The impact of motorcycle traffic on soil and vegetation of stabilized coastal dunes, Israel

This study aimed to assess the response of soil and annual plant vegetation of stabilized coastal dunes in Israel, to varying intensities of off-road motorcycle (ORM) traffic, and to assess their resistance and resilience to such a disturbance. A standard experimental procedure that included 0, 20, 50, 100 and 200 ORM straight passes and 150 ORM turn passes was used. Plant ground cover, mean plant height, species richness, species diversity, soil penetrable depth, organic matter and moisture contents were measured on several dates within a period of 372 days after the experiment. Results have shown that: (1) ORM passes had a significant immediate impact on annual plants that increased with traffic intensity. The impact on the soil was detected only as an increase of penetrable depth. (2) The maximum impact on annual plants was observed in the wheel ruts and turn areas. The impact on the area between the wheel ruts and on the margins outside the wheel ruts was indirect and smaller. (3) Annual plant ground cover and mean plant height were less sensitive parameters than species richness and species diversity for determining the impact of ORM traffic on the area. (4) One year after the experiment, soil and annual plant vegetation in all passes were very similar to their pre-experimental condition. This indicates high resilience and recovery potential of the Mediterranean stabilized coastal dune ecosystem to ORM disturbance.