Ponds represent a large potential resource for biodiversity in agricultural areas of lowland Europe though many are lost through natural succession towards damp woodland depressions (terrestrialisation). Managing ponds back towards their former open-water state may result in dramatic increases of biodiversity, even on heavily farmed land. Here, evidence is presented of the effects of terrestrialised farmland pond restoration on chironomid assemblages. Chironomid pupal exuviae were collected from three terrestrialised ponds on intensively-farmed land in North Norfolk, Eastern England. Two of the ponds had trees, scrub and sediment removed, while the third pond remained undisturbed as a control. Pupal exuviae collection resumed after the restoration period. In addition, nine unmanaged farm ponds and two formerly restored ponds were sampled. Nearby, another five restored ponds were also sampled for chironomid pupal exuviae. Water data revealed alkalinity, conductivity and phosphorus decreased while pH and dissolved oxygen increased after pond restoration. Chironomid species diversity, similarity and species compositional change were compared pre- and post-restoration. Assessments were made of chironomid species associated with colonisation of restored ponds as well as ponds without such management. After scrub and sediment removal the earliest colonisation of the ponds was by mud-eating species with rapid colonisation traits such as parthenogenesis, multiple generations in one year and tolerance of low oxygen conditions. Subsequent plant growth due to the opening up of the canopy led to consequent improved oxygenation and habitat structure. Other chironomid species dependent on these conditions were then able to compete with the early colonisers. Restoration also made a significant improvement in the number of chironomid species, as assessed by rarefaction curves.

中文翻译：

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英国农田池塘摇蚊组合和多样性池塘管理的后果

池塘是欧洲低地农业区生物多样性的巨大潜在资源，尽管许多池塘因向潮湿林地洼地（陆地化）的自然演替而消失。将池塘恢复到以前的开放水域状态可能会导致生物多样性的急剧增加，即使是在大量耕作的土地上。在这里，提供了陆地农田池塘恢复对摇蚊组合的影响的证据。摇蚊蛹蜕皮是从英格兰东部诺福克北部集约化耕地的三个陆生池塘中收集的。其中两个池塘去除了树木、灌木和沉积物，而第三个池塘则作为对照保持不受干扰。恢复期后恢复了蛹蜕皮收集。此外，还对九个未管理的农场池塘和两个以前修复的池塘进行了采样。附近，还对另外五个经过修复的池塘进行了摇蚊蛹蜕皮采样。水数据显示，池塘恢复后，碱度、电导率和磷降低，而 pH 值和溶解氧增加。比较了恢复前后摇蚊物种的多样性、相似性和物种组成变化。评估了与恢复池塘以及没有这种管理的池塘的定殖相关的摇蚊物种。在清除泥沙和沉积物后，最早在池塘中定居的是吃泥的物种，这些物种具有快速的殖民特征，例如孤雌生殖、一年内多代以及对低氧条件的耐受性。由于树冠的开放，随后的植物生长导致氧合和栖息地结构的改善。其他依赖这些条件的摇蚊物种随后能够与早期的殖民者竞争。根据稀疏曲线的评估，恢复还显着改善了摇蚊物种的数量。