Analyzing biological traits of riparian forest along ecoregions and local habitats to define functional targets for their restoration at different scales

Riparian forests perform a variety of functions but are among the most threatened environments. The objective of this study was to define functional targets for the restoration of riparian forest through an analysis of biological traits and its relationship with local geomorphological variables in Yungas subtropical forest and Dry Chaco Forest from northwestern Argentina. The composition and abundance of woody and herbaceous species were sampled. Twelve functional traits were characterized for 91 species based on field data and literature, which were ordered using fuzzy coding. According to RLQ analysis, three types of trait associations were identified: 1) Taller plants, large leaf size, elliptical form, evergreen phenology, flowering and fructification period in winter, associated to adjacent areas of greater slope and altitude, located in the Yungas forest; 2) Shorter plants, lanceolate leaf form, dispersal syndromes anemochory, autochory and hydrochory, flowering period in summer and fructification in autumn, low woody density, associated to greater channel width and flooding area and lower slopes, corresponding to the Dry Chaco; and 3) An intermediate group of sites that are located at the foothills and transition zone between ecoregions, with a variety of trait modalities, mainly medium leaf size, fleshy fruit type, and zoochory dispersal syndrome. Although a group of common functional traits may not be identified in the riparian zones, it was possible to associate some functional characteristics to the dimensions of riparian areas, helping to guide forest restoration targets along different landscape units, both in their species composition and in their functional structure.