00502nas a2200133 4500008004100000022001400041245009800055210006900153100002200222700002400244700002200268700002300290856005500313 2025 eng d a1752-089400aDecadal persistence of grassland soil organic matter derived from litter and pyrogenic inputs0 aDecadal persistence of grassland soil organic matter derived fro1 aLeuthold, Sam, J.1 aSoong, Jennifer, L.1 aEven, Rebecca, J.1 aCotrufo, Francesca uhttps://www.nature.com/articles/s41561-025-01638-y02649nas a2200277 4500008004100000245010000041210007100141300001400212490000700226520171400233653000901947653002501956653001401981653002801995653002902023653002002052653002202072100002402094700002602118700002402144700001502168700002002183700002302203700001502226856013002241 2017 eng d00aBelow‐ground biological responses to pyrogenic organic matter and litter inputs in grasslands0 aBelow‐ground biological responses to pyrogenic organic matter an a260 - 2690 v313 a

1. Terrestrial ecosystems are often burned by both managed and wildfires. During a fire, the above-ground biomass that would typically accumulate and be decomposed as litter on the soil surface is combusted. Pyrogenic organic matter (PyOM) remaining after a fire is a considerably more recalcitrant organic input to the soil than fresh litter. The activity and community composition of soil organisms responsible for decomposition of organic matter and nutrient recycling in the soil could thus be affected by altered resource availability caused by frequent fires.

2. We examined the effect of PyOM vs. fresh litter inputs to soil biota at both an annually burned and an infrequently burned tallgrass prairie site by tracing (13) C-and N-15-labelled litter and PyOM into growing plant roots, microbial phospholipid fatty acids (PLFAs) and soil nematodes for 1 year.

3. Litter-derived C or N was incorporated into microbes, nematodes and roots, while PyOM contributed minimally to soil microbes and plant roots and was not detectable in nematodes. Soil microbial and nematode abundances in the PyOM amended plots did not significantly differ from the bare soil plots, but nematodes were more abundant and microbial PLFAs less abundant in litter-amended plots. The annually burned site had less predator and omnivore nematodes, with increased abundance of microbial feeders and greater microbial uptake of litter C.

4. An alteration of the soil food web structure caused by burning and the removal of the litter layer, along with the accumulation of non-microbially decomposed PyOM in the soil, contributes to the limitation of N cycling in frequently burned ecosystems.

10afire10alitter decomposition10aNematodes10aphospholipid fatty acid10apyrogenic organic matter10aStable isotopes10atallgrass prairie1 aNicolson, Susan, W.1 aWright, Geraldine, A.1 aSoong, Jennifer, L.1 aDam, Marie1 aWall, Diana, H.1 aCotrufo, Francesca1 aSala, Anna uhttp://129.130.186.12/content/below%E2%80%90ground-biological-responses-pyrogenic-organic-matter-and-litter-inputs-grasslands02223nas a2200253 4500008004100000022001400041245009500055210006900150260001600219300001400235490000600249520143500255653002001690653002801710653002801738100001801766700002401784700002301808700002601831700001501857700002001872700002401892856005301916 2015 eng d a1752-089400aFormation of soil organic matter via biochemical and physical pathways of litter mass loss0 aFormation of soil organic matter via biochemical and physical pa cJul-09-2015 a776 - 7790 v83 aSoil organic matter is the largest terrestrial carbon pool1. The pool size depends on the balance between formation of soil organic matter from decomposition of plant litter and its mineralization to inorganic carbon. Knowledge of soil organic matter formation remains limited2 and current C numerical models assume that stable soil organic matter is formed primarily from recalcitrant plant litter3. However, labile components of plant litter could also form mineral-stabilized soil organic matter4. Here we followed the decomposition of isotopically labelled above-ground litter and its incorporation into soil organic matter over three years in a grassland in Kansas, USA, and used laboratory incubations to determine the decay rates and pool structure of litter-derived organic matter. Early in decomposition, soil organic matter formed when non-structural compounds were lost from litter. Soil organic matter also formed at the end of decomposition, when both non-structural and structural compounds were lost at similar rates. We conclude that two pathways yield soil organic matter efficiently. A dissolved organic matter–microbial path occurs early in decomposition when litter loses mostly non-structural compounds, which are incorporated into microbial biomass at high rates, resulting in efficient soil organic matter formation. An equally efficient physical-transfer path occurs when litter fragments move into soil.10aBiogeochemistry10aEnvironmental chemistry10aStable isotope analysis1 aCotrufo, M.F.1 aSoong, Jennifer, L.1 aHorton, Andrew, J.1 aCampbell, Eleanor, E.1 aHaddix, L.1 aWall, Diana, H.1 aParton, William, J. uhttp://www.nature.com/doifinder/10.1038/ngeo2520