The effect of wood ash application on growth, leaf morphological and physiological traits of trees planted in a cutaway peatland

Abstract

Management of cutaway peatlands is a key issue in many countries. Whilst afforestation has been considered as a suitable after use option for cutaway peatlands, growing conditions after peat harvest are often adverse. To increase soil fertility and neutralise soil acidity, wood ash, an energy production by-product, can be used. In this study, we examined whether wood ash fertiliser affects growth (survival, height, root collar diameter), leaf morphological (mass, specific leaf area, leaf water content) and physiological traits (chlorophyll concentration, fluorescence parameters, photosynthetic and transpiration rate) of planted deciduous trees in a cutaway peatland in the central part of Latvia. At our study site in Latvia, we examined Alnus glutinosa, Betula pendula and Populus v. Vesten tree species and tested 0, 5, 10 and 15 t ha-1 wood ash doses in three replications. Tree species used in the study exhibited different reactions to the wood ash fertilisation. A. glutinosa traits were the least affected, whereas for Populus v. Vesten and B. pendula wood ash fertilisation was beneficial. In most cases we detected significant differences between unfertilised and fertilised plots, but rarely saw an effect of increased wood ash dose. Due to the lack of significant benefits and for environmental concerns the lowest wood ash dose is recommended. Overall, the fertilisation improved the success of afforestation and, by increasing the amount of leaf litter, is likely to indirectly alter understorey conditions.

Keywords

• afforestation
• fertilisation
• photosynthesis