Lowland riparian hardwood forests are valuable habitats protected by EU Habitat Directive (EU code: 91F0). Today, in most areas across Europe they are extremely rare due to deforestation, drainage and river engineering. The remaining small forest patches are important parts of riparian ecological corridors and biodiversity hotspots, and provide valuable ecosystem services (ES) to humans. However, unlike other forest types, due to their rarity and often low accessibility their ES potential has not been duly recognized and assessed to date. In this work we propose a set of biophysical indicators to assess the regulating potential of riparian hardwood forests. Indicator values were obtained through extensive field work and direct measurements carried out on selected test sites located along the middle Vistula River. The specific objectives of this work were: (i) to estimate the potential of riparian hardwood forests to provide 11 regulating services and to identify interactions among them; (ii) to examine the effects of forest and environmental attributes on individual ES; (iii) to determine ES drivers. Our results clearly show that riparian hardwood forests may be regarded as multiservice hotspots. Their regulating potential has proved to be substantial and in case of many services higher than the potential of other forest ecosystems. However, disruption of the natural water regime due to the absence of flooding and artificial drainage reduces their potential mainly for water-related regulating services (e.g. water treatment). On the other hand, more mesic habitats are beneficial for melliferous plant species and thus for wild pollinators. Most of the strong and significant interactions among the studied regulating services are synergistic. The high ES potential quantified by the biophysical ecosystem-condition-related indicators can be used effectively to promote the maintenance or restoration of this type of forests. The outcomes of our research suggest that protective actions should focus on ensuring adequate soil-moisture conditions which determine the specificity of these ecosystems.

低地河岸硬木森林是受欧盟人居指令（EU Code：91F0）保护的宝贵栖息地。如今，在欧洲大部分地区，由于森林砍伐，排水和河流工程，它们极为罕见。其余的小片森林是河岸生态走廊和生物多样性热点的重要组成部分，并为人类提供了宝贵的生态系统服务（ES）。但是，与其他森林类型不同，由于它们的稀有性和低可及性，迄今为止它们的生态系统潜力尚未得到适当的认识和评估。在这项工作中，我们提出了一套生物物理指标来评估河岸硬木森林的调节潜力。指标值是通过广泛的现场工作和在维斯杜拉河中段沿途选定的测试地点进行直接测量获得的。这项工作的具体目标是：（i）估计河岸硬木森林提供11种调节服务并查明其中的相互作用的潜力；（ii）研究森林和环境属性对个体生态系统的影响；（iii）确定ES驱动程序。我们的结果清楚地表明，河岸硬木森林可能被视为多服务热点。事实证明，它们的调节潜力是巨大的，而且在许多服务方面都比其他森林生态系统的潜力更高。但是，由于没有洪水和人工排水，自然水状况受到破坏，从而降低了它们主要用于与水有关的调节服务（例如水处理）的潜力。另一方面，更多的中性生境有利于有毛的植物物种，从而有利于野生传粉媒介。所研究的调节服务之间的大多数强烈而重要的相互作用是协同的。由生物物理生态系统状况相关指标量化的高ES潜力可有效地用于促进此类森林的维护或恢复。我们的研究结果表明，保护措施应着重于确保适当的土壤水分条件，这些条件决定了这些生态系统的特异性。