Kenton Sena

Evaluating the Use of Tree Shelters for Direct Seeding of Castanea on a Surface Mine in Appalachia

American chestnut (Castanea dentata), once a primary constituent of the eastern hardwood forest ecosystem, was nearly extirpated from the forest canopy by the accidental introduction of chestnut blight (Cryphonectria parasitica). An intensive breeding program has sought to breed blight resistance from Chinese chestnut into American chestnuts, while maintaining as much of the desirable American chestnut phenotypes as possible. Previous studies suggest that these blight resistant American chestnuts, termed “restoration chestnuts”, are capable of thriving on reclaimed surface mines. We direct seeded pure Chinese, pure American, and three backcross lines into brown sandstone minesoil on a mine site in Pike County, KY. To investigate the effects of tree sheltering on survival and growth, we installed tree shelters on half the plots, and left the rest of the plots unsheltered. Results indicated that shelters were highly effective at reducing initial mortality. In addition, while pure Chinese chestnut survival was highest, the three backcross lines have also survived well on this site. Our study demonstrates that American, Chinese, and backcrossed chestnuts can survive through five growing seasons on reclaimed surface mines with the use of tree shelters.

Long-Term Response of Stream and Riparian Restoration at Wilson Creek, Kentucky USA

Degradation, impoundment, and channelization of streams is a global problem. Although stream restoration projects have increased in recent years, post-restoration, long-term monitoring is rare. In 2003, a channelized section of Wilson Creek (Nelson Co., Kentucky) was restored by creating a meandering channel, re-connecting the channel to its floodplain, and planting native riparian species: giant cane and bottomland forest species. Our main objective was to conduct a ten-year post-restoration assessment to determine long-term restoration outcomes of channel water quality, growth of trees planted in the riparian area, and soil development. Water quality, soil, and tree data collected in 2013–2015 was compared to 2004–2006 data. Quality of water parameters changed over time: sulfate, magnesium, calcium, potassium, alkalinity, pH, iron, and temperature decreased, whereas dissolved oxygen increased. Overall, soil pH, extractable ammonium, extractable nitrate, total carbon (TC), and total nitrogen (TN) increased over time. Effects were observed in restored riparian areas for pH, extractable ammonium, and TC; while TC and TN exhibited depth-dependent interactions. The carbon-nitrogen ratio in these soils significantly decreased over time for the reference sites, and the treatments recovered to near reference level. Platanus occidentalis (American sycamore) and Fraxinus pennsylvanica (green ash) individuals had higher survival (80% and 79%, respectively) than individuals of Quercus palustris (pin oak; 22%). Shelter and herbicide treatments had no effect on tree survival or height growth; however, height growth varied by species. Platanus occidentalis exhibited a greater than five-fold increase, F. pennsylvanica slightly increased, and Q. palustris decreased in height growth. Overall, water and soil quality improved over time at the restoration site, while tree survival and height growth exhibited species-specific outcomes.

influence of Tree shelters and Weed Mats on Growth and Survival of Backcrossed Chestnut Seedlings on Legacy Minelands in Eastern Kentucky

Surface mining for coal has contributed to wide-scale deforestation and forest fragmentation in the eastern United States. Over the last thirty years, mine reclamation practices involving heavy compaction and introduction of nonnative vegetation have produced large areas of reclaimed land, which exist in a state of arrested natural succession, termed legacy sites. These sites were reclaimed to standards of the day, which usually involved compaction of the surface material and seeding an aggressive ground cover to control erosion. These sites are typically dominated by non-native grasses and legumes (e.g., tall fescue and lespedeza) and are often colonized by invasive and undesirable woody shrubs (e.g., autumn olive). Interest in restoring native hardwood forest on these sites has grown over the past decade. The development of techniques to mitigate the unfavorable soil and vegetative conditions on these legacy sites is essential to forest restoration in Appalachia. In addition to representing a good opportunity for native hardwood reforestation in Appalachia, legacy sites present a unique opportunity to reintroduce improved blight resistant American chestnut across much of its native range. This study investigated the impacts of tree shelters and weed mats on the growth and survival of planted American chestnuts on legacy mine sites in eastern Kentucky. Shelters significantly reduced browse pressure from deer and therefore improved growth and survival in most instances. Weed mats did not significantly influence tree growth or survival and were unpredictable in their effect on herbaceous biomass. This study demonstrates that properly prepared legacy mine sites can support the establishment of improved American chestnuts.

Converting Abandoned Hayfield to Switchgrass Increases Small Mammal Relative Abundance

Abstract Switchgrass (Panicum virgatum L.) has been identified as a versatile and broadly useful bioenergy feedstock, with potential for use in coal-fired power plants as well as ethanol production. However, in order for switchgrass use to markedly influence energy production, conversion to this grass species must occur at a large scale. Little is known about the potential ecological consequences of widescale conversion of land to switchgrass. This study was conducted to identify potential effects of switchgrass planting on small mammal populations. An abandoned perennial cool season grass hayfield in central Kentucky was subdivided into two fields; one field was planted with switchgrass and the control field was maintained as an unmanaged hayfield. Small mammal relative abundance was quantified using a tracking method through the third year following switchgrass planting. Small mammal relative abundance was greater in the switchgrass field than in the control field. Vegetative community analysis showed the control field was dominated by tall fescue, suggesting that thickness of stand and/or fescue toxicity may have been a factor in reduced small mammal abundance. These data suggest that conversion of abandoned old fields to switchgrass will not have a negative effect on small mammal populations. Further research should target potential mechanisms for this variation in small mammal relative abundance, as well as other species in the community which may be affected by conversion to switchgrass.