Large wood dynamics along the tagliamento river, italy: Insights from field and remote sensing investigations

Abstract

Large wood plays a vital role in many fluvial systems through its influence on a wide variety of hydromorphological and ecological processes. Growing recognition of the significance of large wood has led to its increasing use as a river restoration measure but this remains juxtaposed against its traditional perception as a flood risk hazard. Improved understanding of when, where and how large wood is recruited by rivers, and its behaviour and effects once entrained, is therefore of critical importance to river management. This paper integrates the findings of a number of recent studies to characterise and explain large wood dynamics along the Tagliamento River, Italy. A combination of remotely-sensed and field data are used together with historical hydrometeorological data to quantify and explain spatio-temporal variability in large wood recruitment and associated geomorphological adjustment. The results highlight strong longitudinal differences in large wood supply rates, dominant recruitment process and consequences as a result of the changing environmental conditions along the river. These insights serve to illustrate how universal rationales and approaches to the management of large wood in rivers can be misguided and should be informed by detailed knowledge of the system for which they are developed.