Survival and growth of alders (Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench) on fly ash technosols at different substrate improvement

Abstract

Difficulties in disposal of fly ash resulting from coal combustion at electric power plants are of increasing concern. Establishment of vegetation is often an effective means of stabilizing solid wastes. This paper presents an evaluation of adaptation based on survival, growth and nitrogen supply of black alder and grey alder introduced on the landfill fly ash resulting from lignite combustion in ‘Bełchatów’ Power Plant (Central Poland). The research was conducted at 3 substrate variants: control with pure fly ash (CFA), with addition (3dm3 in planting hole) lignite culm (CFA+L) and Miocene, acidic and carboniferous sands from overburden of ‘Bełchatów’ Lignite Mine (CFA+MS). Before putting the experience uniformly on the whole surface sewage sludge (4Mgha−1) mixed with grass seedling (200kgha−1) and mineral fertilization (N – 60, P – 36 and K – 36kgha−1) were applied by hydroseeding. The results show the high adaptability of alders for extremely hard site conditions on the landfill ash. After 5 years of investigation the survival of black alder was from 61% (at CFA+MS) to 88% (at CFA+L), and grey alder from 81% (at CFA+MS) to 87% (at CFA). Black alder was characterized by higher growth parameters (diameter growth d0 and height h) compare to grey alder. The best substrate for fly ash enhancement was lignite culm. Therefore, if the goal of biological stabilization of fly ash landfill would be the greatest increase of tree biomass for example for energy plantations, the recommend solution for substrate improvement is using of lignite culm and Black alder. However, the introduction of alders directly on the fly ash using start up NPK fertilising and hydroseeding with seed sludge may be recommend mainly for economic reasons, especially when the introduced alders are to have primarily protective and phytomelioration functions and thus prepare the substrate for the afforestation and next generation of target species.