scholarly journals Strong Interactive Effects of Warming and Insect Herbivory on Soil Carbon and Nitrogen Dynamics at Subarctic Tree Line

2021 ◽  
Vol 4 ◽  
Author(s):  
Nele Meyer ◽  
Tarja Silfver ◽  
Kristiina Karhu ◽  
Kristiina Myller ◽  
Outi-Maaria Sietiö ◽  
...  
Keyword(s):  
Root Growth ◽  
Insect Herbivory ◽  
Leaf Damage ◽  
Plant Production ◽  
The Arctic ◽  
Microbial Biomass C ◽  
Soil C ◽  
Soil C And N ◽  
C And N ◽  
C Input

Warming will likely stimulate Arctic primary production, but also soil C and N mineralization, and it remains uncertain whether the Arctic will become a sink or a source for CO2. Increasing insect herbivory may also dampen the positive response of plant production and soil C input to warming. We conducted an open-air warming experiment with Subarctic field layer vegetation in North Finland to explore the effects of warming (+3°C) and reduced insect herbivory (67% reduction in leaf damage using an insecticide) on soil C and N dynamics. We found that plant root growth, soil C and N concentrations, microbial biomass C, microbial activity, and soil NH4+ availability were increased by both warming and reduced herbivory when applied alone, but not when combined. Soil NO3– availability increased by warming only and in-situ soil respiration by reduced herbivory only. Our results suggest that increasing C input from vegetation under climate warming increases soil C concentration, but also stimulates soil C turnover. On the other hand, it appears that insect herbivores can significantly reduce plant growth. If their abundance increases with warming as predicted, they may curtail the positive effect of warming on soil C concentration. Moreover, our results suggest that temperature and herbivory effects on root growth and soil variables interact strongly, which probably arises from a combination of N demand increasing under lower herbivory and soil mineral N supply increasing under higher temperature. This may further complicate the effects of rising temperatures on Subarctic soil C dynamics.

scholarly journals C and N urban soil budget and its spatial differentiation in comparison with natural areas in the Wroclaw region of Poland

2018 ◽  
Vol 45 ◽  
pp. 00085
Author(s):  
Izabela Sówka ◽  
Yaroslav Bezyk ◽  
Maxim Dorodnikov
Keyword(s):  
Urban Soil ◽  
Spatial Differentiation ◽  
Clay Content ◽  
Dry Mass ◽  
Microbial Biomass C ◽  
Natural Areas ◽  
Soil C ◽  
Soil C And N ◽  
C And N ◽  
Natural Grassland

An assessment of C and N balance in urban soil compared to the natural environment was carried out to evaluate the influence of biological processes along with human-induced forcing. Soil C and N stocks were quantified on the samples (n=18) collected at 5 - 10 cm depth from dominated green areas and arable lands in the city of Wroclaw (Poland) and the relatively natural grassland located ca. 36 km south-west. Higher soil carbon and nitrogen levels (C/N ratio = 11.8) and greater microbial biomass C and N values (MBC = 95.3, MBN = 14.4 mg N kg-1) were measured in natural grassland compared with the citywide lawn sites (C/N ratio = 15.17, MBC = 84.3 mg C kg-1, MBN = 11.9 mg N kg-1), respectively. In contrast to the natural areas, the higher C and N concentration was measured in urban grass dominated soils (C = 2.7 % and N = 0.18 % of dry mass), which can be explained mainly due to the high soil bulk density and water holding capacity (13.8 % clay content). The limited availability of soil C and N content was seen under the arable soil (C = 1.23 %, N = 0.13 %) than in the studied grasslands. In fact, the significantly increased C/N ratios in urban grasslands are largely associated with land conversion and demonstrate that urban soils have the potential to be an important reservoir of C.

Soil carbon and nitrogen pools and processes in an old-growth conifer forest 13 years after trenching

1998 ◽  
Vol 28 (8) ◽  
pp. 1261-1265 ◽  
Author(s):  
Stephen C Hart ◽  
Phil Sollins
Keyword(s):  
Water Content ◽  
N Mineralization ◽  
Microbial Biomass C ◽  
Net N Mineralization ◽  
Conifer Forest ◽  
Old Growth ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Soil C And N ◽  
C And N

We measured surface soil (0-15cm) C and N pools and processes inside and outside an area that had been trenched 13 years earlier in an old-growth conifer forest (>450 years) to assess the long-term impacts of reduced root inputs on C and N turnover. Trenching, combined with frequent clipping of understory plants, was originally conducted to prevent nutrient uptake by plants, as part of a study of the role of vegetation in ecosystem retention of N. Thirteen years following trenching, the median values of bulk density, pH, total C and N concentrations, annual rates of in situ net N mineralization and nitrification, microbial biomass C and N, microbial respiration, and anaerobically mineralizable N in the trenched plot were all within the 25-75% interquartile range of values found in the replicated, untrenched plots. The trenched plot had higher rates of net N mineralization (41% higher in October, 484% higher in June) and net nitrification (25% higher in October, and lower net NO3- immobilization in June) during laboratory incubation and a 22% higher water content in October. In June, soil water content in the trenched plot was about 8% lower than in the untrenched plots. Our results suggest that soil C and N dynamics in these old-growth forests are relatively resistant to perturbations resulting from major reductions in root input to the soil.

The effect of crop rotation and sheep grazing management on plant production and soil C and N stocks in a long-term integrated crop-livestock system in Southern Brazil

2020 ◽  
Vol 203 ◽  
pp. 104678
Author(s):  
Lucas Aquino Alves ◽  
Luiz Gustavo de Oliveira Denardin ◽  
Amanda Posselt Martins ◽  
Cimélio Bayer ◽  
Murilo Gomes Veloso ◽  
...  
Keyword(s):  
Crop Rotation ◽  
Grazing Management ◽  
Plant Production ◽  
Southern Brazil ◽  
Sheep Grazing ◽  
Soil C ◽  
Soil C And N ◽  
C And N ◽  
Livestock System

SOIL C AND N AS INDICATORS OF VINEYARD SOIL QUALITY IN THE RAVNI KOTARI REGION OF CROATIA

2020 ◽  
Author(s):  
Sonia C. Clemens ◽  
◽  
Mia Brkljaca ◽  
Delaina Pearson ◽  
C. Brannon Andersen
Keyword(s):  
Soil Quality ◽  
Soil C ◽  
Vineyard Soil ◽  
Soil C And N ◽  
C And N

scholarly journals Spatially Related Sampling Uncertainty in the Assessment of Labile Soil Carbon and Nitrogen in an Irish Forest Plantation

2021 ◽  
Vol 11 (5) ◽  
pp. 2139
Author(s):  
Junliang Zou ◽  
Bruce Osborne
Keyword(s):  
Spatial Variability ◽  
Soil Carbon ◽  
Sampling Effort ◽  
Limited Information ◽  
Sampling Area ◽  
Soil C ◽  
Distribution Maps ◽  
Soil C And N ◽  
C And N ◽  
Highly Correlated

The importance of labile soil carbon (C) and nitrogen (N) in soil biogeochemical processes is now well recognized. However, the quantification of labile soil C and N in soils and the assessment of their contribution to ecosystem C and N budgets is often constrained by limited information on spatial variability. To address this, we examined spatial variability in dissolved organic carbon (DOC) and dissolved total nitrogen (DTN) in a Sitka spruce forest in central Ireland. The results showed moderate variations in the concentrations of DOC and DTN based on the mean, minimum, and maximum, as well as the coefficients of variation. Residual values of DOC and DTN were shown to have moderate spatial autocorrelations, and the nugget sill ratios were 0.09% and 0.10%, respectively. Distribution maps revealed that both DOC and DTN concentrations in the study area decreased from the southeast. The variability of both DOC and DTN increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. The cokriging technique performed better than the ordinary kriging for predictions of DOC and DTN, which are highly correlated. This study provides a statistically based assessment of spatial variations in DOC and DTN and identifies the sampling effort required for their accurate quantification, leading to improved assessments of forest ecosystem C and N budgets.

Impacts of irrigation on soil C and N stocks in grazed grasslands depends on aridity and irrigation duration

Geoderma ◽  
2021 ◽  
Vol 399 ◽  
pp. 115109
Author(s):  
Paul L. Mudge ◽  
Jamie Millar ◽  
Jack Pronger ◽  
Alesha Roulston ◽  
Veronica Penny ◽  
...  
Keyword(s):  
Soil C ◽  
Soil C And N ◽  
C And N

Comparison of carbon and nitrogen storage in mineral soils of graminoid and shrub tundra sites, western Greenland

2016 ◽  
Vol 2 (4) ◽  
pp. 165-182 ◽  
Author(s):  
Chelsea L. Petrenko ◽  
Julia Bradley-Cook ◽  
Emily M. Lacroix ◽  
Andrew J. Friedland ◽  
Ross A. Virginia
Keyword(s):  
Vegetation Type ◽  
Mineral Soil ◽  
Biotic Interactions ◽  
The Arctic ◽  
Soil C ◽  
N Storage ◽  
C Storage ◽  
Arctic Soils ◽  
C Pools ◽  
C And N

Shrub species are expanding across the Arctic in response to climate change and biotic interactions. Changes in belowground carbon (C) and nitrogen (N) storage are of global importance because Arctic soils store approximately half of global soil C. We collected 10 (60 cm) soil cores each from graminoid- and shrub-dominated soils in western Greenland and determined soil texture, pH, C and N pools, and C:N ratios by depth for the mineral soil. To investigate the relative chemical stability of soil C between vegetation types, we employed a novel sequential extraction method for measuring organo-mineral C pools of increasing bond strength. We found that (i) mineral soil C and N storage was significantly greater under graminoids than shrubs (29.0 ± 1.8 versus 22.5 ± 3.0 kg·C·m−2 and 1.9 ± .12 versus 1.4 ± 1.9 kg·N·m−2), (ii) chemical mechanisms of C storage in the organo-mineral soil fraction did not differ between graminoid and shrub soils, and (iii) weak adsorption to mineral surfaces accounted for 40%–60% of C storage in organo-mineral fractions — a pool that is relatively sensitive to environmental disturbance. Differences in these C pools suggest that rates of C accumulation and retention differ by vegetation type, which could have implications for predicting future soil C pool storage.

Simulation of protozoa-induced mineralization of bacterial carbon and nitrogen

1992 ◽  
Vol 72 (3) ◽  
pp. 201-216 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma
Keyword(s):  
N Mineralization ◽  
Ecological Research ◽  
Clay Loam ◽  
Glucose Addition ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Soil C And N ◽  
C And N ◽  
Typic Cryoboroll ◽  
Bacterial C

Modelling in soil ecological research is a means of linking the dynamics of microbial and faunal populations to soil processes. The objectives of this study were (i) to simulate bacterial-protozoan interactions and flows of C and N in clay loam Orthic Black Chernozemic soil under laboratory condtions; and (ii) to quantify the flux of C and N (inputs and outputs) through various pools using the simulation model. The unique features of this model are: (i) it combines the food chain with specific soil C and N pools, and (ii) it simultaneously traces the flows of C, 14C, N and 15N. It was possible to produce a model that fitted the data observed for the soil. The simulated CO2-C evolved during the first 12 d was due mainly to glucose addition (171 μg C g−1 soil) and cycling of C in the soil (160 μg C g−1 soil). During this interval, bacterial C uptake was 5.5-fold greater than the initial bacterial C pool size. In the first 12 d protozoa directly increased total CO2-C evolution by 11% and increased NH4-N mineralization 3-fold, compared to soil containing only bacteria. Mineralization of C and N was rapid when bacterial numbers were increased as a result of glucose addition. Key words: Acanthamoeba sp., modelling, N mineralization-immobilization, organic matter, Pseudomonas sp., Typic Cryoboroll

scholarly journals Patterns of water infiltration and soil degradation over a 120-yr chronosequence from forest to agriculture in western Kenya

2011 ◽  
Vol 8 (4) ◽  
pp. 6993-7015 ◽  
Author(s):  
G. Nyberg ◽  
A. Bargués Tobella ◽  
J. Kinyangi ◽  
U. Ilstedt
Keyword(s):  
Bulk Density ◽  
Soil Degradation ◽  
Agricultural Land ◽  
Infiltration Rate ◽  
Water Infiltration ◽  
Native Forest ◽  
Western Kenya ◽  
Soil C ◽  
Soil C And N ◽  
C And N

Abstract. Soil degradation is commonly reported in the tropics where forest is converted to agriculture. Much of the native forest in the highlands of western Kenya has been converted to agricultural land in order to feed the growing population, and more land is being cleared. In tropical Africa, this land use change results in progressive soil degradation, as the period of cultivation increases. Sites that were converted to agriculture at different times can be evaluated as a chronosequence; this can aid in our understanding of the processes at work, particularly those in the soil. Both levels and variation of infiltration, soil carbon and other parameters are influenced by management within agricultural systems, but they have rarely been well documented in East Africa. We constructed a chronosequence for an area of western Kenya, using two native forest sites and six fields that had been converted to agriculture for varying lengths of time. We assessed changes in infiltrability (the steady-state infiltration rate), soil C and N, bulk density, δ13C, and the proportion of macro- and microaggregates in soil along a 119 yr chronosequence of conversion from natural forest to agriculture. Infiltration, soil C and N, decreased rapidly after conversion, while bulk density increased. Median infiltration rates fell to about 15 % of the initial values in the forest and C and N values dropped to around 60 %, whilst the bulk density increased by 50 %. Despite high spatial variability in infiltrability, these parameters correlated well with time since conversion and with each other. Our results indicate that landscape planners should include wooded elements in the landscape in sufficient quantity to ensure water infiltration at rates that prevent runoff and erosion. This should be the case for restoring degraded landscapes, as well as for the development of new agricultural areas.

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