Remote sensing tools assess vegetation in salt-marsh LIDAR mapping of tidal marshes proves a useful tool to investigate the interaction between vegetation and salt-marsh. New insights into marsh development enhance the available knowledge for rules that dictate tidal areas. Climate Change and Environment © PhotoDisc The International Ramsar Convention on wetlands considers wetlands as ecosystems of vast importance for biodiversity conservation and human communities' welfare. Problems encountered in tidal areas have been recognized by Ramsar Convention and 445 European wetlands (out of 844) are listed as protected areas. Under this notion, concerted efforts for mapping morphological, biological and ecological evolution of tidal environments through the development and validation of coupled models are essential. In this frame the TIDE project researchers have developed new tools for ecomorphological dynamic modelling. Taking advantage of LIDAR technology for remote sensing, the topographic features of salt marshes were associated with their stability and the presence and distribution of vegetation. LIDAR system uses laser pulses to determine distance to an object or surface estimating travel delay between pulse transmission and reflected signal. The suggested algorithm exploits this principle for assessing canopy architecture and vegetation height joining the waveform of the backscatter signal with vertical distribution of leaves. The wide applicability of LIDAR technology is due to laser imaging at wavelengths that allow high resolution topographic measurements at small scale targets such as vegetation structure. Although LIDAR is sufficient for surface topography observations, the vertical resolution required to measure the height of low vegetation directly is limited. Therefore, LIDAR measurements were validated by either comparison with local ground elevation contribution obtained by independent GPS observations or local statistics of LIDAR observations. The results showed that LIDAR and GPS observations are connected, approximately, with linear relationship when projected at the same reference system. Hence, LIDAR technique could serve as valid measurement tools. LIDAR mapping of tidal marshes not only sheds light on vegetation height but also bridges physical processes with ecological evolution (hydrodynamics, sediment and ecological dynamics). Dissection of this interconnecting process employing a holistic approach is a valuable repository for environmental management.
