So what do we do in Ecology Lab? What’s it all about? Well, it’s about a few key processes. First, students learn how to gather and then statistically analyze data. Next, they learn how to convey these findings using proper formatting techniques often seen in peer reviewed journal articles. Lastly they develop and analyze their own experiments.
Let’s face it, many scientific texts are often times boring. But to learn the skill set necessary for what we are passionate about we grit our teeth and work through them. Procedural texts are even more so as is exemplified by many sampling manuals. To counteract this I’ve written a custom field manual for students at UNC Charlotte which includes classical studies often conducted in Ecology Lab to more novel sections such as a Chi-rash course in statistics and an exercise in article formatting review called “Take Notice!” where students follow a hummingbird through the text. Many ecology lab texts use beads or small models to simulate ecological studies. I believe field experience is invaluable and in my ecology class nearly 100 percent is student survey or study driven. A complete copy of my Ecology Field Manual is available upon request. Just shoot me an email!
Drawing by Brianna Mazzio
Gathering data:
Sampling Methods
Many methods of sampling are used in the field. Students learn to use a variety of measurement tools including Vernier calipers, tree calipers, colorimeters, turbidometers, dissolved oxygen pens, soil corers, and plankton nets – just to name a few. Students learn that conducting studies in the field is hard work when they realize that the temperature outside is 34 degrees, they’ll be sampling plankton, and their waders leak. Other times, they find their true strength when they’re able to somehow bend steel soil corers through twisting alone:
Lastly, often times before or after measurements are taken it is necessary to identify species.
Species identification
All field sampling requires at least some expertise in identification of the local flora and fauna. Often times it is assumed that students will be familiar with local species. However, this is usually not the case. So how to we gather data when it’s necessary to know familiar species and yet there is a lack of familiarity? Dichotomy keys are the answer. By teaching students a few important characteristics and allowing them to make decisions and narrow down there options. Many dichotomy keys exist in the literature, however, many of them contain an excess of information.
For example, when identifying tree species often times keys exist for the entire east coast. To increase efficiency in a class with limited time I’ve made custom dichotomy keys for many activities that include only local species likely found in the UNCC Ecological Reserve where many of our studies are conducted. Here is an example of a dichotomy key I created which includes the most popular species found in the reserve:
I’m not the best at using Microsoft paint but you can tell that all you need to know in a few basic characteristics of leaves such as arrangement, edge, and general shape. To accompany this I’ve made a custom alphabetized tree guide on trees in the reserve so that a decision can be quickly made as to what species of tree is being looked at. This also accelerates the process of learning species identification. This methodology is used throughout studies in the lab to maximize data collection whether it be in relation to trees, plankton, macroinvertebrates, or microarthropods.
Analyzing Data
Index Calculation
In ecological field studies it is often necessary to calculate indices. Some of the most popular indices we use are the Importance Value 300 and the Shannon Diversity Index (SDI). Importance values are generated to assess how prevalent and dominant a particular species of tree is in a certain area. The calculation of this index starts with the measuring of the diameter at breast height of each tree in a specified area. For the methods on how to calculate the IV300 Click here. For a sample Excel worksheet shoot me an email!
Another popular ecological index is the Shannon Diversity Index (SDI). It is often used to estimate diversity of a group of organisms whether it be plankton or soil microarthropods in a particular area. In my class not only do we analyze abundance of organisms but we use this index to estimate diversity as well. The SDI is easier to calculate than the IV300. The methods for doing so are here.
Statistical analysis
Once we gather data for our studies we analyze it statistically. Many programs for doing so exist but there are great programs available online. In ecology we use the public Vassarstats program. It’s free and accessible from anywhere online!
Final Product
Articles
Students then use all of this information to write articles similar in formatting to those submitted in peer reviewed journals. They include an introduction that uses peer reviewed sources, methods that are repeatable by any outside reader be it professional or amateur, clear and concise results, and then interpretation and deduction based on their findings.
Student Led Experiments
Many studies in field ecology and ecology laboratory are classical in nature. They are tried and true studies that enable learning of both practical skills and proper analysis. These often include the following: studies in relation to forest ecology and estimating species importance, water sampling (in either stream or pond/lake scenarios) and correlation to water quality characteristics, and soil sampling that also aims to study the effects of species on soil characteristics and vice versa. These studies are indispensable in nature.
However, it is also incredibly important to harness students’ ability to design and evaluate their own studies. By the end of each semester I have my students do just this. Many of them have developed extremely unique studies and methods of sampling. For example, analyzing tardigrade abundance in differing elevations along a slope and using animal sightings to estimate population density differences between urban and rural habitats. If you’d like some new ideas for your own field studies send me an email and I’d be happy to share some of these ideas!
Tardigrades
Also known as water bears, they almost became the poster child for biology years ago. These guys can survive in outer space! Some people even believe the arrived on earth from a meteor!
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