崇明东滩冬季不同管理模式下水稻田水鸟群落特征及其生境分析

Community Characteristics and Habitat Analysis of Wintering Waterfowls between Different Manage Patterns of Rice Paddy in Chongming Dongtan

崇明东滩是亚太地区候鸟迁徙路线的重要中转站,也是上海地区促淤圈围的重点区域。水稻(Oryza sativa)田作为当地分布广泛且重点改造的人工湿地,研究其是否具有水鸟招引效果具有重要意义。本研究于2013和2014年冬季采用样方法对崇明东滩两种不同管理模式的水稻田,即2013年开始改造的传统模式水稻田和改造多年的机械化模式水稻田,进行了水鸟群落及生境因子调查,以探究不同管理模式下水稻田内生境差异,水鸟对不同生境的利用程度及其不同生境中的关键因子对水鸟分布的影响。调查期间共记录到水鸟5目7科18种1 795只次,其中传统模式水稻田记录到水鸟5目6科17种1 756只次,优势种为绿翅鸭(Anas crecca)、斑嘴鸭(A.poecilorhyncha)、鹤鹬(Tringa erythropus);机械化模式水稻田录到水鸟4目5科6种39只次,优势种为小??(Tachybaptus ruficollis)和凤头麦鸡(Vanellus vanellus)。T检验结果显示,传统模式水稻田对水鸟的招引效果(即多度和物种丰富度)显著优于机械化模式水稻田,2014年改造后传统模式水稻田的水鸟招引效果显著优于2013改造初期。多元回归分析显示,明水面面积比例是影响水稻田水鸟种类、数量分布的最重要因子。结果表明,明水面面积和适合的水位高度是影响冬季水稻田水鸟招引效果的主要因素,为提高冬季水稻田水鸟保育效果,应注重营造、维护冬季水稻田中水文条件。

Chongming Dongtan is one of the important transit points of Asia-Pacific Flyway, as well as a key coastal reclamation area in Shanghai. As a kind of artificial wetland, rice （Oryza sativa） paddy-field is widely distributed in this area and the main goal of restoration management, it′s necessary to find out whether the paddy-field is attractive to the waterfowls. In our study area, there are two different manage patterns （traditional and mechanized） of rice paddy-field. The traditional paddy-field samples region located in Chongming Dongtan National Nature Reserve （Fig. 1）, composed of rice paddies and diversion trench, and farming in traditional manual administration with low density of cultivation. Traditional manage patterns rice paddy retained some rice and guarantee water conditions with the depth of 0.5﹣15 cm in winter. Mechanized manage pattern rice paddy sample region located in Yaoquan farm （Fig. 1）, a typical coastal farmland ecosystem, managed in large scale mechanization farm mode, with high density cultivation. It is also composed of rice paddies and diversion trench. Mechanized manage pattern rice paddy-field is normally abandoned or planted as rotation in winter, with no water in rice paddies. Quadrat methods were taken to measure the differences of waterfowl diversity and habitat factor of two patterns of rice paddy in winters of 2013 and 2014, and we tried to find out which manage pattern of the rice paddy would attract more waterfowls and analyzed the environmental factors impacting the waterfowls′ distribution. During the two-year investigation, up to 1 795 waterfowl individuals were recorded, subordinated in 5 orders, 7 families and 18 species. In traditional manage pattern of paddy field, there were 1 756 waterfowl individuals subordinated in 5 orders, 6 families and 17 species, and the dominant species were Common Teal （Anas crecca）, Spot-billed Duck （A. poecilorhyncha）, Spotted Redshank （Tringa erythropus）. In mechanized manage pattern of rice paddy, 39 waterfowl individuals were counted, subordinated in 4 orders, 5 families and 6 species, and the dominant species were Little Grebe （Tachybaptus ruficollis） and Northern Lapwing （Vanellus vanellus）. T-test analysis indicated that firstly the paddy fields under traditional manage pattern performed better than another kind of fields in terms of abundance, richness of waterfowls, and secondly the paddy fields after transformation in 2014 performed better effect of waterfowl attraction than the ones in early transformation in 2013. Linear Regression （Backward Elimination） showed that the proportion of open water area being the most important factor to influence waterfowl species and abundance. Our study suggested that hydrological condition of rice fields is the main factor of attracting waterfowls in winter, and it is important for waterfowl biodiversity conservation.