以水鸟保育为目标的水稻田构建技术及效果评估

海岸带自然湿地具有重要的水鸟保育价值。近年来,大规模的海岸带围垦造成了海岸带自然湿地的消失和质量退化,导致水鸟栖息地面积和质量的急剧下降,严重降低了水鸟的保育效果。海岸带自然湿地围垦后,部分转化为水鸟保育效果较差的工业模式水稻田。提升水稻田的水鸟保育效果,关键在于改善水稻田的构建技术。根据海岸带水稻田的种植管理模式和水鸟的生境选择特点,提出了一种以水鸟保育为目标的水稻田构建技术,以生态工程手段提升水稻田的水鸟保育效果。该技术的核心内容为在水稻田中构建水池单元,并设置生境小岛等功能组件,建立水稻田复合生态系统,实现多种种植和养殖。在满足水稻田生产管理需要的同时,为水鸟提供丰富的食物和适宜的多样性栖息场所。为验证该技术的水鸟保育效果,2013年夏季在崇明东滩依此技术构建了10 hm~2水稻试验田。2013年秋季至2014年春季,对比工业模式水稻田,各选取总面积10 hm~2的调查样方,开展一个完整年度的水鸟群落调查,每个季度调查5次,共计15次水鸟调查。水稻试验田共记录到水鸟34种,平均密度为41.87±6.62只/hm~2;工业模式水稻田共记录到水鸟12种,平均密度为2.08±0.45只/hm~2,水稻试验田的水鸟种类和密度均显著高于工业模式水稻田。结果表明,水稻田构建技术能够显著增加水稻田的水鸟种类和数量,提升水稻田的水鸟保育效果,从而弥补海岸带自然湿地缺失对水鸟造成的影响。水稻田构建技术可以为海岸带水稻田的水鸟保育工作提供了科学依据,同时为海岸带受损湿地的修复和水鸟栖息地的优化改造提供了参考案例。

A NEW CONSTRUCTION TECHNOLOGY OF RICE FIELDS FOR WATERBIRD CONSERVATION AND ITS EFFECTS

Coastal wetlands are important to waterbirds conservation. However, some coastal wetlands in China were cultivated greatly, resulting in the coastal wetlands qualities declines, and harm to the waterbirds and their habitats. Some of these wetlands have been cultivated to rice farms through large-scale mechanized planting, which had significantly negative impacts on the migratory waterbirds. In this study, we propose a new way to reform those rice fields, it can match the both requirements of rice growth and waterbirds habitats. The key step of the experiment is to set up a pond with an open water area in the rice field, and build ecological islands in the pond unit, thus create an agro-ecological system that can provide waterwirds habitats while the rice can be cultivated inside. To explore how this new technology benefit waterbirds’ biodiversity, we selected two sites (10 ha for each) on the Chongming Island (Shanghai, China), the experimental site rice fields are treated by above technology and the control site fields are cultivated by common industrial managements. In this experiment, we carried out fifteen times of waterbird surveys between August 2013 and May 2014. A total of 34 species were recorded with waterbirds density of 41.87 ± 6.62/hm2 in the experimental rice fields, whereas only 12 species were recorded at the control site with waterbirds density of 2.08 ± 0.45/hm2. The results of this study suggest that this technology could significantly increase waterbirds biodiversity in the present rice fields, and it may be applied to other coastal wetlands restoration in China.