North Central Forest Experiment Station 2.06 HARDWOOD NOTES

Bottomland hardwood forests normally regenerate with species found in the overstory. These species reflect the timing, duration, depth of water, and nature of the sediment in past flooding. The longer water stands during the growing season and the deeper the sediment, the fewer the species that are able to survive. Flooding patterns often change over the life of a bottomland hardwood stand. If conditions moderate, more species can regenerate the site; if flooding worsens and sediment builds up, fewer species can occupy the site. There are three sources of reproduction in bottomland forests-“advanced ” under-story seedlings (seedlings already growing), stump and root sprouts from harvested trees, and new seedlings. Advance reproduction over 18 inches tall is the most dependable source of regeneration of moderately tolerant to tolerant species and the only dependable source for oak. Sprouts from the stumps of cut trees under 12 inches d.b.h. are a major source of acceptable regeneration for most species; maples, green ash, and sweetgum are the most prolific. Sweetgum is also a good root sprouter. American elm, sycamore, green ash, sweetgum, boxelder, red an