SIGNAL


Location Temperature (annual mean) Precipitation (annual) Elevation above sea level Land use
Dornburg (Thuringia) 9.9°C 608 mm 289 m Cropland
Forst (Brandenburg) 9.6°C 568 mm 66 m Cropland
Mariensee (Lower Saxony) 9.6°C 661 mm 42 m Grassland
Vechta (Lower Saxony) 9.3°C 806 mm 43 m Cropland
Wendhausen (Lower Saxony) 9.6°C 637 mm 82 m Cropland

The SIGNAL project investigated from 2015 to 2024 whether agroforestry systems in Germany can represent a sustainable and at the same time profitable land use option. For this purpose, agroforestry landscapes were compared with conventional agriculture and the effects on various ecosystem functions such as carbon sequestration, yield, and erosion control were examined. The project was a cooperation of various institutes and universities and was funded by the BonaRes programme.

The Department of Bioclimatology investigated land–atmosphere exchange at five different sites: Vechta, Mariensee, Wendhausen, Dornburg, and Forst. All sites were croplands with the exception of Mariensee, which was managed as grassland. Tree strips were planted at all sites. Tree species selected were poplars (Populus nigra × Populus maximowiczii) at Vechta, Wendhausen, and Dornburg, willows (Salix schwerinii × S. viminalis) at Mariensee, and poplars and black locusts (Robinia pseudoacacia) at Forst. The trees were harvested every three to four years and the agricultural crops were grown in an annual rotation.

At all sites, meteorological data were recorded and the exchange of CO2 and water with the atmosphere was measured using the eddy covariance method. Data were collected between 2019 and 2024. The exact measurement period varied by site.



  • Callejas-Rodelas JÁ, Van Ramshorst J, Knohl A, Siebicke L, Fellert D, Peksa M, Böttger D, Markwitz C (2026). A multiyear eddy covariance and meteorological dataset from five pairs of agroforestry systems with open cropland or grassland in Northern Germany. Earth System Science Data 18, 845–874. doi: 10.5194/essd-18-845-2026
  • Markwitz C, Knohl A, Siebicke L (2020). Evapotranspiration over agroforestry sites in Germany. Biogeosciences 17, 5183–5208. doi: 10.5194/bg-17-5183-2020
  • Markwitz C, Siebicke L (2019). Low-cost eddy covariance: A case study of evapotranspiration over agroforestry in Germany. Atmospheric Measurement Techniques 12, 4677–4696. doi: 10.5194/amt-12-4677-2019