研究者詳細 - 篠田　雅人

論文 - 篠田　雅人

分割表示 172 件中 1 - 20 件目／全件表示 >>

Transboundary air pollution in coastal urban area in Japan: Transport model and positive matrix factorization analysis for SPM-PM<inf>2.5</inf> and PM<inf>2.5</inf> 査読有り国際誌 Open Access

Onishi K., Yumimoto K., Okuda T., Fukuike A., Maki T., Nojima M., Shinoda M., Nakayama T., Kurozawa Y., Yamagata Z., Kurosaki Y.

Urban Climate 59 巻 2025年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Urban Climate

Transboundary air pollutants have raised serious health concerns, particularly in regions with minimal local pollution sources. Distinguishing between local pollution and transboundary contributions is crucial for accurately assessing the health risks to local populations. This study aimed to analyze the differences in coarse and fine particulate matter and develop methods to obtain exposure data for epidemiological studies, thereby providing a scientific basis for public health interventions. We collected SPM-PM2.5 (physically excluded PM2.5 from SPM) and PM2.5 samples in Yonago City, a coastal urban area in Tottori Prefecture, Japan, from 19 October 2015 to 25 July 2016 using a novel slit jet impactor (MCAS-SJ). Positive matrix factorization analysis used heavy metal, ion, and carbon concentrations to identify pollutant sources. This study identified four major air pollution events during the sampling period, primarily attributed to transboundary transport. Episode I was dominated by nitric aerosols, Episodes II and III by Asian dust, and Episode IV by sulfate aerosols. An analysis using global chemical transport models and backward trajectories confirmed that these events verified the contribution of transboundary pollution. In conclusion, identifying the impact of transboundary pollution on local air quality enables an accurate risk assessment of populations. This study provides scientific evidence for developing effective public health strategies and preventive measures. Additionally, the methodology used in this study holds the potential for international contributions and future research applications, helping to address air pollution challenges on a broader scale.

DOI： 10.1016/j.uclim.2024.102237

Open Access

Scopus

Seasonal and Annual Rainfall Patterns Modify Summer Energy Balance and Nutritional Condition of Grazing Sheep Via Vegetation Communities 査読有り国際共著国際誌

Yoshihara Y., Tanaka C., Choijilsuren B., Tserendorj J., Byambajav B., Umemura K., Kinugasa T., Shinoda M.

Rangeland Ecology and Management 95 巻頁： 77 - 83 2024年7月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Rangeland Ecology and Management

Spring and summer rainfall patterns in Mongolian semi-arid grazing lands vary greatly from year to year, and are thought to affect the energy balance and nutritional conditions of sheep via plant community changes. To test this, climatic and vegetation data in Mongolian semiarid grasslands were obtained from spring to summer over 3 yr. For 2 yr, sheep energy intake and expenditure were calculated, and the energy balance and nutrition indicators were compared among years with different seasonal rainfall patterns. In 2019 and 2022, rainfall patterns were characterized by the presence and absence of early summer drought, respectively. Compared to 2019, plants were tall and abundant in 2022; thus, the mean bite size, energy intake, and body weight were higher. Estimated energy intake and expenditure were 4.56 and 2.10 Mcal in 2019, and 6.75 and 1.63 Mcal in 2022, respectively, indicating that rainfall timing and amount affected vegetation assemblage, plant height, herbage nutrition, grazing behavior, animal energy balance, and nutrition conditions. Insufficient rainfall before early summer in semiarid grazing lands resulted in low energy intake and balance, and delayed body weight gain could not be recovered. These results can inform the management of grazing lands to ensure optimal livestock conditions.

DOI： 10.1016/j.rama.2024.04.009

Scopus

Projected distributions of Mongolian rangeland vegetation under future climate conditions 査読有り国際共著国際誌 Open Access

Suzuki K., Tsuyama I., Tungalag R., Narantsetseg A., Tsendeekhuu T., Shinoda M., Yamanaka N., Kamijo T.

Journal of Plant Ecology 17 巻 ( 3 ) 2024年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Plant Ecology

Mongolian herder households maintain the health and condition of their livestock by adapting to the characteristics of the local vegetation distribution. Thus, predicting future vegetation changes is important for stable livestock grazing and sustainable rangeland use. We predicted the distributional extent of rangeland vegetation, specifically desert steppe, steppe and meadow steppe communities, for the period 2081-2100, based on vegetation data obtained from a previous study. Rangeland vegetation data collected in Mongolia (43-50° N, 87-119° E) between 2012 and 2016 (278 plots) were classified into community types. Species distribution modeling was conducted using a maximum entropy (MaxEnt) model. Distribution data for desert steppe, steppe and meadow steppe communities were used as objective variables, and bioclimatic data obtained from WorldClim were used as explanatory variables. CMIP6-downscaled future climate projections provided by WorldClim were used for future prediction. The area under the curve values for the desert steppe, steppe and meadow steppe models were 0.850, 0.847 and 0.873, respectively. Suitable habitat was projected to shrink under all scenarios and for all communities with climate change. The extent of reduction in potential suitable areas was greatest for meadow steppe communities. Our results indicate that meadow steppe communities will transition to steppe communities with future climate change.

DOI： 10.1093/jpe/rtae028

Open Access

Scopus

Sensitivity and regulation factors of soil organic carbon content in steppe and desert—steppe grasslands of the Mongolian Plateau 査読有り国際共著国際誌 Open Access

Quan Z., Cheng Y., Tsubo M., Shinoda M.

Plant and Soil 2024年

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Plant and Soil

Background and aims: Soil organic carbon (SOC) content dominates the organic carbon pools in grasslands. Thus, factors that influence and regulate SOC content must be clarified when addressing global climate change. Methods: We investigated SOC in the top 10 cm of the soil layer from 109 plots of the Mongolian Plateau, including both desert-steppe and steppe landscapes. We then examined the association between SOC with grazing intensity, climatic factors, soil properties, and vegetation diversity indices. Results: Desert-steppe samples had lower mean SOC than steppe samples (0.3% versus 1.5%). Desert-steppe SOC did not vary with grazing intensity, but steppe SOC did. Instead, desert-steppe SOC decreased and increased, respectively, with higher growing season temperature and soil electrical conductivity; these two variables were the major factors influencing SOC in this grassland type. Besides grazing, outside growing season precipitation and soil pH were the major environmental factors that correlated positively with steppe SOC. Conclusion: The SOC of steppe grasslands was more sensitive to grazing than SOC of desert-steppe grasslands. Additionally, while climate, grazing, soil, and vegetation all regulated SOC, the most influential variables differed between the two grassland types. These findings enhance our understanding of SOC regulatory mechanisms in different grasslands on the Mongolian Plateau. Such knowledge is crucial for predicting the consequences of environmental change on carbon sequestration.

DOI： 10.1007/s11104-024-06867-5

Open Access

Scopus

乾燥放牧地における家畜行動と牧草資源の時空間相互作用を捉える：エージェントモデルによる多角的フィールド調査の統合招待有り査読有り国際誌

宮坂隆文, 吉原佑, 甲野耀登, 篠田雅人

沙漠研究 33 巻 ( 1 ) 頁： 77 - 83 2023年6月

担当区分：最終著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：日本沙漠学会

気候変動下の乾燥放牧地における植生の量，質（栄養価や家畜嗜好性）の時空間変動と家畜行動のダイナミクスを明らかにするため，牧民の放牧意思決定に関する質問紙調査，家畜行動を捉えるバイオロギング，植生量分布を把握する衛星リモートセンシング，そして種組成分布を明らかにする独自の広域植生調査手法を，エージェントモデルにより統合するアプローチを提案した．本アプローチをモンゴルに適用した結果，各種調査の実効性が確認された．現在は得られたデータをもとにモデルの実装を行っている段階である．

DOI： 10.14976/jals.33.1_77

CiNii Research

2022年秋季シンポジウム「遊牧を考える―過去・現在・未来」

篠田雅人

沙漠研究 33 巻 ( 1 ) 頁： 1 - 1 2023年6月

モンゴルの隣接遊牧民が所有する家畜ウマの草原利用：GPS追跡による重複度評価招待有り査読有り国際共著国際誌

伊藤健彦, 森永由紀, 篠田雅人, Tserenpurev BAT-OYUN, Yadamjav PUREVDORJ, 土屋竜太

沙漠研究 33 巻 ( 1 ) 頁： 85 - 90 2023年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：日本沙漠学会

複数の遊牧民が同じ空間を利用する，モンゴルの草原の持続的利用を考えるためには，同じ地域を利用する可能性のある家畜の動きを同時かつ長期的に観測する必要がある．共有草原における複数遊牧民の利用実態を把握するために，馬乳酒の名産地であるモンゴル北部のボルガン県モゴド郡で遊牧を営む2軒の隣接遊牧民が所有する家畜ウマを対象に，GPS首輪を用いた1年以上の同時追跡を行い，行動圏と利用分布重複を解析した．家畜ウマは2頭とも1年目と2年目で利用分布の大部分が重なったが，同一月内における個体間の利用分布重複は比較的小さく，隣接する遊牧民間における放牧戦略の違いの存在も示唆された．遊牧の持続可能性を探る上で，GPSを用いた多個体同時追跡研究は有効だろう．

DOI： 10.14976/jals.33.1_85

CiNii Research

Composition, distribution and environmental drivers of Mongolian rangeland plant communities 査読有り国際共著国際誌

Suzuki K., Tungalag R., Narantsetseg A., Tsendeekhuu T., Shinoda M., Yamanaka N., Kamijo T.

Journal of Plant Ecology 16 巻 ( 3 ) 2023年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Plant Ecology

In Mongolia, overgrazing and the resulting degradation of rangelands are recognized as serious issues. To address rangeland degradation, we sought to develop a broad-scale vegetation classification of Mongolian rangeland communities focusing on regional characteristics. Moreover, we sought to clarify the spatial distributions of communities and the environmental drivers of the distributions. Between 2012 and 2016, we surveyed vegetation in 278 plots (each 10 m × 10 m) in different regions of Mongolia (43-50° N, 87-119° E) in plots where grazing pressure is low relative to adjacent areas. The data were grouped into vegetation units using a modified two-way indicator species analysis (TWINSPAN). We then explored the regional characteristics of species compositions and community distributions, as well as relationships between distributions and climatic variables. The modified TWINSPAN classified the vegetation data into three cluster groups, each of which corresponds to a particular type of zonal vegetation (i.e. forest steppe, steppe and desert steppe). The aridity index was identified as an important driver of the distributions of all cluster groups, whereas longitude and elevation were important determinants of the distribution of clusters within cluster groups. Western regions, which are characterized by higher elevation and continentality compared with eastern regions, have lower mean temperature and precipitation during the wettest quarter, leading to differences in species composition within cluster groups. Regional differences in species composition reflect differences in phytogeographic origin. Thus, the framework of species composition and distributional patterns in Mongolian rangeland communities was demonstrated in relation to climatic and geographical factors.

DOI： 10.1093/jpe/rtac100

Scopus

Effects of cold-season climate hazards on livestock health and mortality in Mongolia 査読有り国際共著国際誌

Erdenebadrakh M., Shinoda M., Nandintsetseg B.

International Journal of Disaster Risk Reduction 90 巻 2023年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Disaster Risk Reduction

Recent global climatic changes have caused frequent cold-season climate hazards and associated damage to societies in Mongolia. Here, we investigated the interannual variability of cold-season hazard indicators and their relationships to livestock health (mortality, health, and weight). A principal component analysis was applied to indicators (snow depth in January, SD1; air temperature for October–March, AT10-3) to extract significant modes. Then, we performed correlation and regression analyses to identify the contribution of each indicator to mortality and weight. Prior to analysis, we classified the cold season into two periods: early winter (EW) and late winter (LW). To our knowledge, this is the first study involving a detailed analysis of monthly indicators for livestock that reveals the dynamics of how weather affects health over time. The results showed that the higher SD1 and lower AT10-3 coefficients of the first modes coincided with severe winters (SW) and, conversely, mild winters (MW). Compositing SW and MW, mortality increased seven times per winter, and weight decreased twice as fast per month during SW. Focusing on EW and LW, the accumulated temperature of cold outbreak events was most significantly correlated with mortality during EW. This indicates that when temperatures are moderate, a sudden drop in temperature may have deleterious effects on livestock, leading to rapid weight loss and death because they have not had sufficient time to acclimatize. These seasonally changing dynamics connecting weather events and health will provide vital information for disaster risk management, including timely weather forecasts and proactive countermeasures to avoid a mass loss of livestock.

DOI： 10.1016/j.ijdrr.2023.103658

Scopus

Satellite-Based Analysis of Spatiotemporal Wildfire Pattern in the Mongolian Plateau

Bao Y., Shinoda M., Yi K., Fu X., Sun L., Nasanbat E., Li N., Xiang H., Yang Y., DavdaiJavzmaa B., Nandintsetseg B.

Remote Sensing 15 巻 ( 1 ) 2023年1月

出版者・発行元：Remote Sensing

Burned area is a critical input to biomass burning carbon emissions algorithms and for understanding variability in fire activity due to climate change. This study presents the spatial and temporal patterns of wildland fires in the Mongolian Plateau (MP) using Collection 6 NASA MCD64A1 500 m global Burned Area product from 2001 to 2021. Both inter- and intra-annual fire trends and variations in two subregions, Mongolia and China’s Inner Mongolia, were analyzed. The results indicated that an average area of 1.3 × 104 km2 was consumed by fire per year in the MP. The fire season has two peaks: spring (March, April, and May) and autumn (September, October, and December). The profiles of the burnt area for each subregion exhibit distinct seasonality. The majority of wildfires occurred in the northeastern and southwestern regions of the MP, on the border between Mongolia and China. There were 2.7 × 104 km2 of land burned by wildfires in the MP from 2001 to 2021, 57% of which occurred in spring. Dornod aimag (province) of Mongolia is the most fire-prone region, accounting for 51% of the total burned area in the MP, followed by Hulunbuir, at 17%, Sukhbaatar, at 9%, and Khentii at 8%. The changing patterns of spatiotemporal patterns of fire in the MP were analyzed by using a spatiotemporal cube analysis tool, ArcGIS Pro 3.0.2. The results suggested that fires showed a decreasing trend overall in the MP from 2001 to 2021. Fires in the southern region of Dornod aimag and eastern parts of Great Xing’an Mountain showed a sporadic increasing trend. Therefore, these areas should be priorities for future fire protection for both Mongolia and China.

DOI： 10.3390/rs15010190

Scopus

Social Causes of Dzuds in Mongolia Since the 1990s

Chadraabal A., Odkhuu U., Shinoda M., Suzuki Y.

Journal of Disaster Research 17 巻 ( 7 ) 頁： 1183 - 1191 2022年12月

記述言語：英語出版者・発行元：富士技術出版株式会社

Locally known as dzuds, extreme winter weather events that are believed to arise from the interaction of hydrometeorological and climate drivers and socioeconomic forces have become increasingly frequent in Mongolia in the past few decades. As they cut off access to forage, these extreme events are associated with mass livestock deaths. Since the socioeconomic changes in the 1990s, and due to climate change, Mongolia has weathered major dzuds in 1999–2000, 2000–2001, 2001–2002, and 2009–2010. They wiped out about 4 million (11.6%), 5 million (18.5%), 3 million (12.3%), and 10 million (22%) heads of livestock, respectively. As a result, the country has been fac-ing the challenge of examining these complex phenom-ena, finding ways to reduce their risk, and building resilience against them. This study adopts a systems approach to review key research and trace the occur-rence of dzuds in Mongolia, understand why measures to reduce their risk have failed, and what can be done to fix this. Specifically, we focus on two dzud events that occurred 10 years apart in 1999–2000 and 2009– 2010 and examine the effectiveness of social responses and countermeasures taken to tackle them. We find that a lack of accountability mechanisms and failure to treat dzud as a systemic issue have hindered efforts to reduce risk and minimize mortality. Our findings highlight the need for inclusive, integrated, and ac-countable handling of dzuds.

DOI： 10.20965/jdr.2022.p1183

Scopus

CiNii Research

遊牧と砂漠化

篠田雅人

沙漠研究 32 巻 ( 1 ) 頁： 17 - 23 2022年6月

記述言語：日本語出版者・発行元：日本沙漠学会

人類史の中で，世界の気候植生地域には，その自然資源に適合した農法（農業様式）が発生，変化したが，農業の自然改変力が再生能力を上回る場合は，その地域特有の砂漠化を引き起こした．このような農法の変化と砂漠化の過程は，森林，疎林，草原・砂漠の3時系列に類型化され，中央ユーラシアでは草原・砂漠の時系列がみられる（篠田，2021）．同地域では，数千年前から遊牧が行われ，深刻な砂漠化は発生しなかったが，ソ連時代の大規模な穀作やかんがい農業は同地域には適合しない農法であり，その結果として，風食や土壌塩類化といった同系列特有の砂漠化を引き起こした．現在，モンゴル国では市場経済の中で家畜数が急増し，草原の収容力をすでに超えているものと考えられるが，この状況が続くと，最終氷期以降形成されてきた草原生態系が砂漠化する可能性があり，早急な対応が必要である．

DOI： 10.14976/jals.32.1_17

CiNii Research

Estimating winter energy balance and actual changes in nutrition of Mongolian grazing sheep 査読有り国際共著

Yoshihara Y., Dian L., Choijilsuren B., Koto S., Umemura K., Yamanaka N., Tserendorj J., Shinoda M.

Applied Animal Science 37 巻 ( 5 ) 頁： 589 - 594 2021年10月

担当区分：最終著者記述言語：英語出版者・発行元：Applied Animal Science

Objective: We aimed to estimate the energy intake and expenditure of grazing Mongolian sheep during the winter months using indirect methods of bite mass, number of bites, ME content per bite, traveling distance, body condition, and blood parameters. Materials and Methods: Energy intake was calculated as the bite mass × number of bites × ME per bite. Daily energy expenditure was calculated as the sum of the expenditures incurred for maintenance, grazing, and thermoregulating, as well as during pregnancy. We also investigated the sheep nutrition indicators (body condition and blood biochemical parameters) before and after winter. Results and Discussion: Average daily bite number, bite weight, and daily feed ME of sheep were 12,094, 53 mg in March, and 1.16 Mcal, respectively, and thus, total daily ME of intake was 0.86 Mcal. The daily energy expenditure for maintenance, grazing, thermoregulation, and fetus were 1.58, 1.56, 2.27, and 0.41 Mcal, respectively, accounting for a total daily energy expenditure per sheep of 5.82 Mcal. The total protein (70.2 to 49.1 g/L), albumin (37.4 to 16.9 g/L), and leptin contents (37.1 to 10.9 ng/mL) in the blood decreased remarkably after winter. Implications and Applications: The energy intake and expenditure results showed that the estimated total negative daily energy balance was 4.96 Mcal/d during the winter season. These results indicated that Mongolian sheep did not maintain a sufficient energy balance during winter and, thereby, required compensation for the negative energy balance using their body fat and protein stores.

DOI： 10.15232/aas.2021-02137

Scopus

人類と砂漠化査読有り

篠田雅人

沙漠研究 31 巻 ( 2 ) 頁： 45 - 61 2021年9月

担当区分：筆頭著者記述言語：日本語出版者・発行元：日本沙漠学会

砂漠化は各乾燥地特有の人為および気候の作用による複合現象であることから，本論は，その発生，強化，拡散の過程を農業史および気候史の中でとらえることを目的とした．世界の気候植生地域には，その自然資源に適合した農法（農業様式）が発生，変化したが，農業の自然改変力が再生能力を上回る場合は，その地域特有の砂漠化を引き起こした．このような農法の変化と砂漠化の過程は，森林，疎林，草原・砂漠の3時系列に類型化されることを示し，砂漠化対処についても同類型の農法・砂漠化対処法を水平移転，時間移転できる可能性を示唆した．

DOI： 10.14976/jals.31.2_45

CiNii Research

Impacts of Land Surface Conditions and Land Use on Dust Events in the Inner Mongolian Grasslands, China 査読有り国際共著

Yong M., Shinoda M., Nandintsetseg B., Bi L., Gao H., Wang Y.

Frontiers in Ecology and Evolution 9 巻 2021年8月

記述言語：英語出版者・発行元：Frontiers in Ecology and Evolution

Aeolian processes in temperate grasslands (TGs) are unique because the plant growth–decay cycle, soil water, and land-use interactions affect the seasonal and inter-annual changes in dust events. Land-use types in Inner Mongolian TGs are unique (settled grazing and grass mowing) compared with those in Mongolian TGs. Since 2003, land use has been controlled by grassland protection legislation, which is intended to prevent desertification and dust storms. In this study, we used process-based ecosystem (DAYCENT) and statistical modeling, along with dust event observations from March to June of 1981–2015, to (1) identify critical land surface factors controlling dust emissions (vegetation components, live grass, standing dead grass, litter, and soil moisture) at typical and desert steppe sites in Inner Mongolia and (2) estimate the impact of controlled land-use legislation on dust events. The DAYCENT model realistically simulated the dynamics of the observed vegetation components and soil moisture in 2005–2015. At both sites, similar significant correlations were obtained between spring dust events and wind speed or a combination of all surface factors that retained anomalies (memory) from the preceding year. Among the surface factors, vegetation was a critical factor that suppressed dust in Inner Mongolian TGs, similar to that in Mongolian TGs. In the desert steppe, standing dead grass had the strongest memory and was significantly correlated with dust events, whereas no significant correlations were observed in the typical steppe. This suggests that, in a typical steppe region, heavy grazing and mowing result in few dead grasses, thereby inhibiting the prevention of dust events. Moreover, the simulations of dust events under controlled (light grazing) and uncontrolled (heavy grazing) land-use conditions demonstrated that the grassland protection legislation reduced the occurrence of dust events in typical and desert steppe sites by 25 and 40%, respectively, since 2003.

DOI： 10.3389/fevo.2021.664900

Scopus

Seasonal variations in threshold wind speed for saltation depending on soil temperature and vegetation: A case study in the Gobi Desert 査読有り国際共著

Kong K., Nandintsetseg B., Shinoda M., Ishizuka M., Kurosaki Y., Bat-Oyun T., Gantsetseg B.

Aeolian Research 52 巻 2021年7月

記述言語：英語出版者・発行元：Aeolian Research

The threshold wind speed for saltation (Ut), an index of soil susceptibility to wind erosion, is affected by dynamics of various land surface conditions. Little information is available on the primary factors that affect Ut in the Gobi Desert. This study explored seasonal variations of Ut and its relations with land surface conditions at Tsogt-Ovoo, which is a dust source hotspot in East Asian drylands, based on a 6-year (2012–2017) measurement. The land surface parameters (soil moisture and temperature, and vegetation components of live, standing dead, and litter) were simulated by an ecosystem model. Results show that saltation tended to occur during February–June under strong western winds (>10 m s−1), with the highest frequencies in 2012 and 2015. The saltation season was divided into two periods: spring (February–early May) with an increase in saltation (i.e., a decrease in Ut); and early summer (late May–July) with a decrease in saltation (i.e., an increase in Ut). For 2012 and 2015, multi-regression analysis reveals that Ut negatively correlated with soil temperature in spring (R2adjusted = 0.39) and positively with vegetation components of live and standing dead in early summer (R2adjusted = 0.70). We assume that wind erosion was possibly enhanced through soil freeze–thaw processes and then was suppressed through plant growth in addition to dead leaves that were residues from the preceding summer. We establish a statistical model of Ut for this hotspot to analyze the relative contributions of erosivity and erodibility to wind erosion during 2012–2017.

DOI： 10.1016/j.aeolia.2021.100716

Scopus

How plant production in the Mongolian grasslands is affected by wind-eroded coarse-textured topsoil 査読有り国際共著

Kong K., Nandintsetseg B., Shinoda M.

Journal of Arid Environments 189 巻 2021年6月

担当区分：最終著者記述言語：英語出版者・発行元：Journal of Arid Environments

Wind erosion results in soil redistribution and textural changes on topsoil. There is little information about how these changes affect plant production. Here, we compared simulations of vegetation growth between a wind-eroded scenario and an actual condition at two sites in Mongolian grasslands (steppe and desert steppe) using an ecosystem model. The wind-eroded scenario, topsoil (0–0.1 m depth) with 1% clay and 99% sand, was designed to represent an extremely wind-eroded soil surface that had permanently lost the fine particles and gained sand particles. Effects of temperature, nutrient, and water stresses on vegetation were quantitatively estimated. The model gave reasonably good simulations of the vegetation and soil water dynamics. Results show that water had more effect on plant production than nitrogen and temperature. In the wind-eroded scenario, stresses because of a lack of water and nutrients affected plant production. For the wind-eroded topsoil, plant production decreased (20.2%) in the desert steppe with increasing water stress, but it was slightly increased (5.0%) in the wetter steppe because of an inverse texture effect, where water infiltrates from the coarse topsoil to the deeper root-zone due to lower soil evapotranspiration and facilitates growth. Plant growth was, therefore, affected by the nitrogen supply.

DOI： 10.1016/j.jaridenv.2021.104443

Scopus

High Sensitivity of Asian Dust Emission, Transport, and Climate Impacts to Threshold Friction Velocity 査読有り

Kawai K., Matsui H., Kimura R., Shinoda M.

Scientific Online Letters on the Atmosphere 17 巻 ( 0 ) 頁： 239 - 245 2021年

担当区分：最終著者記述言語：英語出版者・発行元：公益社団法人日本気象学会

The emission of Asian dust in arid regions of East Asia is controlled by many land surface parameters such as snow cover, soil moisture, and vegetation. In climate models, these factors are represented by the threshold friction velocity u*t, but its treatment has large uncertainties. Here we show that the treatment of u*tis important for estimating the emissions, transport, and climate impacts of Asian dust. Our global aerosol model simulates dust event frequencies that better agree with observations in East Asia when u*t over a smooth surface is changed from the default value of 0.23 m s−1 to an observation-based value of 0.40 m s−1. Also, seasonal Asian dust emissions become more variable, increasing by 31% in spring and decreasing by 46% in summer and fall, and the annual amounts of Asian dust transported and deposited over the North Pacific (Arctic) increase by 43% and 49% (130% and 73%), respectively. Our results demonstrate that better representation of u*t in climate models is necessary to improve estimates of the emissions and transport of Asian dust and better understand its roles in the Earth system, such as its interactions with radiation, clouds, snow/ice albedo, and land and ocean biogeochemistry.

DOI： 10.2151/sola.2021-042

Scopus

Assessment of Drought Characteristics, and Its Impacts on Vegetation and Wheat Yield in Tunisia 査読有り国際共著

Ben Mhenni N., Shinoda M., Nandintsetseg B.

Environmental Science and Engineering 頁： 1931 - 1935 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Environmental Science and Engineering

Tunisia, located on the shores of the Mediterranean, is projected to experience most predominant droughts. However, detailed drought assessments at the regional scale of Tunisia are limited to date, with most studies only focusing on a specific region and/or making use of one drought index. This study identifies both vegetation and agricultural region-specific drought indices over the country. Tunisia was divided into three main vegetation zones: the northern forest, central steppe, and southern desert. Monthly meteorological (Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI)) and soil moisture (Palmer Drought Severity Index (PDSI) and soil moisture percentiles, Wp) drought indices were used to analyze drought characteristics using gridded-meteorological and ground-measured soil data, and compared with the weekly Normalized Difference Vegetation Index (NDVI) and the winter wheat yield data to assess vegetation and agriculture responses to drought, respectively. We found that short-term meteorological droughts were frequent, triggering soil moisture droughts that were more persistent and severe. The most important finding of this study was that SPI is the best indicator for assessing a drought impact on both vegetation and agriculture in the northern forest, while PDSI in the central steppe for vegetation and agriculture and in the southern desert for vegetation (no agricultural data on southern desert). The results of this study highlight the importance of region-specific drought indices which are most likely to provide a very useful measure for drought monitoring and mitigation in Tunisia.

DOI： 10.1007/978-3-030-51210-1_304

Scopus

Arid Land Systems: Sciences and Societies

篠田雅人

2019年8月

　前のページ - 次のページ　

<篠田 雅人>

論文 - 篠田 雅人

<篠田　雅人>

論文 - 篠田　雅人