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@#Abstract: Objective To predict the potential distribution of talaromycosis marneffei (TSM) and analyze its driving factors, so as to provide evidence for the surveillance and prevention of this disease. Methods The data of all laboratory-confirmed, non-duplicating TSM published in the English and Chinese literature from the first case in January 1964 to December 2018 was collected. A Maxent ecology model using environmental variables, Rhizomys distribution and HIV/AIDS epidemic was developed to forecast ecological niche of TSM worldwide, as well as identify the driving factors. Results A total of 705 articles (477 in Chinese and 228 in English) were obtained during the study period. After excluding imported cases, a total of 100 foci information were included in the model. The area under the receiver operating characteristic (ROC) curve (AUC) of the model was 0.997 for the training set and 0.991 for the test set. Maxent model revealed that Rhizomys distribution, mean temperature of warmest quarter, precipitation of wettest month, HIV/AIDS epidemic and mean temperature of driest quarter were the top 5 important variables affecting TSM distribution. In addition to identifying traditional TSM endemic areas (South of the Yangtze River in China, Southeast Asian, North and Northeast India), other potential endemic areas were also identified, including parts of the North of the Yangtze River, Central America, West Coast of Africa, East Coast of South America, the Korean Peninsula and Japan. Conclusion Our finding has discovered hidden high-risk areas and provided insights about driving factors of TSM distribution, which will help inform surveillance strategies and improve the effectiveness of public health interventions against TM infections.
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Chuanxiong Rhizoma is a traditional Chinese medicinal material mainly produced in Sichuan and Chongqing of China. In recent years, the cadmium content in Chuanxiong Rhizoma produced in most of the genuine producing areas has exceeded the standard, which makes Chuanxiong Rhizoma difficult to be exported. To solve the problem of excessive cadmium content in soil, this study employed the MaxEnt model to simulate the potential geographic distribution of Ligusticum chuanxiong and evaluate important environmental factors, and re-plan its ecologically suitable areas based on the mineral distribution characteristics and soil cadmium pollution status. The results showed that the places suitable for L. chuanxiong growing covered an area of 335 523.69 km~2, mainly in central and eastern Sichuan, southern Shaanxi and most parts of Chongqing. Among them, the highly suitable areas of L. chuanxiong were mainly concentrated in Chengdu, Ya'an, Deyang, and Mianyang. Solar radiation, annual precipitation, and annual range of temperature were evaluated as important variables affecting the distribution of L. chuanxiong, with the contribution rates of 62.3%, 13.3%, and 6.8%, respectively. In addition, Qionglai county, Chongqing county, Mianyang city(Youxian district and Fucheng district), Qingchuan county, and Xinjin county were classified into the first-class ecologically suitable zone, covering a total area of 2 768.87 km~2. The se-cond-class ecologically suitable zone was even wider, involving such counties as Tongjiang county, Renshou county, Jianyang county, and Nanjiang county, and the total area reached 43 616.92 km~2. The re-planning of the ecologically suitable areas for L. chuanxiong has provided strong data support for the cultivation and resource development of L. chuanxiong and also new ideas for solving the problem of excessive cadmium content in L. chuanxiong.
Subject(s)
Cadmium/toxicity , Environmental Pollution , Ligusticum , Rhizome , SoilABSTRACT
Objective:To analyze the main factors affecting the <italic>Ziziphus jujuba</italic> distribution and expand the understanding of its distribution and the corresponding influencing factors by comparing the distribution sites of <italic>Z. jujuba</italic> predicted by models with those recorded in the literature. Method:More than 200 distribution sites of <italic>Z. jujuba</italic> accompanied by 55 environmental factors were obtained from literature and specimen review. The environmental factors that affect the distribution of <italic>Z. jujuba</italic> were explored by maximum entropy （MaxEnt） model， and the potential distribution areas of <italic>Z. jujuba</italic> in China were analyzed by ArcGIS， followed by the verification of the main environmental factors using receiver-operating characteristic （ROC） curve and Jackknife method. Result:The area under the curve （AUC） values for the test data and training data were both greater than 0.9， which perfectly satisfied the standard， indicating that the research results were accurate and reliable. Conclusion:The annual average temperature， the average temperature in May， the average temperature in the warmest season， vegetation type， soil type， average temperature in June， average temperature in September， and average temperature in August are proved to be the main environmental factors affecting the distribution of <italic>Z. jujuba</italic>， which can be found almost all over China， except for Heilongjiang and Tibet. <italic>Z. jujuba</italic> is most suitable to be planted in southeastern Sichuan， Chongqing， southern Gansu， Ningxia， most areas of central Shaanxi， eastern and southwestern Shanxi， Henan， eastern and northern Hubei， northern and eastern Anhui， Shandong， Hebei， Beijing， Tianjin， western Liaoning， and Zhejiang. As revealed by literature review， the most suitable growing areas of <italic>Z. jujuba</italic> are southeastern Sichuan， central Shaanxi， southwestern Shanxi， western and northern Henan， Shandong， and southwestern and eastern Hebei.
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Objective:To explore the potential suitable distribution area and the high-quality distribution area of <italic>Sabia parviflora</italic>. Method:Combined with the distribution information and environmental factors，the maximum entropy （MaxEnt） model and ArcGIS software were used to predict the potential suitable distribution area of <italic>S. parviflora</italic>. Based on the correlation between environmental factors and total saponins，total flavonoids，quercetin-3-<italic>O</italic>-gentiobioside，camellianoside，tsubakioside A，kaempferol-3-<italic>O</italic>-rutinoside and isobariclisin-3-<italic>O</italic>-rutinoside，the quality regionalization was conducted by using spatial interpolation method and fuzzy superposition function in ArcGIS software. Result:<italic>S. parviflora</italic> is mainly distributed in Yunnan，Guizhou，Guangxi province in China. The medium and high suitable areas accounts for about 2.88% of the national area. The precipitation in October and November，the precipitation in the warmest and driest seasons，the standard deviation of seasonal changes in temperature and altitude are the main environmental factors that affect the distribution of <italic>S. parviflora</italic>. Slope，precipitation，solar radiation and temperature change had great influence on the accumulation of secondary metabolites. Based on the results of potential suitable distribution and spatial interpolation of each component，the high-quality areas of <italic>S. parviflora</italic> are mainly concentrated in the southwest of Guizhou，with Qinglong，Guanling，Zhenning，Pu'an，Xingren county and other areas as the core. Conclusion:This study provides a scientific guidance for the site selection of artificial planting and the procurement of medicinal materials for <italic>S. parviflora</italic>.
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The study aims at providing a new suitable way to promote artificial cultivation, solving the problem of resources increasingly endangered wild medicine, and protecting the wild resources of Tibetan medicine. The content of quercetin,kaempferol and isorhamnetin was determined by HPLC. The correlation between flavonoids components and ecological factors was analyzed using partial least-squares regression (PLSR). Based on Maxent model combining using ArcGIS software, suitable regionalization for H.rhamnoides subsp. sinensis was studied.The results showed that the difference of quercetin,kaempferol and isorhamnetin content in samples from different regions were obvious. The main factors effecting quercetin content accumulation were the altitude andthe average monthly precipitation in January and August. The main factors effecting kaempferol accumulation were the altitude andthe average monthly precipitation in the coldest quarter and December. The main factors effecting isorhamnetin accumulation were the average monthly precipitation in August, January and the coldest quarter.The regional distribution suitability index for H.rhamnoides subsp. sinensis was 0-0.708. The suitable area 590 500 km², accounting for 6.13% of the total area. The preferably suitable area was 552 500 km², accounting for 5.73% of the total area.The methods used in the study is simple and feasible, the result is reliable which provide a new approach for Tibetan medicine resources sustainable exploitation and utilization.
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In order to study the ecology suitability of Pterocephalus hookeri, and provide a reference for GAP planting location and regional development, the Maxent model and GIS technology were used to investigate ecology suitability regions for P. hookeri based on the distribution points collected from Chinese virtual herbarium, the references and field trips. The potential distribution areas mainly concentrated in the eastern Tibet, western Sichuan, southern Qinghai, northwest Yunnan, and southern Gansu. There were 7 major environmental factors to have obvious influence on ecology suitability distributions of P. hookeri, including altitude (contribution rate of 62%), precipitation of warmest quarter (contribution rate of 14.4%), coefficient of variation of precipitation seasonality (contribution rate of 7.2%), mean temperature of driest quarter (contribution rate of 3.5%), the electrical conductivity of top and sub-soil (contribution rate of 3%), the total exchangeable bases in the top- and subsoil (contribution rate of 2.4%) and SD of temperature seasonality (contribution rate of 2.2%). The study of the ecological suitability regionalization of P. hookeri based on Maxent model can provide scientific basis for the selection of artificial planting base and GAP planting location.
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Apocynum venetum belongs to apocynaceae and is a perennial medicinal plant, its stem is an important textile raw materials. The projection of potential geographic distribution of A. venetum has an important significance for the protection and sustainable utilization of the plant. This study was conducted to determine the potential geographic distribution of A. venetum and to project how climate change would affect its geographic distribution. The projection geographic distribution of A. venetum under current bioclimatic conditions in northern China was simulated using MaxEnt software based on species presence data at 44 locations and 19 bioclimatic parameters. The future distributions of A. venetum were also projected in 2050 and 2070 under the climate change scenarios of RCP2.6 and RCP8.5 described in 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The result showed that min air temperature of the coldest month, annual mean air temperature, precipitation of the coldest quarter and mean air temperature of the wettest quarter dominated the geographic distribution of A. venetum. Under current climate, the suitable habitats of A. venetum is 11.94% in China, the suitable habitats are mainly located in the middle of Xinjiang, in the northern part of Gansu, in the southern part of Neimeng, in the northern part of Ningxia, in the middle and northern part of Shaanxi, in the southern part of Shanxi, in the middle and northern part of Henan, in the middle and southern part of Hebei, Shandong, Tianjin, in the southern part of Liaoning and part of Beijing. From 2050 to 2070, the model outputs indicated that the suitable habitats of A. venetum would decrease under the climate change scenarios of RCP2.6 and RCP8.5.
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The study aims at predicting ecological suitability of Ephedra intermedia in China by using maximum entropy Maxent model combined with GIS, and finding the main ecological factors affecting the distribution of E. intermedia suitability in appropriate growth area. Thirty-eight collected samples of E. intermedia and E. intermedia and 116 distribution information from CVH information using ArcGIS technology were analyzed. MaxEnt model was applied to forecast the E. intermedia in our country's ecology. E. intermedia MaxEnt ROC curve model training data and testing data sets the AUC value was 0.986 and 0.958, respectively, which were greater than 0.9, tending to be 1.The calculated E. intermedia habitat suitability by the model showed a high accuracy and credibility, which indicated that MaxEnt model could well predict the potential distribution area of E. intermedia in China.
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Specific information on geographic distribution of a species is important for its conservation. This study was conducted to determine the potential geographic distribution of Alhagi sparsifolia, which is a plant used in traditional Uighur medicine, and predict how climate change would affect its geographic range. The potential geographic distribution of A. sparsifolia under the current conditions in China was simulated with MaxEnt software based on species presence data at 42 locations and 19 climatic variables. The future distributions of A. sparsifolia were also projected in 2050 and 2070 under the climate change scenarios of RCP2.6 and RCP8.5 described in 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).The result showed that mean temperature of the coldest quarter, annual mean temperature, precipitation of the coldest quarter, annual precipitation, precipitation of the wettest month, mean temperature of the wettest quarter and the temperature annual range were the seven climatic factors influencing the geographic distribution of A. sparsifolia under current climate, the suitable habitats are mainly located in the Xinjiang, in the middle and north of Gansu, in the west of Neimeng, in the north of Nei Monggol. From 2050 to 2070, the model simulations indicated that the suitable habitats of A. sparsifolia would decrease under the climate change scenarios of RCP2.6 and scenarios of RCP8.5 on the whole.
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The application of ArcGIS and Maxent modelto analyze the ecological suitability of Gardenia jasminoides.Taking 85 batches of Gardenia as the basis of analysis, the selection of ecological factors for the growth of Gardenia. The results showed that the average precipitation in April, the average precipitation in November and the average precipitation in August were the most important factors affecting the growth of Gardenia. The relative concentration of Gardenia suitable growth region,north to the south of Shaanxi province, south of Henan, central Anhui, south to the north of Hainan province, west to central Sichuan province, east of Zhejiang coastal area, northeast of Taiwan.
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At the urgent request of Coptis chinensis planting,growth suitability as assessment indicators for C. chinensis cultivation was proposed and analyzed in this paper , based on chemical quality determination and ecological fators analysis by Maxent and ArcGIS model. Its potential distribution areas at differernt suitability grade and regionalization map were formulated based on statistical theory and growth suitability theory. The results showed that the most suitable habitats is some parts of Chongqing and Hubei province, such as Shizhu, Lichuan, Wulong, Wuxi, Enshi. There are seven ecological factor is the main ecological factors affect the growth of Coptidis Rhizoma, including altitude, precipitation in February and September and the rise of precipitation and altitude is conducive to the accumulation of total alkaloid content in C. chinensis. Therefore, The results of the study not only illustrates the most suitable for the surroundings of Coptidis Rhizoma, also helpful to further research and practice of cultivation regionalization, wild resource monitoring and large-scale cultivation of traditional Chinese medicine plants.
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The distribution information of Glycyrrhiza uralensis was collected by interview investigation and field survey, and 46 related environmental factors were collected, some kinds of functional chemical constituents of G.uralensis were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. The AUC of ROC curve was both above 0.95, indicating that the predictive results with the maximum model were highly precise. The results showed that 5 major ecological factors have obvious influence on ecology suitability distributions of G. uralensis, including July average temperature, soil sub category, Dec precipitation, vegetation types and standard deviation of seasonal variation in temperature, et al. It is suitable for the living habits of the G. uralensis, adequate light, low rainfall, summer heat and large temperature difference between day and night, which is suitable for distribution in the northern temperate plains and mountains. In addition, the ecological suitability regionalization based on the chemical constituents of G.uralensis also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of G.uralensis.
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The distribution information of Lycii Fructus was collected by interview investigation and field survey, and 46 related environmental factors were collected, some kinds of functional chemical constituents the of Lycii Fructus were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. The AUC of ROC curve was both above 0.95, indicating that the predictive results with the maximum model were highly precise. The results showed that 5 major ecological factors had obvious influence on ecology suitability distributions of Lycii Fructus, including soil pH, soil subclass, vegetation type and in August the average temperature et al. It is suitable for the living habits of the Lycii Fructus, dry, cool weather, more hardy, drought-resistant, alkali soil, which is suitable for distribution in the northern temperate plains. In addition, the ecological suitability regionalization based on the chemical constituents of Lycii Fructus also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of Lycii Fructus.
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The distribution information of Chinese angelica was collected by interview investigation and field survey, and 43 related environmental factors were collected, some kinds of functional chemical constituents of Angelica sinensis were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. Application of R language to establish the relationship between the effective component of Chinese angelica and enviromental factors model, using ArcGIS software space to carry out space calculation method for the quality regionalization of Chinese angelica. The results showed that 4 major ecological factors had obvious influence on ecology suitability distributions of Chinese angelica, including altitude, soil sub category, May precipitation and the warmest month of the highest temperature, et al. It is suitable for the living habits of the Chinese angelica, cold and humid climate, which is suitable for the deep area of the soil. In addition, the ecological suitability regionalization based on the effect of Chinese angelica also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of Chinese angelica.
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In this paper, the potential distribution information and ecological suitability regionalization for Gastrodia elata in Zhaotong were studied based on the climate, terrain, soil and vegetation factors analysis by Maxent and ArcGIS. The results showed that the highly potential distribution (suitability index>0.6) mainly located in Zhaotong, Yunnan province（Zhenxiong,Yiliang and Daguan county, with an area of 2 872 km²）, and Bijie, Guizhou province （Hezhang,Bijie,Weining county, 1 251 km²）. The AUC of ROC curve was above 0.99, indicating that the predictive results with the Maxent model were highly precise. The main ecological factors determining the potential distribution were the altitude, average rainfall in November, average rainfall in October, vegetation types, average rainfall in March, average rainfall in April,soil types,isothermal characteristic and average rainfall in June. The environmental variables in the highly potential areas were determined as altitude around 1 450-2 200 m,annual average temperature around 18.0-20.4 ℃,annual average precipitation around 900 mm,yellow soil or yellow brown soil,and acid sandy loam or slightly acidic sandy loam.The results will provide valuable references for plantation regionalization and the siting for imitation wild planting of G. elata in Zhaotong.