7 results
Search Results
2. Analysis of Dynamic Changes in Vegetation Net Primary Productivity and Its Driving Factors in the Two Regions North and South of the Hu Huanyong Line in China.
- Author
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Liu, Weimin, Yan, Dengming, Yu, Zhilei, Wu, Zening, Wang, Huiliang, Yang, Jie, Liu, Simin, and Wang, Tianye
- Subjects
VEGETATION dynamics ,GLOBAL environmental change ,VEGETATION greenness ,BROADLEAF forests ,TREND analysis ,DRIVERS' licenses - Abstract
Human activities and global environmental changes have transformed terrestrial ecosystems, notably increasing vegetation greenness in China. However, this greening is less effective across the Hu Huanyong Line (Hu Line). This study analyzes dynamic changes and driving factors of nine vegetation net primary productivities (NPPs) in regions divided by the Hu Line using remote sensing data, trend analysis, and the Geodetector model. Findings reveal that from 2001 to 2022, 38.22% of regional vegetation NPP in China increased, especially in the Loess Plateau, Sichuan Basin, and Northeast Plains, while 2.39% decreased, primarily in the southeastern region and southern Tibet. Grasslands contributed 39.71% to NPP north of the Hu Line, and cultivated vegetation contributed 50.58% south. The driving explanatory power of factors on vegetation NPP on the north side of the Hu Line is generally greater than that on the south side. Natural factors primarily drive NPP changes, with human activities having less impact. Combined factors, particularly climate and elevation, significantly enhance the driving explanatory power (q, 0–1). The joint effects of elevation and precipitation on grassland NPP dynamics (q = 0.602) are notable. GDP's influence on broadleaf forests north of the Hu Line (q = 0.404) is significant. Grasslands respond strongly to land use changes and population density, with a combined effect of q = 0.535. Shrubs, alpine vegetation, and meadows show minimal response to individual factors (q < 0.2). These findings offer insights for devising ecological protection measures tailored to local conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Species Diversity and Geographical Distribution Patterns of Balsaminaceae in China.
- Author
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Chen, Yi, Chen, Jun, Yong, Qin-Qin, Yuan, Tao-Hua, Wang, Qiu, Li, Mei-Jun, Long, Sheng-Wei, and Bai, Xin-Xiang
- Subjects
BIOGEOGRAPHY ,SPECIES diversity ,COLD (Temperature) - Abstract
Balsaminaceae are world-famous ornamental flowers because of their high species diversity, rich variation, peculiar flower patterns, and long ornamental cycles. To study the species diversity, distribution patterns, and distribution hotspots of Balsaminaceae in China, we updated the list of Balsaminaceae by systematically searching the related literature. The distribution pattern and hotspots of Impatiens spp. were analyzed using the ArcGIS 10.8.2 software. Combining 19 meteorological factors and one elevation factor, the Maxent model was applied to analyze the dominant environmental factors that govern the distribution of Impatiens spp. As of February 2023, Balsaminaceae in China included 360 taxa in two genera, including one taxon in the genus of Hydrocera, 359 taxa in the genus Impatiens, 271 national endemic species, and 157 provincial endemic species. Impatiens spp. showed a diffusion pattern from the tropical and subtropical regions to the high-latitude and high-elevation regions concentrated in Southwest China, especially in the Hengduan Mountains in the broad sense, Southern Tibet, the Yunnan–Guizhou–Guangxi karst region, the Qinling–Daba Mountains, and the southeastern hills. The highest species richness was found in the 1200~1500 m elevation range, with 164 species of Impatiens spp. This high species richness was maintained at between 900 and 2700 m, the elevation range where Impatiens spp. are concentrated. When 100% of the species were screened out, 110 hotspots were found, including Southeast Yunnan, Northwest Yunnan, Southern Tibet, and Western Sichuan, where most of the hotspots were concentrated and overlapped with global biodiversity centers, but other hotspots were more scattered. Annual precipitation, the minimal temperature of the coldest month, the altitude and temperature annual range, and four environmental variables with a cumulative contribution of 93.7% were the dominant environmental factors affecting the distribution of Impatiens spp. in China. This study lays the foundation for subsequent studies of Balsaminaceae diversity and is conducive to the development and use of Impatiens spp. resources. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Dry Deposition of Hydrophilic Black Carbon Aerosols in China.
- Author
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Zhang, Xiaolin, Mohammed, Awad Hussien Ahmed, Zhou, Yu, and Mao, Mao
- Subjects
CARBON-black ,WIND speed ,AEROSOLS ,SPRING ,ATMOSPHERIC deposition ,CARBONACEOUS aerosols - Abstract
Atmospheric dry deposition of black carbon (BC) is a significant but poorly understood and inadequately described process in aerosol-climate models. The 40-year detailed dry deposition velocities of hydrophilic BC over China from 1981 to 2020 were systematically studied based on the MERRA-2 reanalysis data, which hopefully will be beneficial for its applications in atmospheric systems for climate and air quality. The average dry deposition flux of hydrophilic BC over China was 0.00059 ± 0.00014 μg m
−2 s−1 , while its dry deposition velocity was estimated to be 0.00051 ± 0.00004 m s−1 . The monthly mean dry deposition fluxes of hydrophilic BC varied nearly 1.5 fold, ranging from the lowest 0.00046 ± 0.00011 μg m−2 s−1 in August to the highest 0.00068 ± 0.00019 μg m−2 s−1 in January. The spring season had the highest mean dry deposition flux of hydrophilic BC, followed by summer and winter, whereas autumn showed relatively weaker dry deposition flux. The mean dry deposition velocities of hydrophilic BC over the Beijing-Tianjin-Hebei region, Yangtze River Delta, Pearl River Delta and Tibet Plateau were estimated to be 0.00042 ± 0.00004, 0.00042 ± 0.00004, 0.00051 ± 0.00006 and 0.00078 ± 0.00005 m s−1 , respectively. The monthly and seasonal patterns of dry deposition velocities of hydrophilic BC differed from each other in different regions, and high air temperature or surface wind speed seemed to fortify dry deposition velocities of hydrophilic BC. Our study pointed to high dry deposition flux of hydrophilic BC in the northern China Plain and Sichuan Basin but large dry deposition velocities in the Tibet Plateau region. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
5. The Namuyi: Linguistic and Cultural Features.
- Author
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Lakhi, Libu, Hefright, Brook, and Stuart, Kevin
- Subjects
- *
ETHNIC groups , *ETHNOLOGY , *RITES & ceremonies , *LANGUAGE & languages - Abstract
The Namuyi live in southern Sichuan Province, the People's Republic of China, and form part of the officially recognized Tibetan ethnic group. This paper first introduces the Namuyi in terms of location, population, and ethnonym. It then provides brief background on the Namuyi language, including a comparison of the dz∂11 qu11 and Luóguōdĭ varieties and a 207-item Swadesh list of English words with their dz∂11 qu11 Namuyi equivalents. Finally, it discusses Namuyi religion and provides a transcription of the ka11 ju11 bu44 ritual. [ABSTRACT FROM AUTHOR]
- Published
- 2007
6. Taxonomic studies on the genus Ectatosticta (Araneae, Hypochilidae) from China, with descriptions of two new species.
- Author
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Yejie Lin and Shuqiang Li
- Subjects
SPIDERS ,JUMPING spiders - Abstract
Species of the spider family Hypochilidae Marx, 1888 from China are studied, including two known species and two new species of the genus Ectatosticta Simon, 1892. The new species are E. wukong sp. nov. (♂♀) from Sichuan and E. xuanzang sp. nov. (♀) from Tibet. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
7. Post-Treatment Follow-Up Study of Abdominal Cystic Echinococcosis in Tibetan Communities of Northwest Sichuan Province, China.
- Author
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Tiaoying Li, Akira Ito, Renqing Pengcuo, Yasuhito Sako, Xingwang Chen, Dongchuan Qiu, Ning Xiao, and Craig, Philip S.
- Subjects
ECHINOCOCCOSIS ,ECHINOCOCCUS granulosus ,ECHINOCOCCUS - Abstract
Background: Human cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus, with the liver as the most frequently affected organ, is known to be highly endemic in Tibetan communities of northwest Sichuan Province. Antiparasitic treatment with albendazole remains the primary choice for the great majority of patients in this resource-poor remote area, though surgery is the most common approach for CE therapy that has the potential to remove cysts and lead to complete cure. The current prospective study aimed to assess the effectiveness of community based use of cyclic albendazole treatment in Tibetan CE cases, and concurrently monitor the changes of serum specific antibody levels during treatment. Methodology/Principal Findings: Ultrasonography was applied for diagnosis and follow-up of CE cases after cyclic albendazole treatment in Tibetan communities of Sichuan Province during 2006 to 2008, and serum specific IgG antibody levels against Echinococcus granulosus recombinant antigen B in ELISA was concurrently monitored in these cases. A total of 196 CE cases were identified by ultrasound, of which 37 (18.9%) showed evidence of spontaneous healing/involution of hepatic cyst(s) with CE4 or CE5 presentations. Of 49 enrolled CE cases for treatment follow-up, 32.7% (16) were considered to be cured based on B-ultrasound after 6 months to 30 months regular albendazole treatment, 49.0% (24) were improved, 14.3% (7) remained unchanged, and 4.1% (2) became aggravated. In general, patients with CE2 type cysts (daughter cysts present) needed a longer treatment course for cure (26.4 months), compared to cases with CE1 (univesicular cysts) (20.4 months) or CE3 type (detached cyst membrane or partial degeneration of daughter cysts) (9 months). In addition, the curative duration was longer in patients with large (.10 cm) cysts (22.3 months), compared to cases with medium (5- 10 cm) cysts (17.3 months) or patients with small (,5 cm) cysts (6 months). At diagnosis, seven (53.8%) of 13 cases with CE1 type cysts without any previous intervention showed negative specific IgG antibody response to E. granulosus recombinant antigen B (rAgB). However, following 3 months to 18 months albendazole therapy, six of these 7 initially seronegative CE1 cases sero-converted to be specific IgG antibody positive, and concurrently ultrasound scan showed that cysts changed to CE3a from CE1 type in all the six CE cases. Two major profiles of serum specific IgG antibody dynamics during albendazole treatment were apparent in CE cases: (i) presenting as initial elevation followed by subsequent decline, or (ii) a persistent decline. Despite a decline, however, specific antibody levels remained positive in most improved or cured CE cases. Conclusions: This was the first attempt to follow up community-screened cystic echinococcosis patients after albendazole therapy using ultrasonography and serology in an endemic Tibetan region. Cyclic albendazole treatment proved to be effective in the great majority of CE cases in this resource-poor area, but periodic abdominal ultrasound examination was necessary to guide appropriate treatment. Oral albendazole for over 18 months was more likely to result in CE cure. Poor drug compliance resulted in less good outcomes. Serology with recombinant antigen B could provide additional limited information about the effectiveness of albendazole in CE cases. Post-treatment positive specific IgG antibody seroconversion, in initially seronegative, CE1 patients was considered a good indication for positive therapeutic efficacy of albendazole. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
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