Grazing management
Grazers play an important role in the continuous removal of leaf litter and generating available space for new recruitment (Lengyel et al ., 2012; Török et al ., 2018), which can promote species richness (Towne et al ., 2005; Klaus et al ., 2018). Germination of the native North American prairie grass, Nassella pulchra was enhanced by burning and sheep grazing (Dyer, 2002). Moderate grazing (30-50 within a 303ha enclosure) from Bos bisonsignificantly improved the species richness of a Prairie grassland within its later stages of development (approximately 10-years after revegetation) (Wilsey & Martin, 2015), this was also observed within tallgrass prairies (Towne et al ., 2005). Livestock can transport seeds of important species over great distances via endo or ectozoochory if remnant sites are available (Lengyel et al ., 2012; Töröket al ., 2018). Further, the careful management of paddock rotations for grazing livestock has been identified to be critical in maintaining genetic diversity for plants threatened by fragmentation (Plue et al ., 2019). High genetic diversity can allow for a population to react more responsively to disturbance events through improved resilience.
Overgrazing by livestock is one of the leading causes of grassland degradation (Bartolome et al ., 2009; Zha & Gao, 2011; Wortleyet al ., 2013). The effects of different degrees of overgrazing were observed by Török et al . (2018) within four different Hungarian steppe grassland communities. They found that the highest richness was achieved from low grazing (less than one animal per hectare), but medium was also suitable (1-2.5 animals per hectare), and grazing densities above this had detrimental effects of species richness. Further, the different grassland communities responded differently to the grazing intensities suggesting they are grassland specific (Török et al ., 2018). Competition dynamics between forb and grass species were altered by livestock grazing in southern Argentina (Díaz Barradas et al ., 2001). Under sheep grazing, the grasses did not produce inflorescences and forbs became taller and more abundant compared to non-grazing tracts, where grass species dominated (Díaz Barradas et al ., 2001). Forb cover was also observed to increase in Prairie grasslands when exposed to grazing from cattle and bison (Towne et al ., 2005). Therefore, grazing intensities should be carefully managed, particularly during drought periods to promote competition from native perennial grasses (Klaus et al ., 2018), and resting paddocks from grazing when natives are emerging, particularly if herbage is sparse, could improve their establishment and survival (Clarke & Davison, 2014).