混交林和树种间关系的研究现状

以往人工林营造以单纯林为主,造成病、虫、火等灾害严重,林地生产能力衰退等弊端,这引起念来愈多的造林学家、生态学家和病虫害学家的关注。混交林和树种间相互关系的研究进展很快。本文从混交林的生态效益、防护效益和社会效益,混交林的造林技术以及混交林内树种间在生物化学、生物波、生物量和营养元素循环等方面的相互关系出发,阐述了国内外混交林营造及其机理研究的概况。

The Survey of Mixed Forests and the Interaction of Tree Species

Most of Man-made forests are of pure forests up to now.But a pureforest has many defects,Serious plant diseases and insects,high fire hazard index and low productivity from generation to generation.Progress in protection of purestands,and chemical control of plant deseases and insects has been relatively slow-er.Therefore,establishing or reestablishing mixed forest is a major measure offundamental importance for avoiding the hidden dangers.Mixture of tree specieshas tremendous influence on stability,productivity and ecological benefits,andthe development of this area has been followed with interest by more and moresilviculturists,fosest ecologists,forest pathologists and entomologists.Studieson mixture and interaction of tree spieses have made remarkable progress.This pa-per deals with historical gist and present situation of the area concerning speciesmixture and machanism,including conception,scope and development,itsecological,economical and social benefits,choice of tree species,their propor-tion,mixture methods in planting or sowing,young stand tending,interactionof tree species in respect of allelopathy,biophysics,link up of the roots,biomass and cycle of nitrogen and other nutrient elements.