scholarly journals Fire in lichen-rich subarctic tundra changes carbon and nitrogen cycling between ecosystem compartments but has minor effects on stocks

2021 ◽  
Author(s):  
Ramona Julia Heim ◽  
Andrey Yurtaev ◽  
Anna Bucharova ◽  
Wieland Heim ◽  
Valeriya Kutskir ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Ambient Air ◽  
Fire Effects ◽  
Long Term Effects ◽  
Fire Scars ◽  
Microbial Decomposition ◽  
Carbon And Nitrogen ◽  
Arctic Regions ◽  
C And N

Abstract. Fires are predicted to increase in Arctic regions due to ongoing climate change. Tundra fires can alter carbon and nutrient cycling and release a substantial amount of greenhouse gases with global consequences. Yet, the long-term effects of tundra fires on carbon (C) and nitrogen (N) stocks and cycling are still unclear. Here we used a space-for-time approach to investigate the long-term fire effects on C and N stocks and cycling in soil and aboveground living biomass. We collected data from three large fire scars (> 44, 28 and 12 years old) and corresponding control areas and used linear mixed-effects models in a Bayesian framework to analyse how the stocks and cycling were influenced by fire. We found that tundra fires did not affect total C and N stocks because a major part of the stocks was located belowground in soils, which were largely unaltered by fire. However, fire had a strong effect on stocks in the aboveground vegetation, mainly due to the reduction of the lichen layer. Fire reduced N concentrations in graminoids and herbs on the younger fire scars, which affected respective C / N ratios and indicated an increased post-fire competition between vascular plants. Aboveground plant biomass was depleted in 13C in all three fire scars. This could be related to a lower 13C abundance in CO2 in the ambient air because of increased post-fire decomposition, providing a source of 13C-depleted CO2. In soil, the relative abundance of 13C changed with time after fire because of the combined effects of microbial decomposition and plant-related fractionation processes. Our results indicate that in lichen-rich subarctic tundra ecosystems, the contribution of fires to the release of additional carbon to the atmosphere might be relatively small as soil stocks appear to be resilient.

scholarly journals Distribution and altitudinal patterns of carbon and nitrogen storage in various forest ecosystems in the central Yunnan Plateau, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianqiang Li ◽  
Qibo Chen ◽  
Zhuang Li ◽  
Bangxiao Peng ◽  
Jianlong Zhang ◽  
...  
Keyword(s):  
Forest Ecosystems ◽  
Sustainable Forest Management ◽  
Carbon And Nitrogen ◽  
Pinus Yunnanensis ◽  
Yunnan Plateau ◽  
Baseline Information ◽  
C And N ◽  
Quercus Semecarpifolia ◽  
Management Policies

AbstractThe carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.

scholarly journals Long-term Carbon and Nitrogen Dynamics at SPRUCE Revealed through Stable Isotopes in Peat Profiles

2016 ◽  
Author(s):  
Erik A. Hobbie ◽  
Janet Chen ◽  
Paul J. Hanson ◽  
Colleen M. Iversen ◽  
Karis J. Mcfarlane ◽  
...  
Keyword(s):  
Industrial Revolution ◽  
Continuous Variables ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Dynamics ◽  
Aerobic Decomposition ◽  
C And N ◽  
C And N Cycling ◽  
Δ15n And Δ13c ◽  
Forested Bog

Abstract. We used δ15N and δ13C patterns from 16 peat depth profiles to interpret changes in C and N cycling in the Marcell S1 forested bog in northern Minnesota over the past ~ 10 000 years. In multiple regression analyses, δ15N and δ13C correlated strongly with depth, plot location, C / N, %N, and each other. Continuous variables in the regression model mainly reflected 13C and 15N fractionation accompanying N and C losses, with an estimated 40 % of fractionations involving C-N bonds. In contrast, nominal variables such as plot, depth, and vegetation cover reflected peatland successional history and climate. Higher δ15N and lower δ13C in plots closer to uplands may reflect distinct hydrology and accompanying shifts in C and N dynamics in the lagg drainage area surrounding the bog. The Suess effect (declining δ13CO2 since the Industrial Revolution) and aerobic decomposition lowered δ13C in recent surficial samples. A decrease of 1 ‰ in the depth coefficient for δ15N from −35 cm to −25 cm probably indicated the depth of ectomycorrhizal activity after tree colonization of the peatland. Low δ13C at −213 cm and −225 cm (~ 8500 years BP) corresponded to a warm period during a sedge-dominated rich fen stage, whereas higher δ13C thereafter reflected subsequent cooling. Because of multiple potential mechanisms influencing δ13C, there was no clear evidence for the influence of methanogenesis or methane oxidation on bulk δ13C.

Long-term effects of ambient air pollutants to blood lipids and dyslipidemias in a Chinese rural population

2020 ◽  
Vol 256 ◽  
pp. 113403 ◽  
Author(s):  
Shuyuan Mao ◽  
Gongbo Chen ◽  
Feifei Liu ◽  
Na Li ◽  
Chongjian Wang ◽  
...  
Keyword(s):  
Rural Population ◽  
Air Pollutants ◽  
Blood Lipids ◽  
Ambient Air ◽  
Long Term Effects ◽  
Ambient Air Pollutants

Response of the Cache Creek macroinvertebrates during the first 10 years following disturbance by the 1988 Yellowstone wildfires

2001 ◽  
Vol 58 (6) ◽  
pp. 1077-1088 ◽  
Author(s):  
G Wayne Minshall ◽  
Todd V Royer ◽  
Christopher T Robinson
Keyword(s):  
Large Scale ◽  
Fire Effects ◽  
Terrestrial Vegetation ◽  
Long Term Effects ◽  
Taxa Richness ◽  
Site Coefficients ◽  
Coefficients Of Variation ◽  
Reference Stream ◽  
Stream Size

We evaluated the effects of disturbance on stream benthic macroinvertebrates at the ecological scales of time, stream size, and burn extent in six segments of Cache Creek over the first 10 postfire years. Postfire changes in macroinvertebrate taxa richness, density, and dominant taxa in the burn streams were significantly different from those in the reference stream. Chironomidae and Baetis typically comprised 40–60% of the macroinvertebrate assemblages of burned streams but only 15–18% of the assemblage in the reference site. Coefficients of variation for the 10-year period indicated that richness, density, biomass, and Baetis abundance were more variable (1.2–3.5 times higher) in the burn streams than in the reference stream and that variability in Chironomidae abundance in burn sites increased with stream size. Fire effects were not attenuated progressively with increasing stream size, probably because the proportion of the catchment burned did not decrease. However, similar-sized streams in which 68–71% of their catchments burned were more severely disturbed than those in which only 39–47% burned. Long-term effects on the macroinvertebrate community were due largely to the loss of terrestrial vegetation and increased runoff, which caused severe alterations in stream channel conditions and large-scale bedload movement.

Long-term effects of harvest residue management on soil total carbon and nitrogen concentrations of a replanted Chinese fir plantation

2013 ◽  
Vol 33 (13) ◽  
pp. 4205-4213
Author(s):  
胡振宏 HU Zhenhong ◽  
何宗明 HE Zongming ◽  
范少辉 FAN Shaohui ◽  
黄志群 HUANG Zhiqun ◽  
万晓华 WAN Xiaohua ◽  
...  
Keyword(s):  
Chinese Fir ◽  
Residue Management ◽  
Total Carbon ◽  
Long Term Effects ◽  
Carbon And Nitrogen ◽  
Nitrogen Concentrations ◽  
Chinese Fir Plantation ◽  
Harvest Residue

scholarly journals Trade-offs between the short- and long-term effects of residue quality on soil C and N dynamics

2010 ◽  
Vol 338 (1-2) ◽  
pp. 159-169 ◽  
Author(s):  
Roberta Gentile ◽  
Bernard Vanlauwe ◽  
Pauline Chivenge ◽  
Johan Six
Keyword(s):  
Residue Quality ◽  
Long Term Effects ◽  
N Dynamics ◽  
Soil C ◽  
Trade Offs ◽  
Short And Long Term ◽  
Soil C And N ◽  
C And N ◽  
C And N Dynamics

Effect of leaching and clay content on carbon and nitrogen mineralisation in maize and pasture soils

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 535 ◽  
Author(s):  
R. L. Parfitt ◽  
G. J. Salt ◽  
S. Saggar
Keyword(s):  
Clay Content ◽  
N Mineralisation ◽  
Incubation Experiment ◽  
Nitrogen Mineralisation ◽  
Total N ◽  
Carbon And Nitrogen ◽  
Maize Sample ◽  
C Mineralisation ◽  
C And N

We conducted a 7-week laboratory incubation experiment to evaluate the effect of leaching on net C and N mineralisation in soils. The soils were collected from adjacent fields of long-term pasture and maize, where each field contained an Inceptisol and an Andisol. The concentration of clay mineral was 200 g/kg halloysite in the Inceptisol and 120 g/kg allophane in the Andisol. Half the samples were leached weekly with 0.002 M CaCl2 at a suction of 20 kPa to remove soluble products, and half were not leached. Carbon mineralisation was determined from CO2-C evolved each week. Net N mineralisation was measured for the leached samples from the NH4-N and NO3-N in the CaCl2 extracts, and for the batch of non-leached samples by extraction in 0.5 M K2SO4. Carbon and net N mineralisation were greater in the soils under pasture than in soils under maize. The proportion of total C mineralised as CO2-C, and of total N mineralised as NH4-N and NO3-N, followed the order Inceptisol-pasture > Inceptisol-maize > Andisol-pasture > Andisol-maize, suggesting that allophane and Al ions reduced net mineralisation. Dissolved organic carbon (DOC) produced during incubation, as a proportion of total C, was greatest for the Inceptisol-maize sample and least for the Andisol-pasture sample. Non-leaching resulted in the accumulation of acids and solutes, and decreased C mineralisation for the Inceptisol samples.

Short-term and long-term effects of bacterivorous nematodes and nematophagous fungi on carbon and nitrogen mineralization in microcosms

1994 ◽  
Vol 17 (4) ◽  
pp. 249-256 ◽  
Author(s):  
L. A. Bouwman ◽  
J. Bloem ◽  
P. H. J. F. van den Boogert ◽  
F. Bremer ◽  
G. H. J. Hoenderboom ◽  
...  
Keyword(s):  
Nitrogen Mineralization ◽  
Nematophagous Fungi ◽  
Long Term Effects ◽  
Short Term ◽  
Carbon And Nitrogen

scholarly journals Long-Term Effects of Forest Plantation Species on Chemical Soil Properties in Southern Rwanda

Soil Systems ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 59
Author(s):  
Peter Rwibasira ◽  
Francois Xavier Naramabuye ◽  
Donat Nsabimana ◽  
Monique Carnol
Keyword(s):  
Soil Properties ◽  
Tree Species ◽  
Native Species ◽  
Water Soluble ◽  
Hot Water ◽  
Eucalyptus Species ◽  
Long Term Effects ◽  
Soil Functioning ◽  
C And N

Understanding the long-term effects of tree species on soil properties is crucial for the development of forest restoration policies in relation to the choice of species that meet both environmental and local livelihood needs. This study was performed in the Arboretum of Ruhande, Southern Rwanda, where monocultures of 148 deciduous and 56 conifer species have been established in 0.25 ha replicated plots from 1933 onwards. We investigated the effects of six exotic and two native tree species planted in monoculture plots and native species mixed within one self-regenerated plot on soil properties in two layers (0–5 cm and 5–10 cm depth). We measured general soil properties (pH, SOM, exchangeable base cations) and water-soluble C and N as a proxy for soil functioning. Changes in soil properties were observed in the upper soil layer for all tree species. Planting Eucalyptus species caused soil acidification, whereas soil exchangeable cations and pH were higher under native species (Entandrophragma excelsum and Polyschias fulva) and mixed native species. The effects of tree species were more pronounced for hot water-extractable C and N than for other soil properties. Their analyses could be used for detecting changes in soil functioning linked to vegetation types.

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