Cm Depth Of Mineral Soil Research Articles

Soil organic carbon pool's contribution to climate change mitigation on marginal land of a Mediterranean montane area in Italy

To evaluate the mitigation potential provided by the SOC pool, we investigated the impact of woody encroachment in the 0–30 cm depth of mineral soil across a natural succession from abandoned pastures and croplands to broadleaves forests on the central Apennine in Italy. In parallel, to assess the effect of the land use change (LUC) from cropland to pasture, a series of pastures established on former agricultural sites, abandoned at different time in the past, were also investigated.Our results show that woody encroachment on former pastures and croplands contributes largely to mitigate climate change, with an increase of the original SOC stock of 45% (40.5 Mg C ha−1) and 120% (66.5 Mg C ha−1), respectively. Also the LUC from croplands to pastures, greatly contributes to climate change mitigation trough a SOC increase of about 80% of the original SOC (45.9 Mg C ha−1).The management of abandoned lands represent a crucial point in the mitigation potential of agriculture and forestry activities, and particularly the role of the SOC pool. A policy effort should focus on minimizing the risk of speculative management options, particularly when the value of woody biomass become convenient to supply new energy systems allowing monetizing a long term forests productivity.In conclusion, despite both the land abandonment and the LUC can have a different impact on the SOC pool under different climatic conditions, these results can be useful to improve the SOC estimates in the National greenhouse gases Inventory at country level.

Nitrogen deposition and its impact on forest ecosystems in the Czech Republic - change in soil chemistry and ground vegetation

Abstract: A repeated soil survey (1995 and 2006) on 66 ICP Forests pair plots in the Czech Republic revealed a significant relationship between modeled nitrogen deposition and nitrogen concentration in the soil. Nitrogen deposition was modeled for the years 1995, 2004 and 2006. We found a more significant relationship between deposition data in 2004 and soil data in 2006 than between deposition and soil data from the same year 2006. Concentration of total nitrogen in forest soil increased from 1995 to 2006. Forest soil showed effects of increased nitrogen input from the humus layer to around 20 cm depth of mineral soil. The occurrence and cover of nitrophilous species in the herb layer increased from 1995 to 2006 in 25% of the analyzed plots, which corresponds to the nitrogen increase in forest soil. The results suggest that nitrogen deposition still represents a threat for Czech forest ecosystems.

Differences in soil properties in adjacent stands of Scots pine, Norway spruce and silver birch in SW Sweden

Soil properties were compared in adjacent 50-year-old Norway spruce, Scots pine and silver birch stands growing on similar soils in south-west Sweden. The effects of tree species were most apparent in the humus layer and decreased with soil depth. At 20–30 cm depth in the mineral soil, species differences in soil properties were small and mostly not significant. Soil C, N, K, Ca, Mg, and Na content, pH, base saturation and fine root biomass all significantly differed between humus layers of different species. Since the climate, parent material, land use history and soil type were similar, the differences can be ascribed to tree species. Spruce stands had the largest amounts of carbon stored down to 30 cm depth in mineral soil (7.3 kg C m −2), whereas birch stands, with the lowest production, smallest amount of litterfall and lowest C:N ratio in litter and humus, had the smallest carbon pool (4.1 kg C m −2), with pine intermediate (4.9 kg C m −2). Similarly, soil nitrogen pools amounted to 349, 269, and 240 g N m −2 for spruce, pine, and birch stands, respectively. The humus layer in birch stands was thin and mixed with mineral soil, and soil pH was highest in the birch stands. Spruce had the thickest humus layer with the lowest pH.

Towards the application of soil organic matter as an indicator of forest ecosystem productivity: Deriving thresholds, developing monitoring systems, and evaluating practices

Abstract Soil organic matter (SOM), typically measured as soil organic carbon (SOC), has been widely recognized as a critical linkage between forest management and long-term site productivity. However, its use as an indicator of sustainable forest management practices has been limited both by difficulties in detecting changes in soil carbon due to inherent high variability and by challenges associated with determining appropriate thresholds for loss. In this study we evaluate a methodology for using field measures of total SOC (forest floor to 60 cm depth in mineral soil) in conjunction with a mechanistic forest growth model to derive threshold values for total SOC with respect to the maintenance of ecosystem productivity for a lodgepole pine ( Pinus contorta ) forest in the central interior region of British Columbia. We also examine the practicality of implementing a sustainable forest management (SFM) monitoring program around this measure and the potential long-term impact of alternative management scenarios on the indicator. Total SOC contents for the different site types sampled in the Quesnel region ranged from 35 to 57 t ha −1 . Long-term simulations of biomass extraction over several rotations showed a near 1:1 ratio in the relative decline of ecosystem productivity associated with relative declines in total SOC. A power analysis revealed that a mean sampling intensity of n = 12–25 and n = 8–17 would be required to detect 20% and 30% losses of total SOC, respectively, depending on the level of statistical power desired. The sampling intensity required for an effective monitoring program was significantly reduced by summing SOC for all soil layers to limit sampling error related to determination of layer boundaries. A modelling analysis of the effect of rotation length on SOC for the Quesnel forest types, suggests that rotation lengths shorter than 75 years should be avoided to prevent declines in ecosystem productivity. Our results confirm that the combination of modelling and statistical techniques can be successfully used to develop cost-efficient monitoring plans of sustainability of forest management, with SOC as a valid indicator of ecosystem productivity.

Root effects on soil carbon and nitrogen cycling in a Pinus radiata D. Don plantation on a coastal sand

Although the contribution of roots to soil carbon (C) fluxes and biochemical processes is recognised, it is difficult to quantify. One approach to assess their importance is the use of trenched plots, in which C inputs to the soil and respiration by living roots has ceased. We give here an account of C and nitrogen (N) pools and mineralisation in samples taken 27 months after trenching in a 26-year-old Pinus radiata D. Don plantation on a coastal sand (an Aquic Udipsamment); above-ground litter inputs continued throughout the 27-month period.Moisture contents were higher in FH material and mineral soil from the trenched than from the control plots. Trenching had no effect on total organic C and N concentrations, but led to decreases in extractable C, microbial C and N, and CO2-C production values at some depths in the soil profile. Mineral-N concentrations and gross nitrification rates were, in contrast, initially higher in the trenched-plot samples, but were similar in both treatments after incubation of the samples at 25°C for 57 days. Mineral-N concentrations were also higher in the trenched than control mineral soil after in situ incubation. On an area basis (to 20 cm depth of mineral soil), inputs from roots were estimated to account for about 40% of the extractable C pool, 28% of microbial C, 26% of microbial N, and 23% of heterotrophic CO2-C production (0–7 days at 25°C) in the control soil. Overall, our results suggest a tight connection between N cycling rates and the labile C pools derived from below-ground inputs, with nitrification in particular increasing as C availability declined as a result of trenching.

Seasonal changes in soil temperature and snow-cover under different simulated winter conditions: Comparison with frost hardiness of Scots pine (Pinus sylvestris) roots

Seasonal changes in soil temperature and in the frost hardiness of the roots of adult Scots pine (Pinus sylvestris L.) trees were studied between August 1992 and May 1993 in a pine forest growing on dry heathland soil. The study area is located in Finnish Lapland (67°N, 29°E). Air (2 m above ground) and soil (5 cm depth of mineral soil) temperatures were measured continuously every second hour. The frost hardiness of the roots in the soil (down to 10 cm) was measured by means of the electrolyte-leakage method. The air temperature remained consistently below 0°C after the first week of October. The coldest month was February with a daily average temperature of −10.3°C. Snow accumulation started in the first week of October and reached a depth of 129 cm in April. The temperature in the mineral soil varied between +15.4°C and 0.8°C. The frost-hardiness of the pine roots was at its lowest in September (−6°C), and at its highest in December (−21°C). Soil temperature and precipitation as snow in different winter conditions were simulated using the SOIL model. The simulations show that the insulating effect of the snow cover is crucial for the frost survival of Scots pine roots even during a moderate winter.

Microbial processes in relation to carbon, nitrogen and temperature regimes in litter and a sandy mineral soil from a central Siberian Pinus sylvestris L. forest

The coniferous forests of Siberia contain a significant fraction of the world's terrestrial C. We have assessed organic matter storage and potential metabolic activities in one of these forest stands by determining C and N pools, microbial properties and C and N mineralization at different temperatures in litter and a sandy mineral soil (a Pergelic Cryochrept) from a 215-y old forest of Pinus sylvestris L. Relationships between CO 2–C production in the laboratory and field were also assessed. The site was near Zotino in central Siberia at 61° N, 89° E and has an average air temperature of ca. −4°C and an annual precipitation of ca. 620 mm; it is subject to water deficits during summer and to recurrent fires. Results were evaluated by comparisons with data from other coniferous forests, including those with sandy or sandy loam soils at three temperate sites under Pinus radiata D. Don in New Zealand. The very acid (pH 4.1) litter (ca. 3 cm depth) from the Zotino site contained (to 50 cm depth of mineral soil) ca. 41% of the total C (2.8 kg m −2), 34% of the total N (86 g m −2) and about 50% of the microbial biomass and respiratory and net N-mineralizing activity. The low values in the mineral soil were, except for total N which was lowest at the Zotino site, generally similar to those in two young coastal sands under P. radiata in New Zealand. Rates of C and net N mineralization in the Zotino mineral soil declined proportionately more between 13.5°C and 5.5°C than between 25 and 13.5°C. Use of temperature relationships suggested that less than half of the CO 2–C produced from the soil profile in the field under well-watered conditions during summer would have originated from microbial respiration. In litter and in mineral soil, ratios of microbial C and N-to-total C and N, microbial C-to-microbial N, rates of CO 2–C and net mineral-N production on a total C and N basis, and metabolic quotients (qCO 2 values) were all similar to at least some of the values found for the temperate pine-forest soils. Our results strongly suggest that soil organic matter content is low at this Zotino site, not because of distinctive metabolic potentials of the microbial populations, but because of environmental constraints on ecosystem processes.

Seasonal changes in soil temperature and in the frost hardiness of Scots pine (Pinus sylvestris) roots under subarctic conditions

The seasonal changes in soil temperature and in the frost hardiness of adult Scots pine (Pinus sylvestris L.) trees was studied between September 1991 and February 1993 in a pine forest located in Finnish Lapland. Air and soil (humus layer and 5 cm depth of mineral soil) temperatures were measured continuously every second hour. The frost hardiness of the roots in the humus layer and in the mineral soil (down to 10 cm) was measured by means of the electrolyte-leakage method. The temperature in the humus layer varied between 21.2°C and –3.2°C and in the mineral soil between 21.6°C and –2.4°C. The temperature in the humus layer was continuously slightly colder than in the mineral soil from late August until May. The frost hardiness of the pine roots was lowest (about –5°C) in May and during the first week of September. Frost hardiness stayed at its maximum of about –20°C during November and December and slightly decreased in January and February. During most of the sampling time, the frost hardiness of the roots in the humus layer was greater than in the mineral soil. There was a clear relationship between the soil temperature and the frost hardiness of roots.

Seasonal changes in soil temperature and in the frost hardiness of Scots pine (<i>Pinus sylvestris</i>) roots under subarctic conditions

The seasonal changes in soil temperature and in the frost hardiness of adult Scots pine (Pinus sylvestris L.) trees was studied between September 1991 and February 1993 in a pine forest located in Finnish Lapland. Air and soil (humus layer and 5 cm depth of mineral soil) temperatures were measured continuously every second hour. The frost hardiness of the roots in the humus layer and in the mineral soil (down to 10 cm) was measured by means of the electrolyte-leakage method. The temperature in the humus layer varied between 21.2°C and –3.2°C and in the mineral soil between 21.6°C and –2.4°C. The temperature in the humus layer was continuously slightly colder than in the mineral soil from late August until May. The frost hardiness of the pine roots was lowest (about –5°C) in May and during the first week of September. Frost hardiness stayed at its maximum of about –20°C during November and December and slightly decreased in January and February. During most of the sampling time, the frost hardiness of the roots in the humus layer was greater than in the mineral soil. There was a clear relationship between the soil temperature and the frost hardiness of roots.

Microbial biomass, and C and N mineralization, in litter and mineral soil of adjacent montane ecosystems in a southern beech ( Nothofagus) forest and a tussock grassland

Comparisons were made of total and microbial C and N pools and C and N metabolism in litter and mineral soil of a mountain beech ( Nothofagus solandri var. cliffortioides) forest, ca. 100 m below timberline, and an adjacent tussock grassland (dominated by Chionochloa pallens), ca. 100 m above timberline, in Canterbury, New Zealand. Mean annual precipitation at the sites is ca. 1600 mm and mean annual air temperature ca. 6°C. The silt loam soils are Andic Dystrochrepts. Total C and N and microbial C and N contents in litter and mineral soil (0–50 cm depth) differed appreciably in the two ecosystems and were 1.41, 2.00, 1.71 and 1.98 times, respectively, greater on an area basis at the grassland than at the forest site. Ratios of microbial C-to-total C, microbial N-to-total N and microbial C-to-N generally declined with profile depth. CO 2C production, per unit of total C, and metabolic quotients (qCO 2 values) tended to be greater in mineral soil from the forest than from the grassland. CO 2C production, calculated on an area basis to 50 cm depth of mineral soil, was similar in both ecosystems. Net N mineralization (during 0–56 days at 25°C) was appreciable in the forest litter, but absent in tussock litter; it was similar in both systems at 0–10 cm and 20–50 cm depths of mineral soil, but was lower in the forest than in the grassland at 10–20 cm depth. Nitrification was not detected in the litter samples and was either absent or very low in the samples of mineral soil. Results, overall, show that marked differences in soil and microbial properties can occur in adjacent, indigenous ecosystems in almost the same climatic environment. Although soil microbial biomass levels were lower in the forest than in the grassland, the potential metabolic activity of the component microorganisms tended to be greater in the forest. The relevance of these results to the turnover of organic matter in these ecosystems is briefly discussed.

Soil Carbon Storage and Turnover in Temperate Forests and Grasslands-A New Zealand Perspective

Carbon storage and turnover times of total soil C (up to 1 m depth) and topsoil C (to 23 cm depth of mineral soil) were compared at six sites in native tussock grasslands and three in old-growth forests in New Zealand. Annual C inputs to the topsoils were also determined. Most of the sites approached steady state, and covered a wide range of climoedaphic environments. Total soil C ranged from 44 to 268 t ha1 (to 1 m depth), and was highest in a Spodosol beneath a mixed podocarp-hardwood forest. Turnover times of total soil C, estimated from the radiocarbon content of soil organic matter, mostly ranged from 30 to 125 years. Anomolously slow turnover times for two grassland sites and one forest site were ascribed partly to an accumulation of Al-humus, and partly to intermittent periods of waterlogging. Annual inputs of C to the upper part of the soil profile averaged 7 and 3 t ha 1 for the forest and grassland soils, respectively. Turnover times for decomposable C [(total C inert C)/annual C input] in the topsoil ranged from 11 to 40 years, and were closely related to mean annual temperatures. Application of the approaches described for assessing soil C storage and turnover in a wider range of climates and vegetation types now seems warranted.

Single‐Tree Influence on Soil Properties in the Mountains of Eastern Kentucky

The validity of the concept of "ingle—tree influence circles" was tested in a forest dominated by Tsuga canadensis and Liriodendron tulipifera on steep slopes in the Appalachian Mountains of the eastern USA. Samples of forest floors and the 0—5 cm depth of mineral soil were collected at 135 locations within plots 1.3 ha in total area. Examination of particle—size distribution and pH at 33 of these locations confirmed that parent material to a depth of 100 cm was uniform throughout the study area. Soils were sandy and generally low in nutrients. Levels of pH, Ca, Mg, K, and mineralizable N tended to be higher, and forest floor mass tended to be lower, under the crowns of L. tulipifera compared to T. canadensis. Differnces between tree species were better expressed on areas lacking Rhododendron maximum understories. These results indicate that single—tree influence on soil properties is detectable even in mixed stands on steep slopes, and that the soil landscape may be considered a mosaic of profiles reflecting the occurrence and chemical characteristics of the ground cover vegetation and of individuals of the various tree species present.

Changes in soil ph over a 50-year period under different forest canopies in SW Sweden

Reinvestigation of soil profiles, down to 70 cm depth in mineral soil, sampled for measurements in 1927 revealed a general decrease in pH for spruce and hardwood stands with 0.3 to 0.9 units. The pH-changes in the top soil can partly be explained by biological acidification, increasing with stand age. Stand age and species composition have less influence in deeper soil horizons and much of the acidification there is ascribed to acid deposition.