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IntroductionRhizobacterial communities and their metabolites can affect plant growth, development, and stress resistance, as well as the biosynthesis and accumulation of bioactive compounds in medicinal plants. This relationship has been well-characterized in many medicinal herbs, although much less commonly in medicinal trees.MethodsHere, we analyzed the composition and structure of Cinnamomum migao rhizobacterial communities across nine growing regions in Yunnan, Guizhou and Guangxi, China, as well as differences in soil properties and fruit bioactive compounds.ResultsResults showed that the C. migao rhizobacterial communities exhibited high species richness, but location-specific differences in structure. Site-specific differences in soil properties and bioactive compounds were also observed. Furthermore, rhizobacterial community compositions were correlated with both soil properties and fruit bioactive compounds, metabolism-related functions were most common in C. migao rhizobacteria.DiscussionSeveral bacterial genera, including Acidothermus, Acidibacter, Bryobacter, Candidatus_Solibacter, and Acidimicrobiales, potentially promote the biosynthesis and accumulation of 1,8-cineole, cypressene, limonene, and α-terpineol, Nitrospira and Alphaproteobacteria may play an inhibitory role. Finally, our results emphasized the critical role that soil pH and nitrogen levels play in driving rhizobacterial community structure, and specific functional bacteria can also counteract with soil properties, Acidibacter and Nitrospira can affect soil pH and nitrogen effectiveness. Overall, this study provides additional insight into the complex correlation of rhizosphere microorganisms with bioactive ingredients and soil properties of medicinal plants.

In order to strengthen the protection of ecological environment in Guizhou, speed up the development of ecological animal husbandry, and improve the standardized production level of natural grassland in Guizhou, based on the summary of practical production and scientific research achievements, this paper stipulates the methods and measures of natural grassland improvement in Guizhou karst mountainous areas, as well as their application scope and operation steps. Specific requirements are put forward for forage sowing, field management and utilization of improved grassland in the process of natural grassland improvement. The formulation of this technical regulation has practical significance for scientifically guiding the standardization, standardized development and utilization of natural grassland in Guizhou karst mountainous areas.

The application of CFD (Computational Fluid Mechanics) simulation is more and more extensive in the research field of urban air environment. CFD has its advantages on simulating the complicated air flow phenomenon and presenting intuitional descriptions. Planting work within a city has great ecological effect on city or district air environment, CFD simulation of planting effect on district air environment and its superiority for district air environment planning, the establishment of the model and its application for air environmental evaluation and improvement in district environmental management process is introduced and discussed in this paper. The significance and prospect of CFD simulation of planting effect for district planting planning is also demonstrated. Keywords-CFD; planting effect; district air environment; index for evaluation Ⅰ. INTRODUCTIONThe amount of city energy consumption is vast and going burdensome. Accompanying with this vast energy consumption, city thermal environment is getting worse [1] . Additionally, due to the improper and unreasonable planning of city structure, materials used in the city construction and building settlements and arrangements, thermal environment of cities has been getting further worse, e.g. air pollution and heat island of cities has been significantly existed [2] . The worse the thermal environment of cities, the higher the building cooling load in summer.Many means have been used to solve these problems, all of these corresponding works should be appreciated, but the most important and original work on it is to improved our city planning strategies and technologies with the considering of better or excellent city thermal environment, and only by using CFD simulation can this work be possibly done.Besides other factors, planting work within a city is one of the most effective factors on city air environment, and district air environmental planning is a component and basic work of a city air environmental planning, so CFD simulation of planting effect on district air environment is focused and emphasized in this paper.Three different kinds of planting work within a city district can be accomplished: ground planting, building roof planting and vertical planting along building walls. Each kind of planting work can significantly affect the air environment with a city district. Planting design should be associated with the city elevation, city longitude and latitude, topography and landscape, distribution of wind and water, make a reasonable planting density, leave enough natural and ecological area, reasonably plan the interval, height, style and color of trees, introduce the idea of landscape and pastoralist city, create a delightful ecological environment, excellent view feeling and horizon scenery of a city district.In this paper, schematic plan of distribution of ground trees are focused, CFD simulation and evaluation of air environment within a district based on different distribution of ground trees are presented. Ⅱ. OPTIMAL PLANNING OF DISTRICT PLANTING BY ...