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Recent Efforts in Conserving 20^(th)-Century Heritage:The Getty Conservation Institute’s Conserving Modern Architecture Initiative
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作者 Susan MacDonald Sheridan Burke +1 位作者 Sara Lardinois Chandler McCoy 《Built Heritage》 2018年第2期62-75,共14页
Over the last 25 years the conservation of 20^(th)-century heritage has developed into a distinct area of practice, catalysed by the efforts of dedicated international and local interest groups and the forward thinkin... Over the last 25 years the conservation of 20^(th)-century heritage has developed into a distinct area of practice, catalysed by the efforts of dedicated international and local interest groups and the forward thinking of a number of government and inter-government organisations who identified, protected and developed approaches to its care. Much has been achieved, but more work is needed to address many of the distinct challenges to con­serving the heritage of the 20^(th) century. In 2011, the Getty Conservation Institute (GCI) launched its Conserving Modern Architecture Initiative (CMAI), which seeks to respond to the outstanding current challenges and contrib­ute to advancing practice in this emerging area of conservation. It began with a survey of the field to identify where existing efforts could be best supported and enhanced, or where knowledge gaps could be potentially filled. In re­sponse the GCI built a comprehensive program to meet these identified needs and five years later, a number of ac­tivities and projects are underway. These include a series of publications, a training program, historical and techni­cal research and two field projects at Louis Kahn’s Salk Biological Institute (1965) and the house of Ray and Charles Eames (1949), both in California. This paper outlines current GCI efforts, reports on initial outcomes and describes forthcoming activities. 展开更多
关键词 20^(th)-century heritage Getty Conservation Institute historic thematic framework Salk Biological Insti­tute Eames House conserving modern heritage
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Relationship Between Soil and Water Conservation Practices and Soil Conditions in Low Mountain and Hilly Region of Northeast China 被引量:5
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作者 ZHANG Yubin CAO Ning +4 位作者 XU Xiaohong ZHANG Feng YAN Fei ZHANG Xinsheng TANG Xinlong 《Chinese Geographical Science》 SCIE CSCD 2014年第2期147-162,共16页
The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixin... The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program. 展开更多
关键词 soil and water conservation practices soil property soil organic carbon low mountain and hilly region Northeast China
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Autumn migration routes of fledgling Chinese Egrets(Egretta eulophotes)in Northeast China and their implications for conservation 被引量:2
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作者 Hongying Xu Zeyu Yang +5 位作者 Dongping Liu Ru Jia Lixia Chen Boshi Liang Zhengwang Zhang Guogang Zhang 《Avian Research》 SCIE CSCD 2022年第1期78-86,共9页
The Chinese Egret(Egretta eulophotes)is a globally threatened bird species living on the coast and islands of Liaoning,northeastern China,mainly in summer.To further protect the breeding population of Chinese Egrets,i... The Chinese Egret(Egretta eulophotes)is a globally threatened bird species living on the coast and islands of Liaoning,northeastern China,mainly in summer.To further protect the breeding population of Chinese Egrets,it is important to understand the current protection status of their distribution sites at pre-migration period and migration routes.Thirty-three individuals were tagged with satellite transmitters at Fantuo Island in Changhai and Xingren Island in Zhuanghe,Liaoning Province,northeastern China,in July of 2016,2017,and 2018,to identify important distribution sites during the pre-migration period,as well as detailed migration routes.The results showed that coastal mudflats in Liaoning and the west coast of North Korea were important feeding and roosting sites for fledgling Chinese Egrets from August to September.The home range sizes in August were significantly larger than in September.The eastern coast from Shandong to Guangdong,as well as Taiwan,China,and Manila Bay and Galileo Islands in the Philippines,were important stopover sites during fall migration.Specifically,we found that the egrets’autumn migration could be divided into four routes,i.e.,sea-crossing migration(SCM),coastal migration(CM),inland migration(IM),and mixed migration(MM).The migration distance,timing,speed,and straightness of the four routes also differed.The SCM routes were the straightest,and had the fastest migration speed and shortest travel time,while the IM routes had the lowest straightness and speed,and the longest duration.Manila Bay and Bohol Island in the Philippines,the west coast of Tanintharyi in Myanmar,and the Zengwun River Estuary in Taiwan,China,were wintering sites.Our findings on the key distribution sites along pre-migration and fall migration routes,including some stopover sites,have important implications for the conservation of and global action plan development for the vulnerable Chinese Egret. 展开更多
关键词 Conservation implications Fledgling Chinese Egret Migration route Liaodong Peninsula Satellite tracking
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Effects of soil and water conservation and its interactions with soil properties on soil productivity 被引量:2
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作者 郭旺 李忠武 +7 位作者 申卫平 王晓燕 曾光明 陈晓琳 张雪 张越男 刘桂平 王曙光 《Journal of Central South University》 SCIE EI CAS 2012年第8期2279-2285,共7页
The effects of soil and water conservation (SWC) on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lack... The effects of soil and water conservation (SWC) on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lacking for hilly red soil region of southern China. Experiments were conducted in the hilly red soil region of southern China for seven years in three rtmoffplots, each of which represented different SWC forest-grass measures. Principal component analysis and multiple regression techniques were used to relate the aboveground biomass (representing soil productivity) to soil properties. Based on the final regression equations, soil organic carbon content (Sot) is significantly correlated with soil productivity under the condition of forest-grass measures, whereas pH value and cation exchange capacity (Cee) are the main factors for soil productivity without SWC. Therefore, SWC plays an important role in sequestering Soc and improving soil productivity. 展开更多
关键词 hilly red soil region soil erosion soil organic carbon soil productivity
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Development status and prospect of cultural heritage conservation standardization in China 被引量:2
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作者 Li Enzhong Liu Shunqiang +1 位作者 Wang Jie Ma Yanying 《China Standardization》 2022年第S01期28-32,共5页
The cultural heritage conservation standardization plays a fundamental and leading role in promoting the protection and utilization of cultural relics and the inheritance of cultural heritage.This paper elaborates law... The cultural heritage conservation standardization plays a fundamental and leading role in promoting the protection and utilization of cultural relics and the inheritance of cultural heritage.This paper elaborates laws and regulations related to the cultural heritage conservation standardization in China,summarizes the Chinese standards system and development status of cultural heritage conservation standardization,introduces the main contents and research hotspots of Chinese cultural heritage conservation standards,and forecasts the development of cultural heritage conservation standardization in China. 展开更多
关键词 cultural heritage STANDARDIZATION DEVELOPMENT PROSPECT
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Global prioritisation of renewable nitrogen for biodiversity conservation and food security
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作者 Eisner ROWAN SEABROOK Leonie MCALPINE Clive 《Journal of Geographical Sciences》 SCIE CSCD 2018年第11期1567-1579,共13页
The continuing use of petrochemicals in mineral nitrogen (N) production may be affected by supply or cost issues and climate agreements. Without mineral N, a larger area of cropland is required to produce the same a... The continuing use of petrochemicals in mineral nitrogen (N) production may be affected by supply or cost issues and climate agreements. Without mineral N, a larger area of cropland is required to produce the same amount of food, impacting biodiversity. Alternative N sources include solar and wind to power the Haber-Bosch process, and the organic options such as green manures, marine algae and aquatic azolla. Solar power was the most land-efficient renewable source of N, with using a tenth as much land as wind energy, and at least 100th as much land as organic sources of N. In this paper, we developed a decision tree to locate these different sources of N at a global scale, or the first time taking into account their spatial footprint and the impact on terrestrial biodiversity while avoiding impact on albedo and cropland, based on global resource and impact datasets. This produced relatively few areas suitable for solar power in the western Americas, central southern Africa, eastern Asia and southern Australia, with areas most suited to wind at more extreme latitudes. Only about 2% of existing solar power stations are in very suitable locations. In regions such as coastal north Africa and central Asia where solar power is less accessible due to lack of farm income, green manures could be used, however, due to their very large spatial footprint only a small area of low productivity and low biodiversity was suitable for this option. Europe in particular faces challenges because it has access to a relatively small area which is suitable for solar or wind power. If we are to make informed decisions about the sourcing of alternative N supplies in the future, and our energy supply more generally, a decision-making mechanism is needed to take global considerations into account in regional land-use planning. 展开更多
关键词 concentrated solar ammonia synthesis biofixation
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Spatio-temporal uneven distribution of soil moisture replenishment by rainfall events along a hillslope in the Liupan Mountains, Northwest China 被引量:1
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作者 BAI Yushi YU Pengtao +4 位作者 WAN Yanfang LIU Bingbing WANG Yanhui LIU Zebin Ashley A.WEBB 《Journal of Mountain Science》 2025年第4期1376-1387,共12页
Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution... Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions. 展开更多
关键词 Soil moisture replenishment Lateral replenishment Hillslope position Loess Plateau
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Late spring-early summer drought and soil properties jointly modulate two pine species?decline and climatic sensitivity in temperate Northern China 被引量:1
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作者 Yuheng Li Zhaofei Fan +10 位作者 Lihong Xu Xiao Zhang Zhongjie Shi Xiaohui Yang Wei Xiong Ling Cong Semyun Kwon Leilei Pan f Hanzhi Li Shuo Wen Xiaoyan Shang 《Forest Ecosystems》 2025年第1期146-158,共13页
Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts o... Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes. 展开更多
关键词 Tree rings Climate sensitivity Growth decline Global warming DROUGHT Soil property
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Water deficit affects the nitrogen nutrition index of winter wheat under controlled water conditions 被引量:1
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作者 Ben Zhao Anzhen Qin +7 位作者 Wei Feng Xinqiang Qiu Pingyan Wang Haixia Qin Yang Gao Guojie Wang Zhandong Liu Syed Tahir Ata-Ul-Karim 《Journal of Integrative Agriculture》 2025年第2期724-738,共15页
Nitrogen(N)uptake is regulated by water availability,and a water deficit can limit crop N responses by reducing N uptake and utilization.The complex and multifaceted interplay between water availability and the crop N... Nitrogen(N)uptake is regulated by water availability,and a water deficit can limit crop N responses by reducing N uptake and utilization.The complex and multifaceted interplay between water availability and the crop N response makes it difficult to predict and quantify the effect of water deficit on crop N status.The nitrogen nutrition index(NNI)has been widely used to accurately diagnose crop N status and to evaluate the effectiveness of N application.The decline of NNI under water-limiting conditions has been documented,although the underlying mechanism governing this decline is not fully understood.This study aimed to elucidate the reason for the decline of NNI under waterlimiting conditions and to provide insights into the accurate utilization of NNI for assessing crop N status under different water-N interaction treatments.Rainout shelter experiments were conducted over three growing seasons from 2018 to 2021 under different N(75 and 225 kg N ha^(-1),low N and high N)and water(120 to 510 mm,W0 to W3)co-limitation treatments.Plant N accumulation,shoot biomass(SB),plant N concentration(%N),soil nitrate-N content,actual evapotranspiration(ET_a),and yield were recorded at the stem elongation,booting,anthesis and grain filling stages.Compared to W0,W1 to W3 treatments exhibited NNI values that were greater by 10.2 to 20.5%,12.6to 24.8%,14 to 24.8%,and 16.8 to 24.8%at stem elongation,booting,anthesis,and grain filling,respectively,across the 2018-2021 seasons.This decline in NNI under water-limiting conditions stemmed from two main factors.First,reduced ET_(a) and SB led to a greater critical N concentration(%N_(c))under water-limiting conditions,which contributed to the decline in NNI primarily under high N conditions.Second,changes in plant%N played a more significant role under low N conditions.Plant N accumulation exhibited a positive allometric relationship with SB and a negative relationship with soil nitrate-N content under water-limiting conditions,indicating co-regulation by SB and the soil nitrate-N content.However,this regulation was influenced by water availability.Plant N accumulation sourced from the soil nitrate-N content reflects soil N availability.Greater soil water availability facilitated greater absorption of soil nitrate-N into the plants,leading to a positive correlation between plant N accumulation and ET_(a)across the different water-N interaction treatments.Therefore,considering the impact of soil water availability is crucial when assessing soil N availability under water-limiting conditions.The findings of this study provide valuable insights into the factors contributing to the decline in NNI among different water-N interaction treatments and can contribute to the more accurate utilization of NNI for assessing winter wheat N status. 展开更多
关键词 critical nitrogen concentration shoot biomass plant nitrogen accumulation soil nitrate N concentration soil water content
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Moult-breeding trade-offs in the Crested Ibis(Nipponia nippon)could have management applications
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作者 Jia Li Dongping Liu +3 位作者 Wei Li Wenbin Duan Jie Gao Chao Wang 《Avian Research》 2025年第2期244-250,共7页
Moult is an essential event in the annual cycle of birds.Moult patterns and strategies of birds are crucial for understanding their life-history trade-offs and adaptations to the environment.However,moult knowledge is... Moult is an essential event in the annual cycle of birds.Moult patterns and strategies of birds are crucial for understanding their life-history trade-offs and adaptations to the environment.However,moult knowledge is still lacking for many Eastern Palaearctic birds,especially large endangered species,mainly because of the difficulty in data collection.Here,we used field photography,a non-invasive method,to detect and score moult in the endangered Crested Ibis(Nipponia nippon)and explored the moult timing variations and moult-breeding tradeoffs.The adult Crested Ibis sequentially moults its primaries outward,and secondaries inward from three foci from April to October.Age(adult versus sub-adult)and breeding status(breeding or not)have a significant effect on moult timing.Moult timing does not differ between the sexes,likely because of similar parental investments in breeding.Crested Ibis exhibits significant moult-breeding overlap,because moult is time constrained and needs to finish before the season of food scarcity in winter.Breeding timing(first egg laying date)has a strong impact on moult duration,with late breeders experiencing a longer moult duration,indicating that the moult intensity is slowed down during the breeding period because of trade-offs between moult and breeding.This reflects that energy allocation of late breeders is challenging during extensive periods of moult-breeding overlap,which might partly contribute to their high breeding failure.Our results strongly suggest the existence of a negative relationship between breeding time on one hand,and fitness and moult on the other:early breeders show higher reproductive output and higher quality plumage,whereas late breeders show lower reproductive output and lower quality plumage. 展开更多
关键词 Field photography Life history trade-offs Moult strategies Moult timing
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Spatiotemporal variations in sap flow in a larch plantation:sampling size for stand scale estimates
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作者 Zebin Liu Songping Yu +3 位作者 Lihong Xu Yanhui Wang Mengfei Wang Pengtao Yu 《Journal of Forestry Research》 2025年第1期321-331,共11页
The sap flow method is widely used to estimate forest transpiration.However,at the individual tree level it has spatiotemporal variations due to the impacts of environmental conditions and spatial relationships among ... The sap flow method is widely used to estimate forest transpiration.However,at the individual tree level it has spatiotemporal variations due to the impacts of environmental conditions and spatial relationships among trees.Therefore,an in-depth understanding of the coupling effects of these factors is important for designing sap flow measurement methods and performing accurate assessments of stand scale transpiration.This study is based on observations of sap flux density(SF_(d))of nine sample trees with different Hegyi’s competition indices(HCIs),soil moisture,and meteorological conditions in a pure plantation of Larix gmelinii var.principis-rupprechtii during the 2021 growing season(May to September).A multifactorial model of sap flow was developed and possible errors in the stand scale sap flow estimates associated with sample sizes were determined using model-based predictions of sap flow.Temporal variations are controlled by vapour pressure deficit(VPD),solar radiation(R),and soil moisture,and these relationships can be described by polynomial or saturated exponential functions.Spatial(individual)differences were influenced by the HCI,as shown by the decaying power function.A simple SF_(d)model at the individual tree level was developed to describe the synergistic influences of VPD,R,soil moisture,and HCI.The coefficient of variations(CV)of the sap flow estimates gradually stabilized when the sample size was>10;at least six sample trees were needed if the CV was within 10%.This study improves understanding of the mechanisms of spatiotemporal variations in sap flow at the individual tree level and provides a new methodology for determining the optimal sample size for sap flow measurements. 展开更多
关键词 Sap flow Environmental conditions COMPETITION MODELLING Optimal sample size
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Surface weathering process of earthen heritage under dry-wet cycles:A case study of Suoyang City,China
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作者 Qi Zhang Qingling Guo +4 位作者 Huihui Zhang Yanwu Wang Ping Li Bo Zhang Chun'an Tang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期5224-5239,共16页
Dry-wet cycle is a key factor in surface weathering of earthen heritage,which remains insufficiently explained.It involves the interaction of humidity,stress,and damage.Using the RFPA(realistic failure process analysi... Dry-wet cycle is a key factor in surface weathering of earthen heritage,which remains insufficiently explained.It involves the interaction of humidity,stress,and damage.Using the RFPA(realistic failure process analysis)numerical method,this study reproduced the processes of humidity diffusion,deformation,stress,and damage evolution under dry-wet cycles in the soil site of Suoyang City,China.The numerical results indicate that the drying phase following rainfall has the most significant deteriorative impact on the earthen heritage.The evaporation of surface moisture during this phase causes volume shrinkage,which in turn generates tensile stress and leads to the formation of numerous desiccation cracks.Desiccation cracks provide channels for moisture diffusion,which further exacerbates generation of the cracks,leading to a mutual promotion between the two phenomena.Furthermore,during the wetting phase,the model elements undergo hygroscopic expansion,resulting in a slight increase in strain and displacement.Previously formed cracks may exhibit temporary narrowing or closure,but will revert during the subsequent drying phase.Ultimately,the overall displacement increases with the number of dry-wet cycles.The findings provide a theoretical foundation for protection against surface weathering and other damage in earthen heritage in arid regions. 展开更多
关键词 Earthen heritage Dry-wet cycles Numerical simulation Surface weathering Desiccation cracks
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Parameterization of the 3‑PG model for Quercus mongolica by using tree‑ring data and Bayesian calibration
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作者 Wen Nie Qi Wang +7 位作者 Ruizhi Huang Shaowei Yang Yipei Zhao Jingyi Sun Xiangfen Cheng Zuyuan Wang Wenfa Xiao Jianfeng Liu 《Journal of Forestry Research》 2025年第6期69-81,共13页
Although Quercus mongolica is a widely distributed,economically and ecologically important deciduous tree in northern China,models to accurately predict stand growth at a regional scale are limited.The physiological p... Although Quercus mongolica is a widely distributed,economically and ecologically important deciduous tree in northern China,models to accurately predict stand growth at a regional scale are limited.The physiological process model(3-PG)has the potential to predict stand growth dynamics under varying site conditions and climate change scenarios.Here,we used field inventory,tree ring sampling,and Bayesian calibration to parameterize a model for Q.mongolica.Stand volume and productivity were then predicted under present conditions and three future climate scenarios(RCP26,RCP45 and RCP85).Our results demonstrated that after Bayesian calibration,the posterior ranges of the sensitivity parameters apha Cx,wSx1000 and pRn accounted for 34%,45%and 65%,respectively,of their prior range.Calibration and validation results revealed a strong correlation between predicted and measured values(R^(2)>0.87,P<0.01),with<20%bias for all growth indicators.Stand volume was projected to increase by 145%and productivity by 80%by the year 2100 under the RCP85 scenario,although these projections may vary across regions.The present study developed a tailored set of 3-PG model parameters for Q.mongolica,based on a comprehensive range of climate conditions,stand structure,and age classes.These parameters offer a scientific basis to accurately predict growth of other monospecific oak or mixed-species stands. 展开更多
关键词 Quercus mongolica 3-PG model Bayesian calibration Productivity Growth forecast
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Hot temperature extremes and vapor pressure deficits co-explain changes in the timing of peak photosynthetic activity in the forest belt of northeast China
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作者 Yu Zhang Zhen Yu +3 位作者 Junwei Luan Yi Wang Xiaodan Ye Shirong Liu 《Journal of Forestry Research》 2025年第5期8-22,共15页
Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilati... Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilation.However,the spatio-temporal patterns of climatic constraints and seasonal carbon assimilation are poorly understood.In this study,the timing of peak photosynthetic activity(DOY_(pmax))was employed as a proxy for plant adap-tive state to climatic constraints on growth to examine the spatio-temporal dynamics of DOY_(pmax).By using multiple remote sensing metrics,DOY_(pmax)was characterized with changes in the solar-induced chlorophyll fluorescence(SIF)and leaf area index(LAI)from 2000 to 2018.Based on SIF,the DOY_(pmax)was generally around day 190,while based on LAI was about 10 d later.Peak photosynthetic activity of forests occurs earlier compared to other vegetation types.Overall,the advanced DOY_(pmax)were observed based on both SIF and LAI,with annual rates of 0.2(P=0.31)and 0.3(P<0.05)d,respectively.DOY_(pmax)dynamics were influ-enced by hot temperature extremes and vapor pressure defi-cits(VPD)during the early growing season,regardless of sub-zone and different vegetation type.The generalized lin-ear mixed model(GLMM)showed the largest contribution by hot extremes to DOY_(pmax)dynamics accounted for 55.5%(DOY_(pmax_SIF))and 49.1%(DOY_(pmax_LAI)),respectively,fol-lowed by VPD(DOY_(pmax_SIF):23.1%;DOY_(pmax_LAI):29.5%).These findings highlight the crucial role of climate extremes in shaping seasonal carbon dynamics and regional carbon balance. 展开更多
关键词 Peak photosynthetic activity Climate change Hot extremes Leaf area index Solar-induced chlorophyll fluorescence
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Habitat suitability and influencing factors of a threatened highland flagship species,the Black-necked Crane(Grus nigricollis)
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作者 Hongying Xu Ru Jia +7 位作者 Hongrui Lv Ge Sun Dongping Liu Hongyan Yu Cunxin Ma Tian Ma Wenhong Deng Guogang Zhang 《Avian Research》 2025年第2期138-148,共11页
Evaluating the habitat suitability of flagship species and its key influencing factors is vital for understanding potential conservation issues and developing coping strategies.We surveyed the wintering population siz... Evaluating the habitat suitability of flagship species and its key influencing factors is vital for understanding potential conservation issues and developing coping strategies.We surveyed the wintering population size and distribution of the Black-necked Crane(Grus nigricollis)in the Yarlung Zangbo River Basin(YZRB)from 10 to 29 January 2022,and predicted the current potentially suitable habitat distribution and its effective factors using the Max Ent model.A total of 9337 wintering Black-necked Cranes were recorded in the YZRB in 2022,76.58%of which were primarily found in Lhunzub,Samzhubze,Namling,and Lhaze.Compared to 2018,the crane population has exhibited a notable decline in Samzhubze and Taktse,likely due to farmland plowing,winter irrigation,changes in agricultural practices,road construction and hydraulic projects.The crane population within various counties exhibited a significant positive correlation with the suitable habitat area(r=0.70,P=0.002,n=17).We also found that the currently suitable habitat area covered 17,204 km~2,of which only 3244 km~2(18.86%)was effectively protected at the national level,which was predominantly distributed in farmland and rangeland habitats characterized by gentle slopes,altitudes not exceeding 4500 m,and proximity to human settlements along rivers,where suitable isothermal values(51)and less seasonal precipitation(20 mm)prevail.Our study will be helpful for formulating reasonable conservation strategies to protect the core population of this threatened highland flagship species. 展开更多
关键词 Black-necked Crane Flag species Max Ent model Population size Potentially suitable habitat Yarlung Zangbo River
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Morphology and phylogeny of two species of Bathypathes from the tropical western Pacific,with description of a new species
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作者 Ting LÜ Zifeng ZHAN Kuidong XU 《Journal of Oceanology and Limnology》 2025年第1期248-260,共13页
The black coral genus Bathypathes Brook,1889 represents a relatively diverse and ecologically important assemblage comprising the deep-sea hard substrate communities.Recent phylogenetic investigations have revealed th... The black coral genus Bathypathes Brook,1889 represents a relatively diverse and ecologically important assemblage comprising the deep-sea hard substrate communities.Recent phylogenetic investigations have revealed the polyphyletic nature of Bathypathes,urging further morphological analysis to understand its systematics.By combing morphological and molecular data,we describe Bathypathes multifurcata sp.nov.and report B.pseudoalternata Molodtsova,Opresko&Wagner,2022based on the specimens collected from the tropical western Pacific.The phylogenetic topology reconstructed using nuclear ITS1-5.8S-ITS2 and three mitochondrial fragments suggests the separation of Bathypathes into four groups.Our analysis of morphological characters,particularly the colony branch and pinnule patterns also roughly classify Bathypathes into four morphological groups A–D.Group A is characterized by the unbranched colony and the subopposite arrangement of pinnules.In contrast to Group A,Groups B–D have the alternately arranged pinnules.Among these,Group C exhibits a distinctly long unpinnulated stem compared to Groups B and D.Group B has unbranched colony,relatively short unpinnulated stem,and spines on pinnules have blunt apex.Within Group D,large colonies(higher than 40 cm)have one or a few branches,small colonies(less than 40 cm)are unbranched,and spines on pinnules have acute apex.Further data particularly those species without sequences are necessary to verify the classification of these groups. 展开更多
关键词 Antipatharia black coral TAXONOMY PHYLOGENY SEAMOUNT western Pacific
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Potential for improved groundwater recharge and dry-season flows through forest landscape restoration on degraded lands in the tropics
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作者 L.Adrian Bruijnzeel Jorge L.Peña-Arancibia +7 位作者 Douglas Sheil Alan D.Ziegler Jun Zhang Bob W.Zwartendijk Christian Birkel Ge Sun Yanhui Wang Xiaoping Zhang 《Forest Ecosystems》 2025年第6期1204-1223,共20页
As interest in tropical forest restoration accelerates,understanding its hydrological implications is increasingly urgent.While concerns persist that reforestation will reduce annual water yields—particularly in drie... As interest in tropical forest restoration accelerates,understanding its hydrological implications is increasingly urgent.While concerns persist that reforestation will reduce annual water yields—particularly in drier climates—we highlight conditions under which forest landscape restoration(FLR)can improve seasonal water availability,especially during the dry season.We examine the trade-off between increased vegetation water use(“pumping”)and enhanced infiltration and subsurface retention(“sponging”)following forestation of degraded lands,the recovery of vegetation's ability to capture“occult”precipitation(fog)in specific coastal and montane settings,and the role of forest cover in enhancing moisture recycling and transport at multiple scales.A pan-tropical sensitivity analysis shows that in degraded landscapes with deep soils and pronounced rainfall seasonality,infiltration gains following forestation can offset or exceed evaporative losses,thereby supporting groundwater recharge and increasing dry-season flows in approximately 10%of cases,with an additional 8%showing near-neutral(slightly negative)outcomes.These findings challenge the assumption that forestation uniformly reduces water availability and underscore the need to prioritize dry-season flow recovery—rather than annual water yield—as a central hydrological goal of FLR.We call for trans-disciplinary research and long-term monitoring to inform forest restoration strategies,particularly in seasonally dry regions where water scarcity is most acute. 展开更多
关键词 AFFORESTATION BASEFLOW DEFORESTATION Forest landscape restoration(FLR) Infiltration trade-off REFORESTATION Soil degradation
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敦煌莫高窟顶尼龙网栅栏防护效应研究 被引量:27
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作者 汪万福 王涛 +4 位作者 樊锦诗 张伟民 屈建军 AGNEWN 林博明 《中国沙漠》 CSCD 北大核心 2005年第5期640-648,共9页
野外监测和风洞模拟实验结果表明,孔隙度为20%~25%的尼龙网栅栏,其保护范围达23.5H^29.5H,栅栏前后的积沙范围主要集中在2H(栏前)~3H(栏后)。砂砾质戈壁区尼龙网栅栏直接阻止了偏西风向洞窟搬运沙量的80%以上,但其侧导能力微弱,外围栅... 野外监测和风洞模拟实验结果表明,孔隙度为20%~25%的尼龙网栅栏,其保护范围达23.5H^29.5H,栅栏前后的积沙范围主要集中在2H(栏前)~3H(栏后)。砂砾质戈壁区尼龙网栅栏直接阻止了偏西风向洞窟搬运沙量的80%以上,但其侧导能力微弱,外围栅栏对来自主风向的外侧积沙的侧导率平均达到35%;对其内侧的侧导作用,在偏东风时为57.51%,偏西风时平均为15.89%,反映了防护效益的季节变化特征。在网后1H处,20cm、50cm、100cm和150cm高处的风速分别降到网前3H的48.6%、38.6%、40.7%和66%。在NW风作用下,网后10m、2m的输沙量分别是网前10m、2m的1/29和1/43,并受栅栏设置等因素的影响。流沙区尼龙网栅栏的防沙效益亦表现出在三组不同风向上的差异。栅栏的阻沙效益与沙源供给关系密切,沙源充足时以风积为主,相反,则出现较强的风蚀作用。3~5月间,对比分析前方沙源充足(1992年)、基本控制(2002年)和较好控制(2003年)3种情况,窟前栈道不同部位洞前积沙分别减少39.4%~83.3%、75.4%~95.2%和94.0%~98.7%。尼龙网栅栏是比其他材料更优的一种防沙材料,不仅价格便宜,施工简单,而且在沙障被埋后容易移动重设,在阻止沙丘前移和防止过境风沙流具有优势。目前在网栅周围形成的局部积沙,在综合防护体系逐渐建立,前方沙源截留的前提下,利用窟顶输沙能力的季节变化特别是偏东方的反向搬运功能,局部积沙可以得到较好的输导。同时建议维护调整现有砂砾质戈壁区尼龙网栅栏防护体系。 展开更多
关键词 敦煌莫高窟 尼龙网栅栏 防沙效应
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四川唐家河自然保护区扭角羚冬春季日活动模式研究 被引量:57
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作者 李明富 李晟 +3 位作者 王大军 William J McShea 官天培 谌利民 《四川动物》 CSCD 北大核心 2011年第6期850-855,共6页
根据相机陷阱调查获得照片的时间,研究了2008年12月~2009年5月唐家河自然保护区内野生扭角羚Budorcastaxicolor的日活动模式。通过对24个1km×1km样方的调查,共完成686个相机工作日的取样量,获得有效的扭角羚捕捉次数709次(冬季322... 根据相机陷阱调查获得照片的时间,研究了2008年12月~2009年5月唐家河自然保护区内野生扭角羚Budorcastaxicolor的日活动模式。通过对24个1km×1km样方的调查,共完成686个相机工作日的取样量,获得有效的扭角羚捕捉次数709次(冬季322次,春季387次),并分别计算出扭角羚冬季和春季在各时间段的相对活动强度指数RAI。结果显示,扭角羚在冬季和春季的日活动模式没有显著差异(χ2检验,P>0.1),每天都有3个活跃时期(凌晨、早上和下午)和3个紧随的不活跃时期。其中,冬季日活动的最高峰出现在下午17:00~18:00(RAI=12.42),最低谷出现在日出前3:00~6:00(RAI=0.00);春季最高峰出现在早上6:00~7:00(RAI=20.16),最低谷出现在日出前2:00~5:00(RAI=0.26)。在春季,扭角羚在上午活跃期的活动强度明显高于下午活跃期,而在冬季则相反。春季与冬季相比,扭角羚上午和下午的两个活跃时间段都有提前,可能是由于不同季节气温和光照差异的影响。研究表明,相机陷阱调查技术是研究野生动物在野外活动模式和活动节律的有效工具,可为今后深入开展扭角羚行为生态学研究和保护区内野生动物的管理提供基础的科学依据。 展开更多
关键词 扭角羚 相机陷阱 日活动模式 相对活动强度指数 唐家河自然保护区
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敦煌莫高窟典型洞窟空气交换速率的对比分析 被引量:11
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作者 张国彬 汪万福 +3 位作者 薛平 前川信 侯文芳 张正模 《敦煌研究》 CSSCI 北大核心 2009年第6期100-104,共5页
选择敦煌莫高窟10个典型洞窟用六氟化硫(SF6)气体进行洞窟内外空气交换速率的实验测定,结果表明:洞窟内外空气交换速率除受洞窟内外温度差、窟外风场(风向,风速)的影响外,还与洞窟所在层位、洞窟形制、主室大小、有无甬道及大小、有无... 选择敦煌莫高窟10个典型洞窟用六氟化硫(SF6)气体进行洞窟内外空气交换速率的实验测定,结果表明:洞窟内外空气交换速率除受洞窟内外温度差、窟外风场(风向,风速)的影响外,还与洞窟所在层位、洞窟形制、主室大小、有无甬道及大小、有无游客参观密不可分。在有游客参观时,洞窟主室大小、甬道大小与交换速率具有指数相关性。在没有游客参观时,第一层(底层)、第二层洞窟主室体积、甬道体积与交换速率之间存在指数关系,而第三层洞窟体积和甬道体积与空气交换率呈正比例关系。游客参观对洞窟空气交换速率和洞窟空气质量影响较大,不同层位的洞窟影响并不一致。 展开更多
关键词 敦煌莫高窟 典型洞窟 空气交换速率 SF6半衰期 对比分析
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