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The responses of carbon-and nitrogen-acquiring enzymes to nitrogen and phosphorus additions in two plantations in southern China

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Journal of Forestry Research 2020年第4期31卷 1319-1324页

作者： Senhao Wang taiki mori Jiangming Mo Wei Zhang Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems and Guangdong Provincial Key Laboratory of Applied Botany South China Botanical GardenChinese Academy of SciencesGuangzhou 510650GuangdongPeople’s Republic of China Graduate School of Agriculture Kyoto UniversityKitashirakawa Oiwake-choSakyo-kuKyotoJapan University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

In tropical plantations,nutrients such as nitrogen(N)or phosphorus(P)are often applied as management ***,the effects of such nutrient additions on topsoil C-and N-acquiring enzymes activities are *** this study,the impacts of fertilization onβ-1,4-glucosidase(BG),β-D-cellobiosidase(CBH),β-1,4-xylosidase(BX),β-1,4-N-acetyl-glucosaminidase(NAG),and leucine amino peptidase(LAP)enzymes activities from topsoil and litter layer of two tropical plantations(Acacia auriculiformis and Eucalyptus urophylla)were *** results showed that N addition had neutral impact on topsoil enzymes,while significantly elevating the activities of BG,CBH,BX,and NAG in the litter layer.P fertilization had no impacts except for an elevation of NAG in litter *** was no interactions found between N and P additions on these enzyme *** clearer impacts of N over P fertilization were unexpected because that the study site receives a high rate of atmospheric N deposition,and has low soil P *** impact of P fertilization on hydrolytic enzyme activities may be less important compared with that of N.

关键词： Tropical tree plantation Ecoenzymes Fertilization Forest management

Effect of nitrogen addition on DOC leaching and chemical exchanges on canopy leaves in Guangdong Province, China

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Journal of Forestry Research 2019年第5期30卷 1707-1713页

作者： taiki mori Kaijun Zhou Senhao Wang Wei Zhang Jiangming Mo Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650GuangdongPeople’s Republic of China Forestry and Forest Products Research Institute(FFPRI) TsukubaIbaraki 305-8687Japan University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

The impact of nitrogen(N)deposition on dissolved organic carbon(DOC)fractions in throughfall is not well *** performed a laboratory experiment and compared DOC leaching from canopy leaves after dipping leaves in pure water(control)and NH4NO3 solution(N-treatment)for 18 *** changes of DOC,NH4^+,NO3^-,SO4^2-,K^+,Mg^2+,Ca^2+and H^+contents after dipping leaves were determined by comparing solutions with and without *** recorded no differences of DOC leaching between control and N-treatment,implying that N deposition had minor impacts on canopy DOC *** confirmed that previous experiments testing the effects of N addition on DOC dynamics without considering the effects of the canopy reaction successfully described the real *** also confirmed the previously-reported canopy exchange process in spite of a high background N deposition at our study site.N-treatment significantly increased base cation leaching,especially K^+,and the increase was positively correlated with foliar NH4?*** leaching of H^+and SO4^2-was not affected by the N-treatment.

关键词： Canopy exchange Dissolved organic carbon Nitrogen deposition Throughfall

Possibility of avoiding legumes-deriving boost of N 2 O emissions in tropical monoculture tree plantations

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Journal of Forestry Research 2023年第2期34卷 565-573页

作者： taiki mori Chongrak Wachrinrat Duriya Staporn Ryota Aoyagi Ponthep Meunpong Warawich Suebsai Khitja Boonsri Kanehiro Kitayama Forest Ecology Laboratory Graduate School of AgricultureKyoto UniversityKitashirakawa Oiwake-cho Sakyo-kuKyoto 606-8502Japan Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650GuangdongPeople’s Republic of China Forestry and Forest Products Research Institute FFPRI 1 MatsunosatoTsukubaIbaraki 305-8687Japan Faculty of Forestry Kasetsart UniversityChatuchakBangkok 10900Thailand Smithsonian Tropical Research Institute Bocas TownIsla AncónRepublic of Panama

Recent reports warned that planting leguminous trees under monocultures elevates nitrous oxide(N2O)emissions through N-rich litter *** hypothesized that planting trees on sandy soil can avoid the legume-derived boost of N2O emissions through limiting water availability for N2O *** of planting legumes on methane(CH4)uptakes were also examined.N2O emissions and CH4uptakes were compared among five tropical tree plantation stands including three leguminous stands(Acacia auriculiformis,Acacia mangium,and Xylia xylocarpa)and two non-leguminous stands(Eucalyptus camaldulensis,and Hope a odorata).Due to lower water contents of the soil,the N2O fluxes in our study site were at the lower end of the tropical rain *** we hypothesized,no clear differences in N2O emissions were obs erved between leguminous and non-leguminous ***4uptake rates in the present study were lower than those of other tropical ***4uptakes in leguminous stands did not differ from those in non-leguminous ***,we demonstrated that planting leguminous trees on sandy soils has a potential to enable us to manage leguminous monoculture tree plantations without boosting N2O emissions or reducing CH4uptakes.

关键词： Nitrous oxide Methane Fast-growing trees Tropical forest Soil texture

Testing potassium limitation on soil microbial activity in a sub-tropical forest

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Journal of Forestry Research 2019年第6期30卷 2341-2347页

作者： taiki mori Senhao Wang Zhuohang Wang Cong Wang Hui Mo Jiangming Mo Xiankai Lu Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems and Guangdong Provincial Key Laboratory of Applied BotanySouth China Botanical GardenChinese Academy of SciencesGuangzhou 510650GuangdongPeople’s Republic of China Graduate School of Agriculture Kyoto UniversityKitashirakawa Oiwake-choSakyo-kuKyotoJapan University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Department of Biological Sciences Stanford UniversityStanfordCA 94305-5020USA Department of Forest Site Environment Forestry and Forest Products Research InstituteTsukubaIbaraki 305-8687Japan

Because potassium(K)is a rock-derived essential element that can be depleted in highly-weathered tropical soils,K availability may limit some portion of soil microbial activity in tropical forest *** this paper we tested if K limits microbial activity in the condition of sufficient labile C *** incubation experiment was performed using surface soil samples(0–10 cm depth)obtained from four permanent ecological research plots in a natural sub-tropical forest in southern *** samples were taken in September *** soil respiration rates and microbial biomass were measured after the addition of glucose(both D and L)with and without K(potassium chloride).We did not observe any effects of K addition on soil microbial respiration,suggesting that K does not limit the microbial activity in the condition of sufficient labile C *** lack of microbial response to added K can be attributed to the high mobility of K in forest ecosystems,which may have provided sufficient K to microbes in our soil samples(already provided at the beginning of the incubation).However,at the present stage,we cannot conclude that K is not a limiting factor of soil microbial activity in other tropical forest ecosystems because of the heterogeneity of tropical forest ecosystems and few *** hypothesis needs to be tested in larger numbers of tropical forests.

关键词： Nutrient limitation Rock-derived nutrients Soil biology Nutrient dynamics Potassium addition

长期磷添加对热带森林土壤磷酸单酯酶与磷酸二酯酶活性比值的影响

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Journal of Plant Ecology 2023年第3期16卷 203-207页

作者： taiki mori Senhao Wang Cong Wang Ji Chen Cheng Peng Mianhai Zheng Juan Huang Faming Wang Zhanfeng Liu Jiangming Mo Wei Zhang Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems Guangdong Provincial Key Laboratory of Applied BotanySouth China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Kyushu Research Center Forestry and Forest Products Research InstituteFFPRIKurokami 4-11-16Kumamoto 860-0862Japan Center for Plant Ecology Core Botanical GardensChinese Academy of SciencesGuangzhou 510650China State Key laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China Department of Agroecology Aarhus University8830 TjeleDenmark Aarhus University Centre for Circular Bioeconomy Aarhus University8830 TjeleDenmark iCLIMATE Interdisciplinary Centre for Climate Change Aarhus University4000 RoskildeDenmark University of Chinese Academy of Sciences Beijing 100049China

热带森林土壤微生物可以通过改变不同类型的磷酸酶活性来适应低磷的环境。以往的研究认为,低磷环境中土壤微生物更倾向于分解有机磷单酯键而非二酯键。因此,磷酸单酯酶(PME)的活性变化对生态系统磷输入的响应可能更敏感,其与磷酸二酯酶(... 详细信息

热带森林土壤微生物可以通过改变不同类型的磷酸酶活性来适应低磷的环境。以往的研究认为,低磷环境中土壤微生物更倾向于分解有机磷单酯键而非二酯键。因此,磷酸单酯酶(PME)的活性变化对生态系统磷输入的响应可能更敏感,其与磷酸二酯酶(PDE)活性的比值在磷输入后将显著降低。为了检验土壤微生物在低磷的热带森林中对不同磷酸酶的“投资”策略,我们在鼎湖山3种热带森林进行了长达10年的磷添加实验。与以往的研究不同,本研究发现长期磷添加没有改变原生林与次生林的PME:PDE比值,但显著提高了人工林土壤PME:PDE比值。结果表明,长期磷添加可能减少了凋落物或穿透雨来源的PDE,从而使其土壤PDE活性下降较PME降低更快,因而PME:PDE比值未能降低。

关键词：土壤胞外酶磷酸单酯酶磷酸二酯酶施磷热带森林

模拟大气氮沉降对中国森林生态系统影响的研究进展

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热带亚热带植物学报 2019年第5期27卷 500-522页

作者：鲁显楷莫江明张炜毛庆功刘荣臻王聪王森浩郑棉海 mori taiki 毛晋花张勇群王玉芳黄娟中国科学院华南植物园退化生态系统植被恢复与管理重点实验室广东省应用植物学重点实验室广州510650 中国科学院大学北京100049

人类活动加剧了活性氮的生产和排放,并导致氮沉降日益增加并全球化。目前,人类活动对全球氮循环的干扰已经超出了地球系统安全运行的界限。中国已成为全球氮沉降的高发区域,高氮沉降已经威胁到生态系统的健康和安全,并成为生态文明建设... 详细信息

人类活动加剧了活性氮的生产和排放,并导致氮沉降日益增加并全球化。目前,人类活动对全球氮循环的干扰已经超出了地球系统安全运行的界限。中国已成为全球氮沉降的高发区域,高氮沉降已经威胁到生态系统的健康和安全,并成为生态文明建设过程中亟待理清和解决的热点问题。对国际上和中国森林生态系统模拟氮沉降研究的概况进行了综述,并从生物学和非生物学两大过程重点阐述模拟氮沉降增加对中国主要森林生态系统影响的研究进展。中国自2000年以后才开始重视大气氮沉降产生的生态环境问题,中国科学院华南植物园在国内森林生态系统模拟氮沉降试验研究上做出了开创性的贡献。模拟氮沉降研究表明,持续高氮输入将会显著改变森林生态系统的结构和功能,并威胁生态系统的健康发展,特别是处于氮沉降热点区域的中国中南部。森林生态系统的氮沉降效应依赖于系统的氮状态、土地利用历史、气候特征、林型和林龄等。最后,对未来的研究提出了一些建议,包括加强长期跟踪研究和不同气候带站点之间的联网研究,特别是在森林生态系统对长期氮沉降响应与适应的过程机制、地下碳氮吸存潜力研究、以及与其他全球变化因子的耦合研究等方面,以期为森林生态系统的可持续发展提供理论基础和管理依据。

关键词：氮沉降全球变化森林生态系统氮饱和氮限制氮素生物地球化学循环生物多样性碳吸存

Contour detection with bicubic spline surfaces

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International Journal of Digital Earth 2023年第1期16卷 1801-1827页

作者： Hiroyuki Goto taiki Otsuka Department of Industrial and Systems Engineering Hosei UniversityTokyoJapan Faculty of IT and Business Cyber UniversityTokyoJapan

Contour detection has a rich history in multiplefields such as geography,engineering,and earth *** predominant approach is based on piecewise planar tessellation and now being challenged concerning the extraction of contour objects for non-linear elevation functions,particularly with respect to bicubic spline functions.A storage-efficient method was developed in previous research,but the detection of the complete set of contour objects is yet to be *** intractable,theoretical underpinnings pertinent to curvature resulted in an approach to realize the complete detection of *** a digital elevation model dataset,in this study,a bicubic spline surface function wasfirst ***,candidate initial points on the edges across the region of interest were identified,and the recursive disaggregation of rectangles was repeated if the non-existence of a solution could not be assured.A developed tracking method was then *** advancement,other initial points on the same contour curve were identified and eliminated to circumvent duplicate *** completeness of the outlets provides analytical tools for elevation and other geographical *** experiments included the development of a three-dimensional contour-based network and slope *** latter application transforms the slope analysis type from raster-based to *** of a complete set of contour objects amenable to bicubic spline surfaces..Small closure inside a single patch is detectable if size exceeds the standard..Curvature&tolerances central to step length adjustment and tangent angle determination..Redundant initial points are identified and eliminated during the tracking process..Various potential applications in addition to geographical elevations.

关键词： Contour detection bicubic spline surface curvature tolerance patch disaggregation

Influence of image classification accuracy on saliency map estimation

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CAAI Transactions on Intelligence Technology 2018年第3期3卷 140-152页

作者： taiki Oyama Takao Yamanaka Department of Information and Communication Sciences Sophia University 7-1 Kioi-cho Chiyoda-ku Tokyo 102-0094 Japan

Saliency map estimation in computer vision aims to estimate the locations where people gaze in images. Since people tend to look at objects in images, the parameters of the model pre-trained on ImageNet for image classification are useful for the saliency map estimation. However, there is no research on the relationship between the image classification accuracy and the performance of the saliency map estimation. In this study, it is shown that there is a strong correlation between image classification accuracy and saliency map estimation accuracy. The authors also investigated the effective architecture based on multi-scale images and the up-sampling layers to refine the saliencymap resolution. The model achieved the state-of-the-art accuracy on the PASCAL-S, OSIE, and MIT1003 datasets. In the MIT saliency benchmark, the model achieved the best performance in some metrics and competitive results in the other metrics.

关键词：计算机视觉图像处理发展现状计算机技术

Water-assisted self-sustained burning of metallic single-walled carbon nanotubes for scalable transistor fabrication

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Nano Research 2017年第9期10卷 3248-3260页

作者： Keigo Otsuka taiki Inoue Yuki Shimomura Shohei Chiashi Shigeo Maruyama Department of Mechanical Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Energy NanoEngineering Lab. National Institute of Advanced Industrial Science and Technology (AIST) 1-2-1 Namiki Tsukuba 305-8564 Japan

Although aligned arrays of semiconducting single-walled carbon nanotubes (s-SWNTs) are promising for use in next-generation electronics owing to their ultrathin bodies and ideal electrical properties, even a small portion of metallic (m-) counterparts causes excessive leakage in field-effect transistors (FETs). To fully exploit the benefits of s-SWNTs for use in large-scale systems, it is necessary to completely eliminate m-SWNTs from as-grown SWNT arrays and thereby obtain purely semiconducting large-area arrays, wherein numerous FETs can be flexibly built. In this study, we performed electrical burning of m-SWNTs assisted by water vapor and polymer coating to eliminate m-SWNTs over a long length for the scalable fabrication of transistors from the remaining s-SWNT arrays. During the electrical-breakdown process, the combination of water vapor and the polymer coating significantly enhanced the burning of the SWNTs, resulting in a self-sustained reaction along the nanotube axis. We found that m-SWNT segments partially remaining on the anode side resulted from one-way burning from the initial breakdown position, where Joule-heating-induced oxidation first occurred. The s-SWNT-enriched arrays obtained were used to fabricate multiple FETs with a high on-off current ratio. The results indicate the advantages of this approach over conventional electrical breakdown for the large-scale purification of s-SWNTs.

关键词： single-walled carbon nanotubes field-effect transistor selective removal electrical breakdown one-way burning