Dongting Lake Wetland Research Articles

Characterization of an H4N2 avian influenza virus isolated from domestic duck in Dongting Lake wetland in 2009

In January 2009, an H4N2 subtype of avian influenza virus [A/duck/Hunan/8-19/2009 (H4N2)] was isolated from domestic ducks in Dongting Lake wetland. The whole genome of the virus was sequenced and the results indicated that multiple gene segments of the virus had a high homology with viruses isolated from wild waterfowl, which indicated that the virus was probably transmitted from wild waterfowl to domestic ducks. Phylogenetic analysis revealed that the each gene belonged to the Eurasian lineage of avian influenza viruses, but genetic reassortment occurs between viruses of different subtypes.

Analysis of vegetation response to rainfall with satellite images in Dongting Lake

We analyzed the Normalized Difference Vegetation Index (NDVI) from satellite images and precipitation data from meteorological stations from 1998 to 2007 in the Dongting Lake wetland watershed to better understand the eco-hydrological effect of atmospheric precipitation and its relationship with vegetation. First, we analyzed its general spatio-temporal distribution using its mean, standard deviation and linear trend. Then, we used the Empirical Orthogonal Functions (EOF) method to decompose the NDVI and precipitation data into spatial and temporal modes. We selected four leading modes based on North and Scree test rules and analyzed the synchronous seasonal and inter-annual variability between the vegetation index and precipitation, distinguishing time-lagged correlations between EOF modes with the correlative degree analysis method. According to our detailed analyses, the vegetation index and precipitation exhibit a prominent correlation in spatial distribution and seasonal variation. At the 90% confidence level, the time lag is around 110 to 140 days, which matches well with the seasonal variation.

Characterization of an H10N8 influenza virus isolated from Dongting lake wetland

BackgroundWild birds, especially those in wetlands and aquatic environments, are considered to be natural reservoirs of avian influenza viruses. It is accepted that water is an important component in the transmission cycle of avian influenza virus. Monitoring the water at aggregation and breeding sites of migratory waterfowl, mainly wetland, is very important for early detection of avian influenza virus. The epidemiology investigation of avian influenza virus was performed in Dongting lake wetland which is an international important wetland.ResultsAn H10N8 influenza virus was isolated from Dongting Lake wetland in 2007. Phylogenetic analysis indicated that the virus was generated by multiple gene segment reassortment. The isolate was lowly pathogenic for chickens. However, it replicated efficiently in the mouse lung without prior adaptation, and the virulence to mice increased rapidly during adaptation in mouse lung. Sequence analysis of the genome of viruses from different passages showed that multiple amino acid changes were involved in the adaptation of the isolates to mice.ConclusionsThe water might be an important component in the transmission cycle of avian influenza virus, and other subtypes of avian influenza viruses (other than H5, H7 and H9) might evolve to pose a potential threat to mammals and even humans.

Characterization of H9N2 influenza viruses isolated from Dongting Lake wetland in 2007

In 2007, a total of eight H9N2 influenza viruses were isolated from the water and fowl feces in Dongting Lake wetland, China. The genomes of the eight viruses were sequenced, and all eight gene segments were subjected to phylogenetic analysis. The results showed that all the isolates belonged to the same genotype, in which the HA, NA and NS gene segments were Chicken/Beijing/94-like; the PB2, PB1, PA and NP gene segments were Chicken/Shanghai/F/98-like; and the M gene was Quail/Hong Kong/G1/97-like. Animal experiments showed low pathogenicity of the selected viruses for chickens, although some chickens died after inoculation. The viruses showed no overt clinical signs in mice, but they could replicate in murine lungs prior to adaptation.

The preliminary study on landscape culture orientation and exploitation of the south dongting lake wetland

Dongting Lake is internationally an important wetland. We studied and summarized the conception, function, classification and current situation of the wetland-landscape culture in this region. The results showed that the culture of Dongting Lake wetland was rich in diversity, which are the Rice Cultivation Culture, high-balustrade dwelling, Nuo Culture, Ship Culture, Dragon Boat Culture, Chu Culture, Ancient Architecture Landscape, Wetland Foodstuff and Cuisine Culture, Civil Art, Historic Heritage and Cultural Relics, Revolutionary Sites and Ruins, and Production and Living Culture, etc. We also evaluated the eco-tourism value of wetland landscape culture, and analyzed its features and orientation. The results revealed that the south Dongting Lake wetland plays a key role on the Changjiang (Yangtze) River reaches civilization and Chinese civilization, even has great influence on the global civilization. We summarized that the soul of the south Dongting Lake Culture was Wetland Culture, Water Culture, Rice Cultivation and Chu Culture. The thoughts, principles and approaches of sustainable exploitation and utilization of the wetland landscape culture were formulated and suggested.