Abstract |
The changing ecosystem of the Mentor Marsh, in northeastern Ohio, is an important topic of discussion among ecologists. Over decades, the diverse native swamp forest in this marsh has declined and has been replaced by a single species, the common reed Phragmites australis, that is salt-tolerant. Many experts believe this is due to the large amount of road salt dumped adjacent to the marsh. Using a greenhouse experiment, we tested the effect of road salt on five dominant swamp-forest species that are representative of those in decline at the Mentor Marsh. We hypothesized that trees exposed to high levels of salt would be less healthy than those exposed to low levels of salt. Experimentally, this can be tested by comparing the growth rates and levels of nutrients, specifically nitrogen and nonstructural carbohydrates, in the plants. Surprisingly, we found that there was no significant difference in the amount of nutrients between trees exposed to high salinity and trees exposed to low salinity. In conclusion, the increasing amount of road salt at the Mentor Marsh alone has not influenced the ecology of the marsh. However, further research is being conducted to determine if the combination of road salt and agricultural run-off has negative effects on the tree species.
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Modified Abstract |
In northeastern Ohio, the Mentor Marsh has experienced a decline in native swamp tree species while the salt-tolerant common reed species, Phragmites australis, has started to take over. Experts believe that the changing ecosystem may be due to a large amount of road salt dumped adjacent to the marsh. Using a greenhouse experiment, we tested the effect of road salt on five swamp-forest tree species, representative of those in decline at the Mentor Marsh. We hypothesized that trees exposed to higher levels of salt would be less healthy than those exposed to lower levels of salt. By comparing the growth rates and nutrient levels of the plants, we found that there was no significant difference in nutrients between the trees with various salt treatments.
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