• Evapotranspiration / sap flow
• Soil hydrology / saturated hydraulic conductivity, focus on humid tropics
• Data management / FAIR data / data publication
• Sampling strategies / monitoring design

Current projects:

• CAOS: DFG research unit FOR 1598 (From Catchments as Organized Systems to Models based on Functional Units)
• V-FOR-WaTer: Virtual research environment for water and terrestrial environmental research, funded by the 'Ministerium für Wissenschaft, Forschung und Kultur Baden-Württemberg'
• ASAP: Agroforestry in Southern Africa - new Pathways of innovative landuse sytems under a changing climate. Subproject 3: Water fluxes. Funded by BMBF. 
• BRIDGET: Bridging the scales of evapotranspiration (ET). Bridging postdoc project within Digital Earth.

Former projects:

• Agua Salud project: Reforestation of degraded lands in the Panama Canal watershed. The subproject led by the soil science group of Potsdam University focused on the change of soil hydraulic properties during reforestation (PhD thesis topic).
• Investigation of vegetation patterns in semiarid savannas in northwest Namibia using a hexagonal sampling design (Diplom thesis topic).

• Support of the Hydrological Lab and Field Exercises within Hydrological Measurements in Environmental Systems
• Supervision of Bachelor Theses

Community service

• 2016/05: Co-organisation of the workshop "Joint enviromental monitoring in Baden-Württemberg" within the Water Research Network Baden-Württemberg
• 2016/02: Co-organisation of the kickoff workshop "Geteilte Daten - halbes Leid und doppelte Freude" within the Water Research Network Baden-Württemberg, basis for V-For-WaTer project
• Guest editor (Special Issue) for Hydrology and Earth System Sciences (HESS)/Earth System Science Data (ESSD), Topical Editor for Earth System Science Data (ESSD)
• Convener of sessions at AGU and EGU meetings (2017, 2018, 2019, 2020)
• Referee for Vadose Zone Journal (VZJ), Hydrological Sciences Journal (HSJ), Journal of Hydrology (JoH), Ecohydrology (ECO)

Memberships

• European Geosciences Union (EGU)
• American Geophysical Union (AGU)

ORCID

ResearchGate

Peer-reviewed articles in ISI-listed journals

• Sheppard, J.P., Bohn Reckziegel, R., Borass, L., Chirwa, P.W., Cuaranhua, C.J., Hassler, S.K., Hoffmeister, S., Kestel, F., Maier, R., Mälicke, M., Morhart, C, Ndlovu, N.P., Veste, M., Funk, R., Lang, F., Seifert, T., du Toit, B., Kahle, H.-P. (2020): Agroforestry: An Appropriate and Sustainable Response to a Changing Climate in Southern Africa? Sustainability, 12(17), 6769. (link)
• Mälicke, M., Hassler, S.K., Blume, T., Weiler, M., Zehe, E. (2020): Soil moisture: Variable in space but redundant in time. Hydrol. Earth Syst. Sci., 24(5), 2633-2653. (link to pdf)
• Casper, M.C., Mohajerani, H., Hassler, S., Herdel, T., Blume, T. (2019): Finding behavioral parameterization for a 1-D water balance model by multi-criteria evaluation. J. Hydrol. Hydromech., 67(3), 213-224. (link)
• Dijke, A., Mallick, K., Teuling, A., Schlerf, M., Machwitz, M., Hassler, S., Blume, T., Herold, M. (2019): Does the Normalized Difference Vegetation Index explain spatial and temporal variability in sap velocity in temperate forest ecosystems? Hydrol. Earth Syst. Sci., 23(4), 2077-2091. (link to pdf)
• Zehe, E., Loritz, R., Jackisch, C., Westhoff, M., Kleidon, A., Blume, T., Hassler, S.K., Savenije, H.H. (2019): Energy states of soil water - A thermodynamic perspective on soil water dynamics and storage-controlled streamflow generation in different landscapes. Hydrol. Earth Syst. Sci., 23(2), 971-987. (link to pdf)
• Hassler, S.K., Weiler, M. & Blume, T. (2018): Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration. Hydrol. Earth Syst. Sci., 22(1), 13-30. (link to pdf)
• Loritz, R., Hassler, S. K., Jackisch, C., Allroggen, N., van Schaik, L., Wienhöfer, J. & Zehe, E. (2017): Picturing and modeling catchments by representative hillslopes. Hydrology and Earth System Sciences, 21(2), 1225-1249. (link to pdf)
• Renner, M., Hassler, S.K., Blume, T., Weiler, M., Hildebrandt, A., Guderle, M., Schymanski, S.J. & Kleidon, A. (2017): Dominant controls of transpiration along a hillslope transect inferred from ecohydrological measurements and thermodynamic limits. Hydrol. Earth Syst. Sci., 20(5), 2063-2083. (link to pdf)
• Hassler, S.K., Lark, R.M., Zimmermann, B. & Elsenbeer, H. (2014): Which sampling design to monitor saturated hydraulic conductivity? Eur. J. Soil Sci., 65(6), 792-802.
• Hassler, S.K., Lark, R.M., Milne, A.E. & Elsenbeer, H. (2011): Exploring the variation in soil saturated hydraulic conductivity under a tropical rainforest using the wavelet transform. Eur. J. Soil Sci., 62(6), 891-901.
• Hassler, S.K., Zimmerman, B., van Breugel, M., Hall, J.S. & Elsenbeer, H. (2011): Recovery of saturated hydraulic conductivity under secondary succession on former pastures in the humid tropics. For. Ecol. Manage., 261(10), 1634-1642.
• Hassler, S.K., Kreyling, J., Beierkuhnlein, C., Eisold, J., Samimi, C., Wagenseil, H. & Jentsch, A. (2010): Vegetation pattern divergence between dry and wet season in a semiarid savanna - Spatio-temporal dynamics of plant diversity in northwest Namibia. J. Arid. Environ., 74(11), 1516-1524.

PhD thesis

• Hassler, S.K. (2013): Saturated hydraulic conductivity in the humid tropics: Sources of variability, implications for monitoring and effects on near-surface hydrological flow paths. Universität Potsdam. (link to pdf )

Conference contributions

• Blume, T., Hassler, S., and Weiler, M. (2018): From groundwater to soil moisture to transpiration: do stable landscape patterns exist and when do they break down? European Geosciences Union General Assembly 2018, Wien, Österreich.
• Hassler, S.K. and Fink, S. (2018): The challenges of measuring sap flow on trees in sloped terrain. European Geosciences Union General Assembly 2018, Wien, Österreich.
• Mälicke, M., S. Hassler, M. Weiler, T. Blume, and Zehe, E. (2018): Revealing process dynamics of soil moisture patterns using spatio-temporal geostatistics. European Geosciences Union General Assembly 2018, Wien, Österreich.
• Strobl, M., Azmi, E., Hassler, S., Mälicke, M., Meyer, J., and Zehe, E. (2018): V-FOR-WaTer – A virtual research environment for storage and processing of environmental data. European Geosciences Union General Assembly 2018, Wien, Österreich.
• Blume, T., Weiler, M., Angermann, L., Beiter, D., Hassler S., Kaplan, N., and Sprenger, M. (2017): From one plot to many and from hillslopes to stream: Improving our understanding of catchment hydrology with a multi-scale experimental approach. European Geosciences Union General Assembly 2017, Wien, Österreich.
• Blume, T., Hassler, S.K., and Weiler, M. (2017): Temporal dynamics and persistence of spatial patterns: from groundwater to soil moisture to transpiration. American Geophysical Union Fall Meeting 2017, New Orleans, USA.
• Hassler, S.K., M. Weiler, and Blume, T. (2017): Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration. European Geosciences Union General Assembly 2017, Wien, Österreich.
• Hassler, S.K., M. Weiler, and Blume, T. (2017): Can sap flow help us to better understand transpiration patterns in landscapes? American Geophysical Union Fall Meeting 2017, New Orleans, USA.
• Mälicke, M., Neuper, M., Jackisch, C. Hassler, S., und Zehe, E. (2017): Static sampling of dynamic processes – a paradox? European Geosciences Union General Assembly 2017, Wien, Österreich.
• Schlerf, M., Mallick, K., Hassler, S.K., Blume, T., Ronellefitsch, F., Gerhards, M., Udelhoven, T., and Weiler, M. (2017): A comparison of airborne evapotranspiration maps and sapflow measurements in oak and beech forest stands. American Geophysical Union Fall Meeting 2017, New Orleans, USA.
• Strobl, M., Azmi, E., Hassler, S., Mälicke, M., Meyer, J., and Zehe E. (2017): V-FOR-WaTer – a new virtual research environment for environmental research. European Geosciences Union General Assembly 2017, Wien, Österreich.
• Hassler, S.K., M. Weiler, E. Zehe, and Blume, T. (2016): Can we estimate landscape-scale transpiration patterns from commonly available distributed data sets? European Geosciences Union General Assembly 2016, Wien, Österreich.
• Loritz, R., Hassler, S., Jackisch, C., and Zehe, E. (2016): Picturing and modelling catchments by representative hillslopes. European Geosciences Union General Assembly 2016, Wien, Österreich.
• Renner, M., Hassler, S., Blume, T., Weiler, M., Hildebrandt, A., Guderle, M., Schymanski, S., and Kleidon, A. (2016): Compensating effect of sap velocity for stand density leads to uniform hillslope-scale forest transpiration across a steep valley cross-section. European Geosciences Union General Assembly 2016, Wien, Österreich.
• Blume, T., Hassler, S., Heidbüchel, I., Weiler, M., Simard, S., Güntner, A., and Heinrich, I. (2015): Tracking the diurnal signal of plant water uptake through the hydrologic system. European Geosciences Union General Assembly 2015, Wien, Österreich.
• Blume, T., Heidbüchel, I., Hassler, S.K., Simard, S., Güntner, A., Stewart, R.D., and Weiler, M. (2015): Root water uptake and soil moisture pattern dynamics – capturing connections, controls and causalities. American Geophysical Union Fall Meeting 2015, San Francisco, USA.
• Hassler, S.K., Weiler, M., and Blume, T. (2015): Catchment controls on soil moisture dynamics: from site-specific hysteresis in event responses to temporal stability of patterns. European Geosciences Union General Assembly 2015, Wien, Österreich.
• Hassler, S.K., Weiler, M., and Blume, T. (2015): Explaining spatial patterns of sap flow: day-to-day shifts in relevance of site- and tree-specific controls. European Geosciences Union General Assembly 2015, Wien, Österreich.
• Hassler, S.K., Weiler, M., Zehe, E., and Blume, T. (2015): How landscape characteristics explain spatial patterns of transpiration. American Geophysical Union Fall Meeting 2015, San Francisco, USA.
• Blume, T., Hassler, S.K., and Weiler, M. (2014): Who is in control? Competing influences of geology, land use and topography on soil moisture and soil temperature dynamics. European Geosciences Union General Assembly 2014, Wien, Österreich.
• Hassler, S.K., Lark, R.M., Zimmermann, B., and Elsenbeer, H. (2014): Which sampling design to monitor saturated hydraulic conductivity? European Geosciences Union General Assembly 2014, Wien, Österreich.
• Hassler, S.K., Weiler, M., and Blume, T. (2014): Spatio-temporal soil moisture patterns across gradients of vegetation and topography. European Geosciences Union General Assembly 2014, Wien, Österreich.
• Hassler, S.K., Weiler, M., and Blume, T. (2014): Landscape Controls on Hydrological Processes under Rainfall- and Radiation-driven Conditions. AGU Chapman Conference on Catchment spatial organization and complex behavior, Luxemburg.
• Hassler, S.K., and Blume, T. (2013): Variability of sap flow on forest hillslopes: patterns and controls. European Geosciences Union General Assembly 2013, Wien, Österreich.
• Zehe, E., Jackisch, C., Blume, T., Hassler, S., Allroggen, N., and Tronicke, J. (2013): Functional units and lead topologies: a hierarchical framework for observing and modeling the interplay of structures, storage dynamics and integral mass and energy flows in lower mesoscale catchments. European Geosciences Union General Assembly 2013, Wien, Österreich.
• Hassler, S.K., Lark, R.M., Zimmermann, B., and Elsenbeer, H. (2012): Application of a rotational sampling design to address the spatial mean temporal trend in saturated hydraulic conductivity in reforestation catchments in central Panama. 4th International Congress EUROSOIL2012, Bari, Italien.
• Hassler, S.K., Lark, R.M., Milne, A.E., and Elsenbeer, H. (2012): Exploring the variation in soil saturated hydraulic conductivity under a tropical rainforest using the wavelet transform. 2nd International Conference on Hydropedology, Leipzig.
• Hassler, S.K., Ogden, F.L., Crouch, T.D., and Elsenbeer, H. (2011): Exploring the link between soil permeability, overland flow generation and land us and its effect on water flow paths in the humid tropics. American Geophysical Union Fall Meeting 2011, San Francisco, USA.
• Hassler, S.K., and Elsenbeer, H. (2011): Is soil permeability a good predictor for overland flow occurrence? European Geosciences Union General Assembly 2011, Wien, Österreich.
• Hassler, S.K., Zimmermann, B., and Elsenbeer, H. (2010): The influence of forest regrowth on soil permeability in the humid tropics. European Geosciences Union General Assembly 2010, Wien, Österreich.
• Hassler, S., Eisold, J., Beierkuhnlein, C., and Jentsch, A. (2006): Biodiversitätsmuster in Raum und Zeit am Beispiel der Savanen Nordwest-Namibias. Jahrestreffen des  VGDH AK Biogeographie, Bonn.

Academic career

04/2015–today  Karlsruhe Institute of Technology (KIT), Institute of Water and River Basin Management

• PostDoc and co-coordination of V-FOR-WaTer project

01/2012–03/2015  German Research Centre for Geosciences (GFZ), Hydrology Section

• PostDoc within the DFG research unit CAOS

02/2008–02/2012  University of Potsdam, Institute of Earth and Environmental Science

• PhD student within the Agua Salud project
• PhD thesis: Saturated hydraulic conductivity in the humid tropics: Sources of variability, implications for monitoring and effects on near-surface hydrological flow paths

10/1999–02/2007  University of Bayreuth

• studies of geoecology, majors in soil science and biogeography
• 02/2003–03/2004 studies abroad at the university of Cape Town, South Africa
• Diplom thesis: Spatio-temporal Biodiversity Patterns in Semiarid Savanna Ecosystems of the Kaokoveld, Northwest Namibia