DeInVader: Tracing the invasion of an exotic tree species in protected West-Mediterranean dune ecosystems
Dr. André Große-Stoltenberg (JLU)
Prof. Dr. Christiane Werner, Dr. Christiane Hellmann (Albert-Ludwigs-Universität Freiburg)
PD Dr. Jan Thiele (Johann Heinrich von Thünen-Institut)
Dr. Jens Oldeland (Universität Hamburg)
Imaging spectroscopy enables to derive a specific spectral signature for individual objects which can be used to identify chemical and structural characteristics of e.g. plant foliages within and across ecosystems. LiDAR data can be used to assess landscape structure and especially to analyse stratified vegetation structure. We want to combine hyperspectral and LiDAR data to detect the spread of the exotic tree Acacia longifolia that is an "invasive engineer" in Portuguese dune ecosystems. It is able to fix atmospheric nitrogen, to alter the water cycle and to transform the vegetation structure. This causes various problems in many ecosystems worldwide. To understand these ecosystem changes on landscape scale, precise data about A. longifolia distribution is necessary as baseline information. The invader occurs exposed to sky in the open dunes as well as in the undergrowth of dune forests. Local studies already show that it is able to facilitate its invasion by altering the ecosystem properties with negative impact on native and endemic species’ and biodiversity. This innovative approach of combining high resolution LiDAR and hyperspectral data is the appropriate way to track A. longifolia and to generate data of its distribution on landscape scale. Paralelly, this project draws on a huge amount of available information on A. longifolia at the local scale in Portugal and will just allow transporting this information (on strategy, behaviour, interaction) on the larger scale, thus allowing a new dimension of information on the invasive process , i.e. distribution and spatial trends of invasion stages.
Große-Stoltenberg A., Hellmann C., Thiele J., Werner C. & Oldeland J (2018): Early detection of GPP-related regime shifts after plant invasion by integrating imaging spectroscopy with airborne LiDAR. Remote Sensing of Environment 209: 780–792.
Hellmann, C., Große-Stoltenberg A., Thiele J., Oldeland J. & Werner C. (2017): Heterogeneous environments shape invader impacts: integrating environmental, structural and functional effects by isoscapes and remote sensing. Scientific Reports 7:4118.
Große-Stoltenberg, A., Werner, C., Hellmann, C., Oldeland, J. & Thiele, J. (2016): Evaluation of Continuous VNIR-SWIR Spectra versus Narrowband Hyperspectral Indices to Discriminate the Invasive Acacia longifolia within a Mediterranean Dune Ecosystem. Remote Sensing 8:334.
Hellmann C., Große-Stoltenberg A., Lauströer V., Oldeland J. & Werner C. (2015): Retrieving nitrogen isotopic signatures from fresh leaf reflectance spectra: disentangling δ15N from biochemical and structural leaf properties. Frontiers in Plant Science 6: 307.
Lehmann, J., Große-Stoltenberg, A., Römer, M. & Oldeland, J. (2015). Field Spectroscopy in the VNIR-SWIR Region to Discriminate between Mediterranean Native Plants and Exotic-Invasive Shrubs Based on Leaf Tannin Content. Remote Sensing 7:1225–1241.
Isotope-Prize of the Habfast-Foundation, Arbeitsgemeinschaft Stabiler Isotope (ASI) / German Association for Stable Isotope Research (Gasir), 2017.
Helmut-Lieth-Prize for Environmental Sciences, Albert-Ludwigs-Universität Freiburg, 2018.