Nutritional carrying capacity for cervids following disturbance in hardwood forests

Abstract

Closed‐canopy forests dominate the landscape across much of the eastern United States and often lack a well‐developed understory, which limits nutrition available for cervids. We evaluated the influence of timber harvest combined with prescribed fire, herbicide treatment, or fire and herbicide treatment in young mixed‐hardwood forests on forage availability and nutritional carrying capacity (NCC) for elk (Cervus canadensis) and white‐tailed deer (Odocoileus virginianus) in the Cumberland Mountains, Tennessee, USA, July–August 2013–2015. We compared forage availability, NCC using a 12% and 14% crude protein nutritional constraint, and vegetation composition in untreated mature forest stands, reclaimed surface mines, and 6 timber harvest treatments (timber harvest only, with early growing‐season fire, with late growing‐season fire, with herbicide only, with herbicide and early growing‐season fire, and with herbicide and late growing‐season fire). Forage availability in treatments involving timber harvest was greater than in untreated mature forest stands and reclaimed surface mines. Forage availability estimates in treatments involving herbicide and prescribed fire were less than all other timber harvest treatments. Nutritional carrying capacity estimates at the 12% and 14% crude protein constraints were greater in timber harvest treatments and on reclaimed surface mines than in untreated mature forest stands. Herbaceous species coverage was greater and woody species coverage was less on reclaimed surface mines and in timber harvest treatments involving herbicide and prescribed fire than in all other timber harvest treatments and untreated mature forest stands. Greater coverage of herbaceous forage species in treatments involving herbicide and prescribed fire and on reclaimed surface mines compensated for reduced forage availability and resulted in NCC estimates similar to all other timber harvest treatments. Our data indicate using periodic prescribed fire and following an herbicide application with prescribed fire are effective techniques to transition young mixed‐hardwood forest communities to early successional communities and maintain increased forage availability and NCC for elk and deer. © 2018 The Wildlife Society.

Improving Coastal Plain Hardwoods for Deer and Turkeys with Canopy Reduction and Fire

“…Our results 2 years after canopy reduction and immediately following a single fire indicate that implementing these practices in Coastal Plain hardwoods can quickly result in improved understory vegetation composition and structure for deer and turkeys. Specifically, understory vegetation in our study responded similarly to what has been documented in other systems, as canopy reduction resulted in an increase in woody and semiwoody plants, and application of prescribed fire increased coverage of herbaceous plants (Masters et al 1993, Peitz et al 2001, Iglay et al 2010, Nanney et al 2018). Although we did not document a difference in deer forage biomass between FSI and FSI/Burn, we did not conduct nutrient analysis on the collected forage.…”

“…Although we did not document a difference in deer forage biomass between FSI and FSI/Burn, we did not conduct nutrient analysis on the collected forage. Forbs typically are greater quality forage plants than semiwoody or woody plants (Lashley et al 2011, Nanney et al 2018), and it is likely that nutritional carrying capacity in FSI/Burn was greater than FSI because of increased coverage of herbaceous plants.…”

“…Forest management practices that decrease canopy coverage typically increase forage for deer and enhance cover for turkeys. Reductions in canopy coverage are often achieved using various commercial timber harvest methods, and previous work has indicated availability of deer forage improves following implementation of a clearcut, shelterwood harvest, or thinning (Blair and Enghardt 1976, Ford et al 1994, Peitz et al 2001, Lashley et al 2011, Nanney et al 2018). For landowners without merchantable timber, noncommercial techniques, such as forest stand improvement (FSI), are an option to reduce canopy closure.…”

Plant Community Response and Implications for Wildlife Following Control of a Nonnative Perennial Grass

“…We divided the number of stems that had been eaten by the number of stems available on that plant to measure deer browse intensity and selectivity using the Chesson index (Chesson 1983, Shaw et al 2010). A fifteenth percentile cut‐off value was used to rank species selection because that cut‐off value closely matched field observations of deer selectivity and has been used by previous researchers (Nanney et al 2018). Species determined to be selected by deer were included in nutritional carrying capacity calculations.…”

“…We calculated estimates of nutritional carrying capacity for deer using a mixed‐diet approach with nutritional constraints according to Hobbs and Swift (1985). We used a nutritional constraint of 14% crude protein with a 2.4 kg/day intake rate to represent nutritional needs of a 50‐kg doe at peak lactation with twin fawns (National Research Council 2007, Hewitt 2011, Lashley et al 2011, Nanney et al 2018).…”