Soil carbon and nitrogen pools in mid- to late-successional forest stands of the northwestern United States: potential impact of fire

2006 ◽  
Vol 36 (9) ◽  
pp. 2270-2284 ◽  
Author(s):  
Deborah S Page-Dumroese ◽  
Martin F Jurgensen
Keyword(s):  
Soil Depth ◽  
Fire Suppression ◽  
Fire Severity ◽  
Mineral Soil ◽  
Soil Surface ◽  
Burned Area ◽  
Soil Productivity ◽  
N Losses ◽  
C And N ◽  
Surface Mineral

When sampling woody residue (WR) and organic matter (OM) present in forest floor, soil wood, and surface mineral soil (0–30 cm) in 14 mid- to late-successional stands across a wide variety of soil types and climatic regimes in the northwestern USA, we found that 44%–84% of carbon (C) was in WR and surface OM, whereas >80% of nitrogen (N) was in the mineral soil. In many northwestern forests fire suppression and natural changes in stand composition have increased the amounts of WR and soil OM susceptible to wildfire losses. Stands with high OM concentrations on the soil surface are at greater risk of losing large amounts of C and N after high-severity surface fires. Using the USDA Forest Service Regional Soil Quality Standards and Guidelines, we estimate that 6%–80% of the pooled C to a mineral-soil depth of 30 cm could be lost during a fire considered detrimental to soil productivity. These estimates will vary with local climatic regimes, fire severity across the burned area, the size and decay class of WR, and the distribution of OM in the surface organic and mineral soil. Estimated N losses due to fire were much lower (<1%–19%). Further studies on the amounts and distribution of OM in these stands are needed to assess wildfire risk, determine the impacts of different fire severities on WR and soil OM pools, and develop a link between C and N losses and stand productivity.

scholarly journals Carbon, nitrogen and sulfur (CNS) status and dynamics in Amazon basin upland soils, Brazil

2019 ◽  
Author(s):  
Jörg Matschullat ◽  
Roberval Monteiro Bezerra de Lima ◽  
Sophie F. von Fromm ◽  
Solveig Pospiech ◽  
Andrea M. Ramos ◽  
...  
Keyword(s):  
Climate Change ◽  
Amazon Basin ◽  
Forest Canopy ◽  
Regional Climate ◽  
Mineral Soil ◽  
Regional Climate Change ◽  
Wet Season ◽  
N Losses ◽  
Carbon And Nitrogen ◽  
C And N

Abstract. Given the dimensions of the Amazon basin (7.5 million km2), its internal dynamics, increasing anthropogenic strain on this large biome, and its global role as one of two continental biospheric tipping elements, it appears crucial to have data-based knowledge on carbon and nitrogen concentrations and pools as well as on possible intra-annual dynamics. We quantified carbon (Ct, Corg), nitrogen (N) and sulfur (S) concentrations in litter (ORG) and mineral soil material (TOP 0–20 cm, BOT 30–50 cm) of upland (terra firme) oxisols across Amazonas state and present a first pool calculation. Data are based on triplicate seasonal sampling at 29 sites (forest and post-forest) within the binational project EcoRespira-Amazon (ERA). Repeated sampling increased data accuracy and allows for interpreting intra-annual (seasonal) and climate-change related dynamics. Extreme conditions between the dry season in 2016 and the subsequent wet season (ENSO-related) show differences more clearly. Median CNS in the Amazon basin TOP soils (Ct 1.9, Corg 1.6, N 0.15, S 0.03 wt-% under forest canopy) as well as Corg / N ratios show concentrations similar to European soils (FOREGS, GEMAS). TOP Ct concentrations ranged from 1.02 to 3.29 wt-% (medianForest 2.17 wt-%; medianPost-Forest 1.75 wt-%), N from 0.088 to 0.233 wt-% (medianForest 0.17 wt-%; medianPost-Forest 0.09 wt-%) and S from 0.012 to 0.051 wt.-% (medianForest 0.03 wt.-%; medianPost-Forest 0.02 wt-%). Corg / N ratios ranged from 6 to 14 (median 10). A first pool calculation (hectare-based) illustrates forest versus post-forest changes. The elements are unevenly distributed in the basin with generally higher CNS values in the central part (Amazonas graben) as compared to the southern part of the basin. Deforestation and drought conditions lead to C and N losses – within 50 years after deforestation, C and N losses average 10 to 15 %. Regional climate change with increased drought will likely speed up carbon and nitrogen losses.

scholarly journals Vegetative and Edaphic Responses in a Northern Mixed Conifer Forest Three Decades after Harvest and Fire: Implications for Managing Regeneration and Carbon and Nitrogen Pools

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1040
Author(s):  
R. Kasten Dumroese ◽  
Martin F. Jurgensen ◽  
Deborah S. Page-Dumroese
Keyword(s):  
Prescribed Fire ◽  
Forest Floor ◽  
Fire Severity ◽  
Mineral Soil ◽  
Habitat Type ◽  
Larix Occidentalis ◽  
Shrub Species ◽  
Silvicultural Practices ◽  
C And N ◽  
C And N Pools

Research Highlights: This experiment compares a range of combinations of harvest, prescribed fire, and wildfire. Leveraging a 30-year-old forest management-driven experiment, we explored the recovery of woody species composition, regeneration of the charismatic forest tree species Larix occidentalis Nutt., and vegetation and soil carbon (C) and nitrogen (N) pools. Background and Objectives: Initiated in 1967, this experiment intended to explore combinations of habitat type phases and prescribed fire severity toward supporting regeneration of L. occidentalis. At onset of the experiment, a wildfire affected a portion of the 60 research plots, allowing for additional study. Our objective was to better understand silvicultural practices to support L. occidentalis regeneration and to better understand the subsequent impacts of silvicultural practices on C and N pools within the vegetation and soil. Materials and Methods: We categorized disturbance severity based on loss of forest floor depth; 11 categories were defined, including controls for the two habitat type phases involved. We collected abundance, biomass, and C and N concentrations for the herbaceous layer, shrubs, and trees using nested quadrats and 6 to 10 experimental units per disturbance category plot. Moreover, we systematically sampled woody residue from transects, and forest floor, soil wood, and mineral soil with a systematic grid of 16 soil cores per disturbance category plot. Results: We found that (1) disturbance severity affected shrub species richness, diversity, and evenness within habitat type phases; (2) L. occidentalis regenerates when fire is part of the disturbance; (3) N-fixing shrub species were more diverse in the hotter, drier plots; (4) recovery levels of C and N pools within the soil had surpassed or were closer to pre-disturbance levels than pools within the vegetation. Conclusions: We confirm that L. occidentalis regeneration and a diverse suite of understory shrub species can be supported by harvest and prescribed fire, particularly in southern and western aspects. We also conclude that these methods can regenerate L. occidentalis in cooler, moister sites, which may be important as this species’ climate niche shifts with climate change.

Fire severity effects on soil organic matter from a ponderosa pine forest: a laboratory study

2010 ◽  
Vol 19 (5) ◽  
pp. 613 ◽  
Author(s):  
Jeff A. Hatten ◽  
Darlene Zabowski
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Ponderosa Pine ◽  
Fire Severity ◽  
Mineral Soil ◽  
High Severity ◽  
Hydrophobic Compounds ◽  
C And N ◽  
Labile Soil Organic Matter ◽  
Ponderosa Pine Forest

This study investigated the changes in soil organic matter composition by controlling fire severity of laboratory burns on reconstructed surface soil profiles (O, A1 (0–1 cm), and A2 (1–2 cm)). Laboratory burning simulated prescribed burns that would be typical in the understorey of a ponderosa pine forest at low, moderate, and high–moderate severity levels. Soils were analysed for C, N and soil organic matter composition. Soil organic matter was fractionated into humin, humic acid, fulvic acid, soluble non‐humic materials and other hydrophobic compounds. In the O horizon, low‐, moderate‐, and high‐severity treatments consumed an increasing proportion of C and N. Carbon content of the mineral soil was unaffected by burning; however, N content of the A2 horizon decreased after the moderate‐ and high‐severity treatments, likely as a result of N volatilisation. The proportion of non‐soluble material in the O horizon increased with fire severity, whereas the proportion of humin C as total C of the A horizon decreased with fire severity. The decrease in humin was followed by an increase in the other hydrophobic compounds. The higher fire intensity experienced by the burning O horizon created recalcitrant materials while an increase in labile soil organic matter was observed in mineral soil. An increase in labile soil organic matter may cause elevated C and N mineralisation rates often seen after fire.

scholarly journals Afforestation With Tropical N-Fixing Species in The Brazilian Atlantic Rainforest: Carbon and Nitrogen in The Soil Profile

2021 ◽  
Author(s):  
David Pessanha Siqueira ◽  
Emanuela Forestieri Gama-Rodrigues ◽  
Marcos Vinícius Winckler Caldeira ◽  
Carlos Eduardo Rezende ◽  
Claudio Roberto Marciano ◽  
...  
Keyword(s):  
Soil Profile ◽  
Soil Depth ◽  
Mineral Soil ◽  
Species Traits ◽  
Atlantic Rainforest ◽  
Opposite Pattern ◽  
Soil Layers ◽  
Soil C ◽  
Soil C And N ◽  
C And N

Abstract Aims Atlantic Rainforest biome is one of the most threatened in the world by deforestation where afforestation programs are urgently needed. N-fixing species should be prioritized in re-establishing forest covers as they can enhance soil C and N and stimulate cycling of other nutrients. Yet, tropical ecosystems play a key role in global warming and remain underestimated in the global biogeochemical balances. We aimed to investigate the effects of tropical N-fixing species on soil C and N pools after pasture conversionMethods We selected: Plathymenia reticulata, Hymenaea courbaril, and Centrolobium tomentosum 27-year-old monospecific stands. We evaluated soil organic carbon (SOC), nitrogen (STN), and the natural abundance of 13C and 15N in the soil profile up to 100 cm depth. Results SOC was higher for P. reticulata, but an opposite pattern was observed when combining only soil layers up to 30 cm soil depth. Meanwhile, STN was similar across species and d15N values showed enrichment at intermediate soil layers indicating 14N gaseous loss. Most of the SOC originated from the planted trees rather than the former pasture, except beneath C. tomentosum where C4 derived C is decreasing at a slower rate. Conclusion This study presents novel insights in the understanding of tropical N-fixing species effects on soil C and N where specific-species traits appear to mediate SOC retention to the mineral soil rather than the N-fixing ability per se.

Fire suppression impacts on postfire recovery of Sierra Nevada chaparral shrublands

2005 ◽  
Vol 14 (3) ◽  
pp. 255 ◽  
Author(s):  
Jon E. Keeley ◽  
Anne H. Pfaff ◽  
Hugh D. Safford
Keyword(s):  
Sierra Nevada ◽  
Native Species ◽  
Seedling Recruitment ◽  
Fire Suppression ◽  
Fire Severity ◽  
Burned Area ◽  
Mountain Range ◽  
Record Keeping ◽  
Postfire Regeneration ◽  
Mature Stands

A substantial portion of chaparral shrublands in the southern part of California’s Sierra Nevada Mountain Range has never had a recorded fire since record keeping began in 1910. We hypothesised that such long periods without fire are outside the historical range of variability and that when such areas burn, postfire recovery is weaker than in younger stands. We predicted that long fire-free periods will result in loss of shrub species and deterioration of soil seed banks, which, coupled with higher fire intensities from the greater accumulation of dead biomass, will lead to poorer postfire regeneration. The 2002 McNally Fire burned ancient stands that were as much as 150 years old, as well as much younger (mature) stands. Based on shrub skeletons in the burned area as a surrogate for prefire density, we found that ancient stands change in structure, owing primarily to the loss of obligate seeding Ceanothus cuneatus; other species appear to have great longevity. Despite the reduction in C. cuneatus, postfire shrub–seedling recruitment remained strong in these ancient stands, although some seed bank deterioration is suggested by the three-quarters lower seedling recruitment than recorded from mature stands. Total diversity and the abundance of postfire endemic annuals are two other response variables that suggest that these ancient stands are recovering as well as mature stands. The one area of some concern is that non-native species richness and abundance increased in the ancient stands, suggesting that these are more open to alien colonisers. It is concluded that chaparral more than a century old is resilient to such long fire-free periods and fire severity impacts are indistinguishable from those in younger chaparral stands.

scholarly journals Soil Gaseous Emissions and Partial C and N Balances of Small-Scale Farmer Fields in a River Oasis of Western Mongolia

2019 ◽  
Vol 11 (12) ◽  
pp. 3362
Author(s):  
Greta Jordan ◽  
Sven Goenster-Jordan ◽  
Baigal Ulziisuren ◽  
Andreas Buerkert
Keyword(s):  
Soil Surface ◽  
Small Scale ◽  
Gaseous Emissions ◽  
N Losses ◽  
Closed Chamber ◽  
Total N ◽  
Western Mongolia ◽  
C And N ◽  
Soil Emissions ◽  
Small Scale Farmer

During the last decades, Mongolian river oases were subjected to an expansion of farmland. Such intensification triggers substantial gaseous carbon (C) and nitrogen (N) losses that may aggravate disequilibria in the soil surface balances of agricultural plots. This study aims to quantify such losses, and assess the implications of these emissions against the background of calculated partial C and N balances. To this end, CO2, NH3, and N2O soil emissions from carrot, hay, and rye plots were measured by a portable dynamic closed chamber system connected to a photoacoustic multi-gas analyzer in six farms of the Mongolian river oasis Bulgan sum center. Average C and N flux rates (1313 g CO2-C ha−1 h−1 to 1774 g CO2-C ha−1 h−1; 2.4 g NH3-N ha−1 h−1 to 3.3 g NH3-N ha−1 h−1; 0.7 g N2O-N ha−1 h−1 to 1.1 g N2O-N ha−1 h−1) and cumulative emissions (3506 kg C ha−1 season−1 to 4514 kg C ha−1 season−1; 7.4 kg N ha−1 season−1 to 10.9 kg N ha−1 season−1) were relatively low compared to those of other agroecosystems, but represented a substantial pathway of losses (86% of total C inputs; 21% of total N inputs). All C and N balances were negative (−1082 kg C ha−1 season−1 to −1606 kg C ha−1 season−1; −27 kg N ha−1 season−1 to −65 kg N ha−1 season−1). To reduce these disequilibria, application of external inputs may need to be intensified whereby such amendments should be incorporated into soil to minimize gaseous emissions.

When It's Hot, It's Hot... Or Maybe It's Not! (Surface Flaming May Not Portend Extensive Soil Heating)

1992 ◽  
Vol 2 (3) ◽  
pp. 139 ◽  
Author(s):  
RA Hartford ◽  
WH Frandsen
Keyword(s):  
Forest Floor ◽  
Fire Severity ◽  
Mineral Soil ◽  
Soil Surface ◽  
Fire Effects ◽  
Fire Intensity ◽  
Surface Moisture ◽  
Long Duration ◽  
Key Variables ◽  
Duration Of Heating

Fire effects on aplant community, soil, and air are not apparent when judged only by surface fire intensity. The fire severity or fire impact can be described by the temperatures reached within the forest floor and the duration of heating experienced in the vegetation, forest floor, and underlying mineral soil. Temporal distributions of temperatures illustrate heat flow in duff and mineral soil in three instrumented plots: two with slash fuel over moist duff and one with litter fuel over dry duff. Fires in the two slash fuel plots produced substantial flame lengths but minimal heating in the underlying mineral soil. In contrast, smoldering combustion in the dry duff plot produced long duration heating with nearly complete duff consumption and lethal temperatures at the mineral soil surface. Moisture content of duff and soil were key variables for determining f i e impact on the forest floor.

Soil carbon and nitrogen eroded after severe wildfire and erosion mitigation treatments

2019 ◽  
Vol 28 (10) ◽  
pp. 814 ◽  
Author(s):  
Derek N. Pierson ◽  
Peter R. Robichaud ◽  
Charles C. Rhoades ◽  
Robert E. Brown
Keyword(s):  
Soil Carbon ◽  
Mineral Soil ◽  
Organic Soil ◽  
Ecosystem Recovery ◽  
N Losses ◽  
Soil C ◽  
Burned Areas ◽  
Soil C And N ◽  
C And N ◽  
Erosion Mitigation

Erosion of soil carbon (C) and nitrogen (N) following severe wildfire may have deleterious effects on downstream resources and ecosystem recovery. Although C and N losses in combustion and runoff have been studied extensively, soil C and N transported by post-fire erosion has rarely been quantified in burned landscapes. To better understand the magnitude and temporal pattern of these losses, we analysed the C and N content of sediment collected in severely burned hillslopes and catchments across the western USA over the first 4 post-fire years. We also compared soil C and N losses from areas receiving common erosion-mitigation treatments and untreated, burned areas. The concentrations of C and N in the eroded material (0.23–0.98gCkg−1 and 0.01–0.04gNkg−1) were similar to those of mineral soils rather than organic soil horizons or combusted vegetation. Losses of eroded soil C and N were highly variable across sites, and were highest the first 2 years after fire. Cumulative erosional losses from untreated, burned areas ranged from 73 to 2253kgCha−1 and from 3.3 to 110kgNha−1 over 4 post-fire years. Post-fire erosion-mitigation treatments reduced C and N losses by up to 75% compared with untreated areas. Losses in post-fire erosion are estimated to be &lt;10% of the total soil C and N combusted during severe wildfire and &lt;10% of post-fire soil C and N stocks remaining in the upper 20cm of mineral soil. Although loss of soil C and N in post-fire erosion is unlikely to impair the productivity of recovering vegetation, export of C and N may influence downstream water quality and aquatic ecosystems.

Carbon and nitrogen transformations in New Zealand plantation forest soils from sites with different N status

1998 ◽  
Vol 28 (7) ◽  
pp. 967-976 ◽  
Author(s):  
Neal A Scott ◽  
Roger L Parfitt ◽  
Des J Ross ◽  
Gareth J Salt
Keyword(s):  
Forest Floor ◽  
Forest Ecosystems ◽  
Mineral Soil ◽  
Plantation Forest ◽  
N Losses ◽  
Mineral N ◽  
N Transformations ◽  
Clear Cutting ◽  
C And N ◽  
N Status

Interactions between soil nutrient cycling processes are likely to influence N losses following disturbance in forest ecosystems. During a 340-day laboratory incubation, we examined C and N transformations in three sandy soils of different N status from Pinus radiata D. Don plantations before clear-cutting. The soils were a high N status Andisol (losing -N in streamwater) and a fertilized and unfertilized Entisol. In contrast to other forest ecosystems, -N accumulated readily in all mineral soils and in the Andisol forest floor but did not accumulate until day 63 and 210 in the fertilized and unfertilized Entisol forest floor, respectively. However, gross nitrification occurred from day 42 in both Entisol treatments. Net nitrification in the Entisol forest floor began when substrate C/N ratio declined to about 40, possibly because of decreased C availability and decreased competition for both -N and -N in conjunction with a lower microbial C/N ratio. Carbon and gross N mineralization rates (per unit of C or N, respectively) correlated positively (r2 = 0.93) in mineral soil but correlated negatively in the forest floor, probably because of major differences in C and N quality and potential differences in microbial community structure. The mean residence time of N in mineral-N pools was higher for soils from the N-rich site, in part because of lower microbial N demand. These results suggest that sudden removal of C inputs (such as at harvest) may cause greater disruption of internal soil N cycles on nutrient poor sites, increasing the proportional losses of N as compared to nutrient-rich sites.

LYSIMETERS WITH RAINFALL AND SOIL WATER CONTROL

1971 ◽  
Vol 2 (2) ◽  
pp. 79-92 ◽  
Author(s):  
K. J. KRISTENSEN ◽  
H. C. ASLYNG
Keyword(s):  
Soil Moisture Content ◽  
Soil Depth ◽  
Irrigation System ◽  
Drainage System ◽  
Soil Surface ◽  
Trickle Irrigation ◽  
Water Control ◽  
Radiation Equipment ◽  
Different Depths ◽  
Growth Experiments

The lysimeter installation described comprises 36 concrete tanks each with a soil surface of 4 m2. The installation is useful for plant growth experiments under natural conditions involving different treatment combined with various controlled water supplies. The ground installation is at least 20 cm below the soil surface and tillage can be done with field implements. The lysimeter tanks are provided with a drainage system which can drain the soil at the bottom (100 cm depth) to a tension of up to 100 cm. A constant ground-water table at less than 100 cm soil depth can also be maintained. The soil moisture content at different depths is determined from an underground tunnel by use of gamma radiation equipment in metal tubes horizontally installed in the soil. Rainfall is prevented by a movable glass roof automatically operated and controlled by a special rain sensor. Water is applied to the soil surface with a special trickle irrigation system consisting of a set of plastic tubes for each lysimeter tank and controlled from the tunnel. Fertilizers in controlled amount can be applied with the irrigation water.

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