铜陵铜尾矿废弃地细菌多样性研究

[目的]探讨铜尾矿废弃地微生物多样性的变化。[方法]采集铜陵杨山冲和铜官山2尾矿库不同自然层裸地和植物群落以及不同植物发育阶段和土样类型的样本,采用PCR-DGGE技术研究2尾矿库废弃地不同自然生态恢复阶段的细菌多样性以及优势植物根系对细菌多样性的影响。[结果]铜陵铜尾矿废弃地发育过程中,不同恢复阶段的细菌多样性无明显变化;同一植物群落下A-层较C-层表现较高的细菌多样性,这与土壤有机质及氮磷等养分含量的变化相一致;杨山冲尾矿库白茅和结缕草根际的细菌多样性高于非根际的,而木贼的则相反;白茅和木贼成株的根际细菌多样性均高于幼苗,结缕草成株根际的细菌多样性较幼苗降低。[结论]铜尾矿废弃地细菌的多样性同时受养分积累状况和植被类型的影响。     

In the bleak mid-winter: The value of brownfield sites for birds during the winter

Brownfield sites (e.g., wastelands, disused industrial grounds and power stations) are valuable refuges for urban birds during the breeding season. This owes to the presence of vegetation in different stages of succession, which provide a high diversity of food and breeding resources. However, insufficient research has explored their winter value, when temperatures are lower and food is scarcer. Accordingly, 342 bird and habitat surveys were conducted in brownfield sites, and other land-uses, across Greater Manchester. Bird density estimates were then calculated using Distance software and bird-habitat associations were analysed using Canonical Correspondence Analysis (CCA). Moreover, the impact of brownfield site development on winter bird density from 2000 to 2009 in Greater Manchester was explored using the bird density estimates, and historical image function in Google Earth. In brownfield sites, Pica pica had the highest density estimate (142 per km²), although four species had estimated densities > 100 per km² (Turdus merula; Cyanistes caeruleus; Passer domesticus; Aegithalos caudatus). The CCA indicated that Aegithalos caudatus, Cyanistes caeruleus, Parus major, Prunella modularis were associated with Fagus sylvatica, Betula pendula, and Buddleja davidii on brownfield sites, which during the winter 1) produce seeds 2) support overwintering insects, providing a valuable food source. Nevertheless, across land-uses, most species favoured green space and pre-2000 housing. Brownfield sites were most replaced between 2000 and 2009, with 17.8 km², 14.9 km², and 12 km² replaced by commercial, industrial, and post-2000 housing respectively. This is likely to have had a negative impact on the winter density of most bird species, owing to 1) the removal of brownfield site vegetation 2) increases in impervious land cover. Future declines in winter bird abundance could be mitigated by retaining brownfield site vegetation and setting aside brownfield sites in close proximity to green space and pre-2000 housing.