Key message

Water productivity of 3-year-old Paulownia tomentosa x fortunei (Shan Tong) trees in a plantation at Lake Issyk-Kul (Kyrgyzstan) ranged between 4.3 and 8.0 g l⁻¹ over the vegetation period 2019.

Abstract

Central Asia is a region where forests are naturally scarce and additionally are under high anthropogenic pressure due to an unmet demand for timber and fuelwood. Cultivation of fast-growing trees as a means to satisfy this need may, therefore, be instrumental to forest conservation and/or restoration efforts. In recent years, there has been a growing interest in Paulownia spp. as agroforestry or plantation tree. Paulownia is a deciduous tree genus of Chinese origin that is valued for its fast growth and light, yet sturdy wood, among other characteristics. This study investigated the water consumption, biomass production, and water productivity of Paulownia tomentosa x fortunei (trade name: Shan Tong) in a plantation setting on the northern shore of Lake Issyk-Kul (Kyrgyzstan) over the course of the vegetation period 2019. The method employed was Granier’s thermal dissipation probe for measuring sap flow in trees. Estimated trunk biomass production per tree and season ranged from 1.52 to 3.41 kg, and the trees were found to consume between 433 and 613 l of water in total over the growing season. Water productivity, the amount of exploitable stem biomass produced per litre of water input, consequently ranged between 4.3 and 8.0 g l⁻¹. As numerous studies suggest that the thermal dissipation method underestimates tree water consumption to varying degrees, these values likely represent the upper range of the species’ water productivity. A literature review shows its water productivity to be higher than that of regionally employed tree species such as Populus euphratica or Elaeagnus angustifolia.