Studies On Community Character Of The Vegetation Under The Cunninghamia Lanceolata And Pinus Massoniana Planted Forest And The Carbon Capacity Of The Forest Of Da Qing Mountain Area In Guangxi Zhuang Autonomous Region

Diagnoses about the middle-aged Cunninghamia lanceolata and Pinusmassoniana planted forest have been done in details, such as the composing ofthe species and configuration character and the biomass under the forest and thephysical and chemical property of the soil and the biomass of the Cunninghamialanceolata and Pinus massoniana in the tree layer. What's more, the contrastinvestigation of the young and mature Cunninghamia lanceolata and Pinusmassoniana planted forest has also been done in the dissertation. The resultswere shown as followings:1) The difference of number of the species under the forest is not veryobvious, but the difference of the biomass of the predominant species is obviousin different age of the forest. The light demanding species is dominated theforest in young. And when the forest came to middle-aged and mature, thedominate species is shade resistant species and shade demandingmid-tolerance broad-leaved species respectively.2) The difference of biomass under different phase forest is obvious. The biomass of mature forest is more than the young forest, and young forest ismore than that of the middle aged forest. Especially, the biomass under themiddle aged forest is much less than that under the young forest or the matureforest. In the Pinus massoniana planted forest, there is more shrubby layerbiomass in middle aged or mature forest, but there is more biomass in herb layerwhen the forest is young. In the Cunninghamia lanceolata forest the complexionis just reverse to the Pinus massoniana forest.3) In the Pinus massoniana forest the shrub layer biomass is moreobviously increased with the age of the forest than that in Cunninghamialanceolata forest. The shrub layer biomass in mature age is a little less than inmiddle age in Cunninghamia lanceolata forest. Maybe it is because of thealternation felling.4) There is less carbon capacity of the litter in young forest. And there is nomuch difference between middle aged forest and mature forest. The carboncapacity of the litter in middle aged Pinus massoniana forest is more than that inmature forest. In the Cunninghamia lanceolata forest the complexion is justreverse to the Pinus massoniana forest. The carbon capacity of the littter inPinus massoniana is more than that in Cunninghamia lanceolata forest indifferent phase. Maybe the litter in Pinus massoniana forest is more difficult tobe decomposed than that in Cunninghamia lanceolata forest.5) The carbon capacity in the soil in different phase is different.There islittle carbon capacity in mature forest, and less in young forest, and least in middle aged forest. It maybe because the crown of the tree is more closer,there is less light under the forest. The edaphon become less active, and lesslitter to be decomposed. So there is least carbon capacity in soil in middle agedforest..6) Comparing with the average carbon density of forest ecology system inour China, the average carbon density in the several forest investigated by us islower than the average level in China except that the average carbon density inmature Pinus massoniana is a little higher than the average level in China. It isshown that degeneration of the planted forest is serious,so we should take somemeasures to accelerate the recovery progress, such as mixing some ever greenbroadleaf with singular conifer community, so that the singular conifercommunity can become the regionally climax community.