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Differential response of radial growth and δ^(13)C in Qinghai spruce(Picea crassifolia) to climate change on the southern and northern slopes of the Qilian Mountains in Northwest China

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Journal of Forestry Research 2024年第3期35卷 205-218页

作者： Li Qin Huaming Shang Weiping Liu Yuting Fan Kexiang Liu Tongwen Zhang Ruibo Zhang Key laboratory of Tree-Ring Physical and Chemical Research(CMA)/Xinjiang Key laboratory of Tree-Ring ecology Institute of Desert MeteorologyChina Meteorological AdministrationUrimqi 830002People's Republicof China Xinjiang Meteorological Information Center Urimqi 830002People's Republic of China

Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic factors.Tree-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the southern.Tree-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing season.Stomatal conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate did.The response between tree rings and climate in mountains gradually weakened as climate warmed.Changes in radial growth and stable carbon isotope fractionation of P.crassifolia in response to climate in the Qilian Mountains may be further complicated by continued climate change.

关键词： Tree rings Qinghai spruce(Picea crassifolia Kom.) stable carbon isotope(δ^(13)C) Qilian Mountains:Climate change

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Hydraulic properties and drought response of a tropical bamboo (Cephalostachyum pergracile)

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Plant Diversity 2024年第3期46卷 406-415页

作者： Wanwalee Kongjarat Lu Han Amy Ny Aina Aritsara Shu-Bin Zhang Gao-Juan Zhao Yong-Jiang Zhang Phisamai Maenpuen Ying-Mei Li Yi-Ke Zou Ming-Yi Li Xue-Nan Li Lian-Bin Tao Ya-Jun Chen CAS Key laboratory of Tropical Forest ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYunnan 666303China University of the Chinese Academy of Sciences Beijing 100049China T-STAR Core Team Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYunnan 666303China School of Biology and ecology University of MaineOronoMEUSA Climate Change Institute University of MaineOronoME 04469USA School of Biological and Chemical Science Pu’er UniversityXueyuan RoadYunnan 665000China Institute of ecology and Geobotany School of Ecology and Environmental SciencesYunnan UniversityKunmingYunnan 650091China School of ecology and Environment Southwest Forestry UniversityKunmingYunnan 650224China Yuanjiang Savanna Ecosystem Research Station Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYuanjiangYunnan 653300China

Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic properties.Cephalostachyum pergracile,a commonly used tropical bamboo species,exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019,but the underlying mechanisms remain unclear.This study investigated the leaf and stem hydraulic traits related to drought responses,including leaf-stem embolism resistance(P50leaf;P50stem) estimated using optical and X-ray microtomography methods,leaf pressure-volume and water-releasing curves.Additionally,we investigated the seasonal water potentials,native embolism level(PLC) and xylem water source using stable isotope.We found that C.pergracile exhibited strong resistance to embolism,showing low P50leaf,P50stem,and turgor loss point,despite its rapid leaf water loss.Interestingly,its leaves displayed greater resistance to embolism than its stem,suggesting a lack of effective hydraulic vulnerability segmentation(HVS) to protect the stem from excessive xylem tension.During the dry season,approximately 49% of the water was absorbed from the upper 20-cm-deep soil layer.Consequently,significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87±2.33% in the wet season to 12.87±4.09%in the dry season were observed.In summary,this study demonstrated that the rapid leaf water loss,high reliance on surface water,and a lack of effective HVS in C.pergracile accelerated water depletion and increased xylem embolism even in the typical dry season,which may explain its high mortality rate during extreme drought events in 2019.

关键词： Climate change Drought Hydraulic safety Hydraulic vulnerability segmentation stable isotope Tree mortality

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Trophic niche and adaptation in highland lizards:sex has greater influences than species matching

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Integrative Zoology 2024年第3期19卷 564-576页

作者： Shengnan YANG Jiapeng QU Ke TANG Xinquan ZHAO Huakun ZHOU Junhua HU Chengdu Institute of Biology Chinese Academy of SciencesChengduChina Qinghai Provincial Key laboratory of Restoration ecology for Cold Region Northwest lnstitute of Plateau BiologyChinese Academy of SciencesXiningChina University of Chinese Academy of Sciences BeijingChina Qinghai University XiningChina

The plateau environments are typically arid,cool,and high altitude,posing formidable challenges to wildlife survival due to resource scarcity and harsh conditions.Unraveling ecological adaptability in severe conditions requires a deeper understanding of the niche characteristics of plateau species.Trophic niche,which is a comprehensive indicator describing the energy acquisition strategy of animals,remains relatively understudied in plateau species.Here,by combining stable isotopes and morphological data,we quantified the trophic niches of two allopatric lizard species(Phrynocephalus vlangalii and P.erythrurus)that live in the hinterland of the Qinghai–Tibetan Plateau,and explored how their trophic niches correlate with morphological and environmental factors.While both trophic niche and morphological traits were similar between species,noteworthy distinctions were observed between male and female Phrynocephalus lizards.The morphological traits associated with predation(i.***.limb length and head size)and reproduction(i.***.abdomen length),annual mean temperature,and sex played influential roles in shifting trophic niches.These results imply that sexual dimorphism may facilitate inter-sex divergence in resource utilization,leading to trophic niche variations in the highland lizards.Furthermore,extreme environmental stress can constrain interspecific divergence in morphological and trophic traits.Our findings illustrate the dynamic variations of trophic niches in highland lizards,contributing to a more comprehensive understanding of the adaptation strategies employed by lizard species in plateau environments.

关键词： environmental adaptation Phrynocephalus Qinghai-Tibetan Plateau sexual dimorphism stable isotope

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Effects of thinning and understory removal on water use efficiency of Pinus massoniana:evidence from photosynthetic capacity and stable carbon isotope analyses

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Journal of Forestry Research 2024年第2期35卷 42-53页

作者： Ting Wang Qing Xu Beibei Zhang Deqiang Gao Ying Zhang Jing Jiang Haijun Zuo Key laboratory of Forest ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation InstituteChinese Academy of ForestryBeijing 100091People’s Republic of China College of Agronomy and Agricultural Engineering Liaocheng UniversityLiaocheng 252000People’s Republic of China Department of Forest and Conservation Sciences Faculty of ForestryUniversity of British ColumbiaVancouverBC V6T 1Z4Canada

Understanding the relationship between forest management and water use efficiency(WUE)is important for evaluating forest adaptability to climate change.However,the effects of thinning and understory removal on WUE and its key controlling processes are not well understood,which limits our comprehension of the physiological mechanisms of various management practices.In this study,four forest management measures(no thinning:NT;understory removal:UR;light thinning:LT;and heavy thinning:HT)were carried out in Pinus massoniana plantations in a subtropical region of China.Photosynthetic capacity and needle stable carbon isotope composition(δ^(13)C)were measured to assess instantaneous water use efficiency(WUE_(inst))and long-term water use efficiency(WUE_(i)).Multiple regression models and structural equation modelling(SEM)identified the effects of soil properties and physiological performances on WUE_(inst)and WUE_(i).The results show that WUE_(inst)values among the four treatments were insignificant.However,compared with the NT stand(35.8μmol·mol^(-1)),WUE_(i)values significantly increased to 41.7μmol·mol^(-1)in the UR,50.1μmol·mol^(-1)in the LT and 46.6μmol·mol^(-1)in HT treatments,largely explained by photosynthetic capacity and soil water content.Understory removal did not change physiological performance(needle water potential and photosynthetic capacity).Thinning increased the net photosynthetic rate(A_n)but not stomatal conductance(g_s)or predawn needle water potential(ψ_(pd)),implying that the improvement in water use efficiency for thinned stands was largely driven by radiation interception than by soil water availability.In general,thinning may be an appropriate management measure to promote P.massoniana WUE to cope with seasonal droughts under future extreme climates.

关键词： stable carbon isotope Water use efficiency Thinning Understory removal Photosynthetic capacity Needle water potential

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Differential evolution of territorial space and effects on ecological environment quality in China's border regions

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Journal of Geographical Sciences 2024年第6期34卷 1109-1127页

作者： GU Guanhai WU Bin LU Shengquan ZHANG Wenzhu TIAN Yichao LU Rucheng FENG Xiaoling LIAO Wenhui School of Natural Resources and Surveying Nanning Normal UniversityNanning 530100China School of Resources and Environment Beibu Gulf UniversityQinzhou 535011China

The use of territories in border areas is sensitive, unique, and ecologically fragile. A scientific understanding of the transformation of the national territorial space and its ecological and environmental responses is crucial for optimizing spatial patterns and promoting sustainable utilization. This study focused on 45 cities in the land border areas of China and employed techniques such as the land transfer matrix, Theil index, and ecological environment index to explore the spatiotemporal evolution process and eco-environmental effects of territorial space from three dimensions: spatial pattern, structural transformation, and ecological response. The results show that:(1) During the study period, there was an increasing trend in living and production space, along with a decrease in ecological space, and a significant pattern of "one belt, three districts, and multipoints" emerged.(2) In the urbanization process, population growth and industrial agglomeration have led to the transformation and conflict of territorial spaces, with the conversion of ecological spaces into production spaces being the primary form of land-use transformation. Rapid development has resulted in spatial differentiation of the territorial space between regions.(3) During this period, the ecological quality in China's border areas deteriorated, yet the distribution pattern of ecological space remained stable, exhibiting a “high value in the southeast, low value in the northwest” pattern.(4) Improvements and degradation of the ecology coexist in different border areas;transforming agricultural production space into green and potential ecological spaces has positively contributed to enhancing ecological quality. In contrast, converting green ecological space into potential ecological space, agricultural production space, and aquatic ecological space has become a key factor in ecological degradation. Therefore, the border areas of China should utilize national preferential policies and strategies, recognize the vast and varied expanse of

关键词： production-living-ecological space evolution of the pattern multidimensional characteristics ecological environment quality China's land border belt

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The underlying mechanism of variety–water–nitrogen–stubble damage interactions on yield formation in ratoon rice with low stubble height under mechanized harvesting

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Journal of Integrative Agriculture 2024年第3期23卷 806-823页

作者： Jingnan Zou Ziqin Pang Zhou Li Chunlin Guo Hongmei Lin Zheng Li Hongfei Chen Jinwen Huang Ting Chen Hailong Xu Bin Qin Puleng Letuma Weiwei Lin Wenxiong Lin College of Life Sciences Fujian Agriculture and Forestry University(FAFU)/Fujian Key Laboratory for Agroecological Processes and Safety MonitoringFuzhou 350002China College of Agriculture FAFU/Fujian Key Laboratory for Crop Physiology and Molecular EcologyFuzhou 350002China Institute of Oceanography College of Geography and OceanographyMinjiang UniversityFuzhou 350108China Crop Science Department The National University of LesothoRoma 00100Lesotho The Agricultural Extension Station of Pucheng County Nanping 353400China

Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status.Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvest

关键词： mechanized harvesting ratoon rice rice stubble yield attributes

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Identification of a female murder victim found in Burgenland,Austria in 1993

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Forensic Sciences Research 2022年第2期7卷 308-318页

作者： Christine Lehn Andreas Rossmann Matthias Graw Gareth R.Davies Institute of Legal Medicine Ludwig-Maximilians-University of MunichMunichGermany laboratory for stable isotope Analytics Isolab GmbHSchweitenkirchenGermany Faculty of Earth and Life Sciences Vrije Universiteit AmsterdamAmsterdamThe Netherlands

In 1993,the skeletal remains of a female corpse were found in Burgenland,Austria.Initial identification of the approximately 25–35-year-old female appeared impossible,but the case was reopened 23 years later.By applying biogeochemical isotope methods to her body tissues,the geographical origin of the unknown corpse could be predicted.The results of the C,N,S,H,Sr,and Pb isotope analyses suggested that the female did not originate from Europe and most likely spent her youth in the northern Caribbean.Using these findings,the police were able to identify the woman within 2 weeks.The female came from the Dominican Republic and resided in Austria for only a short period before she was murdered.This case shows that isotope biogeochemistry investigations can provide the police with crucial information that enables unknown persons to be identified.

关键词： Forensic sciences forensic anthropology human identification provenance stable isotope analysis bio-elements geo-elements

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Contribution of the cryosphere to runoff in“Chinese water tower”based on environmental isotopes

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Geoscience Frontiers 2023年第5期14卷 173-188页

作者： Zongxing Li Juan Gui Qi Feng Baijuan Zhang Qiao Cui Observation and Research Station of Eco-Hydrology and National Park by stable isotope Tracing in Alpine Region Gansu Qilian Mountains Ecology Research CenterKey Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Cryospheric meltwater is an important runoff component and it profoundly influences changes in water resources in the Tibetan Plateau.Significant changes in runoff components occur in the three-river headwater region(TRHR),which is an important part of“Chinese Water Tower”due to climate warming.However,these effects remain unclear owing to the sparse and uneven distribution of monitoring sites and limited field investigations.Quantifying the contribution of cryospheric meltwater to outlet runoff is a key scientific question that needs to be addressed.In this study,we analyzed 907 precipitation,river water,ground ice,supra-permafrost water,and glacier snow meltwater samples collected from October 2019 to September 2020 in the TRHR.The following results were obtained:(1)There was significant spatio-temporal variation in stable isotopes in different waters;(2)The seasonal trends of stable isotopes for different waters,the relationship between each water body and the local meteoric water line(LWML)confirmed that river water was mainly recharged by precipitation,supra-permafrost water,and glacier snow meltwater;(3)Precipitation,supra-permafrost water,and glacier snow meltwater accounted for 52%,39%,and 9%of river water,respectively,during the ablation period according to the end-member mixing analysis(EMMA);(4)In terms of future runoff components,there will be many challenges due to increasing precipitation and evaporation,decreasing snow cover,glacier retreat,and permafrost degradation.Therefore,it is crucial to establish the“star-machine-ground”observation networks,forecast extreme precipitation and hydrological events,build the“TRHE on the Cloud”platform,and implement systematic hydraulic engineering projects to support the management and utilization of water resources in the TRHR.The findings of environmental isotope analysis provide insights into water resources as well as scientific basis for rational use of water resources in the TRHR.

关键词： Cryospheric meltwater Chinese water tower Hydrograph separation

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Graphdiyne(C_nH2n-2) as an "electron transfer bridge" boosting photocatalytic hydrogen evolution over Zn0.5Co0.5S/MoS2 S-scheme heterojunction

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Rare Metals 2024年第5期43卷 1999-2014页

作者： Mei Li Jing-Zhi Wang Zhi-Liang Jin School of Chemistry and Chemical Engineering North Minzu University School of Chemistry and Chemical Engineering Ningxia Key Laboratory of Solar Chemical Conversion Technology Key Laboratory for Chemical Engineering and Technology State Ethnic Affairs Commission North Minzu University

In the process of photocatalytic water cracking,the migration rate and utilization rate of photogenerated charges determine the hydrogen evolution performance of the catalyst.In this paper,a carbon isotope superconducting material graphdiyne （GDY） is prepared by mechanical ball milling and introduced into the S-scheme heterojunction Zn0.5Co0.5S/Mo S2inorganic system.In terms of hydrogen evolution kinetics,GDY acts as an electron bridge,not only accelerating the migration of photogenerated carriers but also improving the utilization of photogenerated charges.Morphologically,the large twodimensional layer provides more loading and anchoring points for Zn0.5Co0.5S/Mo S2,which increases the number of active sites.The ternary composite catalyst 20%GDY/Zn0.5Co0.5S/Mo2S （20-GCSM） generates 69.94μmol of hydrogen （5 h） in triethanolamine solution.It is 2.97 and1.80 times higher than Zn0.5Co0.5S and Zn0.5Co0.5S/Mo S2,respectively.After the cyclic experiment,it still has stable hydrogen evolution performance after standing for24 h （under dark conditions）.In addition,the potential mechanism of photocatalytic hydrogen evolution is demonstrated through in-situ X-ray photoelectron spectroscopy.This work provides a reference for further research in the field of introducing carbon materials into photocatalytic systems and improving the utilization of photogenerated charges.

关键词： Graphdiyne S-scheme heterojunction Electron transfer bridge Hydrogen production

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Dynamic cooperations between lattice oxygen and oxygen vacancies for photocatalytic ethane dehydrogenation by a self-restoring LaVO_(4)catalyst

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Chinese Chemical Letters 2024年第3期35卷 171-176页

作者： Fen Wei Weichao Xue Zhiyang Yu Xue Feng Lu Sibo Wang Wei Lin Xinchen Wang State Key laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China

Thermocatalytic nonoxidative ethane dehydrogenation(EDH)is a promising strategy for ethene production but suffers from intense energy consumption and poor catalyst durability;exploring technology that permits efficient EDH by solar energy remains a giant challenge.Herein,we present that an oxygen vacancy(O_v)-rich LaVO_(4)(LaVO_(4)-O_v)catalyst is highly active and stable for photocatalytic EDH,through a dynamic lattice oxygen(O_(latt.))and O_(v)co-mediated mechanism.Irradiated by simulated sunlight at mild conditions,LaVO_(4)-O_(v)effectively dehydrogenates undiluted ethane to produce C_(2)H_(4)and CO with a conversion of 2.3%.By loading a small amount of Pt cocatalyst,the evolution and selectivity of C_(2)H_(4)are enhanced to 275μmol h^(-1)g^(-1)and 96.8%.Of note,LaVO_(4)-O_(v)appears nearly no carbon deposition after the reaction.The isotope tracked reactions reveal that the consumed O_(latt.)recuperates by exposing the used catalyst with O_(2),thus establishing a dynamic cycle of O_(latt.)and achieving a facile catalyst regeneration to preserve its intrinsic activity.The refreshed LaVO_(4)-O_(v)exhibits superior reusability and delivers a turnover number of about 305.The O_(v)promotes photo absorption,boosts ethane adsorption/activation,and accelerates charge separation/transfer,thus improving the photocatalytic efficiency.The possible photocatalytic EDH mechanism is proposed,considering the key intermediates predicted by density functional theory(DFT)and monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS).

关键词： Photocatalysis Ethane dehydrogenation Ethene LaVO_(4) Oxygen vacancy

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