Microbial inoculation influences arbuscular mycorrhizal fungi community structure and nutrient dynamics in temperate tree restoration

Abstract

Soil microbial communities have a profound influence on soil chemical processes and subsequently influence tree nutrition and growth. This study examined how the addition of a commercial inoculum or forest‐collected soils influenced nitrogen (N) and phosphorus (P) dynamics, soil microbial community structure, and growth in Liriodendron tulipifera and Prunus serotina tree saplings. Inoculation method was an important determinant of arbuscular mycorrhizal fungi (AMF) community structure in both species and altered soil N dynamics in Prunus and soil P dynamics in Liriodendron. Prunus saplings receiving whole forest soil transfers had a higher rhizosphere soil carbon/nitrogen ratio and ammonia content at the end of the first growing season when compared to unmanipulated control saplings. Inoculation with whole forest soil transfers resulted in increased inorganic phosphorus in Liriodendron rhizosphere soils. The number of AMF terminal restriction fragments was significantly greater in rhizosphere soils of Liriodendron saplings inoculated with whole forest soil transfers and Prunus saplings receiving either inoculum source than control saplings. Forest soil inoculation also increased AMF colonization and suppressed stem elongation in Liriodendron after 16 months; conversely, Prunus AMF colonization was unchanged and stem elongation was significantly greater when saplings were inoculated with whole forest soil transfers. Longer term monitoring of tree response to inoculation will be essential to assess whether early costs of AMF colonization may provide long‐term benefits. This study provides insight into how practitioners can use microbial inoculation to alter AMF community structure and functioning, subsequently influencing tree growth and nutrient cycling during the restoration of degraded lands.

High‐throughput sequencing provides insight into manipulated soil fungal community structure and diversity during temperate forest restoration

“…We found a significant influence of inoculation of rhizosphere fungal community structure in Liriodendron and a weakly significant influence in Quercus; Prunus rhizosphere fungal community structure, however, did not differ between soil treatments. Species‐specific responses to inoculation have been noted previously in temperate trees (St Denis et al ; Lance et al ) and our current study provides further evidence that broadly applicable inoculation protocols are unlikely to be easily developed. Species‐specific inocula, which could be developed using HTS technologies, may result in the best tree growth and performance in restoration contexts.…”

“…Our hypotheses were that the inoculation method would lead to distinct fungal community structure and that soil samples from trees inoculated with whole soil transfers would display greater OTU richness and Shannon's diversity than commercial or control trees. Previous work in this system demonstrated that inoculation with whole soil transfers resulted in an increase in the number of terminal restriction fragments recovered in rhizosphere soils (Lance et al ). Our current approach implements HTS technology to further examine the influence of inoculation on soil fungal community structure and diversity.…”

Rewilding with invertebrates and microbes to restore ecosystems: Present trends and future directions

“…litter transplants with the purpose of improving decomposition rates during restoration have not been attempted before (Box 1).Although the direct mechanisms by which whole-of-community rewilding improves ecosystem function is likely highly contextual, this practice can influence a broad range of functions, including; nutrient dynamics(Lance et al, 2019), plant growth(Emam, 2016),…”

Individual Plant-Soil Feedback Effects Influence Tree Growth and Rhizosphere Fungal Communities in a Temperate Forest Restoration Experiment

“…Therefore, planting a phylogenetically diverse tree restoration site could result in a more diverse fungal community. Future studies should measure ecosystem function (Lance et al, 2019), especially across a phylogenetic diversity gradient in tree restoration.…”

“…Practitioners looking to collect soils for use as an inoculant could either avoid collecting from mature conspecific individuals if pathogens are found to have a primary influence on tree survivorship and growth (e.g., Packer and Clay, 2000), or conversely, target mature conspecific individuals if specific mutualisms elicit improved tree performance (e.g., den Bakker et al, 2004;Ishida et al, 2007). Plant-soil feedbacks that result from the conditioning of soil communities by different focal tree species have a profound influence on the microbial composition of forest soil transfers and the subsequent response of plants to inoculation during restoration (Wubs et al, 2016;Lance et al, 2019). Understanding the factors that influence the development of plant-soil feedbacks is essential to developing best practices for soil microbial community manipulation and is critical for ecological restoration of temperate forest communities.…”