Ontwikkeling systematiek voor structuur (monitoring, NAPRO) (BO-11-019.01-034, BO-11-011.01-078)

Regular mapping of vegetation structure is of importance for biodiversity monitoring. In the Netherlands, vegetation structure mapping is in most cases still done in a traditional way based on field surveys in combination with visual interpretation of aerial photographs. This procedure is time consuming and often limited in its consistency and efficiency to cover large areas. Meanwhile space and airborne imagery are increasingly becoming available at affordable costs and with a high spatial resolution of approximately 50 cm. Therefore, commonly shared Dutch open LiDAR-data such as AHN (LiDAR derived terrain models) in combination with commercially available very high resolution satellite data were used to develop methodologies that can help to increase the updating frequency of vegetation structure maps, based on respectively vegetation height and vegetation cover. A pilot project was carried out in 2016 in cooperation with terrain managers from the coastal nature area Meijendel-Berkheide (Province Zuid-Holland, the Netherlands). In this pilot, we combined LiDAR-data from AHN2 (2008) and AHN3 (2014) with very high resolution satellite imagery from the similar time period in order to detect changes in vegetation structure at 1 meter spatial resolution. The existing habitat map was used to develop a protocol to find Grey Dunes (H2130) that showed significant changes vegetation structure between 2008 and 2014. The Remote Sensing method can also be used for other vegetation structure - or habitat types but requires other specific decision rules in relation to vegetation height and/or vegetation cover which have to be agreed upon by the nature conservation community. Therefore, the developed Remote Sensing monitoring method for vegetation structure is only a start to enable national wide operational monitoring of the vegetation structure of all habitat types.