Soil Carbonate Dominates Calcium-Bound Organic Carbon Storage at the Continental Scale.

Mixing native broadleaved tree species is a widely used method for renovating Pinus massoniana plantations. Soil microbial necromass carbon and organic carbon fractions are important parameters for evaluating the impacts of tree species mixing and soil organic carbon (SOC) stability. However, their responses to the mixing and renovation of P. massoniana plantation has not been understood yet. Here, we selected a pure P. massoniana plantation (PP) and a mixed P. massoniana and Castanopsis hystrix plantation, with ages of 16 (MP16) and 38 years (MP38), respectively, as the research objects. We quantified soil physical and chemical properties, microbial necromass carbon content, and organic carbon components at different soil layers to reveal whether and how the introduction of C. hystrix into P. massoniana plantation affected soil microbial necromass carbon and organic carbon components. The results showed that the mixed P. massoniana and C. hystrix plantation significantly reduced fungal necromass carbon content and the ratio of fungal/bacterial necromass carbon in the 0-20 cm and 20-40 cm soil layers. There were no significant differences in microbial necromass carbon contents, bacterial necromass carbon contents, and their contributions to SOC among the different plantations. The contribution of fungal necromass carbon to SOC was higher than that of bacterial necromass carbon in all plantation types. The contribution of soil mineral-associated organic carbon (MAOC) to SOC was higher than that of occluded particulate organic carbon (oPOC) and light-free particulate organic carbon (fPOC) for all plantation types. Mixing the precious broadleaved tree species (i.e., C. hystrix) with coniferous species (P. massoniana) significantly increased MAOC content and the contribution of MAOC, oPOC, and fPOC to SOC in the 0-20 cm and 20-40 cm soil layers. The MAOC of MP38 was significantly higher than that of PP in all soil layers and the MAOC of MP38 stands were significantly higher than MP16 stands in the 20-40 cm, 40-60 cm, and 60-100 cm soil layers, indicating that hybridization enhanced SOC stability and that the SOC of MP38 stands were more stable than MP16 stands. SOC and total nitrogen contents were the main environmental factors driving the changes in soil microbial necromass carbon, while soil total nitrogen and organically complexed Fe-Al oxides were the primary factors affecting organic carbon fraction. Therefore, SOC stability can be enhanced by introducing native broadleaved species, such as C. hystrix, during the management of the P. massoniana plantation.

Tidal marshes serve as critical carbon (C) sinks, yet face increasing threats from global environmental changes. While previous research has documented how nitrogen (N) loading and sea‐level rise affect total C pools individually, their impacts on soil organic carbon (SOC) stabilization remain critically underexplored, particularly when these factors co‐occur in tidal marsh ecosystems. Through a 3‐yr field experiment, we analyzed how these factors, alone and combined, impact SOC stabilization by examining SOC fraction dynamics. Results showed that N loading increased particulate organic carbon (POC) by 18% and decreased mineral‐associated organic carbon (MAOC) by 13%, reducing SOC stabilization. Conversely, increased inundation raised MAOC by 31% and decreased POC by 19%, promoting SOC stabilization. The decreased MAOC under N loading stemmed from reduced fungal necromass C, while the increased POC related to lower phenol oxidase activity. In contrast, with increased inundation, MAOC rose due to iron‐bound organic C (Fe‐OC) accumulation, while POC declined from increased phenol oxidase activity. When both factors were applied together, SOC stabilization remained at control levels. This occurred because the combined effect maintained oxidative enzyme activities and thus retained POC levels. The simultaneous reduction in fungal necromass C and enhancement of Fe‐OC associations established complementary mechanisms that maintained MAOC at levels equivalent to control. Our findings reveal that N loading and increased inundation drive contrasting patterns of SOC stabilization, while their combination produces uniquely stabilized C dynamics. This insight challenges single‐factor predictions and underscores the importance of multi‐factor experiments in understanding ecosystem responses under concurrent global change scenarios.

Greater variation of soil organic carbon in limestone- than shale-based soil along soil depth in a subtropical coniferous forest within a karst faulted basin of China

PDF HTML阅读 XML下载 导出引用 引用提醒 滇南地区桃树种植模式对土壤有机碳组分及碳库管理指数的影响 DOI: 10.5846/stxb202112103508 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（42071127）；云南大学人才项目（C176220100083） Effects of peach tree planting patterns on soil organic carbon fractions and carbon pool management index in southern Yunnan Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:经果林种植可改变土壤质量、改善生态环境，同时具有较高的经济效益。合理的种植模式可通过物种间的互补性提高资源利用效率，改善土壤碳库质量并提高综合效益。为探讨桃树种植模式对土壤有机碳组分及碳库管理指数的影响，以云南省开远市不同桃树种植模式（桃树单种-SP和桃树南瓜套种-PP）为研究对象，以毗邻的天然林地（CK）为对照，分析不同种植模式下活性碳库，即高锰酸钾氧化有机碳（POXC）、颗粒有机碳（POC），惰性有机碳库即矿物结合态有机碳（MAOC）在0-40 cm土层的分布情况，明确土壤有机碳组分与土壤理化性质的关系；计算碳库活度指数（CPAI）、碳库指数（CPI）以及碳库管理指数（CPMI），明确不同桃树种植模式的碳库变化情况。结果表明：桃树种植模式和对照的土壤有机碳组分的含量均随着土层深度的增加而减少，平均土壤有机碳（SOC）含量为：14.68 g/kg （CK）>9.57 g/kg （PP）>8.58 g/kg （SP）。平均活性有机碳组分所占比例与POC/MAOC均表现为：SP>CK>PP，PP的活性有机碳比例较低，具有较高的有机碳稳定性。两种桃树种植模式的CPMI在10-20 cm土层达到最大值；相较于PP，SP具有较高的CPAI （1.10），而PP则具有更高的CPMI （69.51），表明PP的碳库稳定性和土壤碳库质量均优于SP。桃树种植模式、土层深度以及二者的交互作用对土壤有机碳组分及其分配比例存在不同程度的影响。冗余分析结果显示砂粒、pH是影响不同桃树种植模式以及不同土层深度下土壤有机碳组分及土壤有机碳库的主要环境因子。综上，PP是较好的种植模式，有利于有机碳的固存。经果林的种植应根据土壤性质、碳库基本情况和氮磷等养分的有效性等采取适宜的管理措施，增强其固碳效率和碳汇水平。 Abstract:The ecological environment in southern Yunnan is fragile with serious land degradation. Economic orchard, as a major ecological management, has a certain effect on organic carbon sequestration. Reasonable planting patterns can improve resource utilization efficiency through the complementarity between species, increasing the quality of soil carbon pool and obtaining higher comprehensive benefits. This study was carried out on different planting patterns of peach single species (SP) and peach pumpkin interplanting (PP), located in Taoyuan Village, Kaiyuan City, Yunnan Province. Taking the adjacent natural forest (CK) as control, soil organic carbon (SOC), permanganate oxidizable carbon (POXC), particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) were measured in 0-40 cm soil layer at an interval of 10 cm. Meanwhile, we calculated carbon pool activity index (CPAI), carbon pool index (CPI) and carbon pool management index (CPMI). Our objective was to investigate the effects of peach tree planting patterns on the stability of soil organic carbon and CPMI and clarify the relationship between soil organic carbon fractions and soil physicochemical properties. The results showed that the content of soil organic carbon fractions of the peach tree planting patterns and the control decreased with the increase of soil depths, the average SOC content were 14.68 g/kg (CK), 9.57 g/kg (PP), 8.58 g/kg (SP), respectively. The proportion of average POC, POXC and POC/MAOC showed as SP>CK>PP. PP had a lower proportion of active organic carbon with better organic carbon stability. Moreover, the CPMI of both peach tree planting patterns were lower than CK and reached the maximum value in the layer of 10-20 cm. SP had a higher CPAI (1.10), while PP had a higher CPMI (69.51), indicating that the stability and quality of PP soil carbon pool was better than that of SP. SOC, POXC, POC, and MAOC were all significantly positively correlated with sand, C/N, available phosphorus, exchangeable potassium, pH, and total phosphorus (in order of correlation). Peach tree planting patterns, soil depth and their interaction had different effects on soil organic carbon fractions and its proportion. Redundancy analysis also showed that sand and pH were the main environmental factors affecting the soil organic carbon fractions and soil organic carbon pool under different peach tree planting patterns and soil depths. We concluded that peach tree planting patterns changed the SOC and its fractions. Here, we consider PP as a better planting pattern, which is beneficial to organic carbon sequestration. Appropriate management measures should be taken according to the soil properties, basic situation of carbon pool and the effectiveness of nutrients such as nitrogen and phosphorus, so as to enhance the carbon sequestration efficiency and carbon sink level while improving the economic benefits. 参考文献 相似文献 引证文献

Effects of warming on soil organic carbon pools mediated by mycorrhizae and hyphae on the Eastern Tibetan Plateau, China

Based on a long-term positioning experiment established in 2017 with biochar derived from Eucalyptus plantation waste branches pyrolyzed at high temperature （500℃） under anaerobic conditions， six treatments were established： CK （0%）， T1 （0.5%）， T2 （1.0%）， T3 （2%）， T4 （4%）， and T5 （6%）. The study explored the changes in soil organic carbon （SOC）， labile organic carbon （LOC）， carbon pool management index （CPMI）， and the chemical structure of organic carbon after a single application of different amounts of biochar over 5 years. The study produced several results： ① Compared to the control， biochar application significantly increased the contents of SOC， LOC， particulate organic carbon （POC）， non-labile organic carbon （NLOC）， and mineral-associated organic carbon （MOC） （P<0.05）， with larger increments at high application rates （T4 and T5 treatments）. The soil CPMI showed a significant increasing trend with increase of biochar application. ② Biochar application increased the relative contents of alkyl carbon and aromatic carbon in the soil， while decreasing the relative contents of alkoxy carbon and carboxyl carbon （P<0.05）. At high application rates， there was a significant increase in the alkyl carbon/alkoxy carbon ratio， hydrophobic carbon/hydrophilic carbon ratio， and aromatic carbon/alkoxy carbon ratio， and a decrease in the lipid carbon/aromatic carbon ratio （P<0.05）， with an increased trend toward aromaticity. ③ Correlation and principal component analyses revealed that the soil CPMI was significantly positively correlated with SOC， LOC， POC， alkyl carbon， aromatic carbon， pH value， soil moisture content， total nitrogen， total phosphorus， total potassium， available nitrogen， available phosphorus， available potassium， microbial biomass carbon， microbial biomass nitrogen， and MOC （P<0.01）. It was also positively correlated with MOC （P<0.05） and negatively correlated with alkoxy carbon， carboxyl carbon， and soil bulk density （P<0.01）. Redundancy analysis indicated that soil bulk density， LOC， SOC， total potassium， POC， microbial biomass carbon， and available potassium were key environmental factors affecting the soil CPMI and the chemical structure of organic carbon. In conclusion， the application of biochar to Eucalyptus plantation through 5 years improved soil quality， which is beneficial for enhancing soil carbon sequestration capacity and increasing the stability of soil organic carbon.

Enhancing soil fertility and organic carbon stability with high-nitrogen biogas slurry: Benefits and environmental risks.

Flooding is one of the key environmental factors affecting the carbon sequestration potential of estuarine tidal flat wetlands. In order to reveal the effect of flooding on soil carbon (C) sinks in estuarine tidal wetlands, we investigated and analyzed the soil organic carbon (SOC) storage, the contents of active SOC components, and SOC stability indicators across a tidal flat in the Jiulong River estuary in southeast China. The results showed that the SOC storage gradually decreased by 54% with the increase in flooding frequency. The change pattern of microbial biomass carbon (MBC), dissolved organic carbon (DOC), and liable organic carbon (LOC) followed the change pattern of the SOC storage. With the increase in flooding frequency, DOC/SOC and LOC/SOC increased by 80% and 26%, respectively, whereas MBC/SOC decreased by 29%. As flooding frequency increased, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) contents decreased by 81% and 35%, respectively. The decreases in POC contents were correlated with the increases in soil pH, whereas the decreases in MAOC contents were associated with the decline in clay contents. Soil carbon stability index (CSI) increased by 246% with increasing flooding frequency. These combined results indicated that SOC storage decreased, but SOC stability increased, with the increased flooding frequency. Mineral-bound organic carbon was the main protection mechanism for the SOC stability, which was of great significance to the soil C sink of the estuarine tidal wetlands.

Soil organic carbon (SOC) fractions are vital intrinsic indicators of SOC stability, and soil fungi are the key drivers of soil carbon cycling. However, variations in SOC fractions along an elevational gradient in mountain meadows and the role of the fungal community in regulating these variations are largely unknown, especially in subtropical areas. In this study, an elevation gradient experiment (with experimental sites at 1500, 1700, and 1900 m) was set up in a Miscanthus sinensis community in a meadow on Wugong Mountain, Southeast China, to clarify the effects of elevation on soil fungal community composition, microbial residue carbon, and SOC fractions. The results showed that the contribution of soil microbial residue carbon to SOC was only 16.1%, and the contribution of soil fungal residue carbon to SOC (15.3%) was far greater than that of bacterial residue carbon (0.3%). An increase in elevation changed the fungal community structure and diversity, especially in the topsoil (0-20 cm depth) compared with that in the subsoil (20-40 cm depth), but did not affect fungal residue carbon in the two soil layers. When separating SOC into the fractions mineral-associated organic carbon (MAOC) and particulate organic carbon (POC), we found that the contribution of MAOC (66.6%) to SOC was significantly higher than that of POC (20.6%). Although an increased elevation did not affect the SOC concentration, it significantly changed the SOC fractions in the topsoil and subsoil. The soil POC concentration and its contribution to SOC increased with an increasing elevation, whereas soil MAOC showed the opposite response. The elevational variations in SOC fractions and the POC/MAOC ratio were co-regulated by the fungal community structure and total nitrogen. Our results suggested that SOC stabilization in mountain meadows decreases with an increasing elevation and is driven by the fungal community structure, providing scientific guidance for SOC sequestration and stability in mountain meadows in subtropical areas.

Soil organic carbon dynamics: Impact of land use changes and management practices: A review

Vegetation restoration altered the soil organic carbon composition and favoured its stability in a Robinia pseudoacacia plantation

Soil organic carbon response to global environmental change depends on its distribution between mineral-associated and particulate organic matter: A meta-analysis

Anthropogenic disturbance is an important driver factor of global change, greatly affects the soil organic carbon (SOC) storage. However, the long-term impacts of anthropogenic disturbance on SOC stability in hyperarid deserts remain poorly understood. Through a 16-year anthropogenic disturbance experiment, we evaluated SOC dynamics in hyper-arid desert ecosystems under five treatments: no-disturbance (CK), spring harvest, autumn harvest, fire, and irrigation (simulating artificial flooding). We analyzed SOC composition, sources, and drivers across six soil layers (0-5, 5-15, 15-30, 30-60, 60-100, and 100-150 cm). Results revealed that disturbance ways and particulate organic carbon (POC) dominated SOC variations in topsoil (0-15 cm), while microbial-derived C and plant-derived C controlled subsoil (100-150 cm) dynamics. With the increase of soil depth, the concentrations of SOC, POC, microbial-derived C, and plant-derived C continuously decreased. All disturbance treatments significantly reduced SOC pools compared to CK, with average decreases of 13.2% (SOC), 16.3% (POC), 41.1% (mineral-associated organic carbon, MAOC), 4.2% (plant-derived C), and 16.2% (microbial-derived C). Rises in POC/MAOC (+46.2%), β-1,4-glucosidase/SOC (+21.6%), and cellobiohydrolase/SOC (+13.6%) signify disturbance-induced SOC stability reduction. Autumn harvest and irrigation disturbances caused the largest SOC losses, with SOC reductions of 20% and 21%, respectively, compared to CK. Mechanistically, plant-derived C depletion correlated with reduced plant C inputs, while microbial-derived C decline was linked to altered mineral properties (exchangeable Ca, noncrystalline oxides and free oxides) and microbial properties (enzymes, microbial biomass, fungi and bacteria). Overall, our findings demonstrate that 16 years of anthropogenic disturbance exacerbated SOC loss in hyper-arid deserts, particularly in topsoil. However, the subsoil organic C pool (> 100 cm) mediated by microbial- and plant-derived C also warrants further attention. This study provides the first empirical evidence quantifying depth-specific SOC vulnerability in hyperarid deserts under sustained human pressures, highlighting the critical need to integrate subsurface C dynamics into desert ecosystem management strategies.

Changes in long-term land use alter deep soil microbial necromass and organic carbon stabilization.

The integration of manure and straw substantially affects soil organic carbon (SOC) dynamics, transformation, and long-term stabilization in agricultural systems. Dissolved organic carbon (DOC), particulate organic carbon (POC), and mineral-associated organic carbon (MOC) are the three main components of the SOC pool, each influencing soil carbon dynamics and nutrient cycling. Current research gaps remain regarding how combined fertilization practices affect the inputs of plant-originated and microbe-derived carbon into SOC pools and stability mechanisms. Our investigation measured SOC fractions (DOC, POC, MOC), SOC mineralization rate (SCMR), microbial necromass carbon, lignin phenols, enzyme activities, and microbial phospholipid fatty acids (PLFAs) over a long-term (17 years) field experiment with four treatments: mineral fertilization alone (CF), manure-mineral combination (CM), straw-mineral application (CS), and integrated manure-straw-mineral treatment (CMS). The CMS treatment exhibited notably elevated levels of POC (7.42 g kg−1), MOC (10.7 g kg−1), and DOC (0.108 g kg−1), as well as a lower SCMR value (1.85%), compared with other fertilization treatments. Additionally, the CMS treatment stimulated the buildup of both bacterial and fungal necromass while enhancing the concentrations of ligneous biomarkers (vanillin, syringyl, and cinnamic derivatives), which correlated strongly with the elevated contents of fungal and bacterial PLFAs and heightened activity of carbon-processing enzymes (α-glucosidase, polyphenol oxidase, cellobiohydrolase, peroxidase, N-acetyl-β-D-glucosidase). Furthermore, fungal and bacterial microbial necromass carbon, together with lignin phenols, significantly contributed to shaping the composition of SOC. Through random forest analysis, we identified that the contents of bacterial and fungal necromass carbon were the key factors influencing DOC and MOC. The concentrations of syringyl phenol and cinnamyl phenols, and the syringyl-to-cinnamyl phenols ratio were the primary determinants for POC, while the fungal-to-bacterial necromass carbon ratio, as well as the concentrations of vanillyl, syringyl, and cinnamyl phenols, played a critical role in SCMR. In conclusion, the manure combined with straw incorporation not only promoted microbial growth and enzyme activity but also enhanced plant- and microbial-derived carbon inputs. Consequently, this led to an increase in the contents and stability of SOC fractions (DOC, POC, and MOC). These results suggest that manure combined with straw is a viable strategy for soil fertility due to its improvement in SOC sequestration and stability.