The activities are as follows:
- Teacher Guide
- Student activity, Graph Type A, Level 2
- Student activity, Graph Type B, Level 2
- Student activity, Graph Type C, Level 2
- Grading Rubric
The goopy, mucky, (sometimes stinky!) mud at the bottom of a wetland or lake is a very important part of the ecosystem. Mud is basically wet soil, but because it has different properties than soil because it is wet most of the time. Mud is usually dark brown because it contains partially decomposed plants, called organic matter. Dead organic matter tends to build up in wetlands. Organic matter decomposes more slowly under water than on land. This is because underwater microbes do not have all the oxygen they need to break it down quickly.
Under the right conditions, mud can act like fertilizer for a wetland. Nutrients, such as phosphorus, tend to build up in mud. This makes mud an important source of the phosphorus that algae and other plants need to grow. As a graduate student at Michigan State University, scientist Lauren was interested in what helped phosphorus stick to mud. She also wanted to know why phosphorus builds up more in some wetlands than others.
Although most mud is high in organic matter and high in nutrients, all mud is not created equal! The amounts of organic matter and nutrients are different from one ecosystem to the next. How quickly these materials enter or leave the mud may also change across ecosystems. Even within the same ecosystem mud can be very different from place to place. The molecules in organic matter could be a major source of phosphorus in mud. This would mean that wetlands with more organic matter would have more phosphorus.
Scientist Lauren measured organic matter and phosphorus in mud from 16 ecosystems (four lakes, five ponds, and seven wetlands). She wanted to determine if there was a relationship between the amount of organic matter and the amount of phosphorus in mud.
Featured scientist: Lauren Kinsman-Costello from Kent State University
More photos associated with this research can be found here. There is one scientific paper associated with the data in this Data Nugget. The citation and PDF of the paper is below:
Kinsman-Costello LE, J O’Brien, SK Hamilton (2014) Re-flooding a Historically Drained Wetland Leads to Rapid Sediment Phosphorus Release. Ecosystems 17:641-656