You’re now crossing a boundary between forest and wetland habitats.  This transition zone is called an ECOTONE.  Ecotones can be as abrupt as an actual line, so gradual as to be hardly noticed, or anything in between.  The habitat you are now entering is called OLD-FIELD MEADOW.   This is an open grassland community that is, in some respects, human-made.  An old-field is just that – an old-field – a meadow that was previously pasture, or cropland, or mowed, and has since been abandoned and allowed to grow up with whatever plants happen along.  Right now, this includes only two or three dozen species at best, and most of them are colonizing species that grow fast, produce millions of seeds, and spread rapidly, such as goldenrod (Solidago spp.), thistles (Cirsium spp.), fleabane (Erigeron philadelphicus), and sneezeweed (Helenium autumnale).   Many of them are non-native invaders: Queen Anne's Lace (Daucus carota), knapweed (Centaurea repens), and wild parsnip (Pastinaca sativa).