Ecological restoration of the western-Negev dunes system in light of land-use changes: Aeolian activity and faunal response

Background/Question/Methods

For the last 3 decades, the western-Negev dunes system undergoes a stabilization process in which shifting dunes gradually become stable and covered by biogenic soil-crust, due to the lack of soil-breaking agents, such as Bedouin activity (trampling, grazing, wood collection).  Consequently, we are currently loosing the important shifting-sand habitat as well as the overall habitat heterogeneity of the entire landscape.  In turn, the structure and composition of the faunal communities inhabiting the dunes, including the psammophilic rare and endemic species, change.  In order to reactivate Aeolian activity on the dunes and subsequently restore the shifting-sand habitat, in June 2010 we broke the biogenic soil-crust and partially removed vegetation on extensive area on 8 different dunes, each having a manipulation and control plot.  We monitored changes in the physical environment and the response of reptiles, rodents and ground beetles to these changes.

Results/Conclusions

Our current results show that sand mobility has increased significantly on manipulated plots.  The faunal communities have shown diverse responses, with some species displaying increased population size while others decline, partially based on their affinity to shifting sands.  In particular, the previously well-studied gerbil community structure has changed on manipulated plots according to the species’ differential habitat preferences, as expected by the centrifugal community organization.  Reptile community has shown diverse responses for the manipulation.  Conservation-wise, the rare and endangered Cerastes cerastes (horned viper) has shown clear preference for manipulated plots.  For ground beetles, although high species turnover rate was found at between-seasons and between-year scales, there was no difference between control and manipulated plots.  As time progresses, the effect of manipulation declines, but community attributes do not return to pre-manipulation status.  Our results strongly indicate that actively restoring the habitat mobility of the sand dune, through mechanistically oriented approach, can positively contribute to the landscape conservation of this valuable ecosystem.