Hardwood establishment on compacted mine tailings after subsoiling and native ground cover seeding

Abstract

Since 1930, approximately 2.5 million ha have been disturbed by surface mining in theUnited States. On many mine sites reclaimed since the Surface Mining Control and Reclamation Act of 1977 bothcompacted soils and aggressive nonnative plant communities are common, and sites may require remediationin order to establish forests (Burger and others 2013). Planted grasses and legumes can compete strongly withplanted tree seedlings, and there is a need to identify herbaceous species that are compatible with reforestation(Franklin and others 2012). Browse damage to planted tree seedlings can be extensive in the Southeast and mayalso be influenced by the composition of herbaceous vegetation.An experiment was established to test for tree growth and establishment in four vegetation treatments on 8 haof an old reclaimed mine site in northeastern Tennessee. Soil compaction was first relieved by subsoiling to adepth of 1 m. Bare-root 1-0 seedlings of 15 tree and shrub species were planted on a 2.4-m by 2.4-m spacingin late winter of 2015 (table 1). The herbaceous treatments were applied immediately following tree planting: 1)herbaceous control using an application of glyphosate herbicide in a 0.5-m radius around each planted tree inlate spring, 2) seeding with a mixture of herbaceous annuals and perennials preferred by deer, 3) seeding witha mixture of herbaceous annuals and perennials that are not preferred by deer, and 4) untreated control. Pretreatmentcomposition of vegetation was surveyed in August of 2014 and was dominated by nonnatives witha total herbaceous cover of 93 percent. The composition of herbaceous vegetation was monitored in May andAugust of 2015.Herbaceous cover was reduced to 66 percent across all treatments in May, and by August both seeded andcontrol treatments had returned to initial levels (82–93 percent), while herbicide treatments still had significantlyreduced cover (78 percent). Subsoiling did not reduce the frequency or dominance of lespedeza (Lespedezacuneata), but did reduce the presence of tall fescue (Festuca arundinacea) from 52 percent of plots to 13 percentand its dominance from to 34 to 4 percent of plots. At the end of the first growing season, the percentage of treeand shrub seedlings with obvious signs of browse damage varied from 9–64 percent (table 1). Binary logisticregression was used to test the effect of species and treatment on browse damage and survival. Seedingherbaceous species attractive to deer decreased the likelihood of deer browsing damage to planted seedlings,with 33 percent of seedlings being browsed. The highest rates of browse were seen in the treatment with lowpalatability herbaceous species seeded (45 percent) and herbicide treatment (43 percent), while the controltreatment was intermediate with 37 percent of seedlings browsed. Survival and browse damage of trees, butnot shrubs, was assessed in February of 2017, at which time survival averaged 38 percent and browse damagewas similar to that seen in 2015. The planting of deer-preferred herbaceous species may be a viable strategy toreduce the incidence of browse damage to tree seedlings on young reforestation sites in this region.

Parent Publication

• Proceedings of the 19th biennial southern silvicultural research conference

Citation

Franklin, Jennifer A.; Aldrovandi, Matthew. 2018. Hardwood establishment on compacted mine tailings after subsoiling and native ground cover seeding. In Kirschman, Julia E., comp 2018.Proceedings of the 19th biennial southern silvicultural research conference.e-General Technical  Report SRS- 234.Asheville, NC: U.S.Department of Agriculture Forest Service, Southern Research Station.444 p (pages 127-128) 2 p.