Long-term_pas...li_case_study_Ilan STAVI.pdf

J.Geogr.Sci.2023,33(3):529-546 DOI:https:/doi.org/10.1007/s11442-023-2095-9 2023 Science Press Springer-Verlag Long-term passive restoration of severely degraded drylands divergent impacts on soil and vegetation:An Israeli case study Ilan STAVI1,2,Manuel PULIDO FERNNDEZ3,Eli ARGAMAN4 1.Dead Sea and Arava Science Center,Yotvata 88820,Israel;2.Eilat Campus,Ben-Gurion University of the Negev,Eilat 88100,Israel;3.Geo-Environmental Research Group,University of Extremadura,Cceres 10071,Spain;4.Soil Erosion Research Station,Ministry of Agriculture&Rural Development,POB 30,Bet Dagan 50250,Israel Abstract:Land degradation affects extensive drylands around the world.Due to long-term misuse,the Israeli Sde Zin dryland site has faced severe degradation.The study objective was to assess the feasibility of passive restoration in recovering the site.The study was conducted in four land-units along a preservation-degradation continuum:(1)an area that has not faced anthropogenic disturbances(Ecological land);(2)an area that was proclaimed as a national park in the 1970s(Rehabilitation);(3)an area that was prone,until recently,to mod-erate anthropogenic pressures(Triangle);and(4)a dirt road that was subjected to long-term off-road traffic(Dirtroad).Soil was sampled and analyzed for its properties.The soil physical quality followed the trend of Ecological land Rehabilitation Triangle Dirtroad.Specifically,high soil salinity in the latter three land-units is attributed to long-term erosional processes that exposed the underlying salic horizons.Herbaceous and shrubby vegetation cover was also monitored.The herbaceous vegetation cover followed the trend of Ecological land(86.4%)Rehabilitation(40.3%)Triangle(26.2%)Dirtroad(2.1%),while the shrubby cover was 2.8%in the Ecological land-unit,and practically zero in the other land-units.It seems that despite the effectiveness of passive restoration in recovering the soils physical properties,the recovery of vegetation is limited by the severe soil salinity.Keywords:active rehabilitation;ecosystem functions;land-use change;land degradation and desertification;annual vs.perennial plants;self-restoration 1 Introduction Processes of land degradation are prevalent worldwide.Often,causes of land degradation are anthropogenic,and are attributed to the misuse of lands or the implementation of irra-tional management practices(Morales and Zuleta,2020).Among the land degradation pro-cesses,soil erosion,organic carbon depletion,deterioration of the soil physiochemical qual-Received:2022-05-07 Accepted:2022-10-30 Author:Ilan Stavi,E-mail:istaviadssc.org 530 Journal of Geographical Sciences ity,soil salinization,reduction in primary productivity,biodiversity loss,and species inva-sion are predominant(Olsson et al.,2019).Climatic changes,characterized by reduced pre-cipitation,increasing temperatures,long-term droughts,and surges in extreme weather con-ditions,accelerate the risk of global land degradation,particularly in the worlds drylands(Arneth et al.,2019).Several models have projected degrading climatic conditions of the worlds drylands throughout the 21st century,with the growing frequency and magnitude of droughts and increase in regional aridity on the one hand(Cook et al.,2014;Fu and Feng,2014;Lickley and Solomon,2018),while facing rare but intense rainstorms and devastating floods on the other hand(Care Danmark,2016).Coupled with the forecasted expansion of dryland areas,global land degradation and desertification are expected to further accelerate in the future(Huang et al.,2016).Passive restoration of degraded lands halts the anthropogenic utilization of the target land,thereby allowing self-restoration processes to take place.The most common passive means is fencing of plots to prevent access by humans or livestock(Morrison and Lindell,2011;Zahawi et al.,2014).It is expected that once the degrading factor is halted,the physiochem-ical and biotic components of the target land will gradually recover,and foster each other through positive feedbacks(Aradottir and Hagen,2013).Such passive schemes are different from active restoration programs,where practices such as tillage(Stavi et al.,2018c),appli-cation of soil amendments such as biochar(Stavi,2012),terracing for runoff harvesting and soil erosion control(Bolo et al.,2019),direct seeding of annual vegetation(Louhaichi et al.,2020),or planting of shrubs(Haddad et al.,2022)and trees are implemented(Baumgrtner,2012;Mahmoud et al.,2021).Usually,passive restoration schemes are more likely to be successful in sites where degradation processes are not severe,and where climatic condi-tions can easily support the rehabilitation of ecosystem.At the same time,in extremely de-graded sites that cross certain tipping points,or in drylands and other resource-limited areas,active restoration schemes might be preferred(McIver and Starr,2001;Rohr et al.,2018).Despite this extensive research,knowledge gaps still exist regarding restoration procedures of se