Multidecadal directional shift in shortgrass stocking rates

Bement (1969) developed a stocking rate (SR) guide for yearling cattle grazing shortgrass steppe based on relationships among average daily weight gain (ADG, kg · d?1), beef production per hectare (BP, ha?1), and (animal unit days, AUD ha?1) measured in long-term experiments conducted from 1940 to 1963. These analyses identified an optimal biophysical SR of 13.5 ha?1. Here, we 1) examine modern era (2000?2018) results these same determine if there has been shift the 2) assess influence drought (< 75% normal precipitation) SR. For all years era, occurred at 23.2 ha?1, 72% higher than value reported by (1969). 3 yr, optimum was 14.2 which still exceeded Our show capacity this rangeland produce livestock gains increased substantially between eras. This multidecadal directional is likely driven two nonmutually exclusive factors. First, plant community changed dominance C4 (Bouteloua gracilis) codominance with more productive C3 midgrass (Pascopyrum smithii) era. change resulted pasture-level forage increasing notably Second, entry weights genetic growth potential steers over 8 decades may have influenced efficiency given amount consumed. findings provide guidance incorporating flexible nondrought adaptive management strategies.