Impact of tree species on soil carbon stocks and soil acidity in southern Sweden

Abstract

The impact of tree species on soil carbon stocks and acidity in southern Sweden was studied in a non-replicated plantation with monocultures of 67-year-old ash (Fraxinus excelsior L.), beech (Fagus silvatica L.), elm (Ulmus glabra Huds.), hornbeam (Carpinus betulus L.), Norway spruce (Picea abies L.) and oak (Quercus robur L.). The site was characterized by a cambisol on glacial till. Volume-determined soil samples were taken from the O-horizon and mineral soil layers to 20 cm. Soil organic carbon (SOC), total nitrogen (TN), pH (H 2 O), cation-exchange capacity and base saturation at pH 7 and exchangeable calcium, magnesium, potassium and sodium ions were analysed in the soil fraction B/2 mm. Root biomass ( B/5 mm in diameter) and its proportion in the forest floor and mineral soil varied between tree species. There was a vertical gradient under all species, with the highest concentrations of SOC, TN and base cations in the O-horizon and the lowest in the 10 Á20 cm layer. The tree species differed with respect to SOC, TN and soil acidity in the O-horizon and mineral soil. For SOC and TN, the range in the O-horizon was spruce /hornbeam /oak /beech /ash /elm. The pH in the O-horizon ranged in the order elm/ash /hornbeam /beech /oak /spruce. In the mineral soil, SOC and TN ranged in the order elm/oak /ash 0/hornbeam /spruce/beech, i.e. partly reversed, and pH ranged in the same order as for the O-horizon. It is suggested that spruce is the best option for fertile sites in southern Sweden if the aim is a high carbon sequestration rate, whereas elm, ash and hornbeam are the best solutions if the aim is a low soil acidification rate.

Effects of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia spec.) on soil chemical properties in a mixed deciduous forest

“…The results point at a faster turnover rate of ash litterfall compared to beech litterfall resulting in a faster, more efficient nutrient return to the soil (Oostra et al 2006;Vesterdal et al 2008;Jacob et al 2009). Carbon accumulation in the forest floor depends on several interacting factors: The most important are litter quality (i. e. the lignin content and the lignin:N ratio, compare Berg 2000;Inagaki et al 2004), soil fertility and activity of soil biota.…”

“…Furthermore, results from former studies suggest that these three species differ in their effects on soil acidification and nutrient availability (e.g. Nordén 1994;Neirynck et al 2000;Oostra et al 2006).…”

“…While the relative influence of conifers, as compared to hardwoods, on soil biochemical properties has often been analyzed (Augusto et al 2002;Berger et al 2009a, b;Mareschal et al 2010), research on soil chemical variations under different broadleaved species is a younger and less advanced field. The main findings of studies analyzing soil properties under broadleaved tree species are that pH and base saturation are lower in the topsoil under mullmoderforming species (including beech) compared to mullforming tree species (including ash and lime ;Nordén 1994;Neirynck et al 2000;Oostra et al 2006). Further, Oostra et al (2006) and Vesterdal et al (2008) found out that concentrations and stocks of organic carbon (C org ) and total nitrogen (N t ) in the forest floor were higher for beech than for ash and lime.…”

“…The main findings of studies analyzing soil properties under broadleaved tree species are that pH and base saturation are lower in the topsoil under mullmoderforming species (including beech) compared to mullforming tree species (including ash and lime ;Nordén 1994;Neirynck et al 2000;Oostra et al 2006). Further, Oostra et al (2006) and Vesterdal et al (2008) found out that concentrations and stocks of organic carbon (C org ) and total nitrogen (N t ) in the forest floor were higher for beech than for ash and lime. (The latter was only analyzed by Vesterdal et al 2008.…”

Carbon content of forest floor and mineral soil in Mediterranean Pinus spp. and Oak stands in acid soils in Northern Spain

“…The soils can be classified mainly as Cambisols and Regosols (JCyL, 2013). stand development stage (Turner & Lamber, 2008), land use (Oliver et al, 2004), litter production and decomposition (Kavvadias et al, 2001), disturbances and silviculture or forest management (Oostra et al, 2006;Jandl et al, 2007) play an important role in SOC balance (Lal, 2005). On the other hand, forest floor is an essential component in the relations among soil and vegetation in the wooded ecosystem and litterfall is a principal pathway for the return of nutrients to the soil (Smith et al, 2015).…”