| Investigation Question |
Relevant Observations |
Inference (Possible Answer) |
|---|---|---|
| 1. Where does upland end and the wetland begin? | The upper limits of wetlands are usually marked by changes in vegetation and ground moisture. In most state park marshes, there is a clear transition from trees and shrubs to tall grass-like plants, such as cattails, sedges, rushes or cord gasses. The vegetation changes are less clearly defined on the upper edge of swamps, which are forested. There, soil moisture changes might be the best clue. Unless it has rained very recently or there has been a prolonged dry spell, wetland soil will be noticeably wetter, often squishy or even inundated. | |
| 2. Does the wetland have a lower limit? If so, what is it? | The lower limit will be the adjacent waterway. Not every wetland, such as seashore's cypress swamps, will have a visible lower limit but may seem bound on all sides by uplands or stretch on indefinitely. | |
| 3. What seems to be the conditions necessary for a wetland to thrive? | By finding the upper and lower limits to wetland, students can infer the conditions required for wetlands (i.e. an abundance of water but not deep water or swiftly moving water as by current or waves). | |
| 4. Where might the wetland be changing or being destroyed? | Over geologic time, wetlands are very dynamic places, undergoing rapid change. Trapped sediments can fill wetlands. Rising sea level can flood them and erosion can wash them away. Only erosion may be readily apparent. This is best observed along the lower limits of wetlands bordering swift tidal creeks or open bays or rivers. | |
| 5. What characteristics of the wetland indicate that it can catch and hold sediment such as eroded soil? | Encourage students to observe the abundance of plant stems and leaves and to think of them as filters of water washing off the uplands or being brought in with the tides. | |
| 6. What features of the wetland might help remove excess nutrients and toxins from the water? | (This question might best be reserved for advanced students.) Basically nutrient and toxin removal occurs in two ways. Many nutrients and toxins will be bound to the sediments trapped in the wetland. Others will be assimilated directly into plant tissues. Remind students that nutrients in the water can be taken up in the water can be taken up as fertilizer by the lush wetland plants. | |
| 7. What indicates that the wetland might be part of the aquatic or estuarine food chain? | Encourage students to observe the abundance of dead plant matter (detritus) in the wetland. If necessary, point out that most of the detritus along the waterway edge is likely to be washed into the estuary. From this, students might deduce the importance of wetland plants as a major component of estuarine food chains. | |
| 8. What indicates that the wetland is important to land and water animals? | Wildlife benefits can be inferred by observing animals present, such as fiddler crabs, turtles, snakes, insects and birds, and by finding their signs, such as droppings, tracks and nests. Other wildlife values can be identified by noting seeds and fruits that might be food items. | |
| 9. How might the marsh protect adjacent higher ground from some effects of storms and flooding? | Shoreline erosion protection can be inferred by observing eroded areas along the shoreline where marshes are absent. Examination of the peatlike soil may lead to inferences about its role in absorbing water and buffering flooding effects. |