Lancang County Research Articles

First Report of Ilyonectria coprosmae Causing Root Rot of Bletilla striata in Yunnan province of China.

Bletilla striata is a valuable medicine in China, belonging to the Orchidaceae family, and is used for treating various ailments such as hemoptysis, pyocutaneous disease, and anal fissure by preventing blood flow, reducing swelling, and promoting granulation. In June 2022, a disease with symptoms similar to root rot was observed on B. striata in the pineland (the area was 0.4 hectare) of Lancang County (22°48'17" N, 99°46'58"22 E), Yunnan Province, China. The root rot incidence rate reached 16% (Table S1). The root rot incidence was calculated as follows: root rot incidence (%) = (number of root rot seedlings/total number of seedlings investigated) × 100. In May 2023, the similar symptoms were observed in the field, and the disease incidence was 17% (Table S1). Initially, there were no obvious symptoms on the leaves. Subsequently, the leaves wilted and brown spots appeared. Later, the entire leaf browned, withered and eventually died (Fig. S1A, B). The roots were brown and the browning spread from the root edge to the center, causing vascular bundle browning and dead lignified fibers in the cortex (Fig. S1C, D). To isolate the causal pathogen, 20 symptomatic root tissues were collected from 20 plants. Cutting the diseased tissues into small pieces (0.5 × 0.5 cm). After surface sterilization (30s with 75% ethanol and 3 min with 2% sodium hypochlorite, rinsed three times with sterile water), the disinfected root tissues were plated onto potato dextrose agar (PDA) and incubated at 25℃ for 4 to 6 days with 12 h light/dark photoperiod. A total of 10 single-spore isolates with similar morphology and conidial characteristics were obtained. one representative isolate BJG6 was selected for identification and further study. The fungal colony was reddish-brown or orange-white on PDA after 8 days of incubation at 25℃. The mycelium was like carpet or cotton, and the edge of colony was uniform (Fig. S1E). Large conidia were formed on simple conidial peduncles (Fig. S1F, G). The conidia with 1~3 septates and 1 mostly, with cylindrical shapes and narrow tops but sharp bases (Fig. S1H-J). Conidia with 1 septate measured as 5.5 (4.3-6.7) × 20.7 (16.0-25.4) μm (n=30), while those with 2 septates measured as 6.6 (5.8-7.4) × 26.5 (21.7-31.3) μm (n=30), and those with 3 septates was 6.9 (6.2-7.8) × 31.8 (29.3-34.3) μm (n=30). Ellipsoidal microconidia could be formed on conidiophore and measured as 2.4 (1.9-2.9) × 4.9 (5.9-3.9) μm to 2.7 (2.2-3.2) × 5.4 (4.3-6.5) μm (n=30). Spherical or subspherical chlamydospores were produced on low-nutrient agar, with an average size of 5.8(5.0-6.6) μm×5.3 (4.4-6.2) μm (n=30) (Fig. S1K, L). According to the morphology and conidial features, the pathogen was consistent with the description of Ilyonectria coprosmae (Cabral et al. 2012). The total genomic DNA was extracted, and primer pairs ITS4/ITS5 were used to amplify and sequence the rDNA-ITS region (ITS1-5.8 S rRNA-ITS2 gene regions) (White et al. 1990). The sequences were deposited in GenBank (SUB13905750 for ITS). BLAST searches revealed BJG6 showed 98% homology with corresponding sequences of Ilyonectria coprosmae in GenBank (JF735260). A phylogenetic tree (MEGA 7.0) was constructed using maximum-likelihood methods (Fig. S2). To identify pathogenicity, a cultured medium in a size of 6mm containing isolate BJG6 was inoculated onto ten healthy roots of B. striata, PDA plugs alone were used as the uninoculated controls. All samples were placed in a dark inoculation chamber at 25℃. The pathogenicity test was replicated three times. After two weeks, all inoculated roots appeared similar symptoms identical to those observed on field plants (Fig. S1M, N-P), while control plants remained healthy (Fig. S1Q, R). The same pathogenic fungus was reisolated from the symptomatic root rot, and the characteristics of colony and conidia were the same as the original isolates (Fig. S1S, T). These results confirmed I. coprosmae as the causal pathogen of root rot disease on B. striata in China by Koch's postulates tests for the first time. Further exploration should be conducted to understand the occurrence and migration of this disease, so as to develop specific and efficient disease management strategies in the future.

A new framework for multi-level territorial spatial zoning management: Integrating ecosystem services supply-demand balance and land use structure

The supply-demand balance of ecosystem services (ESs balance) is a research hotspot. Previous studies have explored spatio-temporal patterns of ESs supply, demand, and balance, but have neglected the inherent relationship between ESs balance and land use structure, which impedes the development of direct and effective land use regulatory strategies. This study assessed the balance of six ESs (i.e., timber production (TP), food production (FP), water retention (WR), carbon sequestration (CS), soil retention (SR), and habitat quality (HQ)) by the index of ecological relative surplus ratio (ERSR) at 30 m × 30 m pixel scale, and identified ESs balance bundles (ESBBs) in Lancang County, a typical mountainous region in China. It also defined the land use proportion thresholds for achieving different objectives of ESs balance, and proposed land use regulatory strategies accordingly. The results showed that: (1) From 2010 to 2020, the supply of six ESs exceeded the demand in Lancang County, and the surplus of different ESs changed over time. ESs balance also exhibited spatial heterogeneity, and ESs imbalance aggravated in some areas. Three ESBBs were divided as FP-WR-SR integrated bundle, TP–CS–HQ integrated bundle, and Integrated promotion bundle at the township scale. (2) Cropland, built-up land, and forest were the key land use types that affected the balance of the six ESs. Moreover, the land use proportion thresholds under the objectives of “ERSR ≥0″ and “ERSR ≥1″ were determined, and they differed by ES type and objective. (3) For each ESBB, ESs comprehensive management zones were delineated at the multi-scales of the township and 1 km × 1 km grid. Regulatory strategies oriented by “reducing/increasing/maintaining the proportion of certain land use types” were suggested under different objectives. This study developed a framework for “multi-level zoning management of ‘county – ESs balance bundle – township – grid’ for promoting ESs balance by land use structure regulation” that aligned with China's territorial spatial planning hierarchy at the county and township levels. It could inform the design of a scientific and orderly territorial spatial pattern with a high-level ESs balance at various scales (e.g., counties, agglomerations, provinces, and cities) and regions. However, this framework could not be directly applied to land use spatial optimization at pixel scale. Further research is needed to integrate land use simulation models, such as the mixed-cell cellular automata (MCCA) model, to achieve ESs balance objectives at finer scales.

Safety, immunogenicity, and efficacy of an mRNA COVID-19 vaccine (RQ3013) given as the fourth booster following three doses of inactivated vaccines: a double-blinded, randomised, controlled, phase 3b trial

Heterologous vaccine schedules have been recommended to provide superior immunity and protection against emergent SARS-CoV-2 variants of concern. We aimed to evaluate the safety, immunogenicity, and efficacy of an mRNA COVID-19 vaccine RQ3013 compared with adenoviral vectored vaccine Ad5-nCoV and protein subunit vaccine ZF2001 as the fourth dose in adults primed with three doses of inactivated vaccines in China. We conducted a double-blinded, randomised, controlled, phase 3b trial among healthy Chinese adults at Lancang County, Yunnan, China. Adults who had received three doses of inactivated COVID-19 vaccines at least 6 months prior were randomly allocated (3:1:1) to receive heterologous boosters with RQ3013, Ad5-nCoV, or ZF2001. We assessed safety within 28 days post boost and the serum geometric mean titres (GMTs) of neutralising antibodies (NAbs) against the live SARS-CoV-2 omicron variant BA.5 on day 14 post-boost. We used Poisson regression to assess the vaccine efficacy against the first episode of virologically confirmed symptomatic COVID-19 occurring at least 7 days post boost. Subgroup analyses categorized by age and sex were also performed for safety and immunogenicity outcomes. This trial has been registered with the Chinese Clinical Trial Registry (ChiCTR2200065281) and is now complete. Between December 12 and December 18, 2022, a total of 1382 adults were screened, and 1250 were enrolled and randomly assigned to receive one dose of RQ3013 (n=750), Ad5-nCoV (n=250), or ZF2001 (n=250). Although solicited adverse reactions within 28 days post boost were more frequent in the RQ3013 group (175 [23.3%]) compared to the control groups (24 [9.6%] in both the Ad5-nCOV and ZF2001 groups, P<0.05), incidences of Grade 3 events were low (9 [0.7%]) and comparable across three groups (P>0.05). On day 14 post-boost, RQ3013 (GMT 69.14, 95% CI 47.90-99.81) elicited 4.8-fold and 5.6-fold higher concentrations of NAbs against BA.5 than did Ad5-nCoV (14.37, 7.78-26.56) and ZF2001 (12.21, 5.13-29.06), respectively. On day 28 post-boost, RQ3013 demonstrated a relative efficacy of 62.2% (95% CI 13.7-83.1, P=0.02) compared to Ad5-nCoV, and of 69.0% (33.5-85.7, P=0.002) compared to ZF2001. The administrations of all the three heterologous boosters were well tolerated. The heterologous prime-boost regimen with RQ3013 elicited superior immune responses and demonstrated better protection against symptomatic SARS-CoV-2 infections compared with Ad5-nCoV or ZF2001, supporting the use of RQ3013 as a booster vaccination in adults. Yunnan Province Science and Technology Department (grant no.202302AA310047).

Linking random forest and auxiliary factors for extracting the major economic forests in the mountainous areas of southwestern Yunnan Province, China

Forests are generally extracted from remotely sensed images based on the spectral features, ignoring other important auxiliary information, and the techniques of precise extraction need to be further improved. By using the Sentinel–2 image and auxiliary factors (AFs) including site conditions (SCs) and vegetation indices (VIs), the random forest model with AFs (RF–AFs) was adopted for the extraction of the economic forests in Lancang County, which is a mountainous area with rich biodiversity and is witnessing rapid development of economic forests in Yunnan province of China. The results obtained using the RF–AFs model were compared with those obtained using the random forest model without AFs (RF). The results were as follows: (1) The kappa coefficient for extracting the first–level land use obtained using the RF model was 0.9531. Lancang County is dominated by forests, accounting for 73.76% of the total area. (2) After parameter optimization, the RF–AFs model yielded the highest accuracy in the extraction of the second–level forests, with a kappa coefficient value of 0.9493, which was 14.69% higher than that of the RF model. Thus, the RF–AFs model is more suitable for the precise extraction of economic forests. (3) The evaluation results of the factors’ importance of the RF–AFs model showed that the cumulative importance values of SCs such as temperature (TEM), elevation (EL), precipitation (PRE) and VIs such as plant senescence reflectance index (PSRI), enhanced vegetation index (EVI), transformed soil–adjusted vegetation index (TSAVI) was 76.09%, indicating that they were the main factors for the extraction of economic forests. (4) Economic forests are dominated by Simao pines in Lancang County, which are mainly distributed in the central, southwestern and northern regions, accounting for 31.37% of forests area. The proportion of tea plantations, eucalyptus, and rubber trees is 9.05%, 6.71%, and 3.05% of forests area, respectively. The RF–AFs model is conducive for precisely extracting the economic forests and is thus of great significance in studying the ecological and environmental effects of economic forests, performing forestry management, and maintaining regional ecological security.

Agricultural Productive Carrying Capacity Improve and Water Optimal Allocation under Uncertainty Based on Remote Sensing Data in Lancang County, Southwest China

Through the reasonable calculation of water resources, evaluating the irrigation carrying capacity of farmland under the constraints of water resources is crucial for optimizing the spatial distribution of agricultural production and ecology and rationally adjusting the scale of agricultural production. This paper proposes an optimization framework based on Type 2 fuzzy chance-constrained programming (T2FCCP) to solve the problem of regional water resources optimal allocation and evaluation of farmland irrigation carrying capacity under uncertain conditions. To illustrate the applicability of the proposed framework, this paper conducts a case study on Lancang County, Puer City, Yunnan Province. Methods, such as watershed harmony evaluation method, remote sensing data, and shared socioeconomic pathways (SSPs), are applied and integrated into the proposed optimization framework to systematically deal with uncertainties in water resource systems and agricultural systems. The results include the costs and benefits of regional water and soil resources systems, water resources optimal allocation, and crop planting structure results under different SSPs in Lancang County, Puer City. The results also show that the total cost under T2FCCP is about 5% lower than that under fuzzy chance-constrained programming (FCCP) and about 17% lower than that under chance-constrained programming (CCP). By 2025, the water resources carrying capacity of different tributaries in Lancang County, Puer City will increase, and based on the evaluation results of agricultural production irrigation carrying capacity, suggestions are given to ensure agricultural production carrying capacity.

Characteristics of heavy metal accumulation and risk assessment in understory Panax notoginseng planting system.

Yunnan Province is the main planting area of the precious Chinese herbal medicines (CHM) Panax notoginseng; however, it locates the geological area with high soil heavy metals in China. The frequent land replacement due to continuous cropping obstacles and excessive application of chemicals makes P. notoginseng prone to be contaminated by heavy metals under the farmland P. notoginseng (FPn) planting. To overcome farmland shortage, understory P. notoginseng (UPn) was developed as a new ecological planting model featured by no chemicals input. However, this newly developed planting system requires urgently the soil-plant heavy metal characteristics and risk assessment. This study aimed to evaluate the pollution status of eight heavy metals in the tillage layer (0-20cm), subsoil layer (20-40cm) and the plants of UPn in Lancang County, Yunnan Province. Pollution index (Pi) showed that the contamination degree of heavy metals in the tillage layer and subsoil layer was Cd > Pb > Ni > Cu > Zn > Cr > Hg > As and Pb > Cd > Cu > Ni > Cr > Hg > Zn > As, respectively. Potential ecological risk index (PERI) for the tillage layer and subsoil layer was slight and middle, respectively. The exceeding standard rate of Cd, As, Pb, Hg, Cu in the UPn roots was 5.33%, 5.33%, 13.33%, 26.67% and 1.33%, respectively, while only Cd and Hg in the UPn leaves exceeded the standard 10% and 14%, respectively. The enrichment abilities of Cd and Hg in the roots and leaves of UPn were the strongest, while that of Pb was the weakest. The Hazard index (HI) and target hazard quotient (THQ) of eight heavy metals in the roots and leaves of UPn were less than 1.Therefore, our results prove that Upn has no human health risk and provide a scientific basis for the safety evaluation and extension of UPn.

HIV-1 pretreatment drug resistance and genetic transmission network in the southwest border region of China

BackgroundHIV drug resistance increased with the widespread use of antiretroviral drugs, and posed great threat to antiretroviral therapy (ART). Pu’er Prefecture, lying in the southwest of Yunnan Province, China, borders Myanmar, Laos and Vietnam, is also the area where AIDS was discovered earlier, however, in which there has been no information on HIV drug resistance.MethodsA cross-sectional survey of pretreatment drug resistance (PDR) was conducted in Pu’er Prefecture in 2021. Partial pol gene sequences were obtained to analyze drug resistance and construct genetic transmission network. HIV drug resistance was analyzed using the Stanford University HIVdb algorithm.ResultsA total of 295 sequences were obtained, among which 11 HIV-1 strain types were detected and CRF08_BC (62.0%, 183/295) was the predominant one. Drug resistance mutations (DRMs) were detected in 42.4% (125/295) of the sequences. The prevalence of PDR to any antiretroviral drugs, nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) were 10.8% (32/295), 9.5% (28/295), 1.0% (3/295) and 0.3% (1/295), respectively. The risk of PDR occurrence was higher among individuals with CRF01_AE strain types. HIV-1 molecular network was constructed, in which 56.0% (42/75) of links were transregional, and 54.7% (41/75) of links were associated with Lancang County. Among the sequences in the network, 36.8% (35/95) harbored DRMs, and 9.5% (9/95) were drug resistance strains. Furthermore, 8 clusters had shared DRM.ConclusionThe overall prevalence of PDR in this study was in a moderate level, but NNRTIs resistance was very approaching to the threshold of public response initiation. PDR was identified in the transmission network, and DRMs transmission was observed. These findings suggested that the consecutive PDR surveillance should be conducted in this region.

Seasonal migratory activity of SPODOPTERA FRUGIPERDA (J.E. Smith) (Lepidoptera: Noctuidae) across China and Myanmar.

The fall armyworm (FAW) Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) invaded Myanmar and China in 2018 and greatly impacted agricultural production and ecosystem balance in these areas. FAW is a migratory insect, but its seasonal migration pattern between the two countries has been largely unknown. From 2019 to 2021, we monitored the seasonal migration of FAW in the China-Myanmar border area using a searchlight trap, assessed the reproductive development status of female migrants and traced the migratory routes by trajectory simulation. FAW moths were trapped by the searchlight trap in Lancang County (Yunnan, China) all year, with obvious seasonal differences in the number caught. There were small-scale persistent trapping peaks in spring and summer, and obvious peaks in autumn; only a small number of moths were trapped in winter. Examination of the ovaries of female moths collected in different seasons showed that most females had matured, indicating that the moths were migrating and did not take off from the local area. In the migration trajectory simulation, FAW mainly migrated from Myanmar to Southwest China in spring and summer and back to Myanmar in autumn. Our findings indicate that FAW migrates between China and Myanmar according to the monsoon circulation, which will help guide cross-border regional monitoring and management strategies against this pest. © 2022 Society of Chemical Industry.

First Report of Stemphylium lycopersici Causing Leaf Spot on Polygonatum kingianum in China.

Polygonatum kingianum, a member of the Liliaceae, is valued in traditional medicine and as a vegetable food crop. In July 2019, more than 50% of P. kingianum growth was suppressed in several field nurseries in Simao, Mojiang, Jingdong and Lancang County, Puer City, China. At the early stage of infection, symptoms manifested as a small circular brown spot. As the lesion matured, the spot gradually enlarged, forming an oval to irregular lesion with reddish-brown and dark green borders. In serious cases, the leaves were withered, and became brittle with cracks. The infected plants were collected from six major fields. The tissues of diseased leaves were soaked in 75% ethanol for 10 s, 0.1% mercuric chloride for 2 min, rinsed with sterilized water, and placed on potato dextrose agar (PDA) at 25℃ for 7 days. On PDA, four strains were isolated, and the colony was gray to dark yellowish-brown, flocculent, regular with concentric growth rings. Strain PKLS06 produced a dark red to brown pigment in the agar medium. On lesions, the conidiophores were solitary or in fascicles, straight or slightly curved, brown, with a conical apex, with three to five septa. The conidiogenous cells were pale-brown and swollen at the apex. On PDA, spores were solitary, oblong, bluntly rounded or sometimes with a point at the apex, with two to five transverse septa and one to two longitudinal septa with contractions at the main transverse septum. Morphological characteristics were consistent with published descriptions of Stemphylium lycopersici (Kee et al. 2017; Xie et al. 2018). For molecular identification, rDNA internal transcribed spacer (ITS) and the glyceraldehyde-3-phosphate dehydrogenase (gpd) gene were amplified and sequenced (ITS accessions: MW243098, MW243099, MW243100, MW243101; gpd accessions: MW246803, MW246804, MW246805, MW246806) using published primers (White et al. 1990; Câmara et al. 2002). A phylogenetic tree was developed by Maximum Parsimony (MP), Maximum Likelihood (ML) and Bayesian inference (BI). These four isolates fall into the S. lycopersici clade with strong support and all isolates were distinguished clearly from other species. Pathogenicity tests were performed using these four isolates. Each isolate was cultured on PDA and shake-cultured in V-8 juice broth (Nasehi et al. 2014). Conidia were resuspended in sterilized water (1×106 conidia/mL) and inoculated on intact leaves with injury of 1-year-old P. kingianum. The plants were incubated at 25℃ with a 12 h photoperiod and 90% humidity. A small spot began to appear after 3 days, and symptoms were similar to the those observed in the nursery after 10 days. Interestingly, the pathogenicity of strain PKLS06 was relatively weaker. Control plants treated with sterile water showed no disease symptoms. Re-isolated strains had the same morphological characteristics and the same ITS and gpd sequences as the original isolates, thus fulfilling Koch's postulates. S. lycopersici, an important pathogen, is widely distributed, and can cause a variety of plant diseases. It is noteworthy that the disease was observed on a plant in the Liliaceae, expanding the host range of S. lycopersici, which previously was reported to primarily infect plants in the Solanaceae. Based on the results presented above, P. kingianum is a new host plant of S. lycopersici in China. This disease is a threat for nursery production of P. kingianum, leading to a reduction in yields and economic losses. References Kee, Y. J., et al. 2017. Plant Disease 102 (2): 445-446 Xie, X. W., et al. 2019. Canadian Journal of Plant Pathology-Revue Canadienne De Phytopathologie 41 (1): 124-128 White, T. J., et al. 1990. PCR Protocols: A Guide to Methods and Applications PCR Protocols: A Guide to Methods and Applications 18: 315-322 Câmara M. P. S., et al. 2002. Mycologia 94 (4): 660-672 Nasehi A., et al. 2014. Archives of Phytopathology & Plant Protection, 47 (14): 1658-1665.

First Report of Anthracnose Disease on Bletilla striata Caused by Colletotrichum orchidophilum in Yunnan, China.

Bletilla striata (Thunb.) Reichb. f. has high ornamental and medicinal value. B. striata has been used in Chinese medicine for thousands of years to treat various diseases, such as peptic ulcers, gastrointestinal diseases, lung diseases, and traumatic bleeding (Jiang et al. 2021). In September 2020, about 30% of B. striata plants in a plantation in Lancang County (Puer City, Yunnan Province, 22°48'17" N, 99°46'58" E) were found with symptoms resembling Bletilla anthracnose disease. In May 2021, symptomatic leaves were observed again with a disease incidence rate reached 54.05%, and were collected. The initial symptoms were the appearance of one or more round light brown spots on the leaves. Subsequently, the lesions became larger, forming oval brown-black spots. On severely affected leaves, several spots coalesced, causing withering and death of the leaves. To isolate the pathogen, 10 symptomatic tissues (5mm2) of 10 infected leaves were disinfected in 75% ethanol for 30s then in 2% sodium hypochlorite for 3 minutes, rinsed with sterile water for 3 times, incubated on potato dextrose agar (PDA) plates at 25℃ for 5 to 7 days with a 12 h light/dark photoperiodic cycle. Finally, ten pathogen strains with similar morphology were isolated and pure cultures were obtained by single spore isolation. The morphology of fungal colonies was round, carpet-like, flat and neat, and the color was gray black. The conidiophores were colorless to brown and oval or stick-shaped. The conidia were cylindrical or oblong, consisted of a single cell with blunt round ends, and were on average 12.92 (8.13-21.21) μm×3.96 (2.55-5.90) μm (n=200) in size. Based on the morphology and conidial characteristics, the pathogen was identified as Colletotrichum sp. (Damm et al. 2012). The total genomic DNA of representative isolates (LCTJ-02, LCTJ-03, LCTJ-04, LCTJ-05 and LCTJ-06) was extracted and the ITS region, GAPDH, ACT and HIS3 gene regions were amplified and sequenced using the primer pairs ITS1/ITS4, GDF1/GDR1, 512F/783R, and CylH3F/CylH3R, respectively (Cai et al. 2009). The sequences were deposited in GenBank (MZ433189 to MZ433193 for ITS, MZ436430 to MZ436434 for GAPDH, MZ436435 to MZ436439 for HIS3 and MZ448474 to MZ448478 for ACT). BLAST search revealed that all sequences showed 98% to 100% homology with the corresponding sequences of C. orchidophilum ex-type (CBS 632.80). Phylogenetic trees were constructed using neighbor-joining and maximum likelihood methods for the combined data set of the ITS, GAPDH, ACT, and HIS3 genes by MEGA-X (Kumar et al.2018). In general, LCTJ-02, LCTJ-03, LCTJ-04, LCTJ-05, LCTJ-06, and C. orchidophilum type strains clustered on the same clade. To confirm pathogenicity, the five isolates of C. orchidophilum were inoculated in healthy leaves of potted B. striata, as described by Cai et al. (2009), with slight modifications. Each leaf was inoculated with three drops(10 µl drop-1) of conidia suspension (106 spores mL-1). The control group was mock inoculated with sterile water the same way. All samples were covered with plastic bags and maintained at 70% to 80% relative humidity for seven days. After this period, all inoculated leaves showed similar lesions, and the symptoms were identical to those observed in the field. The control plants remained healthy. The pathogens were re-isolated from two leaves of each treatment and re-identified as C. orchidophilum. To our knowledge, this is the first report of C. orchidophilum causing anthracnose on B. striata in China. In the future, the occurrence and transmission of this pathogen should be further studied in order to develop reasonable control measures.

澜沧县两栖动物多样性及海拔分布格局

PDF HTML阅读 XML下载 导出引用 引用提醒 澜沧县两栖动物多样性及海拔分布格局 DOI: 10.5846/stxb202103150693 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 生态环境部生物多样性调查评估项目（2019HJ2096001006） Species diversity and altitudinal distribution patterns of Amphibians in Lancang County, Yunnan Province, China Author: Affiliation: Fund Project: The Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment, China（2019HJ2096001006) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:海拔梯度综合了温度、降水等气候因子，是影响物种多样性分布格局的重要环境因子，两栖动物多样性及其海拔分布格局一直是生物地理学和生态学研究的重要内容。为了全面掌握云南澜沧县两栖动物多样性现状及海拔分布格局，在调查并掌握澜沧县两栖动物多样性本底数据的基础上，根据地形地貌和生境的不同，在澜沧县99个10km×10km有效网格中按照分层抽样的方法选取45个网格，每个网格设置3-5条样线，于2016-2017年开展野外调查。调查共发现两栖动物1842只，隶属于2目9科30属60种，以树蛙科为主，占两栖动物物种总数的28.3%，其中云南纤树蛙（Gracixalus yunnanensis）为新种，清迈泽陆蛙（Fejervarya qingmaiensis）为中国新纪录种；调查到中国特有种有15种，三有保护动物有25种，受威胁物种有19种，其中极危物种1种，濒危物种4种，易危物种14种；澜沧县两栖动物在海拔600-2400m范围内均有分布，其中，在海拔1800-2000m之间的范围内调查到的两栖动物物种数目和多度均较高，其次是在海拔1600-1800m和1200-1400m范围内；本次调查记录到的两栖动物物种数是历史记录物种数的3倍，属数比历史记录多了1倍，铃蟾科为新记录科；丰富度较高的网格尤其是丰富度在20以上的网格均处于中高海拔，海拔相对较低和较高的网格丰富度相对较低；两栖动物多样性科、属、种的丰富度在海拔梯度上分布格局不太一致，种丰富度的海拔分布格局大体呈双峰型，是由包括平均降水量、平均温度和植被覆盖指数等环境因子的综合作用，各因子与物种丰富度相关性从大到小依次为平均降水量 > 平均海拔=平均温度 > 植被覆盖指数 > 水网密度指数 > 样线距离水域的平均距离 > 植被类型数量。研究摸清了澜沧县两栖动物的多样性状况，分析了两栖动物多样性海拔分布格局，为澜沧县生物多样性保护提供基础数据。 Abstract:The altitude gradient is an important factor for studying the altitudinal pattern of species diversity, which integrates climatic factors such as temperature and precipitation. The diversity and altitudinal pattern of amphibians is important research in biogeography and ecology. In order to fully grasp the current situation and elevation distribution pattern of amphibian diversity in Lancang County, Yunnan Province, the biodiversity of amphibian diversity was surveyed in 2016-2017. On the background data of amphibian diversity in Lancang County, 45 survey grids were selected from the 99 effective grids (10km×10km) according to the topography, landforms and habitats. 3-5 survey lines were set in each grid. Totally, 1842 individuals were recorded, belonging to 60 species, 30 genera, 9 families and 2 orders. Among them, Rhacophoridae is the dominant family, accounting for 28.3% of the total amphibian families. The Gracixalus yunnanensis is a new species. The Fejervarya qingmaiensis is a newly recorded species in China. Among all the surveyed species, there are 15 endemic to China, 25 beneficial or important economic and scientific value wild animals of China. There are 19 threatened species, including one critically endangered species, 4 endangered species and 14 vulnerable species. The amphibians of Lancang County are mainly distributed in the altitude range of 600-2400m. These are the highest number and abundance of amphibian in the altitude range of 1800-2000m. Second are in the range of 1600-1800m and 1200-1400m. The number of the family was tripled and the genera was doubled compared with the previous survey, and the Bombinatoridae was firstly recorded in this county. Grids with high richness, especially those with richness above 20, are at medium and high altitudes. Grid with relatively low richness are at relatively low and high altitude. The distribution pattern of amphibian diversity family, genus and species richness is not consistent along the altitudinal gradient. The altitudinal distribution pattern of species richness is generally bimodal, which is caused by the comprehensive effect of environmental factors including average precipitation, average temperature and vegetation cover index. The order of the correlation between each factor and species richness is:average precipitation > average altitude=average temperature > vegetation coverage index > water network density index > average distance between transect and water area > number of vegetation types. This study found out the diversity of amphibians in Lancang County, analyzed the altitudinal distribution pattern of amphibian diversity, and provided basic data for biodiversity conservation in Lancang County. 参考文献 相似文献 引证文献

Traditional medicinal knowledge in Lancang-Mekong River:a case study in Lancang Lahu autonomous county

Lancang Lahu autonomous county, where the Lancang-Mekong River flows by, was selected as the case site to investigate the traditional medicinal knowledge(TMK). A comparison of TMK between Lancang county and other places in the Lancang-Mekong sub-region was conducted. Research on TMK has been seldom reported although there are abundant medicinal resources in this sub-region. The key informant interview and other methods have been adopted in the field surveys in the past six years. The investigation revealed that there was rich TMK and various herbal medicine resources in Lancang county. A total of 220 folk prescriptions have been collected, which were normally simple with easy processing methods and usages, and most raw materials were freshly used. As for medicinal plants, 121 species in 67 families have been documented. Other findings included that TMK in Lancang county was remained at the level of medication based on experience only. The processing methods of herbal medicines were simple and the bioactive ingredients were not clear. Without text and cultural support for self-teaching, coupled with conservative inheritance, it resulted in massive losses of TMK. The folk doctors have accumulated their factions based on self-study or ancestral experience. There was different treatment experience among folk doctors, but the safety and effectiveness should be paid attention to. The folk doctors used various herbal medicines, but there was a lack of standards or specifications for quality control. Given the problems existing in inheritance and development, conservation strategies were proposed in the present study.

Multiobjective Land-Use Optimization Allocation in Eucalyptus-Introduced Regions Based on the GMDP–ACO Model

Large-scale artificial forests have replaced original land cover types such as arable land, garden land, evergreen broad-leaved forest, and Pinus khasya forest. In particular, the widespread introduction of Eucalyptus has caused great changes in land-use patterns and affected ecosystem service functions. How to rationally allocate land, improve the land utilization rate, and ecosystem service functions in a limited land area have become research hotspots. This paper mainly studies the land-use optimization in Lancang County, a large-scale eucalyptus-introduced region, by using the gray multiobjective dynamic programming (GMDP) model and the ant colony optimization (ACO) algorithm. The maximization of social, economic, and ecological benefits is used as the quantitative structure optimization objective in this model, while land-use suitability and spatial compactness are used as the spatial optimization rules. The results show the following: (1) The economic and ecological benefits are significantly improved after optimization compared with those of the current situation and the integrated land-use planning in Lancang County (i.e., the overall plan hereafter or the overall planning of land use by government departments). The social benefits are lower than those in the current situation and overall plan. (2) The suitability of the land-use spatial structure after optimization is improved to some extent compared with the land-use structures of the current situation and overall plan. In particular, the suitability of urban construction land is significantly improved after optimization. (3) The patch density (PD) index of each land-use type is significantly reduced after optimization. The fractal dimension (FRAC) indexes of urban construction land and natural reserves are increased compared with those in the current situation and in the overall plan. The compactness index (CI) of land use increases after optimization, and the degree of land-use fragmentation is improved significantly. (4) Land transfer is greater for arable land, garden land, forests, and natural reserves after optimization. Compared with the overall plan, more high-quality arable land and forest resources may be protected. In conclusion, optimized land use is conducive to promoting the rational use of land resources, socioeconomic development, and environmental protection in eucalyptus-introduced regions.

Analysis on the Characteristics of Illegal Cutting and Deforestation of Pinus kesiya in Lancang County of Yunnan Province

Lancang county, Yunnan Province is located in the southwestern border of Yunnan Province, , China and has abundant forest resources. At the same time, there are many cases of illegal logging and deforestation in Lancang county. In the county, the cases of illegal logging and deforestation of Pinus kesiya were mainly carried out by rural personnel, the single-person case was converted into a form of gang, the remoteness of the crime site makes it difficult to find and investigate, especially in most of the rural collective forests, etc. The main reasons for its occurrence are: the general public’s lack of legal awareness and economic poverty. A series of preventive measures and strike strategies, such as perfecting the system of recruiting personnel and intensifying the crackdown on such cases, were proposed to provide theoretical support for the protection and development of Pinus kesiya resources Lancang County.

The Rivalry between Old and New Material in Creating Local Environmental Features - Illustrated by the Protection and Remediation of Traditional Environmental Features in Jingmai Village, Lancang County

Through a practical project - the remediation of the landscape and the environment in Jingmai Village ,which analyzes the problem of the application of old and new material in the remediation and design of traditional village. Under the social background of tourism promoting economy, transform the incongruous elements in traditional villages and intend to restore the landscape and the environment of traditional Dai national folk houses, so as to achieve the dual purposes of protection and development.

Feasibility Analysis of Mechanized Upland Rice Cultivation in Mountainous Area

Continuous seasonal drought in past 3 years greatly affects rice production of Yunnan, China. Because upland rice has stronger performance than paddy rice for mountain farming, to develop mechanized production of upland rice is more beneficial to ensure food security of mountainous area. In this study, we investigate and survey traditional upland rice cultivation of peasant household in mountainous rural area of Lancang county, and use Cobb-Douglas production function to analyze the relationship between mechanized and non-mechanized upland rice cultivation. The results show that mechanized upland rice cultivation not only can increase the yield, but also is superior to non-mechanized system in techno-economics. Rational utilizing farm machinery is feasible to upland rice cultivation and will promote the development of the rice production of Yunnan Province.

外来树种桉树引种的景观生态安全格局

PDF HTML阅读 XML下载 导出引用 引用提醒 外来树种桉树引种的景观生态安全格局 DOI: 10.5846/stxb201210011366 作者: 作者单位: 云南大学资源环境与地球科学学院,云南国土资源职业学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(40961031);云南省应用基础研究面上项目(2009CD022);云南大学"中青年骨干教师培养计划"项目(XT412003)资助 Landscape ecological security pattern associated with the introduction of exotic tree species Eucalyptus Author: Affiliation: College of Resource Environment and Earth Science, Yunnan University,Yunnan College of Land and Resources Vocational Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以大面积桉树引种区云南省澜沧县为研究区,以自然栖息地和生物多样性的整体保护为目标,利用最小累积阻力模型开展了桉树引种的景观生态安全格局的定量研究。结果表明:(1)基于GIS技术和"成本距离加权"制图分析工具,将生物和景观等综合因素融入最小累积阻力模型,把"源"扩展的生态过程与景观格局结合起来,应用于桉树引种的景观生态安全格局构建中是可行的。(2)选择次生常绿阔林为保护"源",地表覆盖类型、海拔、坡度、土壤质地和公路等为阻力因子,建立最小累计阻力面,识别了廊道、辐射道和战略点等生态安全格局组分;用最小累积阻力阈值划分了生态缓冲区、生态过渡区、生态边缘区、农业耕作区和居民生活区等生态功能区,并界定桉树禁止种植区和桉树可种植区,最终组合成两个方案的中级和高级景观生态安全格局。方案一,中级和高级安全水平的桉树可种植区面积分别占研究区面积的33.48%和19.27%。方案二,中级和高级安全水平的桉树可种植区面积分别占研究区面积的28.37%和15.17%。(3)从"源"的扩展效果、保护广度、管理成本、难易程度及生态环境和经济社会发展要求等方面评价,认为方案二的中级安全水平格局能够相对满足澜沧县对生态、经济发展的要求。研究结果为制定研究区生态安全策略提供参考。 Abstract:With rapid introduction of exotic trees, natural habitat loss and landscape fragmentation were aggravated in mountainous areas. Construction of landscape eco-security pattern can provide feasible option to prevent landscape fragmentation and to protect natural habitats and biodiversity. Since 2003, a large amount of exotic tree species, Eucalyptus has been introduced into Lancang county of Yunnan province. The Eucalyptus replaced the native forest, farmland, wasteland and other ecosystems, leading to serious natural habitat loss, landscape fragmentation and biodiversity threatening. In this paper, the large areas in Lancang County of Yunnan Province, where Eucalyptus have been extensively introduced were selected as the case study sites to examine the landscape eco-security pattern for Eucalyptus introduction by using the minimum cumulative resistance model. The results indicated: (1) it's feasible, based on the GIS and "cost distance weighing" mapping analysis tool, to construct the landscape eco-security pattern of Eucalyptus introduction by integrating the biological factors and landscape factors into minimum cumulative resistance (MCR) model and combining the "source" extended ecological process with Landscape pattern. This can be a reference approach to constructing the landscape eco-security pattern for the exotic tree introduction in other areas. (2) the components of ecological security pattern such as corridor, radiating routes and strategic point etc. indentified by the minimum cumulative resistances surface which were derived from the GIS-based and MCR model using land cover types, altitude, slope, soil texture and road etc. as resistance factors can preserve ecosystem functions in Eucalyptus-introduced and affect positively the species migration and diffusion in " protection source", which was secondary evergreen broad-leaved forest in natural habitat in this study. By using the minimum cumulative resistance threshold values, we divided the eco-buffer zone, eco-transition zone, eco-fringe zone, farming zone and residential zone for the landscape eco-security construction. We also defined the banned zone and planting zone for Eucalyptus plantation. The medium-security and high-security landscape eco-security patterns were developed on the basis of minimum cost but maximum ecological and economic benefit for the introduction areas in Eucalyptus plantation. To achieve this goal, there will be two schemes. In the first scheme, medium-security and high-security areas for Eucalyptus plantation account for 33.48% and 19.27% of total study areas. In the second scheme, medium-security and high-security areas for Eucalyptus plantation account for 28.37% and 15.17% of total study areas. (3) the second scheme of medium-security pattern could fit ecological and economic conditions of Lancang County better when compared these two schemes from the expansion effect of "source", protection range, management cost, difficulty level, eco-environment capacity as well as economic and social development. In the second scheme, the large and small patches of protection 'sources' were spaced in-between, and large patches can work well for protecting the species and ecosystems better, small patches could be settled foothold to protect distributed rare species or ecological niches. As the "source" patches were small and concentrated, the fragmentation was relatively low, so the protection and management of the "source" will be less difficult and costly. There were 22 corridors and combined circular, so the connectivity among "sources" was good. There were 6 radiating routes, meaning less opportunity for "sources" expansion. There were many strategic points of native tree species for improving the integrity of the "sources". All these results may provide some useful references for developing eco-security strategies in the study areas. 参考文献 相似文献 引证文献

Geochemical Characteristics and Ore Prediction of the Pb-Zn Polymetallic District in Kanmashan of Lancang County, Yunnan

According to the analysis of geological characteristics and Elemental correlation charac –teristics, Threshold and R-factor analysis leading to the results geochemistry characteristics of Kanmashan Pb-Zn polymetallic deposit which is located in Lancang county of Yunnan province, the deposit is discovered in the southern arc of Chong mountain-lincang-menghai mountain, alonging the contact strip of Lincang granitoid batholith and proterozoic group in LanCang, metallogenic conditions near fracture is relatively ideal, which can be used as a further work area.

Assessment of plant species diversity of ancient tea garden communities in Yunnan, Southwest of China

Ancient tea garden has existed in Lancang County, Yunnan Province for more than 1,300 years, and is regarded as the provenance of Pu’er Tea’s seed source. The ancient tea garden ecosystem is a typical model that integrates conservation biodiversity and utilization of natural resources. In order to reveal the role of biodiversity conservation of this ecosystem, plant diversity and application value of ancient tea gardens, normal tea gardens and secondary forestry communities in Lancang County were surveyed and compared. 360 households investigation were also conducted by using household-based agro-biodiversity assessment (HH-ABA). The results showed: (1) Ancient tea garden communities have high biodiversity, whose plant species diversity (H = 3.03) is lower than that of secondary forestry (H = 4.59) and higher than that of normal tea garden (H = 2.62); (2) Life forms analysis of plant species showed the vertical structure of the ancient tea garden communities are intact, herbs, trees, shrubs, vines, epiphytes are included, which is similar to that of secondary forest, while normal tea garden is dominant by herbs and no trees; (3) A large number of protected species, including five endangered, seven vulnerable and three rare, is well conserved in the ancient tea garden, while no protected species were found in secondary forest and normal tea garden; (4) The analysis of agro-biodiversity revealed that 56 % of plant species in the ancient tea garden are effectively used by households, while no plant except tea trees is used in normal tea garden; (5) The integrated values of ancient tea garden and normal tea garden illustrated that both biodiversity conservation and economic income of ancient tea garden are higher than that of normal tea garden. We suggest that the local peoples’ knowledge and experience on resource management and utilization should be well documented and encouraged, and effective conservation and reasonable utilization of ancient tea garden would be achieved through training and demonstration with the participation of the local government, research institution and farmer.

Effects of Crofton weed Ageratina adenophora on assemblages of Carabidae (Coleoptera) in the Yunnan Province, South China

Crofton weed ( Ageratina adenophora) is a highly invasive weed that has spread into several provinces of southern China. This study compares carabid assemblages originating from native pastures with assemblages in Crofton weed dominated communities in the Lancang County, Yunnan Province, to assess how the invasion of this neophyte impacts the community structure of ground-dwelling arthropods. Over a period of 16 months, a total of 1574 carabid beetles representing 28 species were collected at two types of pasture, and 679 carabid beetles representing 34 species at stands of Crofton weed. The most common carabid species, Tetragonoderus arcuatus and Harpalus indicus, were mostly found in the pastures, while four of the five rarest species were present exclusively under Crofton weed. Alpha-diversity and evenness of carabid assemblages were greater under Crofton weed. Three distinct groups of carabid species were separated according to indicator values and a characterization of habitats: habitat generalists, Crofton weed specialists and native pasture specialists. The distribution of carabid species was related to environmental parameters such as depth of litter layer, total phosphorus, height of vegetation, amount of fresh biomass and pH of the soil. According to this study, the invasion of Crofton weed will alter the structure of carabid communities, but will not necessarily reduce the alpha-diversity of carabid assemblages.