To compare methods for bottomland hardwood reforestation on marginal farmlands in the Mississippi Alluvial Valley, four afforestation treatments (natural colonization, sown oak acorns, planted oak seedlings, cottonwood–oak interplant) were established in 1995 on former soybean cropland. Natural, sown, and planted-oak plots were not managed after establishment. Interplant plots received intensive management including two seasons of weed-control disking between planted cottonwoods, after which oaks were interplanted. Previous work found that forest canopy development was accelerated by interplanting; however, the best methods for establishing trees could have different effects on forest community diversity. Multi-year data on understory plant composition were analyzed to determine if less intensive methods promoted greater diversity. Ground-layer vegetation was sampled annually from 1996 to 1998, and again in 2006. Only total biomass was affected by afforestation technique, with the greatest declines in the interplant treatment. Changes in all species composition measures were a function of successional time. Although diversity did not vary substantially with reforestation method, lack of hydrologic restoration favored an understory flora more typical of moist old-fields than natural floodplain forests.
De Steven, Diane; Schweitzer, Callie J.; Hughes, Steven C.; Stanturf, John A. 2015. Afforesting agricultural lands in the Mississippi Alluvial Valley (USA): effects of silvicultural methods on understory plant diversity. In Proceedings of the 17th biennial southern silvicultural research conference. e Gen. Tech. Rep. SRS 203. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 7 p.