Belowground Attributes on Reclaimed Surface Mine Lands over a 40‐year Chronosequence

Abstract

Reclamation following mining activities often aims to restore stable soils that support productive and diverse native plant communities. The soil re‐spread process increases soil compaction, which may alter soil water, plant composition, rooting depths, and soil organic matter. This may have a direct impact on vegetation establishment and species recruitment. Seasonal wet/dry and freeze/thaw patterns are thought to alleviate soil compaction over time. However, this has not been formally evaluated on reclaimed landscapes at large scales. Our objectives were to (1) determine soil compaction alleviation, (2) rooting depth, and (3) spatial patterns of soil water content over a time‐since‐reclamation gradient. Soil resistance to penetration varied by depth, with shallow compaction remaining unchanged, but deeper compaction increased over time rather than being alleviated. Root biomass and depth did not increase with time and was consistently less than the values in the reference location. Plant communities initially had a strong native component, but quickly became dominated by invasive species following reclamation, and soil water content became increasingly homogeneous over the 40‐year chronosequence. Seasonal weather patterns and soil organic matter additions can reduce soil compaction if water infiltration is not limited. Shallow and strongly fibrous‐rooted grasses present in reclaimed sites added organic matter to shallow soil layers, but did not penetrate the compacted layers and allow water infiltration. Strong linkages between land management strategies, soil properties, and vegetation composition can advance reclamation efforts and promote heterogeneous landscapes. However, current post‐reclamation management strategies are incompletely utilizing natural seasonal weather patterns to reduce soil compaction. Copyright © 2017 John Wiley & Sons, Ltd.

Surface mines show little progress towards native species forest restoration following 35 years of passive management after initial reclamation

“…However, passively managed natural succession was not entirely negative. Overall, invasive species prevalence did not increase over time at the reclaimed sites in CVNP, in contrast to other studies finding abundant invasive plants where natural succession had been used as a mine reclamation tool (Bohrer et al, 2017; Cavender et al, 2014). Since native species are becoming more prevalent over time and community composition appears to be changing in a chronological fashion, we suggest that succession has been slowed rather than completely arrested and that native plants are establishing later at these sites.…”

“…Exotics that pose ecological or economic threats are considered invasive species (Alpert, Bone, & Holzapfel, 2000), and often thrive in open areas and disturbed soil conditions such as those commonly present in reclaimed mines (D'Antonio & Meyerson, 2002). Thus, invasive species are often the most abundant species on reclaimed surface mines (Bohrer et al, 2017; Fields‐Johnson et al, 2012). Colonization by invasive species usually results in a decline in species richness and evenness (Hejda, Pyšek, & Jarošík, 2009).…”

“…Additionally, a lack of native species in the seed bank can hinder succession of reclaimed surface mines (Hall, Barton, & Baskin, 2010). However, most studies on reclaimed surface mines have been conducted on coal mines (e.g., Bohrer, Limb, Daigh, & Volk, 2017; Cavender et al, 2014; Fields‐Johnson, Zipper, Burger, & Evans, 2012; Gilland & McCarthy, 2014; Hall et al, 2010), whereas other types of mines with a wider range of soil conditions are less well understood.…”

Reclamation of Soils Degraded by Surface Coal Mining

“…Soil and plant data among a chronosequence of 19 post-mine reclaimed sites (over a 40-year reclamation gradient), and an intact native reference site were evaluated. It was noticed that root biomass in the upper horizons (at 30 cm depth) was greater on the reference site compared with the reclaimed sites as well as the Reclamation of Soils Degraded by Surface Coal Mining DOI: http://dx.doi.org/10.5772/intechopen.93432 organic matter content, ranging from 3•5 to 5•4% on the reclaimed sites (not different across the reclamation chronosequence) and from 5•1 to 6•8% on the reference site [21]. On the other hand, in the Midwestern USA, there was the development of horizons in minesoils in a relatively short period of time (10-15 years), in which the 0.00-0.03 m layer consisted of non-decomposed or partially decomposed organic matter, while the 0.03-0.10 m layer was darker, with visible addition of organic carbon, and the 0.10-0.25 m layer was the least colored with interspersed roots [22].…”

The Forestry Reclamation Approach: Measuring Sediment Mass Accumulation Rates in Reclaimed Mine Lands and Naturally Regenerated Logged Forests of Eastern Kentucky

“…This use of groundcover commonly decreases water infiltration (Clark and Zipper 2016;Bohrer et al 2017) and prevents the establishment of plant species with deep root systems that can reduce soil compaction (Angel et al 2006;Martin 2006). Soil compaction has the potential to decrease the available nutrients and water that plants can uptake, depending on the soil grain sizes present (Arvidsson 1999).…”