Evidence for the grassland–shrubland transition in the Jornada Basin: (a) The initial collapse of Bouteloua eriopoda (black grama) production in pasture 2 during the 1950s drought (see Bestelmeyer et al. 2011a). (b) A photograph of a site near the southern boundary of pasture 2 in 1936, illustrating the effects of overgrazing during the 1930s drought. (c) The appearance of small Prosopis glandulosa shrubs in 1956. (d) The site in 2009, dominated by shrubs and with evidence of significant soil erosion exposing an indurated petrocalcic soil horizon (caliche).
See: Bestelmeyer et al. 2018. The Grassland-Shrubland Regime Shift in the Southwestern United States: Misconceptions and their Implications for Management. Bioscience
