Study On Benefit-cost Analysis And Some Related Characteristics Of Cinnamomum Spp. Planted In Kunming Urban Area

The increasingly deteriorating of urban environment caused by acceleratedurbanization and strengthening influence of human beings on urban ecosystem has madepeople pay more and more attention to the important role of urban forest in improving theenvironment quality in urban area. The quantitative analysis of the comprehensive benefitsproduced by urban forest, the exploration for understanding the relations among thegrowing environments of urban trees and the internal physiological status and the growtheffect of the trees have become the research focuses in the field of urban forestry abroadand in China.Because of the characteristics of evergreen with long life-span, tall and straight bole,elegant crown form and superior timber quality, Cinnamomum spp. have gradually becomemajor species planted widely as landscaping and ornamental trees in Kunming urban area.The integrated sampling method composed of both random and mechanic sampling wasapplied in the study. 18 streets including Wuyi Road, etc., with Cinnamomum spp. plantedas predominant tree species were randomly sampled, meanwhile the JinkangyuanResidential Quarter and the Kunming Government Official Residential Quarter were alsosampled for the study. Consequently, a number of trees were sampled by mechanicsampling and the height, DBH, growth status, pruning intensity of the sampled trees weremeasured, planting structure of these trees and the tending and management items andfrequencies for the trees were recorded. By means of the corresponding data set by Daviscenter for urban forest research, USDA, the ratio of comprehensive benefits produced bythese Cinnamomum spp. trees and the cost invested for tending these trees in the year of2004 was analyzed, accordingly the adaptability of this tree species to be planted forornamental purpose in Kunming urban area was objectively evaluated in quantitative way.Additionally, soils and tree leaves from the above 2 residential quarters and 5 streetswith Cinnamomum spp. planted as predominant tree species with varied planting structureswere typically sampled to determine the chemical properties and nutrient status in the soilsunder different cultivation environment conditions, and the chlorophyll contents andfluorescence values from the sampled leaves were determined in order to explore therelations among the living conditions, physiological phenomenon and growth effect ofthese trees from different angles. It was expected that the results from the research shouldprovide the planting design, cultivation and tending of Cinnamomum spp. in Kunmingurban area with some useful suggestions in the future.The following conclusions were drawn on the basis of analyzing the results fromabove studies:(1)64.4% of Cinnamomum spp. street trees in Kunming urban area grew well; while78.26% and 90.89% of Cinnamomum spp. trees respectively planted for ornamentalpurpose in Jinkangyuan Residential Quarter and in Kunming Government OfficialResidential Quarter grew well, indicating that Cinnamomum spp. were suitable tree speciesto be planted as street trees and yard trees in Kunming.(2)The investigations into planting structure and soil properties showed that thechemical properties and nutrient contents in the soils with varied planting structures wereobviously different. The contents of organic material, soluble nitrogen of the soils sampledunder Cinnamomum spp. street trees with"tree + turf grass"and"tree + shrub + turf grass"...