Assessing the quality of riparian areas: the case of River Ecosystem Quality Index applied to the Marecchia river (Italy).

Riparian areas support a set of river functions and of ecosystem services (ESs). Their role is essential in reducing negative human impacts on river functionality. These aspects could be contained in the River Basin Management Plan, which is the tool for managing and planning freshwater ecosystems in a river basin. In this paper, a new index was developed, namely the River Ecosystem Quality Index (REQI). It is composed of five ecological indices, which assess the quality of riparian areas, and it was first applied to the Marecchia river (central Italy). The REQI was also compared with the Italian River Functionality Index (IFF) and the ESs measured as the capacity of land cover in providing human benefits. Data have shown a decrease in the quality of riparian areas, from the upper to lower part of river, with 53% of all subareas showing medium-quality values. This explains the vulnerability of these areas when exposed to any action taken in the management of natural resources. The REQI is closely related (R2 ¼ 0.71) to ESs. A lower regression was shown in the case of riverine quality, measured by the IFF. The opportunity to add such an assessment to the traditional indices used to assess river quality in the management of aquatic–terrestrial transitional zones was finally discussed.