Forest soil biotic communities show few responses to wood ash applications at multiple sites across Canada

Abstract

There is interest in utilizing wood ash as an amendment in forestry operations as a mechanism to return nutrients to soils that are removed during harvesting, with the added benefit of diverting this bioenergy waste material from landfill sites. Existing studies have not arrived at a consensus on what the effects of wood ash amendments are on soil biota. We collected forest soil samples from studies in managed forests across Canada that were amended with wood ash to evaluate the effects on arthropod, bacterial and fungal communities using metabarcoding of F230, 16S, 18S and ITS2 sequences as well as enzyme analyses to assess its effects on soil biotic function. Ash amendment did not result in consistent effects across sites, and those effects that were detected were small. Overall, this study suggests that ash amendment applied to managed forest systems in amounts (up to 20 Mg ha−1) applied across the 8 study sties had little to no detectable effects on soil biotic community structure or function. When effects were detected, they were small, and site-specific. These non-results support the application of wood ash to harvested forest sites to replace macronutrients (e.g., calcium) removed by logging operations, thereby diverting it from landfill sites, and potentially increasing stand productivity.

MetaWorks: A flexible, scalable bioinformatic pipeline for high-throughput multi-marker biodiversity assessments

“…MetaWorks has already been used in several publications for the Canadian STREAM biomonitoring program, the Government of Canada, Genomics Research and Development Initiative, Metagenomics-based ecosystem biomonitoring (Ecobiomics) project, and by Natural Resources Canada [ 18 , 50 , 51 ]. The benefits of using an automated, scalable, versioned pipeline for biomonitoring are many-fold, from the ability to share reproducible workflows with collaborators to facilitate the re-analysis of data as more samples are collected from year-to-year.…”

Initial responses of influential microbial taxa to metal elements lead to alterations in the forest soil microbial community structure and function

“…Other than the C:N ratio, soil microbial communities are known to be responsive to differences in pH (Smenderovac et al 2022), which is widely recognized as an important soil property in altering microbial community diversity and functions (Lammel et al 2018;Tripathi et al 2018). Increasing acidic precipitation accompanying global climate change could reduce soil pH, thus increasing the availability of metal elements, and reshaping microbial community structure and association patterns (Zhang et al 2022).…”

Wood ash amendments as a potential solution to widespread calcium decline in eastern Canadian forests

“…In studies conducted in Canada, the impacts of wood ash on soil biota have thus far been minimal. A recent metabarcoding study using soil samples from managed forests across Canada revealed little to no effects of adding up to 20 t•ha −1 wood ash on the bacterial, fungal, and arthropod communities (Smenderovac et al 2022). Additionally, the community composition of soil microbes was largely unaffected by the addition of fly ash and bottom ash at doses of up to 5.8 t•ha −1 in field trials conducted in young boreal and mixed-age hardwood north-temperate forest soils in Ontario (Noyce et al 2016).…”