Maintenance of Non-Timber Plants at Low Heights Increased the Solar Radiation Influx and Understory Vegetation Biomass in Woodlands

Abstract

The vast coverage of woodlands in the southeast United States offers a great opportunity for grazing small ruminants. However, not much attention has been given to utilize these resources well. The objectives of the current study were to evaluate the potential of increasing the a) light influx to the woodland floor and b) understory vegetation biomass by altering the height of non-timber (non-pine) plants. The study was conducted in six woodland plots (0.4-ha each) consisting of southern pines, hardwoods, and numerous understory plant species. The non-pine plants were either left uncut (control) or cut to one of the heights from the ground: 0 m, 0.9 m, and 1.5 m (treatments) in summer 2016. Kiko wethers (8) and Katahdin rams (5-6) were rotationally stocked in the study plots (3 plots per animal species) during 2017 and 2018. Photosynthetically active radiation (PAR) data were collected before and after stocking animals and the understory vegetation biomass samples were collected before stocking animals in the study plots. The PAR influx in areas that received cutting treatments increased by 413-1723% when measured before grazing, and by 543-2223% when measured after grazing compared to the control. Similarly, the productivity of understory vegetation biomass was 36-107% greater in the cutting treatment areas compared to the control. The findings suggest that the maintenance of non-pine plants at low heights can significantly increase the PAR influx to the woodland floor, thereby enhancing the productivity of understory vegetation and grazing opportunity for small ruminants.