Student Research Reports
The unbeLEAFable effects of deciduous trees near streams in southeast Wisconsin, USA
Organization(s):Welty Environmental Center
Country:United States of America
Student(s):Oliver Devlin
Grade Level:Secondary School (grades 9-12, ages 14-18)
GLOBE Educator(s):Darien Becker
Contributors:
Report Type(s):Standard Research Report, U.S. Student Research Symposia (SRS)
Protocols:Dissolved Oxygen, Nitrates
Language(s):English
Date Submitted:05/09/2023
Leaf litter can have advantages like microhabitats for macroinvertebrates, but too much leaf litter can cause disadvantages like stream blockages. We studied the effects of different deciduous tree species near streams and what nutrients a gram of biomass is actually adding to the water in southeast Wisconsin, USA. We visited three sites in the Rock River watershed three times, testing dissolved oxygen and nitrate levels. We also made watershed tea using 450mL of water to 1g of biomass to determine the average amount of nitrates leached from leaves into water. We found that when tree density increased, the dissolved oxygen level decreased, but the nitrate level increased. It is likely that when more leaves are added to the stream in the fall, bacterial activity would increase, which would cause dissolved oxygen to decrease. Future studies could investigate other factors that are contributing to nitrate levels and what additional nutrients are being added due to those factors.