Poyang Lake National Nature Reserve Research Articles

鄱阳湖小天鹅越冬种群数量与行为学特征

PDF HTML阅读 XML下载 导出引用 引用提醒 鄱阳湖小天鹅越冬种群数量与行为学特征 DOI: 10.5846/stxb201305060940 作者: 作者单位: 江西省科学院生物资源研究所 江西 南昌,江西师范大学生命科学学院 江西 南昌,江西省科学院 江西 南昌,南昌工学院 江西 南昌,江西师范大学生命科学学院 江西 南昌,江西师范大学生命科学学院 江西 南昌 作者简介: 通讯作者: 中图分类号: 基金项目: 江西省科技重大专项资助项目(20114ABG01100-1-03-4);国家自然科学基金资助项目(31260517,31060285) A preliminary investigation on the population and behavior of the Tundra Swan (Cygnus columbianus) in Poyang Lake Author: Affiliation: Institute of Biological Resources, Jiangxi Academy of Sciences,Nanchang,Jiangxi,China,College of Life Science,Jiangxi Normal University,Nanchang,Jiangxi,Jiangxi Academy of Sciences,Nanchang,Jiangxi,Nanchang Institute of Science and Technology,Nanchang,Jiangxi,College of Life Science,Jiangxi Normal University,Nanchang,Jiangxi,College of Life Science,Jiangxi Normal University,Nanchang,Jiangxi Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:2012年10月-2013年3月,采用直接计数法对鄱阳湖小天鹅Cygnus columbianus种群数量分布进行了5次调查。结果显示,各调查点小天鹅的种群数量均不稳定,可能与食物丰富度、水位等相关。各次调查中以第2次调查观测到的小天鹅数量最多,合计10756 只;调查区域中以鄱阳县白沙洲自然保护区调查到的小天鹅数量最多。5次调查中鄱阳县的小天鹅数量均占每次调查总数的56%以上,平均2239.80 只。小天鹅在各保护区不同湖泊的数量分布存在时间差异,但分布仅局限在几个湖泊中。调查显示,小天鹅的幼体比例为29.04%(n=1150)。采用瞬时扫描法对小天鹅越冬期的行为进行了研究,其用于静止(43.12%)和取食(27.44%)行为的时间较多,用于运动(16.82%)和梳理(11.48%)行为的时间较少,用于社会行为(1.14%)的时间最少。在小天鹅的日间行为节律中,静止行为高峰出现在07:00-08:00和17:00-18:00时段,取食行为高峰出现在16:00-17:00。下午取食强度的增加与冬季夜间长和气温低有关,鸟类必须获得足够的能量以维持其夜间的能量消耗。对小天鹅成幼体行为分配进行检验,发现除社会行为差异显著(Z=-2.310,P=0.021)外,其余行为差异均不显著。但成幼体的行为节律有较大差异,主要体现在静止和取食行为上。 Abstract:The tundra swan (Cygnus columbianus) is listed in the second category of nationally protected wildlife species in China and is regarded as a vulnerable endangered species by the China Red Data Book of Aves. In China, wintering areas include the middle and lower reaches of the Yangtze River and Taiwan among other areas. In recent years tundra swan numbers have decreased in some lakes. The distribution ranges of this species has reduced and it is now concentrated in lakes in Anhui Province and Poyang Lake in Jiangxi Province. Tundra swan inhabit Poyang Lake for approximately 150 days of the year from late October to the middle of March. The wintering ecology of tundra swans was investigated by direct count method in Poyang Lake on five occasions from October 2012 to March 2013. The Poyang Lake National Nature Reserve (PYH), Nanji Wetland National Nature Reserve (NJS), Duchang Migratory-bird Nature Reserve (DC), and the Poyang Baishazhou Nature Reserve (BSZ) were selected to conduct wintering ecology assessments including population dynamics, age structure, and behavior of tundra swans. The results show that tundra swan numbers were not stable at all of the survey sites, indicating that local movement occurs in tundra swan populations. There may be some mechanism by which this local movement is triggered, e.g. food availability or water level. The exact mechanism of local movement requires further study. The tundra swan numbers were highest in the second survey, 10, 756 swans in total. The largest population, 11,199 individuals, was observed in BSZ, accounting for > 56% of total the numbers observed during the experimental period. Temporal variation in the distribution and number of this species was observed in the different lakes of each reserve. However, the species was confined to certain lakes, indicating that only some lakes provide good habitats for this bird. Our results show that the percentage of juveniles was 29.04% (n=1150). The diurnal activity budgets and rhythm of the tundra swan were studied with the instantaneous scan sampling method from December 2012 to March 2013. The birds spent most of their time either motionless (43.12%) or feeding (27.44%), and spent the least amount of time either in motion (16.82%) or cleaning and tidying (11.48%). The motionless behavior peaked between 07:00 and 08:00 h and 17:00 and 18:00 h, whereas, feeding behavior peaked between 16:00 and 17:00 h. The increase in feeding intensity in the afternoon was related to long, cold winter nights. Birds had to acquire enough food and energy to survive through the night. Social behavior differed significantly between adults and juveniles, no differences were found for other behaviors. The diurnal activity budgets and rhythm of adults and juveniles were very different. This difference was mainly observed in their motionless and feeding behaviors. Early research indicates that the tundra swan can forage in deep water areas (about 1 meter), however, none have been observed foraging in grassland. During this investigation we observed many individuals foraging in grasslands and rice fields, which perhaps indicates a lack of food resources in Poyang Lake. 参考文献 相似文献 引证文献

Relationship between the hydrological conditions and the distribution of vegetation communities within the Poyang Lake National Nature Reserve, China

Hydrological characteristics have been recognized as major driving forces for wetland vegetation. The water cycle and hydrological processes of wetland are increasingly influenced by the ongoing climate change and more intensive human activities, which may in turn affect the distribution and structure of vegetation communities. Poyang Lake, located on the south bank of the lower reach of Yangtze River, receives inflows from five tributaries and discharges to the Yangtze River. The unique hydrological conditions of the Poyang Lake wetland create abundant wetland vegetation communities. As a major national hydraulic project, the Three Gorges Dam across the Yangtze River has changed the water regime of Poyang Lake and hence may affect the vegetation distribution. This work aims to investigate the influences of hydrological properties on vegetation structure at broad spatial and temporal scales. Histograms and sensitivity index are used to link the hydrological processes with the vegetation distribution across the Poyang Lake National Nature Reserve. The results show that different vegetation communities react differently to the hydrological conditions. Specifically, certain communities, e.g. Carex and Eremochloa ophiuroides, are able to survive a wide variety of mean water depth and percent time inundated, while others, like Carex–Polygonum criopolitanum, are found to be relatively sensitive to hydrological conditions. It is suggested that this work provides a new insight for evaluating the impact of hydro-engineering projects on vegetation communities and wetland vegetation restoration.

Monitoring the dynamics of wetland inundation by random sets on multi-temporal images

General models are required for better understanding the dynamics of wetland inundations and their water regimes. Extraction by imagery snapshots and use of a crisp data model do not value the inherent uncertainties in space and time. This study addresses parameterization of a mixed Gaussian random set model in a multi-temporal analysis. The model is applied to monitor annual variation of wetland inundation extents from a series of Landsat TM images in 2004 and HJ images in 2009 on the Poyang Lake national nature reserve (PLNNR) in China. We use related indices to represent spatial uncertainties of inundated areas and to delineate the transition zone between wetland vegetation and open water. The PLNNR water regime is investigated by accumulating a series of random sets during one year and determining the water covering days (WCD) at the pixel level. Random sets provide detailed spatial configurations of the WCD which has a strong negative correlation with the underwater DEM. Comparing 2004 and 2009, the study shows that almost half of the PLNNR area experienced drought. We conclude that the mixed Gaussian random set model with three components presented in this study serves as a general method to parameterize the random set model for large datasets. Moreover, it is well suited to capture detailed information on spatial temporal dynamic of wetland inundation and contributes to our understanding of wetlands water regimes from multi-temporal images.

Comparison of extrapolation and interpolation methods for estimating daily photosynthetically active radiation (PAR)

Measurements of photosynthetically active radiation (PAR), which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one interpolation methods for estimating daily PAR reaching the earth surface within the Poyang Lake national nature reserve, China. The daily global solar radiation records at Nanchang meteorological station and daily sunshine duration measurements at nine meteorological stations around Poyang Lake were obtained to achieve the objective. Two extrapolation methods of PARs using recorded and estimated global solar radiation at Nanchang station and three stations (Yongxiu, Xingzi and Duchang) near the nature reserve were carried out, respectively, and a spatial interpolation method combining triangulated irregular network (TIN) and inverse distance weighting (IDW) was implemented to estimate daily PAR. The performance evaluation of the three methods using the PARs measured at Dahuchi Conservation Station (day number of measurement = 105 days) revealed that: (1) the spatial interpolation method achieved the best PAR estimation (R2 = 0.89, s.e. = 0.99, F = 830.02, P < 0.001); (2) the extrapolation method from Nanchang station obtained an unbiased result (R2 = 0.88, s.e. = 0.99, F = 745.29, P < 0.001); however, (3) the extrapolation methods from Yongxiu, Xingzi and Duchang stations were not suitable for this specific site for their biased estimations. Considering the assumptions and principles supporting the extrapolation and interpolation methods, the authors conclude that the spatial interpolation method produces more reliable results than the extrapolation methods and holds the greatest potential in all tested methods, and more PAR measurements should be recorded to evaluate the seasonal, yearly and spatial stabilities of these models for their application to the whole nature reserve of Poyang Lake.

Application of random sets to model uncertainties of natural entities extracted from remote sensing images

Remotely sensed images as a major data source to observe the earth, have been extensively integrated into spatial-temporal analysis in environmental research. Information on spatial distribution and spatial-temporal dynamic of natural entities recorded by series of images, however, usually bears various kinds of uncertainties. To deepen our insight into the uncertainties that are inherent in these observations of natural phenomena from images, a general data modeling methodology is developed to embrace different kinds of uncertainties. The aim of this paper is to propose a random set method for uncertainty modeling of spatial objects extracted from images in environmental study. Basic concepts of random set theory are introduced and primary random spatial data types are defined based on them. The method has been applied to dynamic wetland monitoring in the Poyang Lake national nature reserve in China. Four Landsat images have been used to monitor grassland and vegetation patches. Their broad gradual boundaries are represented by random sets, and their statistical mean and median are estimated. Random sets are well suited to estimate these boundaries. We conclude that our method based on random set theory has a potential to serve as a general framework in uncertainty modeling and is applicable in a spatial environmental analysis.

Monitoring the impact of backflow and dredging on water clarity using MODIS images of Poyang Lake, China

AbstractBackflow from the Yangtze River to Poyang Lake occurs frequently due to their different flood seasons. Based on the reasons for and time period of backflow, this study estimated the spatial‐temporal extent and the change of water clarity influenced by sediments within the backflow and northern Poyang Lake using time‐series Moderate Resolution Imaging Spectroradiometer (MODIS) images. The results revealed that the sediments from backflows together with dredging activities in the northern Poyang Lake not only affected the northern Poyang Lake, but also influenced the central and southern Poyang Lake and the Poyang Lake national nature reserve, and resulted in great decline of water clarity in the regions influenced, which could seriously affect the lake ecosystem. The results indicated that MODIS images have potential for monitoring the distribution of sediments from backflows and dredging activities. However, the potential is limited because of the frequent cloud cover in the study area and the characteristics of backflow itself. The dredging activity combined with backflows might have great negative impacts on the Poyang Lake ecosystem, and it would be worthwhile to explore the possible impacts in order to develop scientific knowledge to support the decisions, which need to be made by the responsible authorities for deciding how to rationally manage this unique lake ecosystem Copyright © 2008 John Wiley &amp; Sons, Ltd.

Comparison of MODIS and Landsat TM5 images for mapping tempo–spatial dynamics of Secchi disk depths in Poyang Lake National Nature Reserve, China

Landsat has successfully been applied to map Secchi disk depth of inland water bodies. Operational use for monitoring a dynamic variable like Secchi disk depth is however limited by the 16‐day overpass cycle of the Landsat system and cloud cover. Low spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) image captured twice a day could potentially overcome these problems. However, its potential for mapping Secchi disk depth of inland water bodies has so far rarely been explored. This study compared two image sources, MODIS and Landsat Thematic Mapper (TM), for mapping the tempo–spatial dynamics of Secchi disk depth in Poyang Lake National Nature Reserve, China. Secchi disk depths recorded at weekly intervals from April to October in 2004 and 2005 were related to 5 Landsat TM and 22 MODIS images respectively. Two multiple regression models including the blue and red bands of Landsat TM and MODIS respectively explained 83% and 88% of the variance of the natural logarithm of Secchi disk depth. The standard errors of the predictions were 0.20 and 0.37 m for Landsat TM and MODIS‐based models. A high correlation (r = 0.94) between the predicted Secchi disk depth derived from the two models was observed. A discussion of advantages and disadvantages of both sensors leads to the conclusion that MODIS offers the possibility to monitor water transparency more regularly and cheaply in relatively big and frequently cloud covered lakes as is with Poyang Lake.

Analysis on the Waterbirds Community Survey of Poyang Lake in Winter

Poyang Lake provides wintering sites for several hundred thousands water birds every year. There are historical records of 310 species of birds in Poyang Lake National Nature Reserve (Abbr. in PYNNR), belonging to 17 orders, 63 families, and 158 genus, and including 125 water birds species belonging to 6 orders, 19 families, and 60 genus. The most amount of waterbirds in Poyang Lake are geese and swans, the second most are shorebirds. Dominant species of bird communities are whistling swan, swan goose and white-fronted goose. There are 19 species listed as threatened by IUCN. The Siberian crane is the most well-known wintering species in Poyang Lake. The number of Siberian cranes stablized in recent years. There are 18 species whose numbers are more than 1% of the total number of their global or migrant route's populations according to three separate of surveys. PYNNR is the most concentrated area for rare waterbird and precious species; at the same time, Nanhu and other adjacent areas to PYNNR such as the middle and south branch of the Gan River are also important habitats for rare waterbirds, and need more attention and conservation actions.

Biodiversity changes in the lakes of the Central Yangtze

The Central Yangtze ecoregion in China includes a number of lakes, but these have been greatly affected by human activities over the past several decades, resulting in severe loss of biodiversity. In this paper, we document the present distribution of the major lakes and the changes in size that have taken place over the past 50 years, using remote sensing data and historical observations of land cover in the region. We also provide an overview of the changes in species richness, community composition, population size and age structure, and individual body size of aquatic plants, fishes, and waterfowl in these lakes. The overall species richness of aquatic plants found in eight major lakes has decreased substantially during the study period. Community composition has also been greatly altered, as have population size and age and individual body size in some species. These changes are largely attributed to the integrated effects of lake degradation, the construction of large hydroelectric dams, the establishment of nature reserves, and lake restoration practices.

Management of Jiangxi Poyang Lake National Nature Reserve, China

Poyang Lake is the largest freshwater lake in the People's Republic of China. It receives water from five main rivers flowing directly to the lake, as well as back-flooding from the Chang Jiang (Ya...