Shrub species exhibit differing long-term responses to a change in the species of ungulate browsing

Hyper-arid rangeland vegetation is typically dominated by large woody species which are often overlooked in herbivory studies. Knowledge of long-term large shrub population responses to change in browsing system in the Arabian Peninsula has been anecdotal. Population and size of 1559 individuals from four shrub species were opportunistically assessed over an 11-year period under two browsing regimes, one in which domestic livestock (camels) were replaced by semi-wild ungulates (oryx and gazelles) before, and the other during, the study period. Each shrub species exhibited a different response to the change in herbivory. Populations of Calotropis procera decreased dramatically. Populations o…