Working group

Land Cover / Dynamics (LACY)

LACY_Logo_Banner_LQ

Short description

Our research focuses on the detection and evaluation of climate (extreme) effects and land-use / land-cover change on terrestrial vegetation. This concerns the following components:

1. Analysing optical-reflective time-series of satellite data to derive forest condition, plant traits (phenology, pigments, leaf area) and ecosystem services (biodiversity, productivity). This is done by inverse parameterisation of radiative transfer models, classical empirical approaches as well as data science methods.

2. Acquisition of remotely sensed hyperspectral (airborne and field) data accompanied by respective trait measurements and in-situ vegetation records

3. Derivation of land-use (crop types, tree species), land-use intensity (mowing events, grazing intensity, fertilisation) and habitats from optical-reflective time-series of satellite data using data science methods

4. Establish / evaluate links between land-use intensity / biodiversity and plant traits / vegetation condition

5. Design von processing chains of remotely sensed raw data

Forest Condition Anomalies 


Changing forest condition in Germany between 2018-2022 Share (%) of deciduous (left column) and non-deciduous (right column) forest area in Germany showing FCA values below −0.15 (strongly damaged or dead forest) in the years 2018 (top row) and 2022 (bottom row). Germany’s state borders are shown as black lines (Lange et al. 2024).

Biodiversity & its representation in remote sensing signals


Methodological approach General workflow from species and trait sampling, over grassland simulations and spectra generation to statistical analysis (Ludwig et al. 2024). Simulations were performed for five different diversity levels (5 to 25 species). Spectra were generated by passing the pixel-wise mean trait values to PROSAIL, for the same grassland simulation. Based on the pixel-wise reflectance values, spectral diversity was calculated. Finally, we calculated the correlation coefficients between the different spectral diversity metrics for Species Richness (SR), Shannon-Index, Simpson-Index and Rao’s Q.

Trait expressions on the relationship between spectral diversity and species richness Trait expressions on the relationship between spectral diversity and species richness (inspired by Diaz & Cabido, 2001).

Land-use intensity in grasslands


Methods and results deriving land-use intensity in grasslands Methods and results deriving land-use intensity in grasslands (Lange et al. 2022).

 Hyperspectral airborne campaigns

CIR-Image
CIR image based on airborn hyperspectral imagery (2 m spatial resolution) showing a mixed broadleaf forest surrounded by agricultural fields.
Chlorophyll
Derived Chlorophyll values for agricultural fields with different crop types as well as pastures based on airborne hyperspectral data. Light green colours indicate bare soil or urban areas, green colours either stressed or senescent vegetation. Dark green colours indicate active green vegetation.

Extracting & simulating phenological metrics

The focus within vegetation phenology is on analysing the response of spring time phenology to climate change using ground and satellite observations. We also assessed the influence of heterogeneous landscapes on computed green-up dates and analysed trends of computed green-up dates on a European scale. A variety of methods to extract phenological metrics has been implemented in R package ’phenex’ to be of public use.

mean green up-dates
Mean green-up dates / start-of-season across Europe for the period 1989-2005 based on AVHRR satellite data (1 km spatial resolution). Brown colours indicate an relatively early mean season onset (e.g. Day of Year 100 = Mid April), predominantly in southern Europe. Blue colours a later onset in northern or mountain areas.

Extraction of biopyhsical vegetation variables / traits

The inversion of radiative transfer models is at the heart of determining e.g. Chlorophyll or water content of vegetation.

wavelength nanometers
Simulated reflection profiles of vegetation based on 4 parameters sets with increasing complexity, i.e. trait value ranges + noise, using PROSAIL (Doktor et al. 2014).

Land-use classification, habitat & biodiversity mapping

This is actually an old (remote sensing) topic which has seen a renaissance in the light of new satellite missions. This allows for example to discriminate tree species or to map crop types at field level (as shown below).

A WebGIS-based crop type map for the year 2016 can be found here.

Tree species classification
Germany-wide tree species classification based on Sentinel-2 time series and employing machine learning techniques + forest inventories (Preidl et al.).

Contact:


  • HySpex airborne hyperspectral sensor (VNIR, SWIR)
  • AISA dual hyperspectral airborne (VNIR, SWIR)
  • ASD field spectrometer (ASD3 and 4)
  • OceanOptics spectrometer, VNIR (QE65000)
  • Skye multi-spectral sensors (4 channels)
  • SPAD 502 Chlorophyll Meter
  • LAI 2000 plant canopy analyzer
  • PAM fluorometer
  • Mini MCA, Tetracam
  • TDR, soil moisture probes
Hyperspectral Sensor AISA in aircraft
Hyperspectral Sensor HySpex in aircraft
Specctral measurements at Eddy Flux Tower
Specctral measurements at Eddy Flux Tower
ASD Fieldspec measurement
LAI measurement
  • Time series analysis of multi-spectral satellite data (dynamic filtering, phenological metrics extraction)
  • Radiative transfer modelling (PROSPECT, PROSAIL, SLC, DART) & inverse model parametrisation
  • Neural networks (e.g. CNN), Machine learning (PCA, randomForest, PLSR, SVR, Gaussian processes)
  • Field work: collecting spectral and in-situ plant trait data of grasslands, crops & forests
  • Radiometric, geometric and atmospheric correction of hyper- and multispectral data
  • High performance cluster computation
  • Geostatistics (Kriging, Variogram estimation, MoransI)
  • RSC4Earth, i.e. University of Leipzig (Faculty of Physics and Earth System Sciences)
  • German Research Center for Geosciences, GFZ (Section "Remote Sensing")
  • German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
  • Julius-Kühn Institut (JKI), Institut für Strategien und Folgenabschätzung
  • Thünen Institute of Forest Ecosystems
  • University of Würzburg, Institute of Geography und Geology, Department of Remote Sensing
  • German Aerospace Center (DLR), German Remote Sensing Data Center (DFD), Oberpfaffenhofen
  • University of Zurich (Department of Geographie, Remote Sensing)
  • HU Berlin (Institute of Geography, Geomatik)
  • FH Dessau (Geoinformation)

Ongoing

  • "Impacts of hydroclimatic extremes on long- term forest condition anomalies" in PhD cohort "Societal and Environmental impacts of complex ExtremeS in a chAnging World" (Helmholtz Association, 2025-2029)
  • "Naturschutzfachliche bundesweite Waldpotenzialkarte für die vorgelagerte Planung - Nawapoka" (BfN, 2023-2026), PI
  • "Satellitengestützte Aufnahme wesentlicher Waldökosystemfunktionen (Resilienzfaktoren) und  Herleitung eines Bewertungsrahmens" (BMEL, 2024-2025)
  • Pixel-spezifische Parametrisierung von Modellen zur Ableitung von Pflanzenzustandsvariablen aus Hyperspektraldaten und zur Ertragsabschätzung - Hy-PiPE (BMVI, 2022-2025)

Finished

  • 'Forest Condition Monitor Germany' (Helmholtz Association, 2021-2024), PI
  • "Towards robust detection of plant diversity & management in grasslands’ spectral signal" (iDiv flexpool, 2022-2024), PI
  • "KI-basierte Integration von Fernerkundungs- und Citizen-Science- Daten zur Ableitung der Biodiversität in Wäldern’, iForest" (BMBF, 2023-2024), PI
  • „Ermittlung naturschutzbezogener Kriterien in der Umweltprüfung der Bedarfsplanung für Stromnetze und in der Bundesfachplanung zur Erhöhung der Planungssicherheit und Verhinderung von Zielkonflikten“ - Wakanaka (BfN, 2017-2019)
  • EU 'Ecopotential' ('Horizon 2020'). 'Derivation of bio-physical variables from remotely sensed imagery' (2015-2018)
  • Helmholtz-Alliance ‘Remote Sensing and Earth System Dynamics’ (Biosphere): 'Fusion of radar (L-band) and hyperspectral data to derive biomass, leaf area index and vegetation disturbance' (2012-2017)
  • BMWi program ‚Vorbereitung der wissenschaftlichen und kommerziellen Nutzung der Sentinel-Missionen und nationalen Missionen‘: ‚PhenoS - Phänologische Strukturierung von zeitlich hochauflösenden Sentinel 2- Datensätzen zur Optimierung von Landnutzungsklassifikationen‘ (2013- 2016)
  • BfN assignement on ‚Characterisation of forest types using remotely sensed imagery‘ (2016)
  • BMWi program ‚Vorbereitung der wissenschaftlichen und kommerziellen Nutzung der Sentinel-Missionen und nationalen Missionen‘: ‘Validierung von Sentinel-Produkten auf Basis kontinuierlicher spektraler und Eddy- Flux-Messungen’ (2012-2015)
  • BMWi program ‚Development of methods and algorithms for data analysis in preparation of the EnMAP mission': ‘Methoden zur Ableitung des funktionellen Zusammenhanges ökosystemarer Prozesse in hyperspektralen Daten unterschiedlicher räumlicher Auflösung’ (2010- 2013)
  • Project within ‚Ecosystem Services under Changing Land-use and Climate‘ (ESCALATE, http://www.ufz.de/escalate/): Ecosystem services assessment in a Central European floodplain forest: an ecosystem approach using reflective and thermal remote sensing data (2013-2016)
  • WP 3 within the BMBF Projekt ‚Sustainable Land and Water Management of Reservoir Catchments‘ (SaLMaR, http://salmar.uni- jena.de/7659.0.html? &L=2): ‚Remote sensing of land use land cover (LULC) and point sources‘ (2012-2015)

 Integrated projects (IP, UFZ fundet):

1) Within the topic 'From local scale processes to regional predictions' (T53) => „Estimation of terrestrial gross primary production (GPP) from remote sensing data“ (2013-2016 and 2016-2019)

2) Within ‚Catchment Dynamics‘ (T31) =>“Estimating organic carbon and plant properties from remotely sensed data“ (2013-2016)


Index:

You could use our publication index for further requests.

2024 (5)

to index

2023 (1)

to index

2022 (3)

to index

2021 (1)

to index

2020 (4)

to index

2018 (1)

to index

2017 (5)

to index

2016 (6)

to index

2015 (3)

to index

2014 (4)

to index

2013 (6)

to index

2012 (1)

to index

2011 (1)

to index

2009 (1)

to index