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The decline in primary natural forests worldwide has intensified research on the effects of forest transformation on soil carbon (C), nitrogen (N), and phosphorus (P) cycles and stocks. However, the extent to which soil C, N, and P stocks and stoichiometry are affected by forest conversion remains unclear. Here, we examined the effects of forest transformation on soil nutrient storage capacity and stoichiometric characteristics in native broadleaf forests (BFs), plantation forests (PFs), tea gardens (TGs), cultivated lands (CLs), and urban artificial green spaces (GSs) at a county scale in subtropical China. The results showed that the other forest types exhibited significantly reduced soil C and N contents and stocks but increased soil P content and stock compared to BFs. The soil C:N:P stoichiometric ratios for BFs and the converted PFs, TGs, GSs, and CLs were sequentially decreased as follows: 444.8:24.2:1, 95.0:10.0:1, 30.2:3.9:1, 23.1:3.7:1, and 19.4:1.9:1, respectively. Within the altitude (AL) span of 180 to 1200 m surveyed, the AL decided the type of forest conversion and significantly influenced the stock levels and stoichiometric ratios of soil C, N, and P. The results of this study highlight the importance of the ecological management of TGs and the optimization of soil P production in CLs, TGs, and GSs. [ABSTRACT FROM AUTHOR]

Context: The goal of increasing sequestration of carbon (C) in soil assumes that management factors can be as influential as intrinsic factors such as climate and parent material. Aim: The hypotheses tested in this study were (i) that soil C would increase more in limed than in unlimed pasture treatments, and (ii) that well-managed perennial pasture treatments would accumulate soil C to a greater depth than annual pasture treatments. Method: An 18-year field experiment was conducted on a duplex soil in the mixed farming zone of south-eastern Australia. The experiment contained four treatment contrasts: limed and unlimed perennial and annual pasture systems. Soils samples to 120 cm were taken annually and analysed for C and nitrogen (N) concentrations. Soil C and N stocks were calculated. Key results: The four treatments produced a similar annual rate of increase in soil C concentration and C stocks. The increase in C stock was confined to the surface 30 cm of soil in all four treatments, leading to the rejection of both hypotheses. Nitrogen concentration and N stocks to 30 cm depth increased significantly over the 18 years, with no difference among treatments. Conclusion: Pasture land use increased soil C storage by ~700 kg ha−1 year−1; however, the increase was confined to the surface soil. Implication: The soil C sequestered in this duplex soil is vulnerable to erosion. The co-retained N might have more value from both production and environmental perspectives. Accumulation of soil organic carbon is considered beneficial to both farm productivity and the environment. Although conservation farming might make little direct contribution to soil carbon stocks, it is likely to be essential for the retention of soil carbon stores in duplex soils. Conversely, the co-retained nitrogen might have more value than the carbon stocks. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate carbon and (C) and nitrogen (N) of the light organic matter in labile and humic fractions of the soil in a chronosequence of clonal Eucalyptus urophylla. The study was carried out on six different sites in the South-Central region of Maranhão state, northeastern Brazil, inserted in the Cerrado biome. Soil was sampled in five clonal Eucalyptus urophylla S.T. Blake stands of different ages and one in the area with old-growth forest (OG), which represents the native vegetation area. Soil samples were collected in the 0–20, 20–40, and 40–60 cm layers to determine textural class, bulk density, C, and N in the light organic matter of labile and humic fractions. Eucalyptus plantations can have great capacity to increase stocks of soil C and N, humic, and labile fractions over the years, presenting results equal or higher than a native Cerrado forest. Thus, Eucalyptus plantations come as an effective lad use to sink C and increase soil nutrient levels. [ABSTRACT FROM AUTHOR]

The composition of vegetation cover in Arctic environments is evolving due to climate change. This study focused on estimating carbon and nitrogen stocks in vegetation and soil for different Arctic habitats (i.e., sub-ecosystem environments) with contrasted plant communities and soil profiles, to better understand the spatial variation of these stocks and the relationships between aboveground vegetation and soil characteristics in these environments. Vegetation composition and soil characteristics were measured in different habitats in a mire and a heathland ecosystem in northern Sweden. Multivariate analyses were used to define dominant vegetation and soil profile types, and carbon and nitrogen stocks were computed and compared across these types. Shrub-dominated and graminoid-dominated vegetation types presented similar carbon stocks but different nitrogen stocks, and shrub-dominated environments presented significantly higher proportions of their stocks distributed in the long-lived (i.e., woody) compartment. Soil stocks varied considerably between ecosystems. However, no clear relationships could be established between current vegetation community composition and soil carbon and nitrogen stocks across environments. The increase in shrub or graminoid abundance may affect carbon and nitrogen cycles most through biomass distribution between plant compartments rather than through the absolute stocks they represent. Ultimately, in Arctic and subarctic ecosystems experiencing climate change, the interactions between plant biomass composition and soil characteristics could have contrasted consequences for ecological functioning and C and N cycles.

• Soil carbon stocks were measured across land-uses in the Cerrado of Northeast Brazil. • Integrated crop-livestock systems increase soil C and N stocks. • Long-term continuous input of plant residues governs C and N stabilization. • Integrated systems can sequester C in soils of Cerrado in Northeast Brazil. The adoption of integrated systems can reduce the pressure for the conversion of areas under native Cerrado to agricultural lands. However, little is known about how these systems affect total organic carbon pools and stocks in the Cerrado of Northeast Brazil. We aimed to evaluate the dynamics of soil organic carbon (SOC) and C and N stocks in a Cerrado under different cropping systems, in the agricultural frontier of Matopiba, Brazil. The systems were (i) Native Cerrado vegetation (NCF), (ii) integrated crop-livestock-forest system (ICLF), (iii) integrated crop-livestock system under no-tillage (ICL1), (iv) integrated crop-livestock with recent soil tillage (ICL2), and (v) pasture (PA). Soil samples were collected at 0.0–0.10, 0.10–0.20, 0.20–0.30, and 0.30–0.50 m depths to determine the soil C and N stocks, SOC fractions, and the carbon management index (CMI). Total C stocks in the 0.0–0.50 m soil profile were highest in ICL2 (127 Mg ha−1), ICL1 (112 Mg ha−1), and PA (101 Mg ha−1) and lowest in NCF (61 Mg ha−1) and ICLF (67 Mg ha−1). Similarly, total N stocks were highest in ICL1 (6.7 Mg ha−1), PA (6.7 Mg ha−1) and ICL2 (6.5 Mg ha−1), and lowest in NCF (4.7 Mg ha−1) and ICLF (4.8 Mg ha−1). ICL2 and ICL1 presented the greatest amount of humic fractions among the systems. The adoption of conservationist management systems that provide a permanent input of organic residues in the long-term is crucial for SOC stabilization and increases in soil C and N stocks. Integrated crop-livestock systems are the most suitable alternative for sequestering C and N in grain production systems in the Cerrado of Matopiba region. [ABSTRACT FROM AUTHOR]

We estimated carbon and nitrogen stocks in aboveground biomass (AGB) and belowground biomass (BGB) along an elevation range in forest sites located on the steep slopes of the Serra do Mar on the north coast of the State of São Paulo, southeast Brazil. In elevations of 100 m (lowland), 400 m (submontane), and 1000 m (montane) four 1-ha plots were established, and above- (live and dead) and belowground (live and dead) biomass were determined. Carbon and nitrogen concentrations in each compartment were determined and used to convert biomass into carbon and nitrogen stocks. The carbon aboveground stock (C(AGB)) varied along the elevation range from approximately 110 to 150 Mg·ha(-1), and nitrogen aboveground stock (N(AGB)), varied from approximately 1.0 to 1.9 Mg·ha(-1). The carbon belowground stock (C(BGB)) and the nitrogen belowground stock (N(BGB)) were significantly higher than the AGB and varied along the elevation range from approximately 200-300 Mg·ha(-1), and from 14 to 20 Mg·ha(-1), respectively. Finally, the total carbon stock (C(TOTAL)) varied from approximately 320 to 460 Mg·ha(-1), and the nitrogen total stock (N(TOTAL)) from approximately 15 to 22 Mg·ha(-1). Most of the carbon and nitrogen stocks were found belowground and not aboveground as normally found in lowland tropical forests. The above- and belowground stocks, and consequently, the total stocks of carbon and nitrogen increased significantly with elevation. As the soil and air temperature also decreased significantly with elevation, we found a significantly inverse relationship between carbon and nitrogen stocks and temperature. Using this inverse relationship, we made a first approach estimate that an increase of 1°C in soil temperature would decrease the carbon and nitrogen stocks in approximately 17 Mg·ha(-1) and 1 Mg·ha(-1) of carbon and nitrogen, respectively.

Northern peatlands have accumulated large stocks of organic carbon (C) and nitrogen (N), but their spatial distribution and vulnerability to climate warming remain uncertain. Here, we used machine-learning techniques with extensive peat core data (n > 7,000) to create observation-based maps of northern peatland C and N stocks, and to assess their response to warming and permafrost thaw. We estimate that northern peatlands cover 3.7 ± 0.5 million km² and store 415 ± 150 Pg C and 10 ± 7 Pg N. Nearly half of the peatland area and peat C stocks are permafrost affected. Using modeled global warming stabilization scenarios (from 1.5 to 6 °C warming), we project that the current sink of atmospheric C (0.10 ± 0.02 Pg C·y−1 ) in northern peatlands will shift to a C source as 0.8 to 1.9 million km² of permafrost-affected peatlands thaw. The projected thaw would cause peatland greenhouse gas emissions equal to ∼1% of anthropogenic radiative forcing in this century. The main forcing is from methane emissions (0.7 to 3 Pg cumulative CH4-C) with smaller carbon dioxide forcing (1 to 2 Pg CO2-C) and minor nitrous oxide losses. We project that initial CO2-C losses reverse after ∼200 y, as warming strengthens peatland C-sinks. We project substantial, but highly uncertain, additional losses of peat into fluvial systems of 10 to 30 Pg C and 0.4 to 0.9 Pg N. The combined gaseous and fluvial peatland C loss estimated here adds 30 to 50% onto previous estimates of permafrost-thaw C losses, with southern permafrost regions being the most vulnerable. [ABSTRACT FROM AUTHOR]

A total of 74 Japanese black pine (Pinus thunbergii Parl.) and red pine (P. densiflora S. et Z.) trees were destructively sampled in southern Korea, which is severely affected by pine wilt disease (PWD). Species-specific allometric equations were developed to estimate the biomass, carbon (C) and nitrogen (N) content of the tree components (i.e., stem wood, stem bark, branches, needles and roots) based on the diameter at breast height (DBH) and stem diameter at 20 cm aboveground (D20). The C concentrations of the various tree components were not correlated with DBH (P > 0.05), except for the C concentration in the stem bark (r = -0.29, P < 0.05) of the black pine and the branches (r = 0.40, P < 0.05) of the red pine. However, the N concentrations in the stem wood (r = -0.53, P < 0.05), stem bark (r = -0.37, P < 0.05) and branches (r = -0.40, P < 0.05) of the black pine were negatively correlated with DBH. The mean C concentrations of the tree components were not significantly different between the black pine and red pine, except for the stem bark, whereas the mean N concentrations were significantly lower in the black pine than in the red pine, except for the stem bark. The allometric equations developed for the biomass, C and N content for all the tree components were significant (P < 0.05). The adjusted coefficient of determination (adj. R2) of the DBH allometric equations ranged from 0.66 to 0.97, while the coefficients for the D20 equations were between 0.66 and 0.95. Black pines consistently exhibited more biomass, C and N content in the tree components compared with the red pines with similar DBH or D20. These results suggest that the accuracy of estimates for biomass, C and N stocks in black pine and red pine forests could be improved by specific allometric equations for PWD-disturbed forests.

As the alpine meadows are degraded globally, the remediation measures are also increasing. However, there are few studies on the effects of vegetation restoration on soil and plant nitrogen pools and nitrogen storage. Changes in soil and plant nitrogen depend on vegetation recovery species. In addition, restoration of vegetation after unrestoration can increase soil and plant nitrogen content. We collected four types of remediation and destruction of unrepaired soil samples and plant samples in Wugong Mountain, Jiangxi Province. By measuring alkaline hydrolytic nitrogen, total nitrogen and microbial bi-omass nitrogen, nitrate nitrogen, ammonium nitrogen, total soluble nitrogen and soluble organic nitrogen, total nitrogen of aboveground plant, total nitrogen of underground plant, aboveground biomass, be-lowground biomass and soil and plant nitrogen storage indicators to understand the change of soil and plant nitrogen pools and nitrogen storage after vegetation restoration. The results of the study showed that the soil nitrogen forms were significantly improved whsnMiscanthus sinensis and Carex chinen-sis were used for vegetation restoration. When the restoration was selected from Fimbristylis wukungshanensis, Arundinella hirta and Miscanthus sinensis, the total nitrogen of aboveground plant, total nitrogen of underground plant, aboveground biomass, belowground biomass reached a maximum of 16.68 g·kg-1, 12.03 g·kg-1, 9228.80kg·ha-1 and 7868.44 kg·ha-1, respectively. When Fimbristylis wukungshanensis, Arundinella hirta and. Miscanthus sinensis were used for vegetation restoration, the total nitrogen of aboveground plant, total nitrogen of underground plant, aboveground biomass, below-ground biomass reached a maximum of 16.68 g·kg-1, 12.03 g·kg-1, 9228.80kg·ha-1 and 7868.44 kg·ha-1, respectively. When Miscanthus sinensis were used for vegetation restoration, the above-ground vegetation nitrogen stocks, underground vegetation nitrogen stocks, total vegetation nitrogen stock reached a maximum of 121.17kg·ha-1, 87.37 kg·ha-1 and 208.55 kg·ha-1, respectively. Soil nitrogen storage in 0-20cm soil layer and soil nitrogen storage in 20-40cm soil layer reached a maximum of 7.96t·ha-1 and 7.68 t·ha-1. Correlation analysis results showed that the correlation between the indicators was significant. In the future restoration of vegetation, it is recommended to use two kinds of rehabilitated grass species, Miscanthus sinensis and Carex chinensis. [ABSTRACT FROM AUTHOR]

A total of 74 Japanese black pine (Pinus thunbergii Parl.) and red pine (P. densiflora S. et Z.) trees were destructively sampled in southern Korea, which is severely affected by pine wilt disease (PWD). Species-specific allometric equations were developed to estimate the biomass, carbon (C) and nitrogen (N) content of the tree components (i.e., stem wood, stem bark, branches, needles and roots) based on the diameter at breast height (DBH) and stem diameter at 20 cm aboveground (D20). The C concentrations of the various tree components were not correlated with DBH (P > 0.05), except for the C concentration in the stem bark (r = -0.29, P < 0.05) of the black pine and the branches (r = 0.40, P < 0.05) of the red pine. However, the N concentrations in the stem wood (r = -0.53, P < 0.05), stem bark (r = -0.37, P < 0.05) and branches (r = -0.40, P < 0.05) of the black pine were negatively correlated with DBH. The mean C concentrations of the tree components were not significantly different between the black pine and red pine, except for the stem bark, whereas the mean N concentrations were significantly lower in the black pine than in the red pine, except for the stem bark. The allometric equations developed for the biomass, C and N content for all the tree components were significant (P < 0.05). The adjusted coefficient of determination (adj. R2) of the DBH allometric equations ranged from 0.66 to 0.97, while the coefficients for the D20 equations were between 0.66 and 0.95. Black pines consistently exhibited more biomass, C and N content in the tree components compared with the red pines with similar DBH or D20. These results suggest that the accuracy of estimates for biomass, C and N stocks in black pine and red pine forests could be improved by specific allometric equations for PWD-disturbed forests. [ABSTRACT FROM AUTHOR]

High-altitude soils potentially store a large pool of carbon ( C) and nitrogen ( N). The assessment of total C and N stocks in soils is vital to understanding the C and N dynamics in terrestrial ecosystems. In this study, we examined effects of altitude and forest composition on soil C and N along a transect from 317 to 3300 m a.s.l. in the eastern Himalayas. We used meta-analysis to establish the context for our results on the effects of altitude on soil C, including variation with depth. Total C and N contents of soils significantly increased with altitude, but decreased with soil depth. Carbon and N were similarly correlated with altitude and temperature, and temperature was seemingly the main driver of soil C along the altitudinal gradient. Altitude accounted for 73% of the variation in C and 47% of the variation in N stocks. Soil pH and cation exchange capacity were correlated with both soil C and N stocks. Increases in soil C and N stocks were related to forest composition, forest basal area as well as quantity of leaf litter that were in turn influenced by altitude and temperature. Concentrations of C in foliage increased by 2.1% for every 1000 m rise in altitude, while that in leaf litter increased by 2.3%. [ABSTRACT FROM AUTHOR]

Disturbances affect almost all terrestrial ecosystems, but it has been difficult to identify general principles regarding these influences. To improve our understanding of the long-term consequences of disturbance on terrestrial ecosystems, we present a conceptual framework that analyzes disturbances by their biogeochemical impacts. We posit that the ratio of soil and plant nutrient stocks in mature ecosystems represents a characteristic site property. Focusing on nitrogen (N), we hypothesize that this partitioning ratio (soil N: plant N) will undergo a predictable trajectory after disturbance. We investigate the nature of this partitioning ratio with three approaches: (1) nutrient stock data from forested ecosystems in North America, (2) a process-based ecosystem model, and (3) conceptual shifts in site nutrient availability with altered disturbance frequency. Partitioning ratios could be applied to a variety of ecosystems and successional states, allowing for improved temporal scaling of disturbance events. The generally short-term empirical evidence for recovery trajectories of nutrient stocks and partitioning ratios suggests two areas for future research. First, we need to recognize and quantify how disturbance effects can be accreting or depleting, depending on whether their net effect is to increase or decrease ecosystem nutrient stocks. Second, we need to test how altered disturbance frequencies from the present state may be constructive or destructive in their effects on biogeochemical cycling and nutrient availability. Long-term studies, with repeated sampling of soils and vegetation, will be essential in further developing this framework of biogeochemical response to disturbance. [ABSTRACT FROM AUTHOR]

Aims: Wetlands provide a variety of ecosystem services, including nitrogen retention and carbon sequestration, and these services are linked through the storage and transformation of organic matter that can be altered by invasive plant species. We hypothesized that within inland temperate wetlands, the degree of invasion by Phragmites australis (Cav) Trin. Ex Steud, Phalaris arundinacea L. and Typha x glauca Godr. X would be positively correlated with soil and ecosystem C and N stocks because these invasive plants produce large amounts of recalcitrant litter. Methods: We surveyed 24 inland wetlands in Michigan for plant community composition and aboveground biomass, litter, soil, and ecosystem C and N stocks. We also performed laboratory incubations to determine C and N mineralization rates from soil collected under the most dominant species. Results: Both soil and ecosystem C stocks increased due to the presence of invasive species, as did aboveground biomass C and N stocks. Additionally, there were significant differences in C and N mineralization in soil collected from monocultures of each invasive species ( Phalaris > Typha > Phragmites) linked to the quality of their litter (C/N ratios). Conclusion: These results suggest that wetland C and N stocks are correlated with degree of invasion, and that these effects can be linked to key traits, including litter quality and aboveground biomass production. [ABSTRACT FROM AUTHOR]

Abstract: Tillage treatments had impact on total soil nitrogen (N) storage and consequently on soil carbon (C) sequestration. The objective of this study was to assess effects of long-term (1992–2010) tillage practices, including a partial-width tillage system (paraplow) on N concentration and stratification. The tillage treatments were: no-tillage (NT), minimum tillage (18–22cm depth) with chisel plow (MT), conventional tillage (25–30cm depth) with mouldboard plow (CT) and zone-tillage subsoiling (25–30cm) with a paraplow (ZT) applied in alternate years in rotation with NT. The soil was a Calcic Haploxeralf from Central Spain. The crop rotation was chick pea (Cicer arietinun L.) cv. Inmaculada/barley (Hordeum vulgare L.) cv. Volley. The equivalent mass approach was used to compare N stocks in the various tillage methods. Tillage treatments had significant effects on soil bulk density and no-till increased soil bulk density of the top layer. At the end of 19 years, the stocks of N had increased under NT compared with MT and CT. Most changes occurred within the 0–5cm layer, where plots under NT had 0.48MgNha−1 and 0.53MgNha−1 greater than in MT and CT, respectively. Zone tillage maintained most of the long-term benefit of NT in increasing N stocks in the top layer (0–5cm). At the end of the experiment, total N concentration in the 0–5cm depth under ZT was 42% and 53% higher that under MT and CT, respectively. Stratification ratios of N from 1992 to 2000 showed no significant differences between NT, MT and CT. In contrast, from 2001 onwards, all stratification ratios were significantly higher in NT than in the other two tillage systems. In addition, in 2010 the stratification ratio of N in NT was >2 and more than 2-fold those obtained in MT and CT. Values of stratification ratios under ZT followed the same trend than under NT and were significantly greater than under MT or CT. These greater stratification ratios of N observed under NT and ZT confirm, in the soil studied, not only the benefits associated with the long-term application of no-till in increasing total N in the top layer, but also the positive impact of the use of a paraplow as a rotational tillage system. [Copyright &y& Elsevier]

Abstract: Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202kgNha−1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean±SE) declined significantly (P ≤0.05) at the highest fertilizer nitrogen treatment (2.16±0.08, 2.02±0.18, and 0.88±0.14, respectively, at 0, 67, and 202kgNha−1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage. [Copyright &y& Elsevier]

The article discusses a study about the implications of carbon sequestration strategies in temporal changes in carbon and nitrogen stocks of restored prairie. This paper focuses on chronosequence approaches applied in space-for-time substitution in order to quantify the recovery of ecosystem carbon and nitrogen stocks. It gives an estimate for the potential restoration practices in carbon sequestration. Distribution in two chronosequence include long-term cultivated lands prairie restorations and remnant prairie on two related soil series.

Subsoil contains about half of the soil organic carbon (C) at the global scale. However, C and nitrogen (N) in the subsoil are assumed to be relatively stable, and their response to agricultural management practices is uncertain. This study compared the effect of 20 different management systems, combining two tillage regimes (inversion tillage vs minimum tillage), two crop residue managements (retained vs harvested) and five different fertilizer sources (liquid swine manure, liquid dairy manure, solid poultry manure, complete mineral fertilizer (NPK) and a no-N control (PK)) on C and N stocks of two Brunisols with contrasting textures (sandy loam and silty clay). We compared C and N stocks of multiple soil layers (0–15, 15–30, 30–45 and 45–60 cm depths) on the 8th year of this field trial. Overall, stock differences among management systems were relatively small in the top 15 cm, varying from 0.36 to 0.76 kg C m−2 and 0.01–0.04 kg N m−2. In subsurface soil layers (15–30, 30–45 and 45–60 cm), however, management practices considerably influenced C and N stocks (differences of up to 3.9 kg C m−2 and 0.3 kg N m−2 between treatments) in ways different than those observed in the topsoil. In the subsurface (> 15 cm) layers of the sandy loam soil, systems combining inversion tillage, residue retention, and liquid animal manure (especially swine manure) resulted in the greatest C and N stocks. Conversely, in systems combining inversion tillage and mineral fertilizer, C and N stocks in the subsurface layers were higher when residues were harvested than when they were not. Subsurface C and N stocks therefore appeared to be particularly responsive to different combinations of fertilizer sources and residue management practices under inversion tillage in the coarse-textured sandy loam soil. In the silty clay, irrespective of tillage treatments, N stocks were the highest in the 30–45 cm layer when residues were harvested, and liquid swine manure was used. Ultimately, management-differences in subsurface C and N stocks were so large compared to those in the topsoil, that they dominated the response of the whole soil profile to management practices in both soil types. These results demonstrate that subsurface C and N dynamics must be considered and that recommendation for C stock management in agricultural soils should include deep soil layers, at least under certain pedoclimatic conditions. • C and N stocks (0–60 cm) changes were studied under 20 cropping systems in 2 soil types. • Stock changes (7 yrs) were larger in the subsurface (> 15 cm) than topsoil layers. • Greater subsurface stocks changes in the coarse than the fine-textured soil. • Tillage and fertilizer-residue management combinations influence subsurface stocks. • C stocks monitoring in agricultural soils should include deep soil layers. [ABSTRACT FROM AUTHOR]

In this work, we studied the effects of centenary Scots pine (Pinus sylvestris L.) afforestation on topsoil properties conducted in a deforested area that was previously occupied by a natural European beech (Fagus sylvatica L.) forest. Organic layers and topsoil Ah mineral horizons (0–10 cm) were sampled in the Scots pine and European beech forests of Moncayo Natural Park (north-eastern Spain). The physical (stoniness, aggregate stability, and water repellency persistence and intensity), chemical (total organic C, total N, C/N, pH, and exchangeable Ca2+, Mg2+, Na+, K+, Al3+, and Fe3+), and physicochemical (cation exchange capacity) properties of soil were analyzed. Total organic C and N were also obtained for litter samples. The studied topsoils shared a series of common properties, such as a high stoniness and aggregate stability, very low base content, high cation exchange capacity, and extreme acidity. Soils that developed under the pinewood showed a higher soil water repellency intensity. However, K+ content was significantly higher in the beechwood soil. In both forest types, total organic C and N were similar in topsoil and litter (Hemimoder type), although C and N were pooled in different O-layers. Results indicate that pine afforestation in a deforested area was an adequate measure for soil protection since it did not show significant differences in the long term (ca. 100 years) compared to the nearby natural beech stands. [ABSTRACT FROM AUTHOR]