exactly right.
  • It’s not necessary to actually identify the plant species from the seeds; the important thing is to group like seeds together.

Once you’ve sorted the seeds into species, count the total number of species you found.

Finally, count all of the seeds in your sample (of all species).

3. Record the data

For each bag, record:

  • The quadrat ID code
  • The total number of seeds
  • The total number of species

It’s not necessary to keep track of the counts of seeds within a species, we’re only interested in the total species count.

You should use the empty data sheet (rarefaction_data_sheet.csv) to record your counts. You can find a link to this data sheet in the course data files section in the Course Materials portion of the course GitHub site.

4. Submit your data sheet in Moodle

Once you’ve completed sorting and counting all of your bags of seeds, one group member will submit your data sheet in Moodle.

5. Reply to the following questions in Moodle.

In addition to uploading the data file, your group will will answer the following questions in the text input field:

  • Why are you taking this course?
  • What do you hope to learn in this course?
  • Provide at least one burning question you have about the course or course materials.
  • Optional: is there anything fun, funny, or interesting you’d like to share?