关键词: 活化石植物, 拯救, 保护

Abstract

Bird communities were surveyed in southern Hangzhou Bay and the Qiantang River estuary from November 2008 to September 2011. A total of 220 bird species belonging to 16 orders and 52 families were recorded, of which, 173 (78.6%) were migrants and 24 were listed as state key protected wildlife grade I or II. The composition and diversity of bird communities in eight habitat types were compared using the G-F index and the Jaccard index. Ninety-five species (43.2%) were observed in the ponds located in Cixi Wetland Centre with common reed (Phragmites australis) marshes, 93 species (42.3%) in the coastal woodland, and 78 species (35.5%) in intertidal mudflats and coastal reservoirs. About 82.5% of the Charadriiformes species were recorded in intertidal mudflats; 69.2% of the Anatidae species in coastal reservoirs, and 73.4% of the Passeriformes species in the coastal woodland which provides the breeding habitat for the Ardeidae birds. Compared with intertidal mudflats, the highest value of the Jaccard index was obtained for bird communities in the newly reclaimed but undeveloped areas (0.56), followed by coastal reservoirs (0.34) and ponds located in Cixi Wetland Centre with common reed marshes (0.30). For the whole bird community, the highest value of G-F index was obtained in coastal reservoirs and coastal woodland, whereas the lowest value was recorded in the intertidal mudflats. However, newly reclaimed but undeveloped sites had the highest value of G-F index for the waterbird community, followed by coastal reservoirs and intertidal mudflats. Our results indicate that suitable habitat availability and human disturbance are the main factors influencing the spatial distribution of bird communities in the Hangzhou Bay and the Qiantang River estuary. The most serious human disturbance in this region was found to be coastal reclamation. Thus, diversity of local avian communities in the Hangzhou Bay and the Qiantang River estuary could increase if moderate-intensity reclamation and reasonable land use patterns were practiced. Moderate-intensity reclamation is the mode that maintains an intertidal wetland containing a sufficient width of mudflat and upper intertidal zone as well as other important habitat variables for shorebirds and other birds. Local governments should take action to protect the natural wetlands while using them reasonably and efficiently. It is necessary to maintain several main high-tide roosting sites with sufficient areas for shorebirds and other waterbirds. Some appropriate management measures such as controlling water level in newly reclaimed but undeveloped areas should be carried out to increase the availability of suitable habitat for waterbirds. A variety of artificial wetlands should also be constructed to provide potential habitats for waterbirds and other birds after large scale coastal reclamation.

Key words: living fossil plants, rescue, conservation