Assessment of ecological service value based on biomass of Populus euphratica in the lower reaches of the Tarim River

Populus euphratica is an important part of the desert riparian forest in the lower reaches of the Tarim River. Changes of biomass characteristics and the ecological service value of P. euphratica were studied in this paper, that can provide scientific basis to the benefit assessments of ecological water conveyance in the lower reaches of the Tarim River. Firstly, characteristics of the biomass of P. euphratica in different years were evaluated by the methods includes field survey and remote sensing interpretation; Secondly, the area of P. euphratica in different years were extracted; Thirdly, the ecological service value of P. euphratica in different years were estimated. The results were as follows:(1) P. euphratica distributed in the range of 0-700 m distances from the river mainly, and the biomass in this range accounted for more than 90% of the total biomass; The average biomass of P. euphratica on Yingsu was the highest, Alagan was the next, Karday and Yiganbjm were very low.(2) Based on the revised formula, the average ecosystem service value of P. euphratica was 78.96 yuan/hm~2 in 2000, and that was 177.14 yuan/hm~2 and 313.55 yuan/hm~2 in 2010 and 2016, respectively. The total ecological service value of P. euphratica was 43.24×10~4 yuan, 93.00×10~4 yuan, and 184.27×10~4 yuan in 2000, 2010, and 2016, respectively.(3) In 2016, the visible service value of P. euphratica was 22.74×10~4 yuan; However, the invisible service value, which was 7.1 times more than the visible service value, was 161.53×10~4 yuan. There was amount of significant effects of ecological water conveyance on the biomass and service value of P. euphratica, and the benefit of ecological water conveyance was very significant.