Land Management Contributes significantly to observed Vegetation Browning in Syria during 2001–2018

[摘要] Climate change and human activities have significantimpacts on terrestrial vegetation. Syria is a typical arid region with awater-limited ecosystem and has experienced severe social unrest over thelast decades. In this study, changes in vegetation and potential drivers inSyria are investigated. By using an enhanced vegetation index (EVI), ageneral browning trend is found in Syria during 2001–2018, with the EVIdecreasing at a rate of − 0.8  ×  10 −3  yr −1 ( p 0.1 ). The decrease of the EVI is mainly found in the north region, whereasthe west region still maintains an increasing trend. The residual analysisindicates that besides precipitation, human activities also contributesignificantly to the EVI decrease, which is confirmed by the decrease inrainfall use efficiency. Moreover, a paired land-use experiment (PLUE)analysis is carried out in the Khabur River basin where croplands are widelydistributed in adjacent regions of Syria and Turkey. The time series of theEVIs over these two regions are highly correlated ( r =0.8027 , p 0.001 ), indicating that both regions are affected by similar climateforcing. However, vegetation in Syria and Turkey illustrates contrarybrowning ( − 3  ×  10 −3  yr −1 , p 0.01 ) and greeningtrends (4.5  ×  10 −3  yr −1 , p 0.01 ), respectively.Relevant reports have noted that social unrest induced insufficientirrigation and lack of seeds, fertilizers, pesticides and field management.Therefore, we concluded that the decline in vegetation in the north Syria isdriven by the change of land management.

[学科分类] 大气科学