关键词: 青藏高原东北边缘, 云杉-冷杉林火烧迹地, 灌木群落特征

Abstract: Objective To study the characteristics of shrub communities in the process of vegetation restoration and reconstruction in the burned areas of spruce-fir forest on the northeast edge of Qinghai-Tibetan Plateau, and clarify the ecological process of diversity pattern and maintenance mechanism of shrub communities in burned areas. Method In spatial instead of time method, the species composition characteristics, α species diversity and β species diversity of shrub communities in 5 a and 15 a of burned areas and understory shrub communities in unburned areas were studied.Result There are differences in plant species composition among shrub communities in burned areas after 5 a and 15 a of restoration, and understory shrub communities in unburned areas, There are 24 species of shrubs belonging to 17 genera in 11 families in the burned areas of 5 a, 17 species of shrubs belonging to 10 genera in 8 families in the burned areas of 15 a, and 35 species of shrubs belonging to 19 genera in the unburned forest areas. The species richness index and Pielou evenness index of 5 a and 15 a burned areas and unburned woodland, and the correlation between species richness index and Simpson index and Shannon-Wiener index of 5 a burned areas are not strong (P < 0.1 or P > 0.1),but the correlation between other indexes in the three communities was strong (P < 0.001 or P < 0.01). The species richness index restored 5 a burned areas > restored 15 a burned areas > unburned forest areas, the Shannon-Wiener index and Simpson index are all restored 15 a burned areas > unburned forest areas > restored 5 a burned areas, the Pielou evenness index 15 a burned areas > unburned forest areas > 5 a burned areas. The Species composition of shrub communities in restored 5 a and 15 a are the most similar, and the understory shrub layer species composition and recovery 15 a are more similar than recovery 5 a burn areasConclusion After severe forest fire disturbance, the species composition of spruce-fir forest on the northeast edge of Qinghai- Tibetan Plateau is different in different restoration time gradients. In a short time after the fire, the species diversity and dominance are low in the burned areas, and the species distribution was uneven. With the succession, the species richness began to decrease, and the species diversity and dominance increased, and the species distribution was relatively uniform. With the normal succession of the burned areas, the similarity of species composition between the shrub community in the burned areas and the unburned areas are increasing, and the shrub community in the burned areas are in the forward succession.

Key words: northeast edge of Qinghai-Tibetan Plateau, spruce-fir forest burned areas, community characteristics of shrubs