Carbon storage in post-mining forest soil, the role of tree biomass and soil bioturbation

Abstract

Carbon storage in aboveground tree biomass and soil organic matter (in depth of A layer development i.e., up to 20 cm) was studied in 22-32 year-old post-mining sites in the northwest of the Czech Republic. Four replicated sites afforested with different tree species (spruce, pine, larch, oak, lime or alder) were compared with sites left to natural regeneration which were dominated by aspen, birch and willow. No topsoil was applied at the sites; hence carbon accumulation resulted from in situ soil development on alkaline tertiary clays that were dumped on the heaps. In aboveground tree biomass, carbon storage ranged from 17.0 ± 5.9 (mean ± SEM) to 67.6 ± 5.9 t ha -1 and the rate of C accumulation increased from 0.60 ± 0.09 to 2.31 ± 0.23 t ha -1 -year -1 (natural regeneration \ pine \ spruce \ oak \ lime \ alder \ larch). Carbon storage in soil organic matter varied from 4.5 ± 3.7 to 38.0 ± 7.1 t ha -1 and the rate of C accumulation in soil organic matter increased from 0.15 ± 0.05 to 1.28 ± 0.34 t ha -1 year -1 at sites in the order: natural regeneration \ spruce \ pine, oak \ larch \ alder \ lime. Carbon storage in the soil was positively correlated with aboveground tree biomass. Soil carbon was equivalent to 98.1% of the carbon found in aboveground tree biomass at lime dominated sites, but only 21.8% at sites with natural regeneration. No significant correlation was found between C storage in soil and aboveground litter input. Total soil carbon storage was correlated positively and significantly with earthworm density, and occurrence of earthworm cast in topsoil, which indicated that bioturbation could play an important role in soil carbon storage. Hence, not only restoring of wood production, but also restoring of soil community is critical for C storage in soil and whole ecosystem.

Forest restoration following surface mining disturbance: challenges and solutions

“…These clear differences among ecosystems should be carefully considered when reconstructing forest soils and re-establishing nutrient stocks so as to ensure that restoration practices are tailor-made for each ecosystem type and its associated climatic conditions. Soil carbon is often used as a proxy for soil quality and is a good indicator of ecosystem recovery in post-mining soils (Frouz et al 2009;Turcotte et al 2009). Results from studies using chronosequences post-fire and post-harvesting indicate that soil carbon may return to pre-disturbance levels after about three decades in boreal forests (Norris et al 2009), while recovery of soil carbon in secondary tropical forests takes between 20 and 100 years (Martin et al 2013).…”

“…Vegetation composition affects organic matter content and quality on reclaimed mine sites, in turn affecting the composition of microbial communities (Mummey et al 2002;Frouz et al 2009;Sorenson et al 2011;Macdonald et al 2012). Sorenson et al (2011) found that coniferous stands were linked with fungal presence, whereas aspen stands had a stronger bacterial component.…”

Carbon, nitrogen and phosphorus release from peat and forest floor-based cover soils used during oil sands reclamation

“…Organic matter plays a central role in the functioning of the overall soil ecosystem; as such, it is often used as a proxy for soil quality in soils undergoing reclamation (Frouz et al 2009;Turcotte et al 2009). Sandy soils, more so than their finer-textured counterparts, depend on organic matter to store nutrients and retain water, sustain a healthy biota and support plant growth.…”

Restoration of Mine Spoil in a Dry Tropical Region: A Review

“…Trees and shrubs usually provide a permanent vegetation cover on mined sites with little or no aftercare. Trees can help maintain or increase the soil organic matter, nitrogen fixation, or decrease the erosion rate, and improve soil physico-chemical and biological properties (Jha and Singh, 1991;Frouz et al, 2009). However, impact of trees on soil fertility will depend on their nutrient cycling characteristics, for example litter chemistry and decomposition (Byard et al, 1996).…”