Effects of Intensive Late-Season Sheep Grazing Following Early-Season Steer Grazing on Population Dynamics of Sericea Lespedeza in the Kansas Flint Hills

Abstract

Sericea lespedeza (Lespedeza cuneata; SL) is a high-tannin, invasive forb in the Tallgrass Prairie ecosystem. In Kansas, sericea lespedeza infests 980 square miles of pasture, primarily in the Flint Hills region. Sericea lespedeza infestations reduce native grass production by up to 92% through a combination of aggressive growth, prolific reproduction, canopy dominance, and chemical inhibition (allelopathy). Herbicides retard the spread of sericea lespedeza, but application is laborious and expensive; moreover, herbicides are lethal to ecologically-important, non-target plant species.Increased grazing pressure on sericea lespedeza by domestic herbivores may slow its spread and facilitate some measure of biological control. Unfortunately, mature plants contain high levels of condensed tannins, which are a strong deterrent to grazing by beef cattle. Small ruminants have greater tolerance for condensed tannins than beef cattle. Sheep, in particular, appear less susceptible to certain plant toxins than beef cattle and may be useful to selectively pressure noxious weeds like sericea lespedeza.The predominant grazing management practice in the Flint Hills region of Kansas involves annual spring burning followed by intensive grazing with yearling beef cattle from April to August. During seasonal grazing, 40 to 60% of annual graminoid production is removed and pastures remain idle for the remainder of the year. Under this prevailing management practice, invasion by sericea lespedeza into the Tallgrass Prairie biome has steadily increased. Sericea lespedeza flowers and produces seed in late summer from August to September. The absence of grazing pressure during this interval strongly promotes seed production, seed distribution, and continued invasion of the Flint Hills ecoregion by this noxious weed. Therefore, the objective of our study was to evaluate effects of late-season sheep grazing following locally-conventional steer grazing on vigor and reproductive capabilities of sericea lespedeza.

The more we do, the less we gain? Balancing effort and efficacy in managing the Solidago gigantea invasion

“…In addition, annuals ( Conyza canadensis , Scleranthus annuus , Vulpia myuros ) and/or disturbance tolerant species ( Eupatorium cannabinum , Lythrum salicaria , Rumex acetosella ) increased their frequencies at these sites, indicating that these treatments have a strong impact on the composition of plant communities. Similar results have been reported in other studies, such as Lemmon et al (2016), who investigated the influence of intensive sheep grazing on Lespedeza cuneate, and Pollock et al (1998), whose experiment looked at the effects of different flooding regimes on species diversity.…”

Effects of high condensed-tannin substrate, prior dietary tannin exposure, antimicrobial inclusion, and animal species on fermentation parameters following a 48 h in vitro incubation1

“…Differences in tannin sensitivity between beef cattle and small ruminants are well documented (Vaithiyanathan et al, 2001;Frutos et al, 2004;Eckerle et al, 2010Eckerle et al, , 2011Lamy et al, 2010;Pacheco et al, 2012;Lemmon et al, 2017). In our study, acetate concentrations following a 48 h in vitro incubation were mildly influenced by inoculum-donor species; however, no other fermentation index was affected.…”