Carbon and Macronutrient Budgets in an Alder Plantation Grown on a Reclaimed Combustion Waste Landfill
Abstract
Combustion waste landfills are unfavorable for revegetation due to nitrogen deficiency, and therefore, the introduction of nitrogen-fixing organisms, such as alder species (Alnus sp.), may be promising for reclamation and restoration of these sites. We investigated the carbon and macronutrient stocks in the combustion waste technosols and biomass of black alder (Alnus glutinosa) and grey alder (Alnus incana) 10 years after introduction onto a combustion waste landfill.
The alder species were planted with or without lignite addition in planting holes, the latter acting as control plots. Black alder biomass was higher than that of grey alder.
The total macronutrient stocks were higher in the uppermost technosol layer (0-30 cm) than in the biomass nutrient stocks. However, the K and P stocks in the black alder biomass were still greater than the exchangeable K+ and available phosphorus (Pav) stocks in technosols.
This is important for the nutrition of the trees planted in combustion waste landfills and confirms the Pav deficit in investigated technosols. The differentiation of nutrients in biomass shows that the largest stock was found in the wood of trunks and branches (40-70% of the stock of individual biomass macronutrients).
Although foliage biomass represented approximately 7% of the total tree biomass, the nutrient stocks therein represented a significant proportion of total nutrient stocks: approximately 27-29% nitrogen, 17-22% calcium, 28% magnesium, 7-10% potassium and 12-16% phosphorus. This is particularly important in the context of the turnover of nutrients from litterfall and soil organic matter and the circulation of nutrients in the ecosystem developed on combustion waste technosols.