Study On Community And Succession Of The Abies Fargesii In Shennongjia

It was a primary study on Abies fargesii Franch , which belongs to the Pinaceae family. Three plots were selected respectively from Liaowangta, Zimeifeng, and Jinhoulin, which are all located in the Shennongjia National Natural Reserve, Hubei province. By use of the method of modern quantitative ecology, combining with traditional field investigation of plant community, we compared Abies fargesii population construction and biodiversity of community in 2002 with those in 1979. In addition, the succession of natural Abies fargesii second growth forest and the growth of artificial Abies fargesii forest were studied primarily. The main results were summarized as follows:1. Abies fargesii community was the climax, which was distributed above 2600 metres in Shennongjia. It existed in different niches . Its main companion species: Betula albo-sinensis, Acer flabellatum, some shrubs including Rhododendron fargesii, Sorbus hupehensis, Sorbus hupehensis, Sinarundinria nidita and some herbs such as Oxalis griffithii, Veratrum puberulum. By way of resource allocation, Abies fargesii and its companion species made use of surrounding resource including light, temperature, medium and water on different levels and thus coexist well in different way. Accompanying with the relationship of both restrain and promotion in the same community, they interacted with each other resulting in the stability of the community. The community energy flow and the cycle of materials were kept in a state of both dynamic balance and relative stability. Our research showed that the habitat and climate in Shennongjia were favorable to the growth of Abies fargesii.2. In the late 23 years, some changes in Abies fargesii population construction took place. Young Abies fargesii (grade I) decreasedsharply in number from 0. 932 to 0. 03 per square meter. In the contrary, the average number increased from 0. 122 to 1.238 in stumpage grade V. At the same time, coarse woody debris of Abies fargesii also increased. No changes took place in stumpages grade II, Illand IV. The Abies fargesii population could not regenerate normally so that individual number decreased and its construction aged.3. There were 38 species (belong to 29 families) in Abies fargesii community, thus its species composition was relatively simple. Compared with that of Abies fargesii community in 1979, the species number increased and some photophilous plants began to enter the pure Abies fargesii community.4. Abies fargesii community in Shennongjia had two succession routes:a. residue after Abies fargesii disafforestation-Sinarundinrianidita and meadow-deciduous broadleaved forest-Abies fargesii.b. Abies fargesii-meadow-Sinarundinria nidita and Sorbushupehensis-Abies fargesii. The two routes interveined, ebbed andflew each other.5. Finally, the importance of restoration ecology of Abies fargesii was demonstrated. And we also discuss how to prevent population degeneration in this paper.