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spatial patterns nitrogen transfer models of ectomycorrhizal networks in a Mongolian scotch pine plantation

Journal of Forestry Research 2018年第2期29卷 337-344页

作者： Yanbin Liu Hongmei Chen Pu Mou College of Life Science Beijing Normal UniversityBeijing 100875People’s Republic of China Institute of Forestry Science Heilongjiang Academy of ForestryHarbin 150081People’s Republic of China Institute of Biology University of LeipzigJohannisallee 2104103 LeipzigGermany State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing 100875People’s Republic of China

Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nutrients,plant competition,and so *** deeply their structure and function in ecosystems,we investigated the spatial patterns and nitrogen(N)transfer of EM networks usingN labelling technique in a Mongolian scotch pine(Pinus sylvestris *** Litv.)plantation in Northeastern *** August 2011,four plots(20 × 20 m)were set up in the plantation.125 ml 5 at.%0.15 mol/LNHNOsolution was injected into soil at the center of each *** and 2,6,30 and 215 days after theN application,needles(current year)of each pine were sampled along four 12 m sampling *** total N andN concentrations were *** observed needle N andN concentrations increased significantly over time afterN application,up to 31 and0.42%,*** was no correlation between needle N concentration andN/N ratio(R2=0.40,n=5,P=0.156),while excess needle N concentration and excess needleN/N ratio were positively correlated across different time intervals(R~2=0.89,n=4,P\0.05),but deceased with time interval ***/N ratio increased with time,but it was not correlated with ***/N ratio was negative with distance before and 6th day and 30th day,positive with distance at 2nd day,but the trend was considerably weaker,their slop were close to *** results demonstrated that EM networks were ubiquitous and uniformly distributed in the Mongolian scotch pine plantation and a random *** found N transfer efficiency was very high,absorbed N by EM network was transferred as wide as possible,we observed N uptake of plant had strong bias forN andN,namely N *** the structure and function of EM networks in ecosystems may lead to a deeper understanding of ecological stability and evolution,and thus provide new theoretical approaches to improve conservation practices for the ma

关键词： Ectomycorrhizal networks spatial patterns Nitrogen transfer Mongolian scotch pine plantation Stable isotope 15N labelling

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spatial patterns of ecosystem vulnerability changes during 2001–2011 in the three-river source region of the Qinghai-Tibetan Plateau, China

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Journal of Arid Land 2016年第1期8卷 23-35页

作者： GUO Bing ZHOU Yi ZHU Jinfeng LIU Wenliang WANG Futao WANG Litao YAN Fuli WANG Feng YANG Guang LUO Wei JIANG Lin Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences University of Chinese Academy of Sciences

The three-river source region (TRSR, including Yangtze, Yellow and Lancang rivers), located in the Qinghai-Tibetan Plateau, China, is a typical alpine zone with apparent ecosystem vulnerability and sensitivity. In this paper, we introduced many interdisciplinary factors, such as landscape pattern indices (Shannon diversity index and Shannon evenness index) and extreme climate factors (number of extreme high temperature days, number of extreme low temperature days, and number of extreme precipitation days), to establish a new model for evaluating the spatial patterns of ecosystem vulnerability changes in the TRSR. The change intensity (CI) of ecosystem vulnerability was also analyzed. The results showed that the established evaluation model was effective and the ecosystem vulnerability in the whole study area was intensive. During the study period of 2001–2011, there was a slight degradation in the eco-environmental quality. The Yellow River source region had the best eco-environmental quality, while the Yangtze River source region had the worst one. In addition, the zones dominated by deserts were the most severely deteriorated areas and the eco-environmental quality of the zones occupied by evergreen coniferous forests showed a better change. Furthermore, the larger the change rates of the climate factors (accumulative temperature of ≥10°C and annual average precipitation) are, the more intensive the CI of ecosystem vulnerability is. This study would provide a scientific basis for the eco-environmental protection and restoration in the TRSR.

关键词： eco-environmental vulnerability climate factors spatial patterns three-river source region

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spatial patterns of the main trees in a plant micro-reserve constructed in the 2022 Beijing Winter Olympics mountainous competition zone

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Journal of Mountain Science 2023年第8期20卷 2228-2241页

作者： WANG Jian-yong ZHANG Zhi-xiang School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing 100083China

Several plant micro-reserves were established to preserve the vegetation in local mountain areas during the construction of the Yanqing competition zone of the 2022 Beijing Winter *** spatial patterns of the main species in one of the micro-reserves and the factors affecting these patterns were characterized in this *** distribution of arbor species was found to be mostly aggregated,especially at fine scales(spatial patterns were found to be affected by habitat heterogeneity,intraspecific relationships,interspecific competition,and seed dispersal *** heterogeneity was found to affect large-scale spatial patterns,and its effects were observed throughout population *** competition is another factor affecting the distribution of the species,and its effects were stronger during the later stages of population *** heterogeneity was found to affect competition among species and is key for species *** these processes are affected by the seed dispersal limitation,and intraspecific relationships are a legacy of seed *** point patterns can be used as a tool for the initial assessment of the status of communities within *** consideration of these relationships in the development,management,and formulation of policies for micro-reserves in mountainous areas will facilitate the achievement of conservation *** careful consideration of habitat conditions when selecting sites for micro-reserves establishment can promote species conservation.

关键词： spatial patterns Point patterns Microreserve Juglans mandshurica forest Beijing mountainous area

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spatial patterns in natural Picea crassifolia forests of northwestern China,as basis for close-to-nature forestry

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Journal of Mountain Science 2018年第9期15卷 1909-1919页

作者： HE Zhi-bin FANG Shu CHEN Long-fei DU Jun ZHU Xi LIN Peng-fei Linze Inland River Basin Research Station Chinese Ecosystem Research NetworkKey Laboratory of Eco-hydrology of Inland River BasinNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Close-to-nature forest management has been proposed as an effective method for improving the quality of plantation forests. Knowledge of spatial distribution patterns, structure, and succession trajectories in natural forests can provide guidelines for the establishment of close-to-nature forest plantations. Such knowledge is lacking in natural spruce(Picea crassifolia) forests in the Qilian Mountains of China, impeding the establishment of production forests. We conducted a case study in the Qilian Mountains to analyze the relationships between the naturally-formed forest patches and terrain factors, spatial heterogeneity of stand characteristics, and stand structure following harvesting disturbance. Our results suggested that spruce plantations will be effective on the N, NE, and NW slopes, at elevations between 2700 and 3300 m, and on slopes ranging from 15° to 45°. Further, planted forest patches should occupy 64% of the slope area on semi-shady slopes(NE, NW). spatial patterns in the studied forest exhibited a strong scale-effect, and an area of 0.25 ha could be used as the most efficient plot scale for the management of spruce plantations. Partial logging is an effective method for the conversion of spruce planted forests into nearnatural forests, and the intensity of partial logging can be determined from the negative exponential function relationship between stand density and DBH. Our results provided critical information for the development of spruce plantations and conversion of existing plantations.

关键词： Picea crassifolia spruce Close-to-nature forestry spatial patterns Qilian Mountains

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spatial patterns of phytoplankton communities in an International Seabed Authority licensed area(COMRA,Clarion-Clipperton Zone)in relation to upper ocean biogeochemistry

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Acta Oceanologica Sinica 2022年第11期41卷 45-57页

作者： Yu Wang Aiqin Han Xuebao He Fangfang Kuang Feng Zhao Peng Xiang Kuidong Xu Third Institute of Oceanography Ministry of Natural ResourcesXiamen 361005China Laboratory of Marine Organism Taxonomy and Phylogeny Chinese Academy of SciencesQingdao 266071China

The Clarion-Clipperton Zone(CCZ)hosts one of the largest known oceanic nodule fields worldwide and is regulated by the International Seabed Authority.A baseline assessment of diversity and distribution patterns is essential for reliable predictions of disturbed ecosystem response scenarios for sustained commercial activities in the *** the present study,the spatial patterns and diversity of phytoplankton communities were analyzed along with upper ocean biogeochemistry,in the licensed China Ocean Mineral Resources R&D Association(COMRA)contract area and the surrounding western CCZ between August 21 and October 8,*** indicated this was a typical low-nutrient low-chlorophyll a(Chl a)environment,characterized by low levels of phytoplankton abundance and *** total 112 species belonging to 4 phyla were recorded(>10μm),with species counts including 82 diatoms,27 dinoflagellates,1 cyanobacteria and 2 *** taxa in successive order of descending abundance and occurrence included Nizschia marina,Cyclotella stylorum,Dactyliosolen mediterraneus,Rhizosolenia setigera,Pseudo-nitzschia delicatissima,Thalassiothrix frauenfeldii,Synedra sp.,Chaetoceros simplex and Pseudo-nitzschia *** depth-averaged abundance and Chl a concentrations were(265±233)cells/L and(0.27±0.30)μg/L,*** accounted for 90.94%of the community with(241±223)cells/L,while dinoflagellates accounted for 5.67%and(15±13)cells/*** distribution pattern exhibited the same trend as abundance,Chl a and species richness,showing subsurface maximum levels at around 100 m,with stations near 10°N having higher levels than in the *** analysis was performed in two assemblages,relating to geographic locations to the south and north of 12°*** subsurface maximum of abundance,Chl a,species richness,dissolved oxygen and nitrite were generally corresponding to the presence of high salinity North Pacific Central Water at depths of 50-120 *** availabilit

关键词： phytoplankton communities spatial patterns diversity upper ocean biogeochemistry Clarion-Clipperton Zone baseline assessment

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spatial patterns and secular trends in human leishmaniasis incidence in Morocco between 2003 and 2013

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Infectious Diseases of Poverty 2016年第1期5卷 404-416页

作者： Mina Sadeq Environmental Epidemiology Unit National Institute of HygieneMinistry of Health27 Avenue Ibn BattutaBP 769 RabatMorocco

Background:Few studies on spatial patterns or secular trends in human leishmanias have been conducted in *** study aimed to examine spatial patterns and trends associated with the human leishmaniasis incidence rate(HLIR)at the province/prefecture level between 2003 and 2013 in ***:Only the available published country data on the HLIR between 2003 and 2013,from the open access files of the Ministry of Health,were *** trends were examined using Kendall’s rank *** exploratory spatial data analysis was also conducted to examine the spatial autocorrelation(Global Moran’s I and local indicator of spatial association[LISA]),and spatial diffusion at the province/prefecture *** influence of various covariates(poverty rate,vulnerability rate,population density,and urbanization)on the HLIR was tested via spatial regression(ordinary least squares regression).Results:At the country level,no secular variation was *** annual incidence rate estimates were 13 per 100000 population(95%CI=12.9–13.1)for cutaneous leishmaniasis(CL)and 0.4 per 100000 population(95%CI=0.4–0.5)for visceral leishmaniasis(VL).The available data on HLIR were based on combined CL and VL cases,however,as the CL cases totally outnumbered the VL ones,HLIR may be considered as CL incidence *** the provincial level,a secular increase in the incidence rate was observed in Al Hoceima(P=0.008),Taounate(P=0.04),Larache(P=0.002),Tétouan(P=0.0003),Khenifra(P=0.008),Meknes(P=0.03),and El Kelaa(P=0.0007),whereas a secular decrease was observed only in the Chichaoua province(P=0.006).Even though increased or decreased rate was evident in these provinces,none of them showed clustering of leishmaniasis *** spatial clusters of high leishmaniasis incidence were located in the northeastern part of Morocco,while spatial clusters of low leishmaniasis incidence were seen in some northwestern and southern parts of Morocco;there was spatial randomness i

关键词： Human leishmaniasis Epidemiology Incidence rates spatial patterns Secular trends Morocco

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spatial patterns of Precipitation Anomalies for 30-yr Warm Periods in China During the Past 2000 Years

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Acta meteorologica Sinica 2012年第3期26卷 278-288页

作者：郝志新郑景云葛全胜张学珍 Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

The spatial patterns of precipitation anomalies during five 30-yr warm periods of 691-720, 1231-1260, 1741-1770, 1921-1950, and 1981-2000 were investigated using a dryness/wetness grading dataset covering 48 stations from Chinese historical documents and 22 precipitation proxy series from natural archives. It was found that the North China Plain （approximately 35^-40~N, east of 105~E） was dry in four warm periods within the centennial warm epochs of 600-750, the Medieval Warm Period （about 900-1300） and after 1900. A wet condition prevailed over most of China during 1741-1770, a 30-yr warm peak that occurred during the Little Ice Age （about 1650-1850）. The spatial pattern of the precipitation anomaly in 1981-2000 over East China （25^-40~N, east of 105~E） is roughly consistent with that in 1231 1260, but a difference in the precipitation anomaly appeared over the Tibetan Plateau. The spatial patterns of the precipitation anomalies over China varied between all five 30-yr warm periods, which implies that the matching pattern between temperature and precipitation change is multiform, and the precipitation anomaly could be positive or negative when a decadal warm climate occurs in different climate epochs. This result may provide a primary reference for the mechanism detection and climate simulation of the precipitation anomaly of the future warm climate.

关键词： spatial patterns precipitation anomalies 30-yr warm periods past 2000 years China

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spatial patterns of residents’ daily activity space and its influencing factors based on the CatBoost model: A case study of Nanjing, China

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Frontiers of Architectural Research 2022年第6期11卷 1193-1204页

作者： Jiemin Zheng Mingxing Hu Chenghui Wang Shuting Wang Bing Han Hui Wang School of Architecture Southeast UniversityNanjing210096China College of Landscape Architecture Nanjing Forestry UniversityNanjing210037China

The complexity and fragmentation of people’s activity space are challenging to ***,the relevant studies are mostly concerned on the relationship between the social attributes and the activity space of residents in a single or several communities,or the spatiotemporal laws of activity space on a macro *** research on the spatial characteristics of residents’activity space still needs to be *** present study analyses the spatial patterns of residents’activity space based on mobile phone signaling data to fill the gap of previous studies that assessed residents’activity space across small geographic ***,according to the spatial scope and direction of an activity space and residents’activity coverage rate,spatial patterns can be divided into three types:compact,extended,and directional extension *** CatBoost method is then used to statistically analyze the influencing variables of spatial patterns,and the order of importance of the following influencing factors is determined:the built environment is more influential than social and economic *** study aims to strengthen the understanding of residents’activity space at the spatial level and provide a basis for the optimization of communities with different spatial patterns.

关键词： spatial patterns Activity space CatBoost Influencing factors Mobile phone signaling data

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Multi-scale spatial patterns and Influencing Factors of Rural Poverty:A Case Study in the Liupan Mountain Region, Gansu Province, China

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Chinese Geographical Science 2018年第2期28卷 296-312页

作者： MA Zhenbang CHEN Xingpeng CHEN Huan Key Laboratory of Western China's Environmental Systems (Ministry of Education) College of Earth and Environmental SciencesLanzhou University Research Institute for Circular Economy in Western China College of Earth and Environmental Sciences Lanzhou University Belle W. Baruch Institute of coastal Ecology and Forest Science Clemson University

The important role of spatial scale in exploring the geography of poverty as well as its policy implications has been noticed but with limited knowledge. To improve such limited understanding, we mainly investigated the spatial patterns and influencing factors of rural poverty(indicated by poor population and poverty incidence) at three different administrative levels in the Liupan Mountain Region, one of the fourteen poorest regions in China. Our results show that from a global perspective, poor areas are clustered significantly at the county-, township-, and village-level, and more greatly at a lower level. Locally, there is spatial mismatch among poverty hotspots detected not only by the same indicator at different levels but also by different indicators at the same level. A scale effect can be found in the influencing factors of rural poverty. That is, the number of significant factors increases, but the degree of their association with poverty incidence decreases at a lower level. Such scale effect indicates that poverty incidence at lower levels may be affected by more complex factors, including not only the new local ones but also the already appeared non-local ones at higher levels. However, the natural conditions tend to play a scale-independent role to poverty incidence. In response to such scale-dependent patterns and factors, anti-poverty policies can be 1) a multilevel monitoring system to reduce incomplete or even misleading single-level information and understanding; 2) the village-based targeting strategy to increase the targeting efficiency and alleviate the mentioned spatial mismatch; 3) more flexible strategies responding to the local impoverishing factors, and 4) different task emphasises for multilevel policymakers to achieve the common goal of poverty reduction.

关键词： poverty spatial scale spatial patterns anti-poverty policy China

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Urbanization of county in China:spatial patterns and influencing factors

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Journal of Geographical Sciences 2022年第7期32卷 1241-1260页

作者： ZHANG Hua CHEN Mingxing LIANG Chen Beijing Key Laboratory of Environmental Remote Sensing and Digital Cities Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

This paper uses the fifth and sixth census data and 2018 demographic statistics to analyze the spatiotemporal evolution of the urbanization of county in China and the factors that influence the *** paper reveals that the urbanization level of counties is a weak area in China’s overall *** the period from 2000 to 2010,the spatial patterns of the urbanization level of counties remained *** with high-level urbanization were concentrated in the coastal areas of the eastern region,while counties that experienced rapid urbanization were mainly located in the central and western *** analyses indicate that harsh natural endowments that constrain economic development are the most important factors that hinder the urbanization of county;these factors include marginalized locations far away from center cities,high altitudes,and a population with a low education *** paper also compares two theoretical modes of new-type urbanization,nearby urbanization and remote urbanization,and argues that the new-type urbanization of county is the main form of nearby urbanization and provides an example of urbanization for developing countries worldwide.

关键词： new-type urbanization urbanization of county nearby urbanization spatial patterns influencing factors

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