检索结果-内蒙古大学图书馆

Effects of Forest Swamp Succession and Soil Depth on distribution pattern of Soil Nematode Communities

FORESTS 2025年第1期16卷

作者： Xuan, Liqiang Che, Lina Wan, Luhe Harbin Normal Univ Coll Geog Sci Harbin 150025 Peoples R China Heilongjiang Wuyiling Wetland Ecosyst Natl Observa Yichun 153000 Peoples R China

The forest swamp ecosystem, as a special wetland ecosystem, is a key link in the material cycle and an important carbon sink in the carbon cycle. The global carbon cycle is of great significance, but the impact of forest swamp succession and soil depth on soil active organic matter and nematode community structure and diversity is unclear. This study used the "space instead of time" method to investigate the succession process of forest swamps from grasslands (WC) and shrubs (WG) to forests (WS) in national nature reserves. The results showed that during the forest succession process, the dominant nematode communities in the WC and WG stages were dominated by the genera Apis and Labroidei, while the dominant genera increased in the WS stage. The total abundance of nematodes increased, and the number of groups was ordered WG > WC > WS. The diversity in soil nematode communities according to Shannon-Wiener (H '), Pielou (J), and Trophic diversity (TD) was WS > WG > WC, which is related to vegetation, soil physical and chemical properties, and microbial community structure. The maturity index (MI) was WG > WS > WC. The soil food web was dominated by bacterial channels and had characteristics in forest metabolic activity and regulation ability. At different soil depths, there were significant differences in the community, with species such as the spiny cushioned blade genus being key. The number and group size of nematodes varied from 0-10 cm > 10-20 cm > 20-30 cm. The relative abundance of feeding nematodes changed with depth, while diversity indices such as H ', J, and TD decreased with depth. Ecological function indices such as MI and PPI showed depth variation patterns, while basic indices (BI) and channel indices (CI) showed significant differences. In terms of soil variables, during the forest succession stage, soil organic carbon (SOC), soluble organic nitrogen (DON), easily oxidizable organic carbon (ROC), microbial biomass carbon (MBC), and microbial biomass ni

关键词： distribution pattern forest swamp succession organic carbon and nitrogen components nematode community structure and diversity soil depth

来源：评论

学校读者我要写书评

暂无评论

Rural depopulation has reshaped the plant diversity distribution pattern in China

引用

RESOURCES CONSERVATION AND RECYCLING 2025年 215卷

作者： Luo, Qing Zhao, Cuiwei Luo, Guangjie Li, Chaojun Ran, Chen Zhang, Sirui Xiong, Lian Liao, Jingjing Du, Chaochao Li, Zilin Xue, Yingying Long, Mingkang Li, Minghui Shen, Xiaoqian Zhang, Xiaoyun Yang, Shu Bai, Xiaoyong Chinese Acad Sci Inst Geochem State Key Lab Environm Geochem 99 Lincheng West Rd Guiyang 550081 Guizhou Peoples R China Guizhou Normal Univ Sch Geog & Environm Sci Guiyang 550001 Peoples R China Guizhou Univ Coll Resources & Environm Engn Guiyang 550025 Peoples R China Chongqing Univ Coll Environm & Ecol Chongqing 400044 Peoples R China Guizhou Educ Univ Guizhou Prov Key Lab Geog State Monitoring Watersh Guiyang 550018 Peoples R China Chinese Acad Sci Inst Earth Environm CAS Ctr Excellence Quaternary Sci & Global Change Xian 710061 Peoples R China

Large-scale rural depopulation has altered the rural environment and reshaped the distribution pattern of species. However, the impact of rural depopulation on biodiversity is unclear. Based on plant species richness data, we used random forest model (RFM) and generalized additive model (GAM) to explore the impact of rural depopulation on plant diversity. The results showed that a 1.82 % decrease in human pressure in rural depopulation areas in China promoted vegetation restoration and increased plant diversity. Plant diversity in rural decreased by 2.25 % on average, while it increased by 3.75 % in rural areas that experienced depopulation. Plant diversity was 1.48 times greater in the severely depopulated rural areas than in the slightly depopulated areas. When the total population reaches around 1.33 billion, the plant diversity affected by population changes will reach a threshold. This research helps understand the potential positive impacts of rural depopulation on environmental restoration and plant diversity increase.

关键词： Rural depopulation Human pressure Plant diversity distribution pattern China

来源：评论

学校读者我要写书评

暂无评论

The distribution pattern and Spatial Morphological Characteristics of Military Settlements Along the Ming Great Wall in the Hexi Corridor Region

引用

BUILDINGS 2025年第7期15卷

作者： Jiang, Baolong Huang, Yuhao Chen, Yile Lu, Jie Yang, Tianfu Xian Univ Architecture & Technol Coll Art Yanta Rd Xian 710055 Peoples R China City Univ Macau Fac Innovat & Design Ave Padre Tomas Pereira Taipa 999078 Macau Peoples R China Macau Univ Sci & Technol Fac Humanities & Arts Ave Wai Long Taipa 999078 Macau Peoples R China Macau Univ Sci & Technol Heritage Conservat Lab Ave Wai Long Tapai 999078 Macau Peoples R China

Military settlements along the Ming Great Wall are typical representatives of the construction of the ancient Chinese military defense system. The location of the military fortification is complex, and the settlements are scattered and affected by multiple factors. The academic community lacks systematic research on the military settlements along the Ming Great Wall. Existing studies focus on local protection, especially the regional connectivity and overall defense mechanism of the military settlements in the Hexi Corridor. This study incorporates the distribution, morphology, and function of the military settlements in the Hexi Corridor into a unified analytical framework to explore the coordinated defense mechanism under the spatial attributes of the military settlements. Additionally, this study looks at the distribution pattern of 173 local military settlements using tools such as the kernel density index, the Moran index, and the buffer zone. It also conducts statistical analyses of 85 existing settlements to determine their scale and morphological index and uses 18 typical settlements as examples to investigate their spatial morphology using space syntax. This study's findings indicate that (1) military settlements are spread out in a straight line, which is affected by many things such as terrain, water systems, oasis, and the Great Wall;(2) military facilities and environmental factors are strongly connected and linked in space;(3) military settlements have obvious cluster characteristics, and most are relatively regular quadrilaterals;and (4) the organizational logic of the internal space form is consistent. The main blocks are highly accessible, and the overall space is recognizable and has certain defensive characteristics. This study systematically constructed an analytical framework for multi-scale collaborative defense mechanisms, revealing a collaborative defense model of "linear distribution-hierarchical defense-functional coordination". This demons

关键词： Hexi Corridor The Great Wall of Ming Dynasty military settlement distribution pattern spatial form

来源：评论

学校读者我要写书评

暂无评论

The Distance From the Sea Determined the distribution pattern of Saline-Alkali Soil Quality Through Indirect Effect

引用

LAND DEGRADATION & DEVELOPMENT 2025年

作者： Liu, Hanwen Chen, Meng Yang, Qingmiao Zhang, Yi Zhang, Haibo Liu, Xiaoling Ma, Qian Cui, Guangxu Wang, Guangmei Chinese Acad Sci Yantai Inst Coastal Zone Res CAS Key Lab Coastal Environm Proc & Ecol Remediat Yantai Peoples R China Shandong Key Lab Coastal Environm Proc Yantai Peoples R China Yellow River Delta Agroecosystem Observat & Res St Dongying Peoples R China Ludong Univ Sch Resources & Environm Engn Yantai Peoples R China Ludong Univ Sch Life Sci Yantai Peoples R China

Soil quality is a crucial attribute for maintaining biological productivity, human health, and ecosystem service function. However, the distribution of saline-alkali soil quality and its influencing factors in the Yellow River Delta region remain poorly understood, posing challenges to sustainable agricultural development. The study evaluated soil quality across various land-use types and depths in the southern Yellow River Delta region. A total of 134 soil samples were collected from two soil layers at 67 soil sample points, distributed across three land use types. Spatial distribution maps revealed that inland areas exhibited improved soil texture and nutrient levels compared to coastal regions. All nutrients, except soil total potassium, were higher in the 0-20 cm soil layer than in the 20-40 cm soil layer. The spatial distribution pattern of Soil Quality Index (SQI) demonstrated a pattern of higher values at the central part of the study area, gradually declining toward the edges. Furthermore, SQI in cultivated land was found to be 1.8%-8% higher than in forest land and 52.7%-84% higher than in wasteland. The Structural Equation Modeling results indicated that distance from the sea indirectly influenced soil quality through different mechanisms between the two soil layers. In the model for the 0-20 cm soil layer, SQI was indirectly affected by chemical properties, nutrients, and base ions, explaining 85% of the variation in SQI. In the model for the 20-40 cm soil layer, SQI was primarily influenced by chemical properties, accounting for 83% of the variation. These findings offer valuable insights for land use and crop selection aligned with soil properties, supporting sustainable agricultural practices in the region.

关键词： distribution pattern saline-alkali soil soil quality index Yellow River Delta

来源：评论

学校读者我要写书评

暂无评论

Revealing the distribution pattern of soybean purine content and its influencing factors based on an ultra-micro detection system

引用

LWT-FOOD SCIENCE AND TECHNOLOGY 2025年 223卷

作者： Li, Jiajia Li, Na Hu, Xiaoyu Wang, Guoji Bai, Pengyu Hu, Yanjiao Yang, Yifan Shao, Deshuai Gao, Huihui Miao, Long Wang, Xiaobo Anhui Agr Univ Sch Agron Hefei 230036 Peoples R China

In this study, an effective method for detecting purine in soybean seeds and products by ultra-micro spectrophotometry (UMS) was established. Addition of 35 % HClO4 to 0.1 g of soybean flour and incubation in a water bath at 100 C-degrees for 30 min and adjustment of the pH to 4 was optimal for purine hydrolysis and extraction of the total purine content of soybean seeds. No significant difference (P > 0.05) in total purine detection was observed between UMS and UPLC, and the relative standard deviation was less than 3 %, ensuring optimal precision and accuracy. Seed from 2083 soybean accessions grown in two years were analysed using UMS. Total purine content ranged from 65.49 to 379.84 mg/100 g, with 5.8-fold variation, and 11 elite accessions with under 100 mg/100 g of total purine were identified. The agronomic traits, environmental factors, and geographical significantly affected soybean total purine content. Furthermore, total purine content correlated positively with seed protein (r = 0.342***) and negatively with oil (r = -0.330***). The geographical distribution revealed that accessions from Southern and Northern China contain lower amounts of total purine content. This study provides a technical and material foundation for breeding low purine soybean.

关键词： Soybean Purine Ultra-micro spectrophotometry method distribution pattern Excellent germplasm

来源：评论

学校读者我要写书评

暂无评论

distribution pattern and geochemical analysis of rare earth elements in deep-ocean sediments

引用

Journal of Oceanology and Limnology 2021年第1期39卷 79-88页

作者： Jingxi LI Chengjun SUN Fenghua JIANG Fenglei GAO Yifan ZHENG Key Laboratory of Marine Eco-environmental Science and Technology Marine Bioresource and Environment Research CenterFirst Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory of Marine Drugs and Bioproducts Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China

The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explored and the resources and geochemical characteristics of REEs in deep-ocean sediments from diff erent oceans were *** total REE abundances(ΣREE)in the diff erent oceans ranged as follows:Eastern Pacifi c,56.88–500.02μg/g;Western Pacifi c,290.68–439.94μg/g;Northern Atlantic,55.33–154.90μg/g;Southern Atlantic,40.83–69.30μg/g;and Southwestern Indian Ocean,20.24–64.76μg/*** corresponding LREE(La-Eu)/HREE(Gd-Lu)average values were 5.18,5.86,9.01,5.21,and 4.59,which indicated that the light REEs were all evidently enriched.δEu andδCe showed slight Eu-negative anomalies and signifi cant Ce-positive anomalies in all *** the contents of REEs in the sediments varied among the diff erent oceans,the distribution patterns of REEs were similar,and the correlation coeffi cient was greater than *** the Eastern Pacifi c sediments,ΣREE showed a signifi cantly positive correlation with Co,Cu,Zn,Mn,Mo and a weak correlation with *** the Western Pacifi c and Southern Atlantic sediments,ΣREE presented no obvious correlation and a weakly negative correlation with Co,Cu,Zn,Mn,Mo and Fe,respectively.ΣREE in the Southwestern Indian Ocean sediments positively correlated with Cu,Zn,Mn,Mo,Fe,and had a weakly negative correlation with Co.

关键词： rare earth elements(REE)geochemistry distribution pattern REE fractionation marine sediment

来源：评论

学校读者我要写书评

暂无评论

distribution pattern and ecological risk assessment of heavy metals in Henan section of the Yellow River

引用

WATER SUPPLY 2022年第7期22卷 6195-6204页

作者： Zhang, Kai Li, Kuangjia Xin, Rui Xu, Zhiheng Zhang, Zhongshuai He, Siyu Zhao, Zhenzhen Tong, Minghui Cui, Yongxin Xinyang Normal Univ Sch Geog Sci Xinyang 464000 Peoples R China Xinyang Normal Univ Henan Key Lab Synergist Prevent Water & Soil Envi Xinyang 464000 Peoples R China Minist Water Resources Peoples Republ China Dev Res Ctr Beijing 100032 Peoples R China Tianjin Univ Sch Marine Sci & Technol Tianjin 300072 Peoples R China

Heavy metals (HMs) pollution in the environment is a persistent issue and draws public attention constantly. However, there is rare research assessing the pollution level of HMs in the Henan section of Yellow River although the river is one of the most important water supply rivers in Henan province. In this research, the fraction contents of six HMs in the Henan section of Yellow River were investigated by adopting the European Community Bureau of Reference (BCR) sequential extraction procedure. Moreover, the potential health risk caused by HMs was evaluated by adopting both the geo-accumulation index (I-geo) and ecological hazard index method. The results indicate the presence of light HM pollution level in Yellow River generally. However, the health risk caused by Cd cannot be neglected. Fraction analysis indicates that the content of B-2 fraction is high, which needs more attention. Overall, branch afflux might be one of the important pathways that anthropogenic activities influence the Yellow River. The results of both the I-geo and ecological hazard index indicate that the potential health risk caused by HMs is low in the Yellow River, and the Yellow River protection policies implemented by Henan province may be the underlying reason.

关键词： distribution pattern heavy metal risk assessment speciation analysis Yellow river

来源：评论

学校读者我要写书评

暂无评论

distribution pattern of polycyclic aromatic compounds in coal gangue from coal city-East China

引用

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 2023年第20期30卷 58674-58683页

作者： Xu, Dandan Zhang, Xiaona Hong, Xiuping Qian, YaHui Liang, Handong State Key Lab Coal Resources & Safe Min Beijing 100083 Peoples R China China Univ Min & Technol Coll Geosci & Surveying Engn Beijing 100083 Peoples R China Huaibei Normal Univ Coll Life Sci Huaibei 235000 Peoples R China

Coal gangue is a by-product of coal, the output of which is as high as 30% of raw coal, whereas only 30% of it is recycled. The leftover remains in the environment from gangue backfilling areas and overlap with residential, agricultural, and industrial areas. Coal gangue accumulated in the environment is easily weathered and oxidized and becomes a source of various pollutants. In this paper, 30 coal gangue samples (fresh and weathered coal gangues) were collected from three mine areas in Huaibei, Anhui province, China. Gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to qualitatively and quantitatively analyze thirty polycyclic aromatic compounds (PACs), including 16 polycyclic aromatic hydrocarbons (16PAHs), preferentially controlled by the United States Environmental Protection Agency (US EPA), and the corresponding alkylated polycyclic aromatic hydrocarbons (a-PAHs). The results showed that PACs existed objectively in coal gangue, and the content of a-PAHs was higher than that of 16PAHs (average values for 16PAHs ranged from 77.8 to 581 ng/g;average values for a-PAHs ranged from 97.4 to 3179 ng/g). Moreover, coal types not only affected the content and type of PACs but also affected the distribution pattern of a-PAHs at different substitution sites. With the increase of gangue weathering degree, the composition of a-PAHs kept changing;the low ring a-PAHs were more easily diffused to the environment, and the high ring a-PAHs remained enriched in the weathered coal gangue. The correlation analysis showed that the correlation between fluoranthene (FLU) and alkylated fluoranthene (a-FLU) was as high as 94%, and the calculated ratios were not more than 1.5. The basic conclusion is that not only 16PAHs and a-PAHs objectively existed in the coal gangue, but also the characteristic compound belonging to the pollution source of coal gangue oxidation have been discovered. The results of the study provide a new perspective for the analysis of exist

关键词： Mine area Fresh coal gangue Weathered coal gangue Polycyclic aromatic compounds (PACs) Alkylated polycyclic aromatic hydrocarbons (a-PAHs) distribution pattern

来源：评论

学校读者我要写书评

暂无评论

distribution pattern and Influencing Factors of Soil Selenium in Northern Hebei Province, China

引用

GEOCHEMISTRY INTERNATIONAL 2023年第7期61卷 750-767页

作者： Zhang, Liting Wang, Zhijun Liu, Yuanchen Wang, Xi Xie, Xiaoyang Zhang, Li Chinese Acad Geol Sci Inst Geophys & Geochem Explorat Key Lab Geochem Cycling Carbon & Mercury Earths Cr Langfang 065000 Peoples R China China Univ Geosci Beijing 100083 Peoples R China Hebei Inst Geol Survey Shijiazhuang 050081 Peoples R China

According to the 1 : 50000 scale soil geochemical survey from a several of key selenium (Se) rich areas in the traditional considered Se deficiency area of northern Hebei Province, China, the content, distribution, and the influencing factors of surface soil Se distribution in this area were determined. The Se concentration of surface soil in this area was calculated to be 0.06-3.74 mg/kg, with a mean of 0.4 mg/kg. The Se-rich (Se >= 0.4 mg/kg) domains are about 116.8 km(2), accounting for 29.05% of the total areas. The concentration of Se in surface soils tends to decrease in the north and increase in the south. The soil Se content and distribution were affected by various factors. Soil parent rocks were the initial sources of Se, but their effects on soil Se content and distribution were limited. The Se content in surface soil had a strong positive correlation with organic carbon (C-org), S, and Fe2O3, but a weak correlation with topographic parameters. The Se content of various soil types, including meadow chestnut soil, calcareous meadow soil, gley meadow soil, and saline meadow soil, and land use types, including natural grassland and other grassland, were relatively high, mainly because of the indirect effect from abundant organic matter and high water content in soil. Additionally, the analysis result of GeoDetector showed that S and C-org were the main driving factors of soil Se distribution and the influence of other factors was limited.

关键词： soil selenium distribution pattern influence factors GeoDetector Hebei province

来源：评论

学校读者我要写书评

暂无评论

distribution pattern of shrimps and fish among Avicennia and Rhizophora microhabitats in the Pagbilao mangroves, Philippines

引用

ESTUARINE COASTAL AND SHELF SCIENCE 1999年第2期48卷 223-234页

作者： Rönnbäck, P Troell, M Kautsky, N Primavera, JH Univ Stockholm Dept Syst Ecol S-10691 Stockholm Sweden Royal Swedish Acad Sci Beijer Int Inst Ecol Econ S-10405 Stockholm Sweden SE Asian Fisheries Dev Ctr Dept Aquaculture Iloilo 5021 Philippines

For sustainable management of mangrove ecosystems, there is a pressing need to increase our knowledge of fish and invertebrates associated with this system. This study sampled microhabitats (89-258 m(2)) inside the mangrove forest at Pagbilao, the Philippines, on two consecutive spring tides using stake nets. distribution patterns of shrimps and fish were compared among four microhabitats that differed in dominant mangrove species (Avicennia marina, A. officinalis or Rhizophora apiculata), structural complexity of the root system, and proximity to open water habitat. A 5 to 6-year-old replanted Rhizophora microhabitat was also sampled to study faunal recolonization following replantation. The mean (+/- SE) density of the shrimp community was 1.5 +/- 0.2 shrimps m(-2), dominated by Palaemonidae, followed by Acetes sp., Penaeus merguiensis and Metapenaeus ensis. The highest shrimp density was observed in the replanted Rhizophora habitat, which also had the highest structural complexity. The mean (+/- SE) density and biomass of the fish community was 5.1 +/- 2.0 fish m(-2) and 10.4 +/- 3.3 g m(-2), respectively, dominated by Ambassis kopsi, A. urotaenia and Atherinomorus balabacensis. The fish community preferred the pneumatophore (Avicennia) microhabitats to the prop root (Rhizophora) habitats. Highest fish abundance and biomass were observed in the most inland habitat, which also lacked larger (total length >100 mm) carnivorous fish. The results demonstrate the extensive use of intertidal mangrove forests by vagile fauna, as well as the successful recolonization by shrimps and fish of replanted Rhizophora habitat. The role of mangroves as predation refuges, based on the distribution pattern of shrimps and fish, is discussed. Sampling strategies in mangrove intertidal habitat are also outlined. (C) 1999 Academic Press.

关键词： mangroves distribution pattern fish penaeid shrimp root complexity predation refuge sampling strategies Philippines coast

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：