Search Results (14)

Limited by water and heat conditions, the southwest alpine valley area has a dry climate, complex terrain, low vegetation coverage, and a very fragile ecological environment. The runoff plots of different slope gradients (10°, 15°, and 20°), slope lengths (2, 5, and 10 m) and reverse slope terrace (RST) in the Lancang River arid valley were taken as the objects. Through in situ observation of the slope runoff and sediment yield of six natural erosive rainfalls, the contribution rate of different factors was quantified, and the effect mechanism was revealed. The main results were as follows: (1) Sediment yields of different rainfalls were closely correlated with rainfall type and duration. Under the conditions of heavy rain (rain II and III), there was a critical slope gradient, and the maximum sediment yield was achieved when the slope gradient was 15°. (2) The runoff and sediment reduction benefits of horizontal terraces were 24.88% and 46.25%, and these benefits were increased by 1.47 times and 1.30 times after setting the RST, and the sediment reduction benefits increased significantly with the increase in the number of RSTs (p < 0.05). (3) In this study, rainfall intensity contributed the most to the runoff yield rate (34.5%), followed by slope length (15.1%) and horizontal terrace (7.2%). Slope length, rain intensity, and horizontal terrace order contributed 25.9%, 18.0%, and 11.4% to the sediment yield rate, respectively. (4) There was a significant linear correlation between sediment yield and runoff yield on different slopes (p < 0.05). The critical runoff yield rate decreased with the increase in slope length, the RST significantly increased the critical runoff yield rate (2.91 times), and it increased with the increase in RST numbers. This study can provide a scientific basis and reference for the prevention and control of soil and water loss and ecological restoration on the slope of the arid valley in the southwest alpine and canyon area. Full article

Forest ecological security is related to national ecological security. Yunnan Province has a significantly stereoscopic climate characterized by diverse and complex vegetation. Therefore, the ecological security of Yunnan Province’s forests, which span multiple climate zones, must be carefully considered. The purpose of this study is to evaluate the forest ecological security situation and influencing factors in Yunnan Province in 2017. Utilizing data from remote sensing, the Yunnan Province Yearbooks, socioeconomic statistical data, and better pressure-state-response modeling, this work produced an index system containing state and societal pressure. The evaluation indicators were weighted using a combination of entropy weighting and expert weighting, using 16 prefectures in Yunnan Province as samples. Using the fuzzy matter-element technique, the forest ecological security situation in Yunnan Province in 2017 was assessed, and the contributing causes were examined. Results indicate that there are spatial distribution differences in ecological security in various regions of Yunnan Province. The regions with the greatest indices of forest ecological security were found in Xishuangbanna in the south and Nujiang and Diqing in the northwest of Yunnan Province, while those areas with the lowest indices were distributed in Qujing and Zhaotong in the northeast and Baoshan in the west. Results of the grey relation analysis show that those factors that influence forest ecological security across different prefectures showed significant diversity. In Yunnan Province, the main influencing factors include days when the air quality reaches Level 2 or higher, the percentage of natural forest acreage and accumulation, the value of forest ecological service function per unit area, the annual average temperature, and forest coverage. The influence of the forest status index was greater than that of the forest pressure index. The findings of this work can guide decisions related to regional forest ecological security construction across multiple climate zones. In view of the differences in ecological security status and influencing factors in different regions, ecological environment governance should be adapted to local conditions to ensure the coordinated development of nature, the economy, and the ecological environment. Full article

The genetic diversity of coronaviruses (CoVs) is high, and their infection in animals has not yet been fully revealed. By RT-PCR detection of the partial RNA-dependent RNA polymerase (RdRp) gene of CoVs, we screened a total of 502 small mammals in the Dali and Nujiang prefectures of Western Yunnan Province, China. The number of overall CoV positives was 20, including β-CoV (n = 13) and α-CoV (n = 7), with a 3.98% prevalence in rectal tissue samples. The identity of the partial RdRp genes obtained for 13 strains of β-CoV was 83.42–99.23% at the nucleotide level, and it is worth noting that the two strains from Kachin red-backed voles showed high identity to BOV-36/IND/2015 from Indian bovines and DcCoV-HKU23 from dromedary camels (Camelus dromedarius) in Morocco; the nucleotide identity was between 97.86 and 98.33%. Similarly, the identity of the seven strains of α-CoV among the partial RdRp sequences was 94.00–99.18% at nucleotide levels. The viral load in different tissues was measured by quantitative RT-PCR (qRT-PCR). The average CoV viral load in small mammalian rectal tissue was 1.35 × 10⁶ copies/g; differently, the mean CoV viral load in liver, heart, lung, spleen, and kidney tissue was from 0.97 × 10³ to 3.95 × 10³ copies/g, which revealed that CoV has extensive tropism in rectal tissue in small mammals (p < 0.0001). These results revealed the genetic diversity, epidemiology, and infective tropism of α-CoV and β-CoV in small mammals from Dali and Nujiang, which deepens the comprehension of the retention and infection of coronavirus in natural hosts. Full article

Mining for rare earth elements is rapidly increasing, driven by current and projected demands for information and energy technologies. Following China’s Central Government’s 2012 strategy to shift away from mining in favor of value-added processing, primary extraction has increased outside of China. Accordingly, changes in mineral exploitation in China and Myanmar have garnered considerable attention in the past decade. The prevailing assumption is that mining in China has decreased while mining in Myanmar has increased, but the dynamic in border regions is more complex. Our empirical study used Google Earth Engine (GEE) to characterize changes in mining surface footprints between 2005 and 2020 in two rare earth mines located on either side of the Myanmar–China border, within Kachin State in northern Myanmar and Nujiang Prefecture in Yunnan Province in China. Our results show that the extent of the mining activities increased by 130% on China’s side and 327% on Myanmar’s side during the study period. We extracted surface reflectance images from 2005 and 2010 from Landsat 5 TM and 2015 and 2020 images from Landsat 8 OLI. The Normalized Vegetation Index (NDVI) was applied to dense time-series imagery to enhance landcover categories. Random Forest was used to categorize landcover into mine and non-mine classes with an overall accuracy of 98% and a Kappa Coefficient of 0.98, revealing an increase in mining extent of 2.56 km², covering the spatial mining footprint from 1.22 km² to 3.78 km² in 2005 and 2020, respectively, within the study area. We found a continuous decrease in non-mine cover, including vegetation. Both mines are located in areas important to ethnic minority groups, agrarian livelihoods, biodiversity conservation, and regional watersheds. The finding that mining surface areas increased on both sides of the border is significant because it shows that national-level generalizations do not align with local realities, particularly in socially and environmentally sensitive border regions. The quantification of such changes over time can help researchers and policymakers to better understand the shifting geographies and geopolitics of rare earth mining, the environmental dynamics in mining areas, and the particularities of mineral extraction in border regions. Full article

Agroforestry has gained increasing attention as a sustainable land use mode to ensure food security, mitigate global climate change, and improve farmers’ livelihoods. Likewise, agroforestry plays a key role in alleviating poverty, mitigating climate change and achieving the Sustainable Development Goals (SDGs) in China. Lanxangia tsaoko, as a typical agroforestry species in Nujiang Prefecture, plays a vital role in improving farmers’ livelihoods. After years of development, the Lanxangia tsaoko industry (LTI) in Nujiang Prefecture has made remarkable achievements and accumulated useful experiences. Taking the development of LTI as an example, this paper analyzes the impact of agroforestry on farmers’ livelihoods and its mechanism through field survey and theoretical deduction. First, by investigating the willingness of households to choose LTI, we found that most farmers have a positive attitude toward LTI, and they actively participate in cooperative organizations. Then, by analyzing the development stage and mode of LTI in Nujiang Prefecture, we found that the industry has made significant progress under the external and internal effects. We also found that the mechanism by which agroforestry affects farmers’ livelihoods is a process in which various stakeholders, including government, enterprises, farmers, etc., participate in industrial development with their production components and advantages. Although agroforestry is an effective way to improve farmers’ livelihoods and promote sustainable agricultural development, it is also necessary to pay attention to risk prevention. This paper discusses the role of agroforestry in farmers’ livelihoods, which provides a reference for lower-income forest areas. Full article

Considering the notion that “lucid waters and lush mountains are invaluable assets”, the effective exploitation of the economic value of forest resources is an important research topic, especially in forest-rich areas. The development of the non-timber forest products (NTFPs) industry has promoted both ecological and economic benefits and has effectively improved farmers’ incomes while protecting forest resources. In order to evaluate the effects of the NTFPs industry on sustaining farmers’ livelihoods and protecting ecological environments, we constructed a performance evaluation index system to determine the poverty alleviation performance of the NTFPs industry in Yunnan Province using the analytic hierarchy process (AHP), which covered three aspects: the achievement of poverty alleviation, the sustainability of poverty alleviation and satisfaction with poverty alleviation. Then, we selected Sanhe Village in Nujiang Prefecture, Yunnan Province, as an example to verify and rationalize the evaluation index system and comprehensively evaluate the poverty alleviation performance of the NTFPs industry. Based on data from questionnaires and field interviews, we found the following: (1) the overall poverty alleviation performance of the NTFPs industry in Sanhe Village was 79.33, which indicated that the effect was good; (2) the scores for the achievement of poverty alleviation, the sustainability of poverty alleviation and satisfaction with poverty alleviation were 50.56, 18.57 and 10.2, respectively; (3) there were some problems with the poverty alleviation performance of the NTFPs industry, such as limited capital investments, the weak roles of cooperatives and enterprises, the low enthusiasm of lower-income households and incomplete poverty alleviation projects. Finally, we devised some suggestions that could improve the poverty alleviation performance of the NTFPs industry. This paper presents the performance evaluation index system for the poverty alleviation performance of the NTFPs industry, which could provide a reference for evaluating the developmental effects of the NTFPs industry in other lower-income forest areas. Through our empirical analysis of the development effects of the NTFPs industry on farmers’ livelihoods and ecological environments in Sanhe Village, we found that the development of the NTFPs industry significantly improved the farmers’ livelihoods and ecological environments. Full article

Absolute poverty has historically been solved in China, and the focus on poor areas has shifted to addressing relative poverty. To realize the organic combination of the rural revitalization strategy and relative poverty governance, multi-dimensional relative poverty identification and governance path research at the village scale in an alpine-gorge region is required. For this study, the Nujiang Lisu Autonomous Prefecture’s research area in a typical alpine-gorge was chosen. This paper constructed an evaluation index system for the rural regional system based on location conditions, ecological environment, productive resources, economic base, and public service, based on the theory of multi-dimensional regional poverty and the human–land relationship. The level of poverty, types of poverty, and spatial distribution characteristics of 255 administrative villages were systematically analyzed, and poverty governance paths were proposed. The results show that: (1) There were 215 multi-dimensional relative poverty villages in Nujiang Prefecture, accounting for 84.31% of the total. The relatively poor villages with poverty grades I and II, which are classified as mild poverty, account for 77.21% of all poor villages; this demonstrated that the relatively poor villages in Nujiang Prefecture had a high potential for poverty alleviation. (2) There are 19 different types of constraints in poor villages. Grades III and IV poor villages were mostly found in high-altitude areas. The economic foundation was very weak, the infrastructure was imperfect, the land use type was relatively single, and traffic conditions were relatively backward. (3) The priority model accounted for 16.67% of relative poverty governance, the steady improvement accounted for 28.79%, and key support accounted for 54.54%. Relative poverty governance paths for various counties have been proposed, including rural revitalization priority demonstration, ecological environment governance, eco-tourism, modern agriculture + mountain agroforestry, and improved people’s livelihood and well-being. The findings provided scientific support and direction for future research on the mode and course of relative poverty governance in poor villages in the alpine-gorge area, as well as the rural revitalization strategy’s implementation. Full article

The geographical environment adaptation of the resettled population is a deep-seated problem that determines whether the goal of the poverty alleviation resettlement (PAR) policy can be achieved. Scientific assessment of adaptive capacity (AC) and adaptation level (AL) provides a basis for subsequent policy formulation, which is of practical significance. This study took the poverty-stricken areas of northwest Yunnan as the study area and calculated the adaptive capacity index (ACI) and adaptation level index (ALI) based on survey data of 1002 resettled households and regional socioeconomic statistics by constructing the vulnerability as expected poverty (VEP) model and multi-factor analysis model. The results showed that (1) The ACI and ALI were 0.660 and 61.2 respectively, indicating that the resettled population has obvious environment adaptation barriers and a relatively high risk of returning to poverty. (2) The AC and AL of the resettled population had significant geographical differentiation. In general, Diqing Prefecture was significantly better than Nujiang Prefecture and the problems in Gongshan County, Fugong County and Lanping County were more prominent. (3) AC is a determinant of AL. However, these two indices in Gongshan and Lanping counties deviated from the general trend due to different policy effects. Based on the evaluation results and differentiation mechanism analysis, the study finally emphasized the importance of formulating and implementing the follow-up development plan of the resettled population and put forward measures to promote the resettled population to adapt to the geographical environment around the three core tasks of employment income increase, public service and bottom guarantee. Full article

Over 80% proteins consumed by the local people in Nujiang Prefecture of Southwest China, a remote and mountainous area in the Eastern Himalayas, are from pork, or Gaoligongshan pig (a landrace of Sus scrofa domestica Brisson). Previous research on the Gaoligongshan pig has focused on nutritional composition, production performance, and genetic resource characteristics, but neglected the reasons behind the local people’s practice. From 2019 to 2022, we have used ethnobiological research methods to comprehensively document the traditional rearing and management patterns and the traditional culture associated with Gaoligongshan pigs. The results show that Gaoligongshan pigs graze in mixed herds with cattle and sheep during the day and prefer to eat 23 wild plant species, in which 17 species have medicinal values. At night, the pigs are artificially fed and rest in the pigsty. The local Bai and Lisu people have developed a creative food culture, rituals, and festivals culture associated with Gaoligongshan pigs. Overall, the biocultural diversity of Gaoligongshan pig contributes to the in situ conservation of genetic diversity of this important hog landrace, and supports rural development in this remote area. Full article

At present, landslide susceptibility assessment (LSA) based on landslide characteristics in different areas is an effective measure for landslide management. Nujiang Prefecture in China has steep mountain slopes, a large amount of water and loose soil, and frequent landslide disasters, which have caused a large number of casualties and economic losses. This paper aims to understand the characteristics and formation mechanism of regional landslides through the evaluation of landslide susceptibility so as to provide relevant references and suggestions for spatial planning and disaster prevention and mitigation in Nujiang Prefecture. Based on the grid cell, this study selected 10 parameters, namely elevation, slope, aspect, lithology, proximity to faults, proximity to road, proximity to rivers, normalized difference vegetation index (NDVI), land-use type, and precipitation. Support vector machine (SVM), certainty factor method (CF), and deterministic coefficient method–support vector machine (CF-SVM) were used to evaluate the landslide susceptibility in Nujiang Prefecture. According to these three models, the study area was divided into five landslide susceptibility grades, including extremely high susceptibility, high susceptibility, moderate susceptibility, low susceptibility, and very low susceptibility. Receiver operating characteristic curve (ROC) was applied to verify the accuracy of the model. The results showed that CF model (ROC = 0.865), SVM model (ROC = 0.892), CF-SVM model (ROC = 0.925), and CF-SVM model showed better performance. Therefore, CF-SVM model results were selected for analysis. The study found that the characteristics of high and extremely high landslide-prone areas in Nujiang Prefecture have the following characteristics: intense human activities, large density of buildings and arable land, rich water resources, good economic development, perfect transportation facilities, and complex topography and landform. In addition, there is a finding inconsistent with our common sense that the distribution of landslide disasters in the study area does not decrease with the increase of NDVI value. This is because the Nujiang River basin is a high mountain canyon area with low rock strength, barren soil, and underdeveloped vegetation and root system. In an area with large slope, the probability of landslide disaster will increase with the increase of NDVI. The CF-SVM coupling model adopted in this study is a good first attempt in the study of landslide hazard susceptibility in Nujiang Prefecture. Full article

Constructing an ecological security pattern is vital to guaranteeing regional ecological security. The terrain and geomorphology of the alpine valley are complex and sensitive, meaning it is difficult to construct ecological security patterns. Therefore, the study takes Nujiang Prefecture as the study area and builds an “Importance–Sensitivity–Connectivity” (Importance of ecosystem service, eco-environmental sensitivity, and landscape connectivity) framework to carry on the comprehensive evaluation of the ecological security and identification of ecological sources. Furthermore, we constructed an ecological resistance surface using land-use type. Using the minimum cumulative resistance (MCR) model, the study identifies the ecological corridors and nodes to build ecological security patterns to optimize the ecological spatial structure of Nujiang Prefecture. The results showed that (1) the importance of ecosystem services was higher in the west and lower in the east. The high-sensitive areas of the ecological environment were distributed discontinuously along the banks of the Nujiang and the Lantsang River, and the areas with high landscape connectivity were distributed in patches in the Gaoligong Mountain Nature Reserve and the Biluo Snow Mountain. (2) The overall ecological security was in a good state, and the ecologically insecure areas were primarily distributed in Lanping County and the southeast region of Lushui City. (3) The primary ecological source area was identified to be 3281.35 km² and the secondary ecological source area to be 4224.64 km². (4) In total, 26 primary ecological corridors, 39 secondary ecological corridors, and 82 ecological nodes were identified. Full article

Eco-compensation is an effective means of coordinating ecological protection and economic development, and the assessment of its standards is core content in the study of eco-compensation projects. To improve the operability of eco-compensation standards, taking Nujiang Prefecture as the study area, we combine the equivalent factor method and water footprint method to evaluate the ecosystem-service-value (ESV) spillover and use the market comparison method to calculate the opportunity cost. The final eco-compensation upper and lower limits model is constructed on the basis of the ESV spillover and opportunity cost. The results show the following: (1) the ecological protection of Nujiang Prefecture has been effective, based on the stabilization of its ESV after an initial increase. The main types of ecosystem services provided are regulation and provision services. Gongshan County makes the most significant contribution to the total ESV. (2) The ratio of the ESV self-consumption in Nujiang Prefecture shows a trend of first rising and then falling. This is mainly explained through the reduction in the use of industrial and agricultural water. After deducting self-consumption through the water footprint method, it can be observed that there is ecological spillover in Nujiang Prefecture. (3) The opportunity cost in Nujiang Prefecture increases yearly from 2005 to 2020 owing to ecological protection policies. Combined with the ESV spillover, it is determined that the rational range of the eco-compensation standard is between CNY 6.17 × 10² million and 120.01 × 10² million in 2005, between CNY 10.02 × 10² million and 128.25 × 10² million in 2010, between CNY 30.34 × 10² million and 197.12 × 10² million in 2015, and between CNY 41.97 × 10² million and 227.52 × 10² million in 2020. The current study can offer decision makers a more flexible eco-compensation standard while coordinating the contradiction between regional ecological protection and economic development. Full article

Luculia yunnanensis (Rubiaceae), an evergreen shrub or small tree, is endemic to China and confined to Nujiang Prefecture, Yunnan Province. This plant is of high ornamental value owing to its attractive pink flowers, sweet fragrance, and long flowering period. Due to the influence of climate change and human factors, the distribution range of L. yunnanensis has exhibited a significant shrinking trend, and it has become a vulnerable species that is in urgent need of conservation and rational utilization research. In this study, the flower transcriptome sequencing of L. yunnanensis was conducted using an Illumina HiSeq platform. We designed and developed a series of EST-SSR primers based on the flower transcriptome data of L. yunnanensis. The results showed that 98,389 unigenes were obtained from the L. yunnanensis flower transcriptome, all of which were aligned with sequences in public databases. Nr, Nt, Pfam, KOG/COG, Swiss-Prot, KEGG, and GO annotated 31,859, 13,853, 22,684, 10,947, 21,416, 9722, and 23,390 unigenes, respectively. The MISA (Microsatellite) tool was used to identify SSR loci from all unigenes, and a total of 15,384 SSRs were identified. Repeat motifs were given priority with mononucleotides, dinucleotides, and trinucleotides. The 81 primer pairs were synthesized randomly, of which 44 pairs showed effective amplification. A total of 17 primers showed stable amplification, and rich polymorphism was observed in 6 populations. We concluded via genetic diversity analysis that the average effective number of alleles (Ne), Shannon’s information index (I), and polymorphism information content (PIC) were 1.925, 0.837, and 0.403, respectively. In conclusion, 17 EST-SSR primers can be used for subsequent population genetic diversity analysis and molecular-marker-assisted breeding, which is of great significance for formulating resource conservation and utilization strategies for L. yunnanensis. Full article