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Journal Articles

Quantitative importance of subsoil nitrogen cycling processes in Andosols and Cambisols under temperate forests

Nakayama, Masataka; Abe, Yukiko; Atarashi-Andoh, Mariko; Tange, Takeshi*; Sawada, Haruo*; Liang, N.*; Koarashi, Jun

Applied Soil Ecology, 201, p.105485_1 - 105485_12, 2024/09

 Times Cited Count:0 Percentile:0.00(Soil Science)

Nitrogen often limits plant growth in forest ecosystems. Plants, including trees, change vertical root distribution when nutrient competition is strong within surface soil layer and take up nitrogen even from subsurface soil layers in addition to the surface soil. However, there is still limited knowledge about nitrogen cycles within deeper soil layers. In this study, we investigated the vertical profiles (0-60 cm) of the net nitrogen mineralization and nitrification rates at four Japanese forest sites with two different soil types (Andosols and Cambisols). The partial least square path modeling (PLS-PM) was used to determine factors affecting nitrogen-cycling processes. The net nitrogen mineralization and nitrification rates per unit soil weight were considerably higher in surface soil layer than in deeper soil layers in Andosols but not in Cambisols. PLS-PM analysis showed that microbial biomass and soil organic matter quantities were the main factors influencing the net nitrogen mineralization and nitrification rates, indicating that a similar mechanism creating the spatial variations of nitrogen-cycling processes in surface soil layer predominantly regulates the processes in subsoil layers. Moreover, it was estimated that the net nitrogen mineralization rate could be comparable at all soil types and depths when the rate was expressed per unit soil volume. Therefore, our results suggest that subsoil layers are a quantitatively important nitrogen source for plant nutrients in Andosols and Cambisols, supporting high forest productivity.

Journal Articles

Validation of the $$^{10}$$Be ground-state molecular structure using $$^{10}$$Be($$p,palpha$$)$$^{6}$$He triple differential reaction cross-section measurements

Li, P. J.*; Beaumel, D.*; Lee, J.*; Assi$'e$, M.*; Chen, S.*; Franchoo, S.*; Gibelin, J.*; Hammache, F.*; Harada, T.*; Kanada-En'yo, Yoshiko*; et al.

Physical Review Letters, 131(21), p.212501_1 - 212501_7, 2023/11

 Times Cited Count:11 Percentile:84.75(Physics, Multidisciplinary)

The cluster structure of the neutron-rich isotope $$^{10}$$Be has been probed via the ($$p,palpha$$) reaction. The triple differential cross-section was extracted and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using the Tohsaki-Horiuchi-Schuck-R$"o$pke wave function and the wave function deduced from Antisymmetrized Molecular Dynamics calculations. The remarkable agreement between calculated and measured cross-sections in both shape and magnitude validates the description of the $$^{10}$$Be ground-state as a rather compact nuclear molecule.

Journal Articles

Multiple mechanisms in proton-induced nucleon removal at $$sim$$100 MeV/nucleon

Pohl, T.*; Sun, Y. L.*; Obertelli, A.*; Lee, J.*; G$'o$mez-Ramos, M.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Cai, B. S.*; Yuan, C. X.*; Brown, B. A.*; et al.

Physical Review Letters, 130(17), p.172501_1 - 172501_8, 2023/04

 Times Cited Count:11 Percentile:89.13(Physics, Multidisciplinary)

We report on the first proton-induced single proton- and neutron-removal reactions from the neutron deficient $$^{14}$$O nucleus with large Fermi-surface asymmetry at $$sim$$100 MeV/nucleon. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively.

Journal Articles

Ten years of warming increased plant-derived carbon accumulation in an East Asian monsoon forest

Zhang, J.*; Kuang, L.*; Mou, Z.*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko; Li, Y.*; Tang, X.*; Wang, Y.-P.*; Pe$~n$uelas, J.*; et al.

Plant and Soil, 481(1-2), p.349 - 365, 2022/12

 Times Cited Count:8 Percentile:67.58(Agronomy)

Journal Articles

Spatial variation in soil respiration rate is controlled by the content of particulate organic materials in the volcanic ash soil under a ${it Cryptomeria japonica}$ plantation

Abe, Yukiko*; Liang, N.*; Teramoto, Munemasa*; Koarashi, Jun; Atarashi-Andoh, Mariko; Hashimoto, Shoji*; Tange, Takeshi*

Geoderma Regional (Internet), 29, p.e00529_1 - e00529_11, 2022/06

 Times Cited Count:1 Percentile:7.47(Soil Science)

This study aimed to clarify the causes of spatial variation in soil respiration rate on volcanic ash soil. From January 2013 to August 2019, soil respiration rates were measured at 40 measuring points periodically at a 35-year-old ${it Cryptomeria japonica}$ plantation in Tokyo, Japan. In August 2019, the carbon content of the litter layer, total carbon content of soil organic matter (SOM), carbon content of the low-density fraction (LF-C) of SOM, fine root biomass, and bulk density of soil were measured at all measuring points. Results of the multiple regression analysis showed that the model with only the LF-C as an explanatory variable had the highest capability for predicting the respiration rate at a soil temperature of 20$$^{circ}$$C, indicating that LF-C, which is considered to be readily available to soil microorganisms, can be the main factor responsible for the spatial variation in soil respiration rate.

JAEA Reports

Practical guide on soil sampling, treatment, and carbon isotope analysis for carbon cycle studies

Koarashi, Jun; Atarashi-Andoh, Mariko; Nagano, Hirohiko*; Sugiharto, U.*; Saengkorakot, C.*; Suzuki, Takashi; Kokubu, Yoko; Fujita, Natsuko; Kinoshita, Naoki; Nagai, Haruyasu; et al.

JAEA-Technology 2020-012, 53 Pages, 2020/10

JAEA-Technology-2020-012.pdf:3.71MB

There is growing concern that recent rapid changes in climate and environment could have a significant influence on carbon cycling in terrestrial ecosystems (especially forest ecosystems) and could consequently lead to a positive feedback for global warming. The magnitude and timing of this feedback remain highly uncertain largely due to a lack of quantitative understanding of the dynamics of organic carbon stored in soils and its responses to changes in climate and environment. The tracing of radiocarbon (natural and bomb-derived $$^{14}$$C) and stable carbon ($$^{13}$$C) isotopes through terrestrial ecosystems can be a powerful tool for studying soil organic carbon (SOC) dynamics. The primary aim of this guide is to promote the use of isotope-based approaches to improve our understanding of the carbon cycling in soils, particularly in the Asian region. The guide covers practical methods of soil sampling; treatment and fractionation of soil samples; preparation of soil samples for $$^{13}$$C (and stable nitrogen isotope, $$^{15}$$N) and $$^{14}$$C analyses; and $$^{13}$$C, $$^{15}$$N, and $$^{14}$$C measurements by the use of isotope ratio mass spectrometry and accelerator mass spectrometry (AMS). The guide briefly introduces ways to report $$^{14}$$C data, which are frequently used for soil carbon cycling studies. The guide also reports results of a case study conducted in a Japanese forest ecosystem, as a practical application of the use of isotope-based approaches. This guide is mainly intended for researchers who are interested but are not experienced in this research field. The guide will hopefully encourage readers to participate in soil carbon cycling studies, including field works, laboratory experiments, isotope analyses, and discussions with great interest.

Oral presentation

Evaluation of long-term soil warming effect on soil organic carbon decomposition

Teramoto, Munemasa*; Kondo, Toshiaki*; Liang, N.*; Zeng, J.*; Nakane, Kaneyuki*; Koarashi, Jun; Atarashi-Andoh, Mariko; Aramaki, Takafumi*; Tomimatsu, Hajime*; Zhao, X.*

no journal, , 

no abstracts in English

Oral presentation

Long-term response and feedback of Asian terrestrial ecosystems carbon cycle to global warming

Liang, N.*; Zhang, Y.*; Chiang, P.-N.*; Lai, D.*; Teramoto, Munemasa*; Takagi, Kentaro*; Kondo, Toshiaki*; Koarashi, Jun; Wang, Y.*; Li, S.*; et al.

no journal, , 

Oral presentation

Soil warming effect on the heterotrophic respiration rate during a decadal experiment in a cool-temperate forested peatland

Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Rythi, K.*; Teramoto, Munemasa*; Kobayashi, Makoto*; Sun, L.*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko

no journal, , 

Oral presentation

Comprehensive field study on Asian forest soil carbon dynamics

Liang, N.*; Teramoto, Munemasa*; Takagi, Kentaro*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko; Hirano, Takashi*; Takahashi, Yoshiyuki*; Takagi, Masahiro*; Ishida, Sachinobu*; et al.

no journal, , 

no abstracts in English

Oral presentation

Long-term monitoring soil carbon dynamics of Asian terrestrial ecosystem by an automated chamber network

Liang, N.*; Chiang, P.-N.*; Wang, Y.*; Teramoto, Munemasa*; Takagi, Kentaro*; Kondo, Toshiaki*; Koarashi, Jun; Zhang, Y.*; Li, S.*; Fang, J.*; et al.

no journal, , 

Oral presentation

Warming-induced enhancement of soil heterotrophic respiration is linearly increased by the current year's litterfall supply in a cool-temperate forested peatland

Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Teramoto, Munemasa*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko

no journal, , 

Oral presentation

Response of soil microbial community to climate change

Kondo, Toshiaki*; Teramoto, Munemasa*; Nakane, Kaneyuki*; Takagi, Kentaro*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*

no journal, , 

Oral presentation

Long-term warming effect on heterotrophic respiration in a warm-temperate evergreen broad -leaved forest in western Japan

Teramoto, Munemasa*; Kondo, Toshiaki*; Liang, N.*; Zeng, J.*; Nakane, Kaneyuki*; Koarashi, Jun; Atarashi-Andoh, Mariko

no journal, , 

Oral presentation

Can soil heterotrophic respiration and its response to warming be estimated from soil organic carbon properties?

Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko*; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Ichii, Kazuhito*; et al.

no journal, , 

no abstracts in English

Oral presentation

An Investigation of carbon dynamics in forest soils using carbon and nitrogen isotopic signatures

Atarashi-Andoh, Mariko; Koarashi, Jun; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*

no journal, , 

Profiles of soil organic matter (SOM) can show striking patterns of carbon and nitrogen isotopic enrichment with increasing depth. Although various factors are involved in the distribution of stable isotope ratios in forest ecosystems, the variation in isotope ratios in SOM is caused by isotopic discrimination during microbially driven processing. Therefore, analyses of the carbon and nitrogen isotope ratios in SOM provide insights into the dynamics and accumulation of the SOM. This study measured the carbon and nitrogen isotope ratios of soil collected in warming and control plots in five forests in Japan, where long-term warming experiments have been conducted. This showed clear differences in SOM quality among the five forests. There was no remarkable difference in the isotope compositions of the warming and control plots, indicating that there has been no marked change in SOM after a decade of warming, probably due to the abundant SOM storage in Japanese forest surface soils.

Oral presentation

Long-term warming effect on soil carbon fluxes in a red pine forest in Tsukuba

Teramoto, Munemasa*; Liang, N.*; Jiye, Z.*; Koarashi, Jun; Kondo, Toshiaki*; Atarashi-Andoh, Mariko; Aramaki, Takafumi*; Zhao, X.*

no journal, , 

Forest soils are a large source for CO$$_{2}$$ and sink for CH$$_{4}$$. Understanding long-term response of these soil carbon fluxes to warmer environment is the key to mitigation and adaptation for future climate change. To examine the long-term response of CO$$_{2}$$ flux to global warming in Asian monsoon forests, we set multi-channel automated chamber measurement system in a red pine forest in Tsukuba. Half of the chambers were artificially warmed by infrared heaters. Recently, we started continuous measurement of soil CH$$_{4}$$ flux using a control unit with CH$$_{4}$$ analyzer. Results showed that soil temperature is the primary factor controlling soil CO$$_{2}$$ fluxes, whereas soil moisture is the main factor controlling soil CH$$_{4}$$ uptake in our study site.

Oral presentation

Responses of soil microbial community structure and heterotrophic respiration to warming

Kondo, Toshiaki*; Teramoto, Munemasa*; Takagi, Kentaro*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*

no journal, , 

no abstracts in English

Oral presentation

Warming effect on soil CO$$_{2}$$ efflux and CH$$_{4}$$ absorption in an evergreen oak forest in Western Japan

Teramoto, Munemasa*; Kondo, Toshiaki*; Liang, N.*; Koarashi, Jun; Atarashi-Andoh, Mariko; Zeng, J.*; Sun, L.*; Nakane, Kaneyuki*; Aramaki, Takafumi*

no journal, , 

no abstracts in English

Oral presentation

Long-term soil warming effect on soil organic carbon decomposition in Asian Monsoon forests

Teramoto, Munemasa*; Liang, N.*; Takagi, Kentaro*; Kondo, Toshiaki*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Naramoto, Masaaki*; et al.

no journal, , 

72 (Records 1-20 displayed on this page)