ABSTRACT

Freshwater ecosystems are exceptionally threatened habitats and suffer biodiversity losses that exceed those in any other ecosystem. Small waterbodies have been typically neglected and excluded from conservation strategies, even though they are essential for maintaining freshwater biodiversity. Dragonflies are considered effective surrogates of the diversity of other taxa and bioindicators of the state of aquatic environments. This study compares, in an intensified farmland landscape of western Spain, the capacity of farm ponds to maintain dragonfly diversity by comparing the Odonata communities of the four type of aquatic systems (river, stream, reservoir and farm pond) present in this region, in which the extant of permanent water bodies is scarce. The results showed higher diversity and abundance values in farm ponds than in any other aquatic system, agreeing with previous studies. Also, farm ponds harbour species from every other aquatic system, thereby occupying an intermediate position in the MDS, which demonstrated their potential value to act as stepping stones. Nevertheless, investigation of the dragonfly community composition revealed a generally low degree of ecological integrity of the studied systems, which are negatively impacted by agricultural and livestock farming intensification. These findings support the role of farm ponds in the maintenance of dragonfly diversity in the study area and emphasise the need of a specific legislation to regulate and protect them.

摘要

淡水生态系统是受到特别威胁的栖息地，遭受的生物多样性损失超过任何其他生态系统。尽管小型水体对于维持淡水生物多样性至关重要，但通常被忽略并被排除在保护策略之外。蜻蜓被认为是其他分类单元和水生环境状态生物指标多样性的有效替代物。这项研究在西班牙西部一个集约化的农田景观中，通过比较四种水生系统（河流，溪流，水库和农田池塘）的Odonata群落，比较了农田池塘保持蜻蜓多样性的能力。）存在于该地区，那里永久水体稀缺。结果表明，与其他任何水生系统相比，农场池塘中的多样性和丰度值更高，这与以前的研究一致。此外，农场池塘还包含其他所有水生系统中的物种，因此在MDS中占据中间位置，这证明了它们作为垫脚石的潜在价值。然而，对蜻蜓群落组成的调查表明，所研究系统的生态完整性普遍较低，这受到农业和畜牧业集约化的负面影响。这些发现支持了池塘在研究区域中维持蜻蜓多样性中的作用，并强调需要制定具体法规来规范和保护它们。