Structure and wood biomass of near-natural floodplain forests along the Central Asian rivers Tarim and Amu Darya

In the Central Asian deserts, the floodplains along the large river systems like the Amu Darya, Syr Darya and Tarim harbour the highest biodiversity and provide a wide range of ecosystem services for men in those regions. Against the background of the potential use of wood biomass and carbon sequestration, we investigate the biomass of floodplain forest (Tugai) ecosystems along the Tarim River, north-west China, and the Amu Darya, Turkmenistan. These forests are dominated by Populus euphratica Oliv. Under very good water supply conditions, the stand biomass, comprising above- and below-ground components of P. euphratica, was 58.4 t ha(-1), corresponding with the highest tree densities. The stand biomass of P. euphratica under non-optimal conditions, i.e. prolonged flooding or periods of drought with sinking groundwater levels, ranged from 16 to 28 t ha(-1). The observed stand biomass values for P. euphratica are in the range of values found by others in Xinjiang and Inner Mongolia, China, but lower than the biomass of temperate forests. However, among the desert, semi-desert and steppe ecosystems, the riparian P. euphratica forest is the ecosystem with the highest above-ground biomass. Thus, the riparian forests in Central Asia contain a regionally remarkable amount of biomass.