Manganese effects on plant residue decomposition and carbon distribution in soil fractions depend on soil nitrogen availability

Modeling Interactive Effects of Manganese Bioavailability, Nitrogen Deposition, and Warming on Soil Carbon Storage

“…These combined effects drove an increase in total MAOM from very low to moderate levels of bioavailable Mn, but a decrease in MAOM at the highest levels of Mn bioavailability as more C was released as CO 2 (Figure 3d). Neupane et al (2023) similarly reported increased CO 2 production and C transfer from POM to MAOM stocks with Mn addition to agricultural soils (Neupane et al, 2023). Overall, total soil C stocks, including the forest floor and mineral soil layers, decreased with higher bioavailable Mn (Figure 4c), similar to patterns observed across multiple biomes (Kranabetter, 2019;Santos & Herndon, 2023;Stendahl et al, 2017).…”

Reply on RC1

“…Because of the infrequent sampling in the incubation studies, the whole pattern of increasing and decreasing MAOM has not been observed so far. For example, C in MAOM increased through time in some studies (Cheng et al, 2023;Neupane et al, 2023;Fulton-Smith and Cotrufo, 2019;Leichty et al, 2021), but in others it decreased (Throckmorton et al, 2015;Wang et al, 2017;Su et al, 2020). N in MAOM tends to increase through time in most studies (Mitchell et al, 2018;Fulton-Smith and Cotrufo, 2019;Nunez et al, 2022), but it can also decrease (Kölbl et al, 2006).…”

“…Reported negative values for any of the considered quantities were removed, but if primary data showed major inconsistencies (e.g., negative fractions of remaining residues) that could not be explained even after contacting the authors, the whole study was excluded. After this screening, the database contained data from 39 published articles (Magid et al, 2002;Kölbl et al, 2006Kölbl et al, , 2007Cotrufo et al, 2015Cotrufo et al, , 2022Throckmorton et al, 2015;Haddix et al, 2016Haddix et al, , 2020Lian et al, 2016;Pries et al, 2017Pries et al, , 2018Wang et al, 2017;Lavallee et al, 2018;Mitchell et al, 2018;Fang et al, 2019;Fulton-Smith and Cotrufo, 2019;Sokol et al, 2019;Liebmann et al, 2020;Su et al, 2020;Almeida et al, 2021;Ferreira et al, Xu et al, 2022;Canisares et al, 2023;Cheng et al, 2023;Duan et al, 2023;Kou et al, 2023b;Lyu et al, 2023;Neupane et al, 2023;Poeplau et al, 2023;Schiedung et al, 2023;Even and Cotrufo, 2024). Some datasets were directly accessible from online repositories (Buckeridge, 2021;Craig et al, 2021;Huys et al, 2022b;Kou et al, 2023a;Ridgeway et al, 2023a).…”

“…A diagnostic model able to interpret observed C and N dynamics in residue, POM, and MAOM during decomposition can be useful also to reconcile different trends that have been reported. In fact, residue-derived POM can both increase (Fulton-Smith and Cotrufo, 2019;Leichty et al, 2021) or decrease through time (Cheng et al, 2023;Neupane et al, 2023). Also MAOM can exhibit contrasting trends (increasing in the studies cited above, but decreasing in e.g., Wang et al, 2017).…”

Reply on RC2

“…Reported negative values for any of the considered quantities were removed, but if primary data showed major inconsistencies (e.g., negative fractions of remaining residues) that could not be explained even after contacting the authors, the whole study was excluded. After this screening, the database contained data from 39 published articles (Magid et al, 2002;Kölbl et al, 2006Kölbl et al, , 2007Cotrufo et al, 2015Cotrufo et al, , 2022Throckmorton et al, 2015;Haddix et al, 2016Haddix et al, , 2020Lian et al, 2016;Pries et al, 2017Pries et al, , 2018Wang et al, 2017;Lavallee et al, 2018;Mitchell et al, 2018;Fang et al, 2019;Fulton-Smith and Cotrufo, 2019;Sokol et al, 2019;Liebmann et al, 2020;Su et al, 2020;Almeida et al, 2021;Ferreira et al, Xu et al, 2022;Canisares et al, 2023;Cheng et al, 2023;Duan et al, 2023;Kou et al, 2023b;Lyu et al, 2023;Neupane et al, 2023;Poeplau et al, 2023;Schiedung et al, 2023;Even and Cotrufo, 2024). Some datasets were directly accessible from online repositories (Buckeridge, 2021;Craig et al, 2021;Huys et al, 2022b;Kou et al, 2023a;Ridgeway et al, 2023a).…”