Jiang H.X.,Beijing Normal University |
Hou Y.Q.,Chinese Academy of Forestry |
Chu G.Z.,Chinese Academy of Forestry |
Qian F.W.,Chinese Academy of Forestry |
And 3 more authors.
Bird Conservation International | Year: 2010
Saunders's Gull Larus saundersi is a breeding endemic of Common Seepweed Suaeda glauca habitats on the east coast of China and south-west coast of South Korea. Much of this habitat has been lost and degraded due to human land use and expansion of the introduced Smooth Cordgrass Spartina alterniflora. Yancheng National Nature Reserve (NNR) is one of three breeding and wintering areas in China. We used satellite images from 1992 to 2007 and visual interpretation combined with ground truthing to classify the land cover and quantify changes in land use and land cover (LULC) in areas of Yancheng NNR used by Saunders's Gull. The Common Seepweed habitat, in which this species nests, decreased in area by 79.1% (27,358 ha) over 15 years, predominantly as a result of conversion to aquaculture ponds (18,929 ha), and is now centred in the south-east of Yancheng NNR. The total population size of Saunders's Gull was maintained at over 900 individuals from 1999 to 2006 in Yancheng NNR, but was only 575 in 2007, and the number of breeding sites decreased from eight in 1992 and 1994 to a single site in 2000-2006 and two sites in 2007. From 1999 to 2007, the breeding population in the core area of Yancheng NNR accounted for 94.93% of the total population, and its nest-site spatial turnover rate was 0.84 ±0.08 (n = 7 years), but it tended to decrease by about 40% in 2007 because of degradation of the Common Seepweed community. The conversion of Common Seepweed habitats to other habitat types and expansion of introduced Smooth Cordgrass were the major and direct reasons for the loss and degradation of breeding habitats of Saunders's Gull. Smooth Cordgrass habitats increased in area by 321.9% (11,057 ha) during this period and centred on the east, gradually occupying the mudflats, except the beach from Liangduo River to the south of Yancheng NNR, where potential breeding sites for the Saunders's Gull could be located. We discuss the implications of our results for the conservation this species and management of its habitats. Copyright © 2010 BirdLife International.
Zhang Y.,Nanjing Forestry University |
Lu D.,Indiana University Bloomington |
Yang B.,Nanjing Forestry University |
Sun C.,Nanjing Forestry University |
Sun M.,Yancheng National Nature Reserve
International Journal of Remote Sensing | Year: 2011
Coastal wetland vegetation classification with remotely sensed data has attracted increased attention but remains a challenge. This paper explored a hybrid approach on a Landsat Thematic Mapper (TM) image for classifying coastal wetland vegetation classes. Linear spectral mixture analysis was used to unmix theTMimage into four fraction images, which were used for classifying major land covers with a thresholding technique. The spectral signatures of each land cover were extracted separately and then classified into clusters with the unsupervised classification method. Expert rules were finally used to modify the classified image. This research indicates that the hybrid approach employing sub-pixel information, an analyst's knowledge and characteristics of coastal wetland vegetation distribution shows promise in successfully distinguishing coastal vegetation classes, which are difficult to separate with a maximum likelihood classifier (MLC). The hybrid method provides significantly better classification results than MLC. © 2011 Taylor & Francis.
Liu H.,CAS Institute of Zoology |
Liu H.,University of Chinese Academy of Sciences |
Yan J.,CAS Institute of Zoology |
Luo J.,CAS Institute of Zoology |
And 5 more authors.
Journal of Wildlife Diseases | Year: 2014
We describe mycobacteriosis caused by Mycobacterium peregrinum in Red-crowned Cranes (Grus japonensis) in China. Isolates were identified by bacteriology, molecular identification methods, and phylogenetic analysis. This study shows that M. peregrinum is an important pathogen for mycobacteriosis and could represent a threat to conservation efforts of endangered species. © Wildlife Disease Association 2014.
Hang Z.,Nanjing Normal University |
Wang G.,Nanjing Normal University |
Liu J.,Nanjing Normal University |
Wang G.,Yancheng Teachers University |
Wang H.,Yancheng National Nature Reserve
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2014
Spartina alterniflora was introduced into China in 1979, and the first plantation of S. alterniflora was successfully constructed in Jiangsu province in 1982. Since it expanded quickly on coastal wetlands, great attentions were paid to its positive and negative effects on native ecosystems. In order to study the components and structural characteristics of soil organic carbon (SOC) pool of S. alterniflora saltmarsh, field observations and soil sampling work were fulfilled at permanent study sites including mudflat (MF), S. alterniflora salt marsh of 1-year (SAF2011), 5-year (SAF2007), 12-year (SAF2000), 23-year (SAF1989) and Suaeda salsa saltmarsh (SSF1989) along the coastal wetland in Yancheng, where located the largest area of S. alterniflora saltmarsh in China. The topsoil SOC, dissolved organic carbon (DOC) and microbial biomass carbon (MBC) were analyzed, and nuclear magnetic resonance (NMR) spectroscopy was utilized to explore the structure of soil organic carbon. The results showed that: (1) the development of S. alterniflora promoted the soil organic carbon sedimentation. The range of SOC was between 0.82—7.60 g/ kg, which occurred as the order of S. alterniflora saltmarsh (5.57 g/ kg)> S. salsa saltmarsh (2.4 g/ kg)> mudflat (1.05 g/ kg); the DOC occurred as the order of S. alterniflora saltmarsh(36.08 mg/ kg)>S. salsa saltmarsh(17.43 mg/ kg)>mudflat(6.92 mg/ kg); the MBC occurred as the order of S. alterniflora saltmarsh(52.51 mg/ kg) >S. salsa saltmarsh(18.27 mg/ kg) >mudflat(13.56 mg/ kg). These indicated that the soil active organic carbon pool was enhanced by the development of S. alterniflora. (2) The SOC contained more alcoxyl and aromatic carbon than other carbon fractions. The average proportion of SOC fractions occurred as the order of aromatic carbons(35.85%) > the alcoxyl carbon (32.83%) > carboxyl carbon (20.62%) > alkyl carbon (11. 76%). The highest value of aromatic carbons, alcoxyl carbon and alkyl carbon occurred at the 5-year S. alterniflora saltmarsh (SAF2007), while the highest value of carboxyl carbon occurred at the 23-year S. alterniflora saltmarsh (SAF1989). (3) The ratio of alkyl carbon/ alcoxyl carbon in topsoil occurred as the order of SAF2007 (0.44) >SSF1989 (0.43) >SAF2000 (0.28) > SAF2011(0.27) >SAF1989 (0.22); the ratio of hydrophobic carbon/ hydrophilic carbon occurred as SAF2007 (0.97)>SSF1989 (0.87)>SAF2000 (0.85)>SAF2011 (0.83)>SAF1989 (0.81). The highest ratio of alkyl carbon/ alcoxyl carbon (0.44) and hydrophobic carbon/ hydrophilic carbon (0.97) occurred at the 5-year S. alterniflora saltmarsh(SAF2007), indicating the highest degree of alkylation and stability of SOC pool. © 2014, Science Press. All rights Reserved.
Xu W.W.,Nanjing Normal University |
Wang G.X.,Nanjing Normal University |
Liu J.E.,Nanjing Normal University |
Chen Z.Y.,Nanjing Normal University |
And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2014
Landward sampling sites along an intertidal zone in Xingyanggang (Mudflat, Spartina alterniflora patch (SAP), S. alterniflora flat infra-edge (SAFI), S. alterniflora flat 2003(SAF03), S. alterniflora flat 1989(SAF89), Suaeda salsa (SS), Grass flat) were selected, 6 sampling plots were set to build 6 situ planting systems (1m length × 1m width × 0.7m depth) at every sampling site, and 3 systems for ramet planting and other 3 for seedling planting. The S. alterniflora seed germination, ramet, seedlings growth and propagation were investigated during the growing seasons of S. alterniflora. The results showed that: (1) Stressed by physical erosion of seawater, waves, tidal flooding and soil water, the seed germination rate in all of sampling sites was low, which was the highest at SAFI (17.8%, P <0.01). The ramet survival rate was greater (> 60.0%) at SAP, SAFI, SAF03, SAF89 and Grass flat than Mudflat (7.8%)and SS (0.0%); the ramet survival rate was much greater than seedling survival rate at SAP, SAFI, SAF03, SAF89 whereas was similarly low at Mudflat and SS. (2) Stem height, leaf length, leaf number, leaf width and leaf thickness of ramet at SAP, SAFI and SAF89 of wwere higher than that of other sites; seedling grew well at SAFI, while grew small or even died at other sites. Totally ramet grew much better than seedling. (3) All the survived ramet successfully settled and fructified, while only the survived seedling at Mudflat and SAFI fructified. The tillers of ramet was of 21.7 at Mudflat, 25.5 at SAP, 23.0 at SAFI, 6.8 at SAF03, 9.0 at SAF89 and 4.1 tillers per ramet at Grass flat, respectively; while seedling did not tiller (tillers per seedling <1.0) at most sites except at Mudflat (with 14.0 tillers per seedling). (4) The individual ramet biomass was significantly greater than individual seedling biomass at all sampling sites. Above-ground biomass allocation of two reproductive modes decreased toward sea and toward land, respectively, while the underground biomass allocation showed the opposite situation trend. Generally, in the study area the asexual propagules performed better than sexual ones at index of settlement, growing and reproduction, indicating that asexual propagules played more important role than sexual ones during the S. alterniflora salt marsh development.
Liu C.,Chinese Academy of Sciences |
Jiang H.,Chinese Academy of Forestry |
Zhang S.,Chinese Academy of Sciences |
Li C.,Yancheng National Nature Reserve |
And 2 more authors.
Current Zoology | Year: 2013
A multi-scale approach is essential to assess the factors that limit avian habitat use. Numerous studies have examined habitat use by the red-crowned crane, but integrated multi-scale habitat use information is lacking. We evaluated the effects of several habitat variables quantified across many spatial scales on crane use and abundance in two periods (2000 and 2009) at Yancheng National Nature Reserve, China. The natural wetlands decreased in area by 30,601 ha (-6.9%) from 2000 to 2009, pre-dominantly as a result of conversion to aquaculture ponds and farmland, and the remaining was under degradation due to expan-sion of the exotic smooth cordgrass. The cranes are focusing in on either larger patches or those that are in close proximity to each other in both years, but occupied patches had smaller size, less proximity and more regular boundaries in 2009. At landscape scales, the area percentage of common seepweed, reed ponds and paddy fields had a greater positive impact on crane presence than the area percentage of aquaculture ponds. The cranes were more abundant in patches that had a greater percent area of common seepweed and reed ponds, while the percent area of paddy fields was inversely related to crane abundance in 2009 due to changing agricultural practices. In 2009, cranes tended to use less fragmented plots in natural wetlands and more fragmented plots in anthropogenic paddy fields, which were largely associated with the huge loss and degradation of natural habitats between the two years. Management should focus on restoration of large patches of natural wetlands, and formation of a relatively stable area of large paddy field and reed pond to mitigate the loss of natural wetlands. © 2013 Current Zoology.