【作者】 葛振鸣；

【导师】 王天厚；

【作者基本信息】 华东师范大学 ， 生态学， 2007， 博士

【摘要】 长江口滨海滩涂湿地资源丰富，其中崇明东滩湿地成为《国际湿地公约》(Ramsar公约)所认定的国际重要湿地。而且九段沙、大小金山、南汇东滩、横沙岛和长兴岛也列入国家重要湿地名录。每年大约有200万只水禽沿着“东亚—澳大利亚”迁飞路线在北半球的西伯利亚中部和阿拉斯加西部、亚洲沿海、澳大利亚和新西兰之间往返迁徙。此迁飞路线包括了鸟类的繁殖地、停歇地以及越冬地。长江口滩涂湿地是重要的中转站，迁徙季节大约有100万只水禽经过，对于亚太地区迁徙水禽完成生活史具有不可替代的作用，是东亚—澳大利亚水禽保护网络中十分重要的环节。然而，长江三角洲区域经济发展、人口密集、城市化程度高，滨海湿地正面临着巨大威胁，其中以围垦开发导致的栖息地结构变化和功能退化效应最为明显。湿地水禽包括涉禽和游禽，本研究对象为长江口滩涂常见的中、小型涉禽和部分游禽(冬季)，其中以迁徙涉禽(主要以鸻形目鸟类为主)的种类和数量居优势。通过(1)迁徙涉禽对长江口滩涂湿地的利用方式：(2)围垦对迁徙涉禽的影响及程度；(3)受损湿地和次生人工湿地水禽群落特征和生境选择；(4)新生湿地迁徙涉禽的能量代谢水平和环境容纳量分析等系统性的工作来探讨湿地保护、功能恢复、鸟类生境调整和科学管理等目前亟待解决的问题，并提出相应的技术体系，进一步协调区域内自然资源保护和可持续发展的新模式。研究概况由下简述：1．1984年至2005年，在长江口滩涂湿地通过野外鸟类调查、捕猎跟踪调查和侯鸟环志／回收记录等手段来了解迁徙涉禽对长江口滩涂湿地的利用方式。1984—2005期间的野外调查和环志数据显示涉禽在北迁期(春季)和南迁期(秋季)的鸟类数量比例在1.5：1～7.2：1之间，1991—1992年所跟踪调查的两名猎户春秋季捕获的涉禽数量比例为2：1左右。最常见种为细嘴滨鹬(Calidris tenuirostris)、红腹滨鹬(Calidris canutus)、斑尾塍鹬(Limosa lapponica)、尖尾滨鹬(Calidris acuminata)和红颈滨鹬(Calidris ruficollis)。2003—2004年对所环志的涉禽进行年龄鉴定，其中春季96.98％为成鸟，3％左右为幼鸟；相反，秋季94.73％为幼鸟。研究结果表明，涉禽成鸟在南北迁徙季节可能沿不同路线迁飞，北迁时首先选择长江口等区域停歇，繁殖后可能选择更直接的路线越过长江口返回越冬地；而刚出生的幼鸟在第一次南迁路线上可能选择多次停歇补充能量的迁飞策略。2．2004年3月至2005年1月，在长江口南岸杭州湾北岸滨海滩涂进行了涉禽野外调查以及鸟类栖息地选择模式分析，共统计到鸟类25种，春季优势种为细嘴缤鹬(Calidris tenuirostris)、尖尾缤鹬(Calidris alpine)和红颈滨鹬(Calidris，ruficollis)；夏季为环颈鸻(Charadrius alexandrinus)、青脚鹬(Tringa nebularia)和蒙古沙鸻(Charadrius mongolus)，秋季为环颈鸻、红颈滨鹬和青脚鹬，冬季为黑腹滨鹬(Calidris alpina)、环颈鸻和泽鹬(Tringa stagnatilis)，鸟类总体数量呈春季＞秋季＞冬季＞夏季，海堤外(自然滩涂)和堤内(人工湿地)鸟类种数四季大致相等，但鸟类平均密度季节差异显著。通过对样点内鸟类与环境因子进行多元分析，初步总结出堤外滩宽和光滩宽是影响鸟类栖息的最关键因子，海三棱藨草(Scirpus×mariquete)覆盖比例和潮上坪宽度的影响程度次之。堤内浅水塘比例和裸地比例是影响鸻形目鸟类分布的关键因子，海三棱蔗草覆盖比例也起正向作用。而人类干扰大、芦苇(Phragmites communis)／互花米草(Spartina alternifloral)密植和高水位的区域不利于鸟类利用。3．由于长江口滨海滩涂高强度的围垦占用对迁徙涉禽的影响机制和程度较少研究，所以，1984／85年和2004／05年在长江口南岸和杭州湾北岸滩涂进行涉禽群落和生境变量调查。主要考察潮间带滩涂20年土地利用方式演变对涉禽时空分布的影响。土地利用方式考察结果显示，以1984年作为初始状态，长江口南岸和杭州湾北岸区域的滨海滩涂面积大约为400 km~2，1998年长江口南岸围垦面积大约为143km~2，杭州湾北岸围垦32 km~2；自然滩涂面积为150 km~2(长江口南岸)和100 km~2(杭州湾北岸)。至2003年，长江口南岸又围垦了大约247 km~2，杭州湾北岸围垦106 km~2。1984／85年所调查的样点全部被围垦，但有一部分滩涂围垦后目前并没有被利用，仍保持着原有地貌和潮水条件，长江口南岸区域有大约151 km~2此类型滩涂，杭州湾北岸有40 km~2。2004／05年在长江口南岸杭州湾北岸堤内外近500 hm~2的调查区域共观察到涉禽25种，鸟类数量与1984／85年没有明显变化，优势种组成略有差异。相比1984／85年，2004／05年涉禽分布较不均匀，突出表现为集中于上述几个围垦后并没有被利用的滩地。对涉禽分布和生境特征的时空比较可知，样方内滩宽和潮上坪宽的变化是影响涉禽分布变化的关键因子。4．2004年12月—2005年5月，对上海崇明东滩1998年大堤内200 hm~2次生人工湿地进行鸟类调查，冬季统计到鸟类8目15科56种，游、涉禽为优势种；春季统计到鸟类10目19科55种，涉禽为优势种。运用多元回归对鸟类种类数、数量、物种多样性、均匀性指数和科属多样性等群落特征以及调查样点内水位、水面积、植被盖度、底栖动物密度、鱼类捕捞和人类干扰等环境因子进行鸟类生境选择分析。回归模型显示冬季鸟类种类数与植被盖度呈显著正相关，鸟类数量、物种多样性、科属多样性等群落特征与水位高低、水面积比例以及鱼类捕捞强度有关，底栖动物密度影响鸟类均匀度和数量；春季鸟类数量与鱼塘的水面积呈正相关，而种类和数量与水位呈显著负相关，物种多样性和均匀性明显受水位、水面积和植被盖度影响，鸟类科属多样性与底栖动物密度呈显著相关，捕捞状况对春季鸟类群落影响不大。5．本研究根据对九段沙湿地2005年春、秋季食物资源调查来计算迁徙期鸻形目鸟类的环境容纳量。结果表明，九段沙湿地春季食物总量为4541.20kg AFDW(去灰分干重)，秋季为2279.64kg AFDW，按鸻形目鸟类有效栖息生境计算，春季鸟类可利用食物资源量为3429.03 kg AFDW，秋季为1700.92kg AFDW。通过鸟类体型类群分类(根据去脂净重、基础代谢率和体长)和能量消耗模型可以得出，九段沙湿地迁徙季节总食物量理论上可维持的鸻形目鸟类最大数量约为春季350万只，秋季175万只。按有效生境计算，春季约为260万只，秋季约为130万只。考虑到食物取入率的影响，九段沙湿地实际可容纳约17.5～35万只鸟类。综上所述，通过长江口迁徙水禽的群落结构特征和生境选择模式的研究结果，以九段沙湿地作为规划对象，针对滩涂湿地保护、鸟类生境调整和科学管理等方面提出初步建议：·春秋季为涉禽迁徙高峰期，研究区域调查到的数量较多；夏季数量较少，以雀形目鸟类为主；冬季鸟类群落主体为越冬游禽；·滩涂宽度和潮上坪宽度是影响涉禽分布的关键因子；人类干扰大、芦苇／互花米草密植和高水位的区域不利于涉禽栖息；·人工湿地水位高低、水面积比例、植被密度对不同鸟类类群的影响机制和效果不同；·建议迁徙季节在不危害保护区生态安全的前提下，在高大植被密植区开辟一些隐蔽性强的裸地滩涂和浅水塘，以提高涉禽对湿地资源的可利用性；·根据迁徙季节(春秋季)和冬季优势鸟类群落的不同，可对湿地生境要素进行人为干预调整，合理利用自然资源。更多还原

【Abstract】 The mouth of the Yangtze River is one of the most ecologically sensitive zones in the world with the indigenous bio-diversity and increasing degenerative pressure, comprising abundant coastal mudflats including the Chongming Dongtan Ramsar wetland, mudflats in the southern Yangtze estuaries and north Hangzhou Bay, Jinshan islands, Changxing & Hengsha islands.Over two million Shorebirds migrate to Australia along the East Asian-Australasian Flyway that stretches from central Siberia and western Alaska south through eastern Asia to Australia and New Zealand. The location of the mouth of the Yangtze River suggests that this area may be the important stopover site for the migrants during the migratory seasons. However, as one of rapidest economic developing metropolises of China, Shanghai which located in the Yangtze River Mouth has about 18 million people and a territory of 6500 km~2, with the highest density of population in the world. Within last 20 years, about 400 km~2 coastal intertidal mudflats were reclaimed. Such an excessive reclamation has nothing benefit on the wildlifes and the habitats.Wetland waterbirds group concludes shorebirds and swimming birds, the research takes the shorebirds as the main objective with some swimming birds as sub-objective to understand: (1) Shorebird use of wetlands at the mouth of the Yangtze River during spring and fall migration; (2) The effects of reclamation on shorebirds; (3) The community characters and habitats selection of the waterbirds at the degenerative and the artificial wetlands; (4) Carrying capacity of shorebirds at new-formed wetland during the migratory seasons. Based on which, the study aimed to discuss some elementary suggestions for wetlands protection, ecosystem restoration, birds’ habitats optimization and sustainable managing.The brief of research process as follows:1. From 1984 - 2004, we conducted censuses, monitored hunting activities, and banded birds at the mouth of the Yangtze River to understand how shorebirds used the study area. Shorebird counts and banding data showed that the ratios of shorebird numbers between northward migration period (spring) and southward migration period (fall) varied from 1.5:1 to 7.2:1 at different sites from 1984 - 2005, and ratios between seasons of 1991 and 1992 based on hunted birds were about 2:1. The most common species observed during spring (northward) migration were Great Knots (Calidris tenuirostris), Red Knots (Calidris canutus), Bar-tailed Godwits (Limosa lapponica), Sharp-tailed Sandpipers (Calidris acuminatd), and Red-necked Stints (Calidris ruficollis). In spring 2003-2004, 96.98% of the shorebirds observed were adults, and 3% were after hatching year birds. In contrast, almost all (94.73%) of birds counted in fall were identified as juveniles. These findings indicate that adults either use a different migration route in the fall or pass by the mouth of the Yangtze River without stopping. Juveniles, however, may depend on coastal stopovers for feeding during their first southward passage.2. From March 2004 to January 2005, we conducted seasonal shorebirds censuses in ten coastal habitats along the south Yangtze River mouth and North Hangzhou Bay, examining the relative seasonal abundance of shorebirds and their spatial distribution simultaneously. A total of 25 species were identified, the seasonal dominant species were Great Knot (Calidris tenuirostris), Sharp-tailed Sandpiper (Calidris alpine) and Red-necked Stint (Calidris ruficollis) in spring; Kentish Plover (Charadrius alexandrinus), Common Greenshank (Tringa nebularia) and Lesser Sand Plover (Charadrius mongolus) in summer; Kentish Plover, Red-necked Stint and Common Greenshank in autumn; Dunlin (Calidris alpine), Kentish Plover and Marsh Sandpiper (Tringa stagnatilis) in winter. These species accounted for more than 85% of all shorebirds counted. The numbers of shorebirds counted were highest in spring and then in autumn, winter and summer consequently. Among the four seasons, there were little significant differences of bird species abundance between the sites outside seawall (natural mudflat) and the sites inside seawall (artificial wetland), but the average density of shorebirds had obvious difference. The habitat-selection analysis of the environmental-factor (outside and inside the seawall) impacting on the shorebird community was made in the ten study sites with Canonical Correspondence Analysis. The study results indicated that: (1) Outside the seawall, total intertidal the widths of intertidal mudflat and bare mudflat were the key factors affecting the shorebirds; the proportion of bulrush (Scirpus × riqueter) covering and supertidal mudflat width had the positive correlation with the bird abundance, the human disturbance and the proportion of reed (Phragmites communis) / smooth cord-grass (Spartina alterniflora) covering had the negative impacts on the bird contribution; (2) Inside the seawall, mudflat with sallow water and the proportion of mudflat were the key factors to increase the bird abundance; the proportion of bulrush covering should benefit to the shorebird appearance. The habitats with heavy human disturbance, dense reed and smooth cord-grass bed or high water table were not good to be used by shorebirds. 3. Until now the influence of intensive reclamation on the shorebirds utilizing the shoreline was little known. The shorebird distribution in ten fixed sample sites in 1984/85 and 2004/05 and the physical changes in inter-tidal wetland and coastal land-use at these sites were investigated. In 2004/05, 25 shorebirds species were counted. The statistical results show that the seasonal abundance of shorebirds present was similar to those recorded in the 1980s, but the bird species counted in both north and south migration periods declined from 1984/85 to 2004/05. During 1984-2004, taking the area of intertidal mudflat in 1984 as the reference point, there has been an overall accretion of between 430 km~2 - 550 km~2 of intertidal mudflat in the south Yantze River estury (SYRE) and north Hangzhou bay (NHB) areas over the last two decades. By 1998, approximately 143 km~2 (SYRE) and 32 km~2 (NHB) of intertidal mudflats had been reclaimed and there was approximately 247 km~2 (SYRE) and 106 km~2 (NHB) intertidal mudflats remaining. In 2003, the two areas of further reclaimed land increased to approximately 266 km~2 (SYRE) and 98 km~2 (NHB). After carrying out fieldwork along the shoreline using GPS points based on the satellite map of 2003, we found that the mudflats that were visually classified from the map were areas that had been reclaimed but were currently undeveloped. These areas maintained natural characteristics of intertidal mudflat, as the tide could still access the area providing nutrients for the macrobenthos. These reclaimed, yet undeveloped areas covered about 151 km~2 in SYRE and 40 km~2 in NHB, which could be considered as relatively available habitats for the shorebirds of high value. Most shorebirds were squeezed into those residual reclaimed but unused mudflats and the spatial distribution of shorebirds has changed significantly, because the physical characteristics of the mudflats were transformed since the decades. The width of mudflats and upper intertidal zones were the key variables affecting the distribution of shorebirds. Some implications for conservation on reclamation rules/guidelines and land-utilization procedures for artificial wetlands were proposed.4. From December 2004 to May 2005, an avian study was undertaken in the artificial wetlands of 200-hm~2 area behind the 1998’s seawall in Chongming Dongtan, Shanghai. A total of 56 bird species of 8 orders and 15 families were counted in the winter of 2004, and the dominant species were waterbirds and shorebirds; 55 species of 10 orders and 19 families were counted in the spring of 2005, which were dominated by shorebirds. Meanwhile, the environmental factors including water level, water area, vegetation coverage, macrobenthos density, fishing status and human disturbance were measured quantitatively. Based on multi-regression analysis between bird community and environmental variables, the study results indicated that in winter, the vegetation coverage positively correlated with bird species abundance; the water level, water area and fishing status impacted on the bird number and diversity of species, genus and family; and the macrobenthos density affected the number and evenness of birds. In spring, the water area had positive relationship with bird species abundance, but the water level became a negative factor on the bird species abundance and number; the birds species diversity and evenness were affected by water level, water area and vegetation coverage; macrobenthos density correlated with bird diversity positively. The research could not prove that the fishing activities produced a significant impact on the bird community. 5. The carrying capacity of the food supply was measured in Jiuduansha wetland, a stopover site of Yangtze River Mouth, for migrating shorebirds during the migratory season (spring and autumn). From March-April and September-October 2005, the macrobenthos resource of Jiudhansha wetland was investigated, and the most macrobenthos species were defined as appropriate foods for the shorebirds. The results showed that the total food resource was 4541.20 kg AFDW (Ash Free Dry Weight) in spring and 2279.64 kg AFDW in autumn. Another calculation was undertaken only within available habitats (Intertidal Bare mudflat and Bulrush zones), the food resource of available habitats in this area was 3429.03 kg AFDW in spring and 1700.92 kg AFDW in autumn. Based on the shorebird body size classification (lean weigh, basic metabolic rate and body length) and energy depletion model, the maximum of carry capacity in term of the all food supply in Jiuduansha wetland can support 3.5 million shorebirds during spring and 1.75 million during autumn. The carry capacity of shorebirds in term of the available food was 2.6 million during spring and 1.3 million during autumn. Considering the effect of intake rate, the real carrying capacity was 0.175-0.35 million shorebirds in the study area.In conclusion, based on the research results, we take the Jiuduansha wetland as planning objective to bring forward some suggestions for wetlands protection, ecosystem restoration, birds’ habitats optimization and sustainable managing, which as follows:· The seasonal dominant birds group is shorebirds in spring and fall; the finches are most in summer; the swimming birds are the dominant species in winter.· The width of mudflats and upper intertidal zones are the key factors affecting the shorebirds distribution. The area with high human disturbance, high water level and dense reed/Spartina plants cover produced a negative impact on the shorebirds.· In the artifical wetland, the habitat variables of water area, water level and vegetatable density play different roles for shorebirds and swimming birds.· The main factor of restriction on shorebirds number in Jiuduansha wetland was the scarcity of available habitats rather than food supply, and we recommend restoring wading pools in the reed or Spartina areas as management strategy to improve the use efficiency of the resource for the shorebirds.· Acorrding to the dominant birds groups during spring/fall and winter, the wetland physical characters could be resized and controlled to make use of the nature resource reasonably and sustainably.更多还原