Wood Ash Application Reduces Bryophyte Cover and Changes Species Composition in a Norway Spruce (Picea abies) Plantation

Abstract

Return of wood ash from power plants to plantations makes it possible to recycle nutrients, counteract acidification, and to reduce economically costly waste deposition of the wood ash. However, current legislation restricts the amount of wood ash that can be applied and it is desirable to increase the allowed application dose, if possible, without negative effects on the plantation ecosystems. Here, we applied wood ash in levels corresponding to 0, 3, 9, 15, 30, and 90 t ash ha−1 and monitored the effect of the different ash doses on bryophytes in a Norway spruce (Picea abies) plantation with a dense bryophyte cover dominated by Hypnum jutlandicum, Dicranum scoparium, and Pleurozium schreberi. We used two complementary methods, image analysis, and pinpoint registration during a three-year period. To our knowledge, we are the first to apply this combined effort, which provides a much more exhaustive description of the effects than the use of each method separately. Moreover, the inclusion of a wide range of different wood ash levels enabled us to establish detailed dose-response relationships, which previous authors have not presented. The bryophyte cover decreased with increasing ash level with concomitant changes in species composition. At ash doses above the currently allowed 3 t ha−1, the ash significantly reduced the bryophyte cover, which only re-established very slowly. With increasing wood ash dose, the dominating species changed to Brachythecium rutabulum, Ceratodon purpureus, and Funaria hygrometrica. We conclude that application of more wood ash in spruce plantations than currently allowed will reduce total cover of bryophytes and cause a pronounced change in bryophyte species composition. These changes will in particular harm bryophyte species with specific environmental requirements and generally impair the bryophyte cover as habitat for invertebrates and its economic value for moss harvesting.

Bacteria Respond Stronger Than Fungi Across a Steep Wood Ash-Driven pH Gradient

“…The experimental site is a secondgeneration plantation established in 1957 on former heathland with a well-developed podzolization formed on a well-drained, sandy glacial till. Mosses dominated the forest floor; in particular Hypnum jutlandicum, Dicranum scoparium and Pleurozium schreberi (Ethelberg-Findsen et al, 2021). The few understory plants are mainly Deschampsia flexuosa and Vaccinium vitisidaea.…”

How does management affect soil C sequestration and greenhouse gas fluxes in boreal and temperate forests? – A review

“…Potential Cd bioaccumulation risk is highest in systems with many earthworms, isopods and snails (Mortensen et al, 2018). WA further shapes the ground vegetation composition, often leading to reduced abundance of shrubs and mosses, and increased abundance of forbs and graminoids (Ethelberg-Findsen et al, 2021;Maljanen et al, 2014). These changes will affect the litter inputs to the soil, as well as the soil communities.…”