Survival and growth of three afforestation species under high saline drip irrigation in the Taklimakan Desert, China

Abstract

AbstractAfforestation of shelterbelts is a sustainable practice to protect highways from shifting sand dunes in desert areas. The Taklimakan Desert Highway Shelterbelt (TDHS) in China is known as “the Great Green Wall of Taklimakan Desert” and borders a 436‐km distance along the highway. This study assessed the early survival, above‐ground growth, and root growth of three salt‐ and drought‐tolerant plant species (Calligonum aborescens Litv., Tamarix ramosissima Ledeb., and Haloxylon ammodendron (C. A. Mey.) Bunge) in TDHS; those were drip‐irrigated with local high saline groundwater. The results demonstrated that more than 80% of Haloxylon ammodendron seedlings could survive regardless of irrigation water salinities ranging from 2.82 to 29.70 g/L. In contrast, survival rates of Calligonum aborescens seedlings were greater than 65% when using irrigation water salinities ≤13.99 g/L and less than 50% when irrigated with water having salinities of 20.99–29.70 g/L, respectively. However, plant survival rates of Tamarix ramosissima were much lower than 50% when irrigated with water having salinities >4.82 g/L. Furthermore, under the same salinity, the height, crown width, and maximum width of basal stems were the greatest for Calligonum aborescens plants and the lowest for Tamarix ramosissima plants. Root length varied among the species depending on tree age and the applied water characteristics. We conclude that afforestation is feasible with saline water in this extreme arid shifting desert, particularly Calligonum aborescens plants should be grown at the outer margin of the shelterbelt due to its faster growth to more quickly stabilize the shifting sand. Our study may provide a good resolution for afforestation and marginal saline water utility in most arid and semiarid regions.