Comparing LAI Field Measurements and Remote Sensing to Assess the Influence of Check Dams on Riparian Vegetation Cover

The Cammarota stream is located in Northern Puglia (Southern Italy) and is characterized by the presence of intact and destroyed check dams. Here in-fields measurements of the Leaf Area Index (LAI) were conducted to detect the variability of riparian vegetation along fifty-three riverbed transects. The observed values ranged from 0.26 to 5.71. The lower ones were found in those reaches where destroyed or strongly damaged check dams are located, and, consequently, riverbed erosive processes are present. The higher LAI values were found in those reaches with the presence of intact or slightly damaged check dams, characterized by a higher geomorphological stability. LAI measurement were also conducted in a nearby stream, named Vallone della Madonna, with intact check dams and sound riparian vegetation. Here the observed values of LAI ranged between 4.08 and 5.93, which are similar to those found in the Cammarota reaches with good geomorphological conditions. LAI values from both streams were also retrieved from Landsat 8 and Pleiades 1A satellite images using three different equations to derive LAI values from the Normalized Difference Vegetation Index (NDVI) and its corrected form. A statistical analysis was performed for every formula used.