Copy number and selection of MHC genes in ruminants are related to habitat, average life span and diet.

The ruminants, as the main group of livestock, have been extensively studied in terms of their physiology, endocrinology, biochemistry, genetics, and nutrition. Despite the wide geographic distribution and habitat diversity of animals in this group, their ecology and evolution remain poorly understood. In this study, we analyzed the gene copy number, selection, and ecological and evolutionary processes that have affected the evolution of major histocompatibility complex (MHC) genes across ruminant lineages based on available genomic data. The 51 species analyzed represented all six families of ruminants. Our finding indicated that the architecture of the MHC region is conserved in ruminants, but with variable copy numbers of MHC-I, MHC-IIA, and MHC-IIB genes. No lineage-specific gene duplication was observed in the MHC genes. The phylogenetic generalized least squares regression (PGLS) model revealed association between ecological and biological factors (habitat and lifespan) and gene duplication in DQA and DQB, but not in DRB. The selection pressure of DQA and DQB were related with lifespan, diet, and the ratio of genetic repeat elements. These results suggest that the MHC evolution in ruminants, including copy number and selection, has been influenced by genetic repeat elements, pathogen exposure risk, and intrinsic cost of possessing multiple MHC genes.

Mechanism underlying temperature sensitivity of soil organic carbon decomposition: A review.

Temperature sensitivity (Q10) of soil organic carbon (SOC) decomposition is an important index to estimate the dynamics of soil C budget. However, the spatial variation of Q10 and its influencing factors remain largely uncertain. In this study, we reviewed the effects of climate environment, spatial geographic pattern, soil physicochemical property, vegetation type, microbial community composition and function, and global climate change on Q10 to summarize the general rule of each factor influencing Q10 and compare the relative contribution of each factor to Q10 in different ecosystems. The results showed that Q10 decreases with the increases of temperature and precipitation, but increases with the rise of latitude and altitude. The Q10 value is higher in grassland than that in forest, and also in coniferous forest and deciduous forest than that in evergreen broad-leaved forest. Carbon quality is negatively correlated with Q10, but the C quality hypothesis is not always valid with exogenous substrate input. For example, the increment of substrate availability may significantly increase Q10 in low-quality soils. Q10 decreases with the enhanced proportion of r-strategy microorganisms (Proteobacteria and Ascomycetes), but increases with the enhanced proportion of K-strategy microorganisms (Acidobacteria and Basidiomycetes). Q10 increases with elevated CO2 concentration, but declines with atmospheric nitrogen deposition. In natural ecosystems, Q10 is mainly regulated by temperature and C quality. Temperature is the main factor regulating Q10 in the topsoil while C quality is the main factor in deep soil. Our review provided a theoretical support to improve the coupled climate-C cycle model and achieved the C neutral strategy under global warming.

Niches of three sympatric montane ground-dwelling squirrels: Relative importance of climate, topography, and landcover.

Species with different ecological niches will likely exhibit distinct responses to a changing environment. Differences in the magnitude of niche specialization may also indicate which species may be more vulnerable to environmental change, as many life-history characteristics are known to affect climate change vulnerability. We characterized the niche space of three sympatric high-elevation ground-dwelling squirrels, yellow-bellied marmot (Marmota flaviventer), Belding's ground squirrel (Urocitellus beldingi), and golden-mantled ground squirrel (Callospermophilus lateralis), in the alpine and upper subalpine regions of the Sierra Nevada in California. We used 5879 observations of individual squirrels, collected from 4 years (2009-2012) of transect survey data, to quantify which ecogeographical variable types (climate, topography, or landcover) were most important in defining the niche of each species. We conducted Ecological Niche Factor Analysis to quantify the niche and generate indices of "marginality" (magnitude of selection) and "specialization" (narrowness of niche space). All three species demonstrated differential use of niche space when compared to the available niche space. Moreover, the relative importance of the variables shaping the niche differed among these species. For example, the presence of meadows was important in defining the niche for U. beldingi and M. flaviventer, but the presence of conifers was important to C. lateralis. Precipitation was important in defining the niche for all three species, positively so for U. beldingi, and negatively for the other two species. The niche breadth of these three species was also positively associated with geographic range size. Mammals in high-elevation mountain systems often are perceived as vulnerable to climate shifts, but our results underscore the importance of also including non-climate-based factors in defining the niche. The overall magnitude of niche selection for all three species was driven by a combination of topographic, climatic, and landcover factors; thus, efforts to forecast areas where these species can persist in the future need to evaluate from more than just a climatic perspective.

Integrative analyses of transcriptome and metabolome reveal comprehensive mechanisms of Epigallocatechin-3-gallate (EGCG) biosynthesis in response to ecological factors in tea plant (Camellia sinensis).

Epigallocatechin-3-gallate (EGCG), a flavoured and healthy compounds in tea, is affected by the ecological factors. However, the biosynthetic mechanisms of EGCG in response to the ecological factors remian unclear. In this study, a response surface method with a Box-Behnken design was used to investigate the relationship between EGCG accumulation and ecological factors; further, integrative transcriptome and metabolome analyses were performed to explore the mechanism underlying EGCG biosynthesis in response to environmental factors. The optimal environmental conditions obtained for EGCG biosynthesis were as follows: 28℃, 70 % relative humidity of the substrate, and 280 µmol·m-2·s-1 light intensity; the EGCG content was increased by 86.83 % compared to the control (CK1). Meanwhile, the order of EGCG content in response to the interaction of ecological factors was as follows: interaction of temperature and light intensity > interaction of temperature and relative humidity of the substrate > interaction of light intensity and relative humidity of the substrate, indicating that temperature was the dominant ecological factors. EGCG biosynthesis in tea plants was found to be comprehensively regulated by a series of structural genes (CsANS, CsF3H, CsCHI, CsCHS, and CsaroDE), miRNAs (miR164, miR396d, miR5264, miR166a, miR171d, miR529, miR396a, miR169, miR7814, miR3444b, and miR5240), and transcription factors (MYB93, NAC2, NAC6, NAC43, WRK24, bHLH30, and WRK70); further, the metabolic flux was regulated and converted from phenolic acid to the flavonoid biosynthesis pathway based on accelerated consumption of phosphoenolpyruvic acid, d-erythrose-4-phosphate, and l-phenylalanine in response to ambient changes in temperature and light intensity. Overall, the results of this study reveal the effect of ecological factors on EGCG biosynthesis in tea plants, providing novel insights for improving tea quality.

Ecological and Socioeconomic Factors in the Occurrence of Rabies: A Forgotten Scenario.

In many third world countries, where rabies is endemic in dog populations, humans continue to be at risk of contracting the disease. Vaccination is the most effective form of prophylaxis for people, yet it often fails to adequately protect dogs. The most major implications are the costs of post-exposure prophylaxis (PEP) after an exposure occurs and the loss of human life and productivity due to early mortality from rabies (about 60,000 deaths annually). The largest rabies death tolls can be found in the world's poorest regions, where rabies vaccinations for domestic dogs are uncommon and PEP is scarce. Mass vaccination of dogs, neutering programs, patient PEP, strengthening laboratory and human resources, education and awareness, and animal and human rabies surveillance are all common methods used to prevent, control, and ultimately eradicate dog-mediated human rabies. Current rabies control initiatives, however, pay little attention to the role that ecological and socioeconomic variables play in the disease's occurrence and spread. To help better inform rabies control strategies, we address in this work the ways in which ecological and socioeconomic factors affect the occurrence and spread of rabies.

Influence of seasonal variations on the distribution characteristics of microplastics in the surface water of the Inner Gulf of Thailand.

This study collected 100-1000 L of surface water from 70 to 74 sites in the Inner Gulf of Thailand in both dry and wet seasons to investigate the relationship between the spatiotemporal distribution of microplastics and environmental variables. The quantity of microplastics in the wet season (34.59 ± 46.02 pieces/L) was significantly higher than the dry season (8.70 ± 15.34 pieces/L). Spatial distribution revealed an abundance of microplastics in river estuaries and seasonal current circulations. Polymeric characterization results showed that the plastic samples primarily consisted of polypropylene and polyethylene. New functional groups, including carbonyl, hydroxyl, and vinyl groups, were found in the chemical structures of the microplastic samples. The amount of freshwater runoff and the negative relationship with salinity confirmed that the river is the key factor in the transportation of microplastics to the coastal sea.

[Fungal community diversity and driving factors in rhizosphere soil of Caragana species across semi-arid regions]. / åŠå¹²æ—±åŒºé”¦é¸¡å„¿å±žæ¤ç‰©æ ¹é™ åœŸå£¤çœŸèŒç¾¤è½å¤šæ ·æ€§åŠé©±åŠ¨å› ç´ .

To investigate fungal community diversity in rhizosphere soil of Caragana species, and their relationships with ecological factors in the semi-arid regions of China, we collected soil samples from Caragana liouana and C. microphylla in different habitats. By using Illumina MiSeq high-throughput sequencing technology, we analyzed fungal diversity, community composition, and the driving factors. Results showed that 7 phyla, 20 classes, 43 orders, 66 families, and 78 genera were recorded from the rhizosphere soil. The dominant phyla in all sample sites were Ascomycota (37.7%), Basidiomycota (13.7%), and Zygomycota (4.3%). At the genus level, Penicillium, Geomyces, and Mortierella were dominant, and Rhizophagus and Glomus were also found in rhizosphere soil. The fungal Chao1 index, ACE index, and Simpson index of C. microphylla were significantly higher than those of C. liouana. There was significant difference between the two species in the composition of fungal communities. Results of redundancy analysis showed that soil organic carbon, total nitrogen, electrical conductivity, available potassium, altitude, total phosphorus and aridity index exhibited significant impacts on soil fungal diversity. Overall, those results enhanced our understanding of the relationships between rhizospheric microbial community diversity of Caragana species and ecological factors, and provided important information on the adaptive mechanisms of desert plants in semi-arid regions.

Effect of altitude on COVID-19 mortality in Ecuador: an ecological study.

BACKGROUND: The SARS-CoV-2/COVID-19 pandemic has claimed nearly 900,000 lives worldwide and infected more than 27 million people. Researchers worldwide are studying ways to decrease SARS-CoV-2 transmission and COVID-19 related deaths. Several studies found altitude having a negative association with both COVID-19 incidence and deaths. Ecuadorian data was used to explore the relationship between altitude and COVID-19. METHODS: This is an ecological study examining province-level data. To explore a relationship between altitude and COVID-19, this study utilized publicly available COVID-19 data and population statistics. ANOVA, correlation statistics, and a multivariate linear model explored the relationship between different Ecuadorian altitudes against incidence, mortality, and case-fatality rates. Population statistics attributed to COVID-19 were included in the linear model to control for confounding factors. RESULTS: Statistically significant differences were observed in the regions of Amazónica, Sierra, Costa of Ecuador for incidence, mortality, and case fatality rates, suggesting an association between altitude and SARS-CoV-2 transmission and COVID-19 disease severity (p-value ≤0.05). In univariate analysis, altitude had a negative association to mortality rate with a 1-unit change in altitude resulting in the decrease of 0.006 units in mortality rate (p-value = 0.03). The multiple linear models adjusted for population statistics showed a statistically significant negative association of altitude with mortality rate (p-value = 0.01) with a 1-unit change in altitude resulting in the decrease in mortality rate by 0.015 units. Overall, the model helped in explaining 50% (R2 = 0.4962) of the variance in mortality rate. CONCLUSION: Altitude may have an effect on COVID-19 mortality rates. However, based on our model and R2 value, the relationship between our variables of interest and COVID-19 mortality may be nonlinear. More research is needed to understand why altitude may have a protective effect against COVID-19 mortality and how this may be applicable in a clinical setting.

Analysis of the soil microbial community of Cistanche deserticola and Cynomorium songaricum in the saline-alkali soil of Ebinur Lake / 药学学报

To explore the characteristics of soil microbial communities of Cistanche deserticola and Cynomorium songaricum, two typical parasitic medicinal plants that live in an extreme saline alkali environment, 16S PCR was used to sequence the soil microbial communities of C. deserticola and C. songaricum in Ebinur Lake, Xinjiang. Redundancy analysis and correlation analysis were carried out based on the abundance of core microbiome and ecoclimatic factors. The results show that the diversity of the soil microbial community of C. deserticola was significantly higher than that of C. songaricum. The core microbial groups of C. deserticola and C. songaricum were Marinomona, Halomonadaceae, Rhizobiales, Halomonas, and Acidimicrobiales. Six specific biomarkers were identified as Micrococcacea, Echinicola, Glutamicibacter, Galbibacter, Pseudoalteromonas, and Marinobacterium_ rhizophilum. The results of redundancy analysis and correlation analysis show that the average temperature in the driest season and the average temperature in the coldest season, and the clay content and soil texture classification were the main ecological factors affecting the composition of these soil microbial communities. This study provides a theoretical basis for finding molecular markers of C. deserticola and C. songaricum and promoting the quality of C. deserticola and C. songaricum.

New Insights into the Impact of Ecological Factor on Bioactivities and Phytochemical Composition of Paeonia veitchii.

Paeonia veitchii has been widely distributed in China under different ecological types. Its roots contain diverse phytochemical constituents, which possess very high bioactivities. However, the influence of ecological factors on activities and ingredients of P. veitchii roots still remains unknown. The purpose of this research was to analyze the variation in bioactivities and phytochemical composition of P. veitchii roots upon exposure to various ecological factors. Seven P. veitchii populations collected from different regions in China were evaluated. The results of correlation analysis suggested that four major ecological factors, including average annual temperature, elevation, total potassium, and organic matter, had a strong correlation with the bioactivities of P. veitchii roots. Further, the major ecological factors were also highly correlated with the contents of naringin, gallic acid, benzoylpaeoniflorin, and paeoniflorin. The principal component analysis results supported four major metabolites as the main contributing ingredients. All populations were classified into three groups, G1, G2, and G3, through hierarchical cluster analysis. G1 showed more significant advantages in the above-mentioned four ecological factors, four active ingredients, and bioactivities compared to the other two groups. P. veitchii roots growing at lower average annual temperature, high elevation, rich total potassium and organic matter in the soils were presumed to have relatively higher bioactivities. These data expand the study on the bioactivities and phytochemical composition of P. veitchii roots and have a guiding significance for the ecological factor selection during the cultivation process of this herbaceous peony species.

Geometric morphometric analysis of the plateau zokor (Eospalax baileyi) revealed significant effects of environmental factors on skull variations.

The plateau zokor (Eospalax baileyi) is employed as an ideal model for examining the relationships between phenotypic and ecological adaptations to the underground conditions in which the skull morphology evolves to adapt to tunnel environment. We evaluated the influence of environmental factors (altitude, temperature, and precipitation) and geographical distance on the variations in skull morphology of a native subterranean rodent plateau zokor population. Thin-plate spline showed that the trend of morphological changes along the CV1 axis was as follows: the two zygomatic arch and the two postorbital processes moved down, the two mastoid processes and the tooth row moved upward, and the tympanic bulla grew longer. The changes along the CV2 axis were as follows: the nasal bone and the tooth row became longer, the distance between the two anterior tips of zygomatic arch lengthened, the infraorbital foramen became smaller, the whole posterior part of the skull became shorter, the zygomatic bone and the two posterior tips of zygomatic arch moved down, and the foramen magnum became bigger. Thus we found significant differences in the skull shape among the seven populations studied. Along with the reduction in the altitude and increase in the mean annual temperature and mean annual precipitation, the nasal bone became shorter, the distance between the two anterior tips of the zygomatic arch became shorter, the whole posterior part of the skull lengthened, the infraorbital foramen became smaller, the two mastoid processes moved upward, and the occipital bone moved down on the dorsal surface of the skull. On the ventral surface of the skull, with an increase in the altitude, mean annual temperature, and mean annual precipitation, the tympanic bulla became shorter, the tooth row moved down, and the foramen magnum became smaller. The morphological changes in the skull were significantly positively correlated with environmental factors. Finally, there was a significant positive correlation between the Procrustes distance matrix of the skull and the geographic distance matrix, which indicates that the evolution of the plateau zokor follows the distance isolation model, but it needs to be further explored from genetic perspectives.

Assessment of aquatic ecological health based on determination of biological community variability of fish and macroinvertebrates in the Weihe River Basin, China.

A healthy aquatic ecosystem plays an important role in the operation of nature and the survival of human beings. Understanding the mechanism of its interaction with the habitat process is conducive to formulating targeted ecological recovery plans. In this study, fish and macroinvertebrates were collected from 49 investigation sites in the Weihe River basin, China, during periods of the summer and the autumn of 2017. Cluster analysis and canonical correlation analysis (CCA) were used to analyze the similarity of community distribution of fish and macroinvertebrates and their response to environmental variables. The biological integrity index of fish (F-IBI) and benthic-macroinvertebrate (B-IBI) was introduced to evaluate the aquatic ecological health. The results showed that fish communities were more coherent than macroinvertebrate communities. The distinguished response to ecological factors was identified for fish and macroinvertebrates. The ecological factors of total nitrogen, conductivity and river width have significant effects on both fish and macroinvertebrate communities. In addition, the fish community was significantly influenced by chlorine, fluorine, pH and flow velocity, while the macroinvertebrate community was significantly influenced by bicarbonate and water depth. The differences in community structure and response to ecological factors between communities were amplified in their environmental quality scores. Although F-IBI and B-IBI tend to be consistent temporally, the correlation is not significant. B-IBI showed decreasing gradient of ecological health status in the downstream area, while F-IBI tended to be different across river systems, which further illustrated the differences in the response of fish and macroinvertebrates to environmental variables.

Study on the correlation between soil microbial diversity and ambient environmental factors influencing the safflower distribution in Xinjiang.

The effects of soil microbial properties and physiographical factors on safflower distributions in the main safflower plantations of Xinjiang province in China were studied. This study may help determine the basis of the environmental factors for evaluating the geoherbalism of this medicinal plant. The soil microbial biodiversity in the bulk soil and rhizosphere of safflower at different growth stages and from different sampling plots were characterized by analyzing the environmental DNAs in the samples. With general primers targeting the 16S ribosomal DNA for bacteria and the internal transcribed spacer 1 gene for fungi, the study was performed using marker gene amplification coupled with Illumina HiSeq high-throughput sequencing technologies. Correlation analysis and a distance-based redundancy analysis were performed to determine the dominant factors affecting the distribution of the microorganism in safflower soils. A total of 16517 bacterial operational taxonomic units (OTUs) were obtained from all the 108 soil samples of nine safflower sampling plots. At the phylum level, 48 phyla have been identified with Actinobacteria (32.9%) and proteobacteria (28.7%) being predominant. For fungi, 8746 OTUs were obtained, which belonged to seven phyla with Ascomycota overwhelmingly superior in relative abundance. A significant positive correlation was found between soil microbe quantity and ASL (above sea level). Safflower was sensitive to changes in elevation, growing more abundantly in the mountainous regions at heights of around 1,200 m above sea level. It is concluded that the dominant factors affecting the distribution of microorganisms in safflower soils were soil moisture, available N, and ASL.

[Correlation between chemical composition,ecological factors and soil factors of Chinese herbal medicine Daphnes Cortex].

In this paper, the correlation between the chemical constituents of Chinese herbal medicines Daphnes Cortex and the ecological factors and soil factors was studied, which provided a reference for the selection of suitable areas for artificial cultivation of Daphne giraldii and wild tending. The geographic information system(GIS) was applied to obtain the ecological factor information of 23 collection sites of Daphnes Cortex, and the soil factor information was determined by the standard procedure in the soil test standard manual. Combining the information of 93 chemical constituents of Daphnes Cortex in 23 collection sites the correlation between components and ecological factors and soil factors was analyzed by statistical methods. The correlation analysis showed that the longitude, annual average rainfall, annual sunshine intensity, annual average temperature in the ecological factors, soil type, effective copper and pH value were the dominant factors affecting the chemical composition of Daphnes Cortex.

Study on ecological suitability of Angelica sinensis in Gansu Province / 中草药

Objective: To study the ecological suitability of Angelica sinensis growing in Gansu Province and guide the rational cultivation. Methods: Through visiting and field investigation, 1 545 batches of Chinese angelica samples were collected from the county areas in Gansu Province. The information about the longitude, latitude, altitude of each sampling point was collected by using the GPS, combining with national environmental factor data, and using Maxent model and spatial analysis function of ArcGIS software. Results: The areas with high suitability of A. sinensis distribution are in the southeast of Gansu Province. The main ecological factors affecting the suitability distribution of A. sinensis were altitude, rainfall in March, May and December, wettest month precipitation, soil pH and other ecological factors. Conclusion: The research findings are basically consistent with the living habits of A. sinensis that cultivated in high-cold mountain areas and plateau flat pasture areas with a cool climate, moderate soil, moisture, slightly acidic to neutral fertile and loose brown sandy loam soil. This result can provide scientific basis for the reasonable distribution of A. sinensis cultivation area in Gansu Province.

Correlation between chemical composition,ecological factors and soil factors of Chinese herbal medicine Daphnes Cortex / 中国中药杂志

In this paper, the correlation between the chemical constituents of Chinese herbal medicines Daphnes Cortex and the ecological factors and soil factors was studied, which provided a reference for the selection of suitable areas for artificial cultivation of Daphne giraldii and wild tending. The geographic information system(GIS) was applied to obtain the ecological factor information of 23 collection sites of Daphnes Cortex, and the soil factor information was determined by the standard procedure in the soil test standard manual. Combining the information of 93 chemical constituents of Daphnes Cortex in 23 collection sites the correlation between components and ecological factors and soil factors was analyzed by statistical methods. The correlation analysis showed that the longitude, annual average rainfall, annual sunshine intensity, annual average temperature in the ecological factors, soil type, effective copper and pH value were the dominant factors affecting the chemical composition of Daphnes Cortex.

[Habitat suitability evaluation for Angelica dahurica planting in Yanting county,Sichuan province based on GIS].

It is of great significance to analyze habitable suitability of genuine medicinal materials for Chinese herbal medicine planting according to local environment,for medicinal resources protecting and for reasonable planning introduction. Based on GIS technology,the analytic hierarchy process was applied to analyze the spatial differentiation of habitat suitability of Angelica dahurica in Yanting county of Sichuan province. The evaluation combined local geographical environment characteristics and habitat requirements for A. dahurica planting and adopted the expert experience method to screen out the evaluation index for establishing evaluation system.With the established evaluation system,the index weight of evaluating index was determined by analytic hierarchy process and their grouping values were assigned by Delphi method. The all evaluating index were translated into index distribution maps using Arc GIS software. Using the comprehensive factor weighted evaluating model and spatial index distribution map,the evaluation was obtained by means of the overlay analysis function of Arc GIS 10. 3 software. RESULTS:: showed that A. dahurica had a wide range of suitable planting areas in Yanting county. Highly suitable areas amounted to 165. 01 km2,and mainly distributed in the low hilly area with moderate elevation and fertile soil. Moderately suitable areas amounted to 798. 92 km2 which had extensive distribution in middle and west part of the county. Marginally suitable areas amounted to 0. 33 km2,where the soil was highly viscous with high altitude and low temperature that was not conducive to the growth and development of A. dahurica. Adapting to local conditions and scientific planning plays an important role in the development of local characteristic planting industry of genuine medicinal materials.

Globally Ecological Suitability Analysis of Phellodendron chinense and Phellodendron amurense / 中国实验方剂学杂志

Objective: Phellodendri Cortex, one of the "three wood medicine materials", is a Chinese traditional medicinal material and also a national second-class protected plant in China. Its is considered as excellent trees for the Natural Forest Conservation Program and the Grain-to-Green Program because of its high economic value and ecological value. The Phellodendron Cortex is divided into Phellodendron chinense and P. amurense according to species and origins. The global potential suitable areas predicted by Global Geographic Information System for Medicinal Plant (GMPGIS) can provide data for us to decide which specie can be selected in different areas. Method: Sample ecological information was collected from global genuine areas, main producing areas and wild distribution areas, and a total of 364 sampling sites of P. chinense and 247 sampling sites of P. amurense were used by GMPGIS to analyze the suitable growth areas in the world. Result: A clear geographical line existed between P. chinense and P. amurense. P. chinense was mainly distributed in tropical monsoon climate and had the most suitable areas in Asia, Europe, North America, South America and Oceania, including 65 countries and regions such as China, the United States, France, Brazil, Japan, Italy and New Zealand. P. amurense was mainly distributed in temperate monsoon climate and had the most suitable areas in Asia, Europe, and North America, including 30 countries and regions such as the United States, China, Russia and Canada.. Conclusion: The results of GMPGIS can provide scientific data for selecting correct species and cultivation areas for Phellodendris Cortex in future.

Habitat suitability evaluation for Angelica dahurica planting in Yanting county,Sichuan province based on GIS / 中国中药杂志

It is of great significance to analyze habitable suitability of genuine medicinal materials for Chinese herbal medicine planting according to local environment,for medicinal resources protecting and for reasonable planning introduction. Based on GIS technology,the analytic hierarchy process was applied to analyze the spatial differentiation of habitat suitability of Angelica dahurica in Yanting county of Sichuan province. The evaluation combined local geographical environment characteristics and habitat requirements for A. dahurica planting and adopted the expert experience method to screen out the evaluation index for establishing evaluation system.With the established evaluation system,the index weight of evaluating index was determined by analytic hierarchy process and their grouping values were assigned by Delphi method. The all evaluating index were translated into index distribution maps using Arc GIS software. Using the comprehensive factor weighted evaluating model and spatial index distribution map,the evaluation was obtained by means of the overlay analysis function of Arc GIS 10. 3 software. RESULTS:: showed that A. dahurica had a wide range of suitable planting areas in Yanting county. Highly suitable areas amounted to 165. 01 km2,and mainly distributed in the low hilly area with moderate elevation and fertile soil. Moderately suitable areas amounted to 798. 92 km2 which had extensive distribution in middle and west part of the county. Marginally suitable areas amounted to 0. 33 km2,where the soil was highly viscous with high altitude and low temperature that was not conducive to the growth and development of A. dahurica. Adapting to local conditions and scientific planning plays an important role in the development of local characteristic planting industry of genuine medicinal materials.

[Study on ecological stereoscopic cultivation mode of Amomum villosum-Dimocarpus longan].

In order to set up a technical standard for planting Amomum villosum in wood forest in the future, we analyzed the relationship between the ecological factors and the yield of A. villosum planted in five Dimocarpus imocarpus longan wood forests and five miscellaneous wood forests in Yangchun city, to find out the dominant factors that affect the yield of A. villosum. The results showed that agricultural measures of fertilization, artificial irrigation and removing the old plants were positively correlated with the yield of A. villosum, the pesticide spraying and soil pH value were negatively correlated with the yield of A. villosum. But the effects of ecological factors on the yield were not significantly. High yield regions are generally located in the ravine, two sides of mountain stream and other places where water is more adequate. The slope of cultivated field with high yield is generally less than 30°, lighting and ventilation are more appropriate; soil type is generally sandy or loam, shade density is generally about 50%, and pollinators are many in quantity and variety. And we found that there was a large difference in mineral nutrient contents of soils among ten plantations. Results indicate that the yield of A. villosum is determined by the combination of each ecological factor. Suitable light intensity, moisture, ventilation and reasonable fertilization are conductive to increase the yield of A. villosum, but the use of pesticides and soil alkalization hinder the increase of A. villosum production. Too high shade density and the abuse of pesticides may be the main reason for limiting the yield of A. villosum planted in D. longan wood forests. This study has obtained key techniques of the ecological stereoscopic cultivation mode of A. villosum-D. longan, which lays a theoretical foundation for the guidance of farmers in planting A. villosum in the D. Longan forest in the future.