scholarly journals Short-Term Litter Manipulations have Strong Impact on Soil Nitrogen Dynamics in Larix gmelinii Forest of Northeast China

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1205
Author(s):  
Ruihan Xiao ◽  
Xiuling Man ◽  
Beixing Duan ◽  
Tijiu Cai
Keyword(s):  
Soil Layer ◽  
Net N Mineralization ◽  
Soil N ◽  
Inorganic N ◽  
Short Term ◽  
N Dynamics ◽  
Litter Addition ◽  
Litter Manipulation ◽  
Soil Inorganic N ◽  
Soil N Dynamics

Changes in above-ground litterfall can influence below-ground biogeochemical processes in forests, which substantially impacts soil nitrogen (N) and nutrient cycling. However, how these soil processes respond to the litter manipulation is complex and poorly understood, especially in the N-limiting boreal forest. We aimed to examine how soil N dynamics respond to litter manipulations in a boreal larch forest. A litter manipulation experiment including control, litter exclusion, and litter addition was performed in the Larix gmelinii forest on the north of the Daxing’an Mountains in China. Monthly soil inorganic N, microbial biomass and the rate of net N mineralization in both 0–10 cm and 10–20 cm layers, and N2O flux were analyzed from May 2018 to October 2018. In 0–20 cm soil layer the average soil inorganic N contents, microbial biomass N (MBN) contents, the rate of net N mineralization (Rmin), and the soil N2O emission in the litter addition plot were approximately 40.58%, 54.16%, 128.57%, and 38.52% greater, respectively than those in the control. While litter exclusion reduced those indexes about 29.04%, 19.84%, 80.98%, and 31.45%, respectively. Compared with the dynamics of the 10–20 cm soil layer, the N dynamics in 0–10 cm soil were more sensitive to litter manipulation. Rmin and N2O emissions were significantly correlated with MBN in most cases. Our results highlight the short-term effects of litter manipulations on soil N dynamics, which suggests that the influence of litter on soil N process should be considered in the future defoliation management of the boreal larch forest.

Relationships between soil nitrogen dynamics and natural 15N abundance in plant foliage from Great Smoky Mountains National Park

1994 ◽  
Vol 24 (8) ◽  
pp. 1636-1645 ◽  
Author(s):  
Charles T. Garten Jr. ◽  
Helga Van Miegroet
Keyword(s):  
N Mineralization ◽  
Enrichment Factors ◽  
High Elevation ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
N Dynamics ◽  
Great Smoky Mountains ◽  
Soil N Dynamics ◽  
Mineral Soils

We tested the hypothesis that naturally occurring nitrogen (N) isotope ratios in foliage (from plants that do not symbiotically fix atmospheric N2) are an indicator of soil N dynamics in forests. Replicate plots were established at eight locations ranging in elevation from 615 to 1670 m in Great Smoky Mountains National Park in eastern Tennessee, U.S.A. The locations selected ranged from N-poor (low-elevation) to N-rich (high-elevation) forest stands. Soils were sampled in June 1992; plants, forest floors, and upper mineral soils were sampled in August 1992. Net N mineralization and net nitrification potentials for surface mineral soils and organic matter layers at each site were determined by aerobic laboratory incubations. Soils and organic layers from high-elevation sites had greater net N mineralization and nitrification potentials than soils from low-elevation sites. There were significant (P ≤ 0.05) differences between study sites in soil 15N abundance. Therefore, we examined correlations between measures of soil N availability and both mean foliar δ15N values and mean enrichment factors (εp−s = δ15Nleaf − δ15Nsoil). In evergreens, maples, and ferns, mean foliar δ15N values and mean enrichment factors were positively correlated with net N mineralization and net nitrification potentials in soil. The observed relationships between natural 15N abundance in plant leaves and soil N availability were explained by a simple model of soil N dynamics. The model predicts how the isotopic composition of plant N is affected by the following factors: (i) varying uptake of soil NH4-N and NO3-N, (ii) the isotopic composition of different soil N pools, and (iii) relative rates of soil N transformations.

EFFECTS OF GRAZING ON MICROBIAL FUNCTIONAL GROUPS INVOLVED IN SOIL N DYNAMICS

2005 ◽  
Vol 75 (1) ◽  
pp. 65-80 ◽  
Author(s):  
A. K. Patra ◽  
L. Abbadie ◽  
A. Clays-Josserand ◽  
V. Degrange ◽  
S. J. Grayston ◽  
...  
Keyword(s):  
Functional Groups ◽  
Soil N ◽  
N Dynamics ◽  
Microbial Functional Groups ◽  
Soil N Dynamics

scholarly journals Plant and soil nitrogen in oligotrophic boreal forest habitats with varying moss depths: does exclusion of large grazers matter?

Oecologia ◽  
2021 ◽  
Author(s):  
Maria Väisänen ◽  
Maria Tuomi ◽  
Hannah Bailey ◽  
Jeffrey M. Welker
Keyword(s):  
Boreal Forest ◽  
Vascular Plant ◽  
Soil N ◽  
Inorganic N ◽  
N Dynamics ◽  
N Content ◽  
Feather Moss ◽  
Foliar N ◽  
Plant Soil ◽  
Plant Soil Interactions

AbstractThe boreal forest consists of drier sunlit and moister-shaded habitats with varying moss abundance. Mosses control vascular plant–soil interactions, yet they all can also be altered by grazers. We determined how 2 decades of reindeer (Rangifer tarandus) exclusion affect feather moss (Pleurozium schreberi) depth, and the accompanying soil N dynamics (total and dissolvable inorganic N, δ15N), plant foliar N, and stable isotopes (δ15N, δ13C) in two contrasting habitats of an oligotrophic Scots pine forest. The study species were pine seedling (Pinus sylvestris L.), bilberry (Vaccinium myrtillus L.), lingonberry (V. vitis-idaea L.), and feather moss. Moss carpet was deeper in shaded than sunlit habitats and increased with grazer exclusion. Humus N content increased in the shade as did humus δ15N, which also increased due to exclusion in the sunlit habitats. Exclusion increased inorganic N concentration in the mineral soil. These soil responses were correlated with moss depth. Foliar chemistry varied due to habitat depending on species identity. Pine seedlings showed higher foliar N content and lower foliar δ15N in the shaded than in the sunlit habitats, while bilberry had both higher foliar N and δ15N in the shade. Thus, foliar δ15N values of co-existing species diverged in the shade indicating enhanced N partitioning. We conclude that despite strong grazing-induced shifts in mosses and subtler shifts in soil N, the N dynamics of vascular vegetation remain unchanged. These indicate that plant–soil interactions are resistant to shifts in grazing intensity, a pattern that appears to be common across boreal oligotrophic forests.

Soil N dynamics in a natural calcareous grassland under a changing climate

1998 ◽  
Vol 27 (3) ◽  
pp. 267-273 ◽  
Author(s):  
N. Jamieson ◽  
D. Barraclough ◽  
M. Unkovich ◽  
R. Monaghan
Keyword(s):  
Calcareous Grassland ◽  
Soil N ◽  
N Dynamics ◽  
Changing Climate ◽  
Soil N Dynamics

Effects of transition season management on soil N dynamics and system N balances in rice–wheat rotations of Nepal

2007 ◽  
Vol 103 (2) ◽  
pp. 98-108 ◽  
Author(s):  
M. Becker ◽  
F. Asch ◽  
S.L. Maskey ◽  
K.R. Pande ◽  
S.C. Shah ◽  
...  
Keyword(s):  
Soil N ◽  
N Dynamics ◽  
Transition Season ◽  
Soil N Dynamics

scholarly journals The simulated N deposition accelerates net N mineralization and nitrification in a tropical forest soil

2019 ◽  
Vol 16 (21) ◽  
pp. 4277-4291
Author(s):  
Yanxia Nie ◽  
Xiaoge Han ◽  
Jie Chen ◽  
Mengcen Wang ◽  
Weijun Shen
Keyword(s):  
N Deposition ◽  
Functional Genes ◽  
Net N Mineralization ◽  
Soil N ◽  
Wet Season ◽  
Inorganic N ◽  
N Transformations ◽  
N Transformation ◽  
Soil N Transformation ◽  
N Additions

Abstract. Elevated nitrogen (N) deposition affects soil N transformations in the N-rich soil of tropical forests. However, the change in soil functional microorganisms responsible for soil N cycling remains largely unknown. Here, we investigated the variation in soil inorganic N content, net N mineralization (Rm), net nitrification (Rn), inorganic N leaching (Rl), N2O efflux and N-related functional gene abundance in a tropical forest soil over a 2-year period with four levels of N addition. The responses of soil net N transformations (in situ Rm and Rn) and Rl to N additions were negligible during the first year of N inputs. The Rm, Rn, and Rl increased with the medium nitrogen (MN) and high nitrogen (HN) treatments relative to the control treatments in the second year of N additions. Furthermore, the Rm, Rn, and Rl were higher in the wet season than in the dry season. The Rm and Rn were mainly associated with the N addition-induced lower C:N ratio in the dry season but with higher microbial biomass in the wet season. Throughout the study period, high N additions increased the annual N2O emissions by 78 %. Overall, N additions significantly facilitated Rm, Rn, Rl and N2O emission. In addition, the MN and HN treatments increased the ammonia-oxidizing archaea (AOA) abundance by 17.3 % and 7.5 %, respectively. Meanwhile, the HN addition significantly increased the abundance of nirK denitrifiers but significantly decreased the abundance of ammonia-oxidizing bacteria (AOB) and nosZ-containing N2O reducers. To some extent, the variation in functional gene abundance was related to the corresponding N-transformation processes. Partial least squares path modelling (PLS-PM) indicated that inorganic N contents had significantly negative direct effects on the abundances of N-related functional genes in the wet season, implying that chronic N deposition would have a negative effect on the N-cycling-related microbes and the function of N transformation. Our results provide evidence that elevated N deposition may impose consistent stimulatory effects on soil N-transformation rates but differentiated impacts on related microbial functional genes. Long-term experimentation or observations are needed to decipher the interrelations between the rate of soil N-transformation processes and the abundance or expression of related functional genes.

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