不同管理主体对泸沽湖流域生态系统影响的比较分析

Sichuan Province is an important ecological barrier in the upper reaches of the Yangtze River. Therefore, it is critical to investigate the temporal and spatial changes, as well as the driving factors, of ecosystem service values (ESVs) in Sichuan Province. This paper used land use data from 2000, 2005, 2010, 2015, and 2020 to quantify the spatiotemporal changes in the ESVs in Sichuan Province. Correlation coefficients and bivariate spatial autocorrelation methods were used to analyze the trade-offs and synergies of ESVs in the city (autonomous prefecture) and grid scales. At the same time, we used a Geographical Detector model (GDM) to explore the synergies between nine factors and ESVs. The results revealed that: (1) In Sichuan Province, the ESVs increased by 0.77% from 729.26 × 109 CNY in 2000 to 741.69 × 109 CNY in 2020 (unit: CNY = Chinese Yuan). Furthermore, ecosystem services had a dynamic degree of 0.13%. Among them, the ESVs of forestland were the highest, accounting for about 60.59% of the total value. Among the individual ecosystem services, only food production, environmental purification, and soil conservation decreased in value, while the values of other ecosystem services increased. (2) The ESVs increased with elevation, showing a spatial distribution pattern of first rising and then decreasing. The high-value areas of ESVs per unit area were primarily distributed in the forestland of the transition area between the basin and plateau; The low-value areas were distributed in the northwest, or the urban areas with frequent human activities in the Sichuan Basin. (3) The tradeoffs and synergies between multi-scale ecosystems showed that ecosystem services were synergies-dominated. As the scale of research increased, the tradeoffs between ecosystems gradually transformed into synergies. (4) The main driving factors for the spatial differentiation of ESVs in Sichuan Province were average annual precipitation, average annual temperature, and gross domestic product (GDP); the interaction between normalized difference vegetation index (NDVI) and GDP had the strongest driving effect on ESVs, generally up to 30%. As a result, the distribution of ESVs in Sichuan Province was influenced by both the natural environment and the social economy. The present study not only identified the temporal and spatial variation characteristics and driving factors of ESVs in Sichuan Province, but also provided a reference for the establishment of land use planning and ecological environmental protection mechanisms in this region.

Taking Sichuan, Guizhou and Yunnan provinces in Southwest China as the research object, this paper establishes a comprehensive measurement system for the degree of coordinated development of industrialization, agricultural modernization, urbanization, informatization and greenization, and uses the entropy evaluation method to assign the indicators and determine the types of coordination stages of each province. The results show that: (1) The comprehensive development index of the five modernization of the three provinces are rising continuously, the development of urbanization is the best, and the degree of informationization and greenization is significantly backward. (2) From 2010 to 2017, the overall coordination degree of the five modernization in the three provinces displays an upward trend, but there was a drop in Yunnan Province. In 2010, the coordination of the three provinces was in a state of imbalance, and the imbalance in Guizhou Province was the most serious. In 2017, Sichuan Province had reached a stage of high-quality coordination, while Yunnan and Guizhou provinces were in a good stage of coordination.

研究历史品种产量潜力变化规律有助于提高小麦育种水平。2007—2009连续2年度将来自四川、云南、甘肃和新疆的代表性59个品种分别种植在四川成都、云南丽江、甘肃武威和新疆昌吉，在肥水供应充足、控制病虫害和倒伏的条件下分析了产量和相关农艺性状的变化趋势。结果表明，四川、云南、甘肃和新疆品种的产量随育成年份显著增加，年遗传增益分别为0.73%、0.34%、0.58%和1.43%。产量遗传增益四川品种表现与产量构成因子关系不密切；云南品种主要表现为减少穗数和增加穗粒数；甘肃品种主要表现为增加穗粒数；新疆品种主要表现为增加主穗粒重和收获指数，并与成熟期提早及株高降低有一定关系。各地区品种中 Rht-B1b 和 Rht-D1b 矮秆基因均来自CIMMYT种质，其产量潜力的提高主要得益于CIMMYT种质的引进和有效利用，在四川和云南，CIMMYT种质的主要贡献是提高品种的条锈病抗性；而在甘肃和新疆，其被利用的主要特性是矮秆、高产、穗粒数多及广泛适应性。

A specific PCR assay for the identification and differentiation of Schistosoma japonicum geographical isolates in mainland China based on analysis of mitochondrial genome sequences

Four new species of Diploderma are described from Sichuan and Yunnan provinces, southwestern China, based on an integrative taxonomic approach, combining morphological and genetic data. The first new species from Danba County, Sichuan Province, is morphologically most similar and phylogenetically closely related to D.flaviceps, but it can be diagnosed from the latter by having a relatively much shorter tail and by a genetic distance of 4.4% in the ND2 gene; the second new species from Muli County, Sichuan Province, is phylogenetically closely related to D.daochengense, D.yongshengense, and D.yulongense, but it can be diagnosed from the latter three species by having a pale yellow gular spot and by genetic distances of 5.6-6.7% in the ND2 gene; the third new species from Jiulong County, Sichuan Province, is morphologically most similar and phylogenetically closely related to D.angustelinea, but it can be diagnosed from the latter by having a relatively much longer tail and by a genetic distance of 2.8% in the ND2 gene; and the last new species from Weixi County, Yunnan Province, is phylogenetically closely related to D.aorun, but it can be diagnosed from the latter by having a pale yellow gular spot and by a genetic distance of 2.9% in the ND2 gene. Our work brings the number of species within the genus Diploderma to 46.

The Normalized Difference Vegetation Index (NDVI) is the most commonly used index for assessing vegetation. However, significant differences among various satellite datasets, complex terrain, and the impact of clouds on optical sensors limit vegetation change assessment based on NDVI. To address these issues, this study utilizes multi-source satellite data (GIMMS3g NDVI, CDR AVHRR NDVI, SPOT NDVI, and MODIS NDVI) to monitor vegetation dynamics at different time scales from 1990 to 2020 in Sichuan Province, China. The results indicate that over time, NDVI values from the four NDVI products in Sichuan Province have shown an upward trend. There are certain differences in the spatial distribution and spatial heterogeneity of the change rate of NDVI values among the four NDVI products at different time scales, and the differences are mainly concentrated in the Sichuan Basin (SB) and the Western Sichuan alpine plateau region (WS). Compared with the other three NDVI products, GIMMS NDVI has the highest value but the smallest increase during the study period. The SPOT NDVI value is the smallest, but the increase is relatively large. However, within the overlapping period of the four NDVI datasets, only the annual average of CDR AVHRR NDVI showed a downward trend (slope2000–2013 = −0.0001·a−1). The annual fluctuation of CDR AVHRR NDVI is the smallest, and compared to other NDVI datasets, its correlation with climate factors shows significantly weaker spatial variability. Moreover, the ability of CDR AVHRR NDVI to distinguish different vegetation land cover types is significantly poor (STD = 0.045). The findings of this study will provide a reference for further research on vegetation changes in Sichuan Province and NDVI reconstruction in cloudy areas.

This article contributes to the literature on the economic impact of ecotourism in regional China with a focus on Yunnan and Sichuan provinces, which attract about 50 per cent of the total number of tourists visiting China annually. Our analysis suggests that tourism significantly contributes to value added, output, income and employment generation in Yunnan and Sichuan provinces, although the level of contribution varies between the two provinces. For example, the impact of an additional tourist dollar would be higher in generating employment and household income in Yunnan province, while the same dollar has a higher impact in generating value added in Sichuan. While in both provinces international tourists generate much higher income per capita than their domestic counterparts, in comparison with Sichuan, Yunnan is considered to be better placed for further development of tourism, particularly ecotourism. The promotion of ecotourism in these provinces will also encourage the Chinese youth to stay in their own provinces rather than to migrate to export-processing provinces—a problem that has already created a concern among the Chinese policymakers.

Cinnamomum mairei H. Lév is a rare and valuable medicinal and timber species in China. It not only has a narrow distribution, but also has few resources, is an endangered species, and is a nationally protected plant. Climate change impacts the growth and development of plants; therefore, it is of great practical significance to predict the current and future distribution of C. mairei H. Lév in suitable areas of China and to protect these endangered plants. In this study, the MaxEnt model was used to predict the suitable growing areas for C. mairei H. Lév according to six environmental factors (the temperature seasonality, max. temperature in the warmest month, min. temperature in the coldest month, precipitation seasonality, precipitation in the coldest quarter and aspect), and three different climate models (SSP126, SSP245, and SSP585) were simulated for three periods (the 2030s, 2050s, and 2070s). In the present study, the suitable ecological environment for C. mairei H. Lév comprised the following: a min. temperature in the coldest month from −0.63 to 4.36 °C, temperature seasonality from 130.67 to 642.58, a max. temperature in the warmest month from 28.86 to 45.97 °C, and precipitation in the coldest quarter from 40.12 to 101.13 mm. Highly suitable habitats for C. mairei H. Lév are located in the Yunnan Province, Guizhou Province, Sichuan Province, and Chongqing City, China (southwestern part of China), and to a lesser extent in the Xizang Province and Shaanxi Province, China. The moderately suitable habitat district overlaps with the highly suitable habitat district, and a small number of suitable habitats are distributed in Guangxi Province, Hunan Province, Hubei Province, and Henan Province. In the future, the highly suitable areas for C. mairei H. Lév will increase slightly, and the gravity points will shift toward northeast China. Our simulations are helpful for understanding the geoecological characteristics of this species and provide a basis for regional projections of this species under current and future climate change scenarios in China. It is proposed to establish nature reserves for C. mairei H. Lév in the Chongqing, Yunnan, Sichuan and Guizhou provinces of China.

Chemical and genetic study of Ligularia anoleuca and L. veitchiana, which belong to section Ligularia, series Speciosae, was carried out. From L. anoleuca samples, collected in Yunnan and Sichuan Provinces of China, a new compound, furanoeremophil‐1(10)‐en‐6α‐ol, was isolated together with known 6β‐{[2‐(hydroxymethyl)prop‐2‐enoyl]oxy}furanoeremophil‐1(10)‐ene and 1β,10β‐epoxy‐6β‐{[2‐(hydroxymethyl)prop‐2‐enoyl]oxy}furanoeremophilane. From L. veitchiana samples, collected in Yunnan Province, euparin, 2‐isopropenyl‐5,6‐dimethoxybenzofuran, and 6‐hydroxy‐3β‐methoxytrementone were isolated. DNA Sequencing of the internal transcribed spacers of the ribosomal RNA gene showed that the two species are not particularly close despite morphological similarities, in agreement with the chemical results.

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever and paratyphoid fever in China from 2004 to 2020, understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The descriptive epidemiological method and spatial analysis method were applied to analyze the epidemiological characteristics of typhoid fever and paratyphoid fever in China during this period by using the surveillance data collected from the National Notifiable Infectious Disease Reporting System of Chinese Center for Disease Control and Prevention. Results: A total of 202 991 cases of typhoid fever were reported in China from 2004 to 2020. More cases occurred in men than in women (sex ratio: 1.18∶1). Most cases were reported in adults aged 20-59 years (53.60%). The incidence rate of typhoid fever decreased from 2.54/100 000 in 2004 to 0.38/100 000 in 2020. The highest incidence rate was reported in young children aged <3 years after 2011, ranging from 1.13/100 000 to 2.78/100 000, and during this period the proportion of cases in this age group increased from 3.48% to 15.59%. The proportion of the cases in the elderly aged ≥60 years increased from 6.46% in 2004 to 19.34% in 2020. The hotspot areas existed in Yunnan, Guizhou, Guangxi and Sichuan Provinces and expanded to Guangdong, Hunan, Jiangxi, and Fujian Provinces. A total of 86 226 paratyphoid fever cases were reported from 2004 to 2020, the male to female ratio of the cases was 1.21∶1. Most cases were reported in adults aged 20-59 years (59.80%). The incidence rate of paratyphoid fever decreased from 1.26/100 000 in 2004 to 0.12/100 000 in 2020. The highest incidence rate of paratyphoid fever was in young children aged <3 years after 2007, ranging from 0.57/100 000 to 1.19/100 000, and during this period the proportion of the cases in this age group increased from 1.48% to 30.92%. The proportion of the cases in the elderly aged ≥60 years increased from 4.52% in 2004 to 22.28% in 2020. The hotspot areas expanded to the east, including Guangdong, Hunan and Jiangxi Provinces, from Yunnan, Guizhou, Sichuan, and Guangxi Provinces. Conclusions: The results showed a low level of incidence of typhoid fever and paratyphoid fever in China with a trend of decreasing per year. The hotspots were mainly in the of Yunnan, Guizhou, Guangxi and Sichuan Provinces, with an expanding trend to eastern China. It is necessary to strengthen the typhoid fever and paratyphoid fever prevention and control in southwestern China, among young children aged <3 years and the elderly aged ≥60 years.

This study presents an innovative investigation into the spatiotemporal dynamics of vegetation growth and its response to both individual and composite climatic factors. The Normalized Difference Vegetation Index (NDVI), derived from SPOT satellite remote sensing data, was employed as a proxy for vegetation growth. Multiple analytical methods, including the coefficient of variation, Mann–Kendall trend analysis, and Hurst index, were applied to characterize the spatiotemporal patterns of the NDVI in Sichuan Province from 2000 to 2020. The Standardized Precipitation Evapotranspiration Index (SPEI) was calculated using monthly precipitation and temperature data from 45 meteorological stations to examine the influence of composite climatic factors on vegetation growth, while the time lag effects between the NDVI and various climatic variables were also explored. Our findings unveil three key insights: (1) Vegetation coverage in Sichuan Province exhibited an overall increasing trend, with the highest NDVI values in summer and the lowest in winter. Significant NDVI fluctuations were observed in spring in the western Sichuan plateau and in winter in northern, eastern, and southern Sichuan. (2) A significant upward trend in the NDVI was detected across Sichuan Province, except for Chengdu Plain, where a downward trend prevailed outside the summer season. (3) On shorter time scales, the NDVI was positively correlated with precipitation, temperature, and the SPEI, with a one-month lag. The response of the NDVI to sunlight duration showed a two-month lag, with the weakest correlation and a five-month lag in western Sichuan. This research advances our understanding of the complex interactions between vegetation dynamics and climatic factors in Sichuan Province and provides valuable insights for predicting future vegetation growth trends.

To assess the ecosystem services value of forests for snail control and schistosomiasis prevention in the Yangtze River Basin, The Benefit Of Forestry Schistosomiasis Prevention Ecological Project, referenced as Specifications for Assessment of Forest Ecosystem Services in China (LY/T 1721-2008), was evaluated scientifically by market value method and shadow engineering method selecting water conservation, soil conservation, carbon sequestration, oxygen released, biodiversity conservation, snail control and schistosomiasis prevention to value ecosystem services. Results showed that ecosystem service ecological benefit of forests for snail control and schistosomiasis prevention in the Yangtze River Basin was great from 2006-2013 with water conservation totaling 16.16×108 tons, soil conservation 1.46×108 tons, carbon sequestration 0.10×108 tons, oxygen released 0.29×108 tons, snail area decreasing 24.35×107 square meters, and the number of schistosomiasis patients decreasing by 613.1 thousand. This was a saving of about 967.20×108 Yuan in all. Snail control and schistosomiasis prevention had the greatest value accounting for 35.87%, oxygen release accounted for 33.06%, carbon sequestration accounted for 13.02%, water conservation accounted for 9.17%, soil conservation accounted for 7.31%, and biodiversity conservation had the least value, accounting for 1.57%. The ecosystem services value for different provinces was Hunan > Hubei > Jiangxi > Anhui > Jiangsu > Sichuan > Yunnan. Of the seven provinces, snail control and schistosomiasis prevention of Anhui Province was greatest accounting for 18.17%. The other five function values were largest in Hunan Province. The study found that the comprehensive ecosystem service of snail prevention and control, oxygen release, carbon sequestration, water conservation, and soil conservation accounted for 98.43% of the ecosystem service value. The government of Hunan Province attached great importance to the prevention and treatment of schistosomiasis and undertook suppressing snail work the most. In hilly regions of Yunnan Province, Oncomelania Snail has a variety of environment, and its vitality is strong and its reproduction is fast, the difficulty of the prevention and control of schistosomiasis is relatively large, and the benefit of the snail suppression is not significant. This study provided a scientific basis for understanding the ecological role of snail prevention and control.

Camphora longepaniculata is an endangered evergreen tree listed as National Class II Protected Tree Species in China, highly valued for its medicinal and economic importance. Currently, research on this species has primarily focused on its pharmaceutical properties, while its potential distribution and responses to climate change remain insufficiently explored. In this study, 36 valid occurrence records and 11 environmental variables were utilized to predict its potential distribution and assess its response to future climate scenarios. The MaxEnt model revealed that the current distribution of C. longepaniculata largely aligns with its predicted suitable habitats, with the primary range located in Sichuan Province. Furthermore, this model identified the highly suitable habitats to be predominantly concentrated in Sichuan and Shaanxi Provinces under climate change. Among the environmental variables, annual precipitation (bio12), minimum temperature of the coldest month (bio6), and elevation (dem) were the most influential, collectively contributing over 70% to the model’s predictive accuracy. Future climate projections compared to the current distribution suggest a northward expansion of suitable habitats for C. longepaniculata, although Sichuan Province is predicted to remain the core habitat under future scenarios. Kernel density analysis of occurrence points indicated that the largest concentration of distribution points is near the Sichuan Basin, reinforcing the importance of this region as a stronghold for the species. Based on the results of potential distribution and kernel density analysis, in situ conservation, artificial cultivation, and the establishment of wild protected areas and local germplasm banks are recommended for stable, suitable habitats, such as Sichuan Province and parts of Yunnan and Guizhou Provinces. This study not only sheds light on the potential geographical distribution of C. longepaniculata and its response to climate change but also provides a scientific basis for the development of targeted conservation strategies for this species.

BackgroundLeptotrombidium scutellare is one of the six main vectors of scrub typhus in China and is a putative vector of hemorrhagic fever with renal syndrome (HFRS). This mite constitutes a large portion of the chigger mite community in southwest China. Although empirical data on its distribution are available for several investigated sites, knowledge of the species’ association with human well-being and involvement in the prevalence of mite-borne diseases remains scarce.MethodsOccurrence data on the chigger mite were obtained from 21 years (2001–2021) of field sampling. Using boosted regression tree (BRT) ecological models based on climate, land cover and elevation variables, we predicted the environmental suitability for L. scutellare in Yunnan and Sichuan Provinces. The potential distribution range and shifts in the study area for near-current and future scenarios were mapped and the scale of L. scutellare interacting with human activities was evaluated. We tested the explanatory power of the occurrence probability of L. scutellare on incidences of mite-borne diseases.ResultsElevation and climate factors were the most important factors contributing to the prediction of the occurrence pattern of L. scutellare. The most suitable habitats for this mite species were mainly concentrated around high-elevation areas, with predictions for the future showing a trend towards a reduction. Human activity was negatively correlated with the environmental suitability of L. scutellare. The occurrence probability of L. scutellare in Yunnan Province had a strong explanatory power on the epidemic pattern of HFRS but not scrub typhus.ConclusionsOur results emphasize the exposure risks introduced by L. scutellare in the high-elevation areas of southwest China. Climate change may lead to a range contraction of this species towards areas of higher elevation and lessen the associated exposure risk. A comprehensive understanding of the transmission risk requires more surveillance efforts.Graphical

The escalation of urbanization in Sichuan Province has resulted in irrational land use and excessive resource exploitation. These developments have consequently diminished the functionality of ecosystem services and exacerbated landscape fragmentation in the region. These challenges pose significant threats to the ecological security of the area. In this study, we computed the ecosystem service value and the landscape ecological risk index of Sichuan Province from 2005 to 2018. We analyzed the spatial autocorrelation between the ecosystem service value and the landscape ecological risk index, constructing a framework for landscape ecological risk assessment and zoning control based on ecosystem service value. The results show the following: (1) Between 2005 and 2018, the total value of ecosystem services in Sichuan Province increased from CNY 10,261.17 × 108 to CNY 10,310.43 × 108, with forest land and grassland being the primary contributors to the ESV. (2) High- and higher-risk areas within the landscape ecology of Sichuan Province are expanding, forming a pattern of high-level risk concentration from west to east. (3) There exists a negative correlation between the ecosystem service value and the landscape ecological risk index in Sichuan Province. (4) In the ecological conservation zone, the principle of low-impact development must be upheld. In the ecological cultivation zone, adjusting the proportion of land use types is necessary to enhance the rationality of the land use structure. The ecological agricultural zone should fully utilize the advantages of agriculture, while the ecological improvement zone requires focused attention to ecological restoration and land remediation.