Habitat Assessment and Community Structure
You can think of this investigation as “part 2” of the abiotic investigation you conducted in lab module 1. Whereas you looked at the physical environment of your research area before, now we will turn our attention to the biological aspects of the environment. Who or what is living there? Why? What isn’t living there? Why not? And why are there so many questions in a row?
So… you will be (ideally) returning to the same research area you used before. (If for some reason you cannot return there, that is all right. You will need to re-measure a research site if that is the case.) Once there, we are going to gather data that tells us more about the biological interactions occurring at this site.
As before, please make sure you understand what you are doing and why before you begin to carry out any of the tests. I would strongly encourage you to read through the lab below several times before you actually conduct the assessment in the field. If you have anyone who can help you with this investigation, I would invite them to come along. They can help you record data in the field and move equipment and provide an extra set of eyes as you look for living things.
Before you go into the field:
Make sure you plan to follow all safety guidelines as outlined in the Lab Orientation.
Read through this entire investigation BEFORE you go out in the field, so you can ask questions about any procedural issues.
You may find an old, sturdy laundry basket or a plastic storage tub is still a good idea. However, you can actually empty everything out of your lab kit box and use it to carry stuff and as part of one of your experiments.
Check the weather forecast for a good day to be outside.
Obtain the following items from your lab kit (those marked with a * need to go into the field with you):
Plastic magnifier
Your empty lab kit box (yep, take everything out of it!) If you do not want to use your box (it will get some holes in it, then you need to have a comparable box that you can use for your Berlese funnel experiment.) Other things that work well are an old coffee can or a gallon milk jug with the top 6” cut off. All of these will need to have a bunch of holes punched in the bottom so that the container can be used as a sifter for a leaf litter sample.
You must be prepared to supply the following items:
small shovel
old pillow case (an old t-shirt, with the arm and head holes tied up, works too).
measuring tape (20-30’)
paper, clip board to take notes
large screw driver
Items you will need once you get back from the field:
desk lamp
plastic beaker
rubbing alcohol
the round hardware cloth found in the bottom of the box
funnel (I recommend the large, 2$-ish funnels from Walmart that are found in the auto department)
YOU WILL NEED A REASONABLY SUNNY DAY (AGAIN) TO CONDUCT THIS ASSESSMENT! If you cannot see shadows, you need to wait for another day.
Return to your search site, or other very good site. It should be as before: ideally the area will be a mixed community that would include small and large trees, some ground vegetation, leaf litter and looks biologically interesting. Avoid areas that look very much the same throughout (like a big grassy area).
Once you are ready to begin, organize your materials so you know where everything is; once you start, you do not want to be looking for items.
Document the area
Record the date and time of your study. Also comment on the weather conditions in general- temperature, light, wind, etc.
Document the living components
Now, slowly and carefully walk through your entire research area and look AND LISTEN for animal signs. Sometimes you have to look very, very closely. I recommend walking a grid pattern so you don’t miss anything. Don’t be afraid to get down close to nature! Use your magnifier!
What are you looking for? Start by