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Assessing the effects of shrubs on ecosystem functions in arid sand dune ecosystems

Abstract Shrub species play an important role in providing ecosystem functions and these functions may vary based on dominant shrubs and their facilitation roles in the arid ecosystems. This study was done to assess the potential of three shrubs (Tamarix macatensis, Calligonum polygonoides, and Haloxylon ammodendron) for providing three functions i.e. soil fertility, soil stability, and habitat provision in sand dune ecosystems of Iran. Two ecological indicators were selected to measure each function (soil organic matter content and litter mass for soil fertility; mound height and clay content for soil stability; understory plants and macrofauna diversity for habitat provision). As well, some shrub traits were measured for each shrub to assess their relationships with ecological indicators. Results showed that shrubs can significantly change ecological indicators (p < 0.05), except H. ammodendron which had no significant effect on habitat provision (p < 0.05). There were some relationships between shrub traits and provision of ecosystem functions. Stem density and litter production were the most important functional traits affecting regulating and habitat functions. Also, there was a significant positive relationship between soil fertility, soil stability and habitat provision (p < 0.05). It can be recommended that planting spherical shrubs with high potential for litter production will enhance functions and can sustainably maintain sand dunes in arid ecosystems.