If you’re at Ferry Beach and you start at the ocean, then walk inland, first you pass up over a sand dune covered with dune grass. Once past the primary dune, you pass over secondary dunes, with low-growing pines and various grasses and forbs growing in sandy soil. From the secondary dune, you pass down into lower ground, generally swampy and poorly drained and sometimes with open water, generally wooded with mixed hardwoods and conifers. If you keep walking inland, the ground gradually gets higher and drier, but the slope is gradual enough that where there are low places you’ll often find swampy areas.
Below is the sketch I made to show the kids in the ecology class how this all looks. And then we walked from the ocean inland, so that we could see it in real life.