KMS Chongqing Institute of Green and Intelligent Technology, CAS
| Spatial distribution pattern of plant community and habitat impact analysis of the drawdown zone of Pengxi river in the three gorges reservoir | |
| Tong, Xiao Xiao1,2; Chen, Chun Di1; Wu, Sheng Jun1; Jia, Zhen Yi1,3; Yi, Xue Mei1; Ma, Mao Hua1 | |
| 2018 | |
| 摘要 | Riparian vegetation has important ecological functions in protecting the water quality, stabilizing the bank and maintaining the habitats connectivity. The impoundment of the Three Gorges Reservoir has destroyed the original riparian vegetation and potentially threatens the reservoir ecosystem’s health and stability in the Three Gorges Reservoir. This research study explored the riparian vegetation community of the newly formed drawdown zone of the Three Gorges Reservoir and the relationship between the spatial distribution patterns of plant community and the habitat influences. A field survey was carried out from August to September 2015, and 93 plant quadrats were investigated. At the same time, 14 factors including three topographic (slope, exposure, and elevation), three hydrology (flooding time, frequency, and depth), seven soil (pH, moisture content, organic matter, available nitrogen, phosphorus, and potassium, and slow-release potassium) and one historical land use (historical land use) factor were measured. These habitat factors were classified into four groups:topographic, hydrology, soil, and historical land use factor groups. The community types were identified using a two way indicator species analysis (TWINSPAN). Additionally, the effects of the four habitat factor groups and their interaction on the total variation of drawdown vegetation were partitioned using variance decomposition. The effects of 14 habitat factors on the drawdown plant communities were analyzed using the canonical correspondence analysis (CCA). The main results were as follows. (1) The drawdown plant communities were classified into five types, which were a Cynodon dactylon plus Paspalum thunbergii, Setaria viridis plus Cynodon dactylon, Vitex negundo, Imperata cylindrica plus Bidens pilosa, and Carex tristachya communities. (2) The results of the CCA indicated that drawdown vegetation and habitat factors had a significant correlation. The cumulative interpretation of the first ordination axis on vegetation spatial variation was 6.83%, accounting for 44.73% of the total interpretation of the habitat. Five types of plant communities were distributed along the first ordination axis following the altitude gradient. (3) The results of the variance decomposition showed that the soil factors group had only a 10.1% contribution. It played a major role in the spatial distribution of the drawdown plant community among the four habitat factor groups. There was a significant interaction between the four habitat factor groups. The CCA also showed that the habitat factors of flooding time, elevation, and soil moisture content played a dominant role in the spatial distribution of the drawdown plant community and their contribution were 5.3%, 3.0%, and 2.9% respectively. (4) Our results demonstrated that the explanatory power of all four habitat factor groups was low (14.6%). This may be because the drawdown zone is a newly established, complex ecotone, where habitats and landscapes are highly heterogeneous. The unexplained portion may come from the influence of anthropogenic activity, various disturbances, and large-scale landscape context. © 2018, Ecological Society of China. All rights reserved. |
| DOI | 10.5846/stxb201610272189 |
| 发表期刊 | Shengtai Xuebao/ Acta Ecologica Sinica
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| ISSN | 10000933 |
| 卷号 | 38期号:2页码:571-580 |
| 语种 | 中文 |
| EISSN | 18722032 |
