$$News and Reports$$

Feb. 18, 2019

Physical Review Letters 122, 048101 – 30 January 2019

Scientists from the Jacob Bluestein Institutes for Desert Research, Ben-Gurion University of the Negev (BGU) have shown in model studies that ecosystems may be rescued from collapsing to bare-soil, or desert states, by means of simple interventions at the desert border.  ​

While a postdoc at BGU, Cristian Fernandez-Oto, a researcher at the University of the Andes in Chile worked with Prof. Ehud Meron, the Swiss Institute for Dryland Environmental & Energy Research and Omer Tzuk to simulate and study the behavior of such desert fronts as they moved through vegetation areas. In particular, the team wanted to know if there was a way to interrupt or destabilize the progression of a desert front that would otherwise leave behind a desert state.

Instabilities generally have negative connotations – events to avoid, but in drylands, they can rescue ecosystems from collapsing to bare-soil or desert states. One form of collapse is a domino-like process of plant mortality at borderlines between bare-soil and vegetation, by which bare-soil areas gradually displace vegetation areas. The reported study demonstrates the utility of mathematical models in unraveling the dynamics of such border lines and in the identification of instability that results in vegetation growth backward into bare-soil areas, as Figure 1 shows. The study also sheds light on possible manipulations at the borderline that can trigger such instability and, thereby, induce a self-recovery process.

Figure 1.jpg

Figure 1. Snapshots of model simulations showing a reversal of desertification induced by a front instability. Green and yellow colors denote, respectively, vegetated and bare-soil areas. The snapshot times are in units of years.