Gita Bodner and Marcos Robles just published this month: “Enduring a decade of drought: Patterns and drivers of vegetation change in a semi-arid grassland” in the Journal of Arid Environments. This paper looks at changes in plant and ground cover in Las Ciénegas between 2004 and 2014. This time period includes some of the driest seasons on record. In addition to documenting grassland conditions across this working landscape, their analyses evaluates several potential drivers of these changes. Their study illustrates the value of monitoring and partners in this work.
- In 11 years of hot drought, perennial grass basal cover and shrub cover both declined, while leaf litter increased and Lehmann lovegrass expanded.
- Several species of perennial grass showed die-offs during the driest years but mortality was patchy.
- Declines were associated with low rainfall in January – June “extended spring” season – contributing to a small but growing set of evidence that C4 “warm season” grasses in this region are vulnerable to cool-season droughts.
- Soil and topography mediated how drought affected plant and ground cover.
- Despite drought impacts, ground cover and grass diversity persisted.
Access the full study at www.azconservation.org.
Photo courtesy U.S. Bureau of Land Management.