Reclamation - restoring disturbed lands

Abstract Topsoil stockpiled for 4 years resulted in an accumulation of NH4-N at depths of 1m or more in mound, as measured by an ammonia gas-sensing electrode. When leached with water these soils were also found to contain high concentrations of dissolved organic C below lm. Both NH4-N and DOC were products of microbial mineralisation of soil organic matter that accumulated under anaerobic conditions. When these soils were restored a flush of decomposition took place, fuelled by labile organic matter and soluble nitrogen. Stockpiled soil which underwent an ammonium-rich perfusion regime in the laboratory indicated that in-mound soils rapidly attained greater nitrification potential than surface mound soils and also had greater potential for further mineralisation of organic matter to NH4-N. This further production was seen as a contribution from the bacterial flush, stimulated by the large labile-C pool already present. As the bulk of stored soil was anaerobic, restored soils were seen as potentially wasteful of their N-reserves; the fate of nitrogen and soluble carbon compounds in restored soils is discussed.

Abstract One technique used to combat the growing global species extinction crisis has been to create artificial refuges—human-made replacements for natural refuges destroyed during habitat modification. However, there is limited knowledge of how closely artificial refuges replicate the natural refuges they seek to replace. Mining threatens many species worldwide through large-scale habitat modification, and artificial refuges have been proposed as a method to offset the resulting habitat loss. Here, we examined the microclimatic, physical, and biotic characteristics of natural dens occupied by the northern quoll (Dasyurus hallucatus)—an endangered marsupial threatened by habitat loss—and compared these to (a) superficially similar unoccupied crevices, and (b) artificial dens created by mining companies for northern quolls. Northern quolls occupied natural dens that were cooler and deeper than unoccupied crevices, likely to avoid lethal air temperatures as well as predators. Artificial dens provided similar thermal properties to occupied dens, but lacked key characteristics in having shallower den cavities, less complex surrounding habitat, increased feral cat visitation, and less small mammal prey compared to occupied dens. This study highlights the need to consider multiple facets when constructing artificial refuges, in order to avoid perverse outcomes, such as inadequate shelter, increased predation, and food shortages.

ABSTRACT Soil stockpiling is a necessary component of opencast coal mining and, because most of the soils involved have arable potential, this involves the possibility of serious soil degradation. A study at four mines on the Highveld of South Africa involved sampling a number of stockpiles of various ages and origins. Samples were also collected from unmined adjacent soils, as well as rehabilitated areas. Results of stockpiling showed a deterioration in all physical and chemical parameters studied. The soil profile texture gradient was disturbed, due to mixing of surface and subsurface materials. Stockpile bulk density rose by 4% from unmined soils and by a further 6% in rehabilitated areas, indicating continuing compaction problems. Cation exchange capacity values did not entirely correspond with the textural changes, suggesting increased leaching, whereas pH values decreased for many stockpiles, requiring post-mining liming to re-establish suitable environments. Organic carbon levels on stockpiles fell by 5%,

and by a further 35% to rehabilitated areas. Increasing age of stockpile did not seem to equate to a correspond- ing increase in degradation, except possibly for pH, which showed a weak correlation. Recommendations from

the study include the use of ‘cut and cover’ rehabilitation techniques; continuous soil specialist consultation, and limitations on stockpile height and duration.___

This rewinding group puts out videos on their progress

cross-posted from: https://mander.xyz/post/2967556

I know I can send soil samples to my local university extension office for testing, but how do I test soil for glyphosate-based herbicides, lead, arsenic, and other contaminates?

As a citizen scientist I'm about to get into composting more on my property and would like to know more.

Organic amendments have been used to restore productivity to disturbed soils such as those on abandoned oil and natural gas wellsites. A study was conducted on three abandoned well- sites in southern Alberta, Canada to examine the effects of one-time applications of alfalfa (Medicago sativa L.) hay or beef cattle (Bos taurus) feedlot manure compost on soil properties under continuous wheat (Triticum aestivum L.). The base amendment rate (1×) [dry wt.] was 5.3 Mg ha−1 for compost and 3.1 Mg ha−1 for alfalfa. The fi ve amendment rates of 0, 1×, 2×, 4×, and 8× were soil-incorporated at the wellsites. Although approximately twice as much C was applied with alfalfa than with compost, fi nal SOC content was similar for the two amendment treatments, indicating the greater stability of compost-derived C. Nitrate N content in the 0- to 60-cm depth was not affected by compost rate (mean 213 kg ha−1) but increased by 7.78 kg ha−1 for each Mg ha−1 increase in alfalfa rate. This result refl ects the greater stability of compost-N compared with alfalfa-N and suggests a lower risk of NO3–N leaching with compost application. Compost rates >20 Mg ha−1 resulted in excessive extract- able P build-up in the topsoil (up to 95.7 mg kg−1), which may pose environmental risk to surface water. We recommend amending wellsites with up to 12 Mg ha−1 of alfalfa or <20 Mg ha−1 of compost during reclamation to improve C storage and nutrient cycling while minimizing nutrient loss to water systems.

Abstract Tomorrow’s forests face extreme pressures from contemporary climate change, invasive pests, and anthropogenic demands for other land uses. These pressures, collectively, demand land managers to reassess current and potential forest management practices. We discuss three considerations, functional restoration, assisted migration, and bioengineering, which are currently being debated in the literature and have the potential to be applied independently or concurrently across a variety of scales. The emphasis of functional restoration is to reestablish or maintain functions provided by the forest ecosystem, such as water quality, wildlife habitat, or carbon sequestration. Maintaining function may call upon actions such as assisted migration—moving tree populations within a species current range to aid adaptation to climate change or moving a species far outside its current range to avoid extinction—and we attempt to synthesize an array of assisted migration terminology. In addition, maintenance of species and the functions they provide may also require new technologies, such as genetic engineering, which, compared with traditional approaches to breeding for pest resistance, may be accomplished more rapidly to meet and overcome the challenges of invasive insect and disease pests. As managers develop holistic adaptive strategies to current and future anthropogenic stresses, functional restoration, assisted migration, and bioengineering, either separately or in combinations, deserve consideration, but must be addressed within the context of the restoration goal.

cross-posted from: https://slrpnk.net/post/1443350

https://web.archive.org/web/20230816012031/https://www.nytimes.com/2023/08/15/science/redwood-trees-logging-california.html

Great paper on how plants use P and how diversity can improve P use.

I tend to avoid posting theses due to their length, but this one is a good one for showing how capping depth tends to have a sweet spot around 15 cm or so.

Pinno looks at intensively planting Alder trees in the oil sands, similar to myawagi method