## 2 Materials and Methods  
### Site Description, Experimental Design, and Methods  
The study was conducted in Sde Zin (30\({}^{\circ}\)86\({}^{\prime}\) N, 34\({}^{\circ}\)79\({}^{\prime}\) E, 475 m. a.s.l. ), adjacent to the Sde Boker settlement, in the arid central Negev of southern Israel (Figure 1). The site is a plateau (with a mean slope incline of 1.0%) surrounded by rocky hills. The lithology consists of the Dead Sea Group conglomerate, and the soil series is classified as calcite xerosol [33]. Mean annual depth of precipitation at the site is 90 mm and the evaporation potential is about 2000 mm. The ratio of precipitation to potential evaporation (P/PET) is 0.04-0.05. The annual temperature is 18 \({}^{\circ}\)C, average daily minimum temperature ranges between 6 and 8 \({}^{\circ}\)C in January, and daily maximum temperature ranges between 32 and 34 \({}^{\circ}\)C in August ([[https://in.bgu.ac.il/en/bidr/Pages/meteorology-online.aspx](https://in.bgu.ac.il/en/bidr/Pages/meteorology-online.aspx)]([https://in.bgu.ac.il/en/bidr/Pages/meteorology-online.aspx](https://in.bgu.ac.il/en/bidr/Pages/meteorology-online.aspx))). Figure 1: The study area: map (**a**) and the research area with the ORV trails (**b**). The vegetation consists of _Haloxylon scoparia_ as the dominant dwarf shrub and herbaceous species and mainly annuals, such as _Erotium crassifolium_, _Reboudiu pinnata_, _Nasturtiopsis coronopifolia_, and _Factorskya ascensioniana_[34]. Since the 1950s, the Sde Zin site has been prone to high anthropogenic pressures imposed by the establishment of the nearby settlement (Kibbutz Sde Boker) and specifically to intensive vegetation cropping, heavy livestock grazing, and ORV activity due to the existence of natural and archeological sites unique to the region (Figure 1). Five ORV trails were selected, each containing a plot of 40 \(\times\) 15 m in size. The plot was divided into two subplots: one subplot was subjected to disk tillage in August (\"Disk\") to a depth of 10 cm, and the second was an impacted ORV trail subplot without soil tillage (\"No Disk\"). Next to the trail, at a distance of 5 m, another subplot was selected, in an undisturbed area, that served as a \"Control\" subplot. The depth of the surface soil disk tillage was determined based on previous studies performed in the Sde Zin, which showed that most of the plant seed bank is concentrated mainly in the upper soil layer at a depth of 0-2.5 cm [35]. Five 1 \(\times\) 1 m quadrats, with one meter between each quadrat, were established in each subplot, from which vegetation data and soil measures were collected for two consecutive years. A total of 25 quadrats were examined in each treatment: Disk, No Disk, and Control. Altogether, 75 quadrats of 1 \(\times\) 1 each were analyzed (Figure 2). All the chosen trails were similar (almost without vegetation cover and with a compacted upper soil layer). The trails were distributed in the area at distances of about 500 m from each other. Each quadrat at each plot was examined for the degree of soil compaction, soil moisture at a depth of 10 cm, and water infiltration duration at saturation using a penetrometer, TDR wet sensor, and infiltrrometer, respectively. Soil compaction was measured by soil penetration resistance between the subplots so as not to damage the various subplot soil crusts. In addition, the vegetation (annual and perennial) cover percentage was visually evaluated, whereas the percentage of each species was estimated based on its relative contribution to the overall vegetation cover. The number of individuals of each species was counted, and their height was measured.