Dr. Jan C. Ruppert - Former Postdoc (until March 2016)
Visit the my new homepage at the University of Tübingen.
I am a vegetation and rangeland ecologist with a strong interest in vegetation dynamics in dryland ecosystems. My research focuses on how biotic and abiotic features of the environment shape primary production, vegetation composition, as well as its stability towards extreme events and disturbances (e.g. drought, grazing; Ruppert et al. 2015). In the past years, I have taken various perspectives ranging from global scale assembly studies (Ruppert et al. 2012, 2015) down to field scale analyses of plant functional types (Linstädter et al. 2014) and functional traits (Moreno García et al. 2014). During this endeavor, I have employed a diverse set of research tools such as data-integration, meta-analysis, as well as monitoring and sampling along natural transects and planning and realizing field experiments (Limpopo Living Landscapes). Recently, I have embraced the quickly emerging field of smart monitoring of vegetation via near-surface remote sensing as it holds various options to economize classically labor-intense field sampling without sacrificing accuracy or quality of obtained data. Thus far, I have gathered long-term field experience in grasslands and savannas of South Africa, and have visited North American as well as Israeli grass- and shrublands.
PhD in Ecology (Dr. rer. nat.), University of Cologne, Germany.
2010 - 2014
PhD studies in Ecology (Focus: Plant and Rangeland Ecology), University of Cologne, Germany.
State Examination in Biology (MSc equivalent), University of Cologne, Germany.
2004 – 2009
Studies of Biology and German Linguistic and Literature, University of Cologne, Germany.
2016 – ongoing
Assistant Professor, Plant Ecology Group, Prof. Dr. Katja Tielbörger, University of Tübigen, Germany.
2014 – 2016
PostDoc in the BMBF funded research program 'LLL - Limpopo Living Landscapes', Range Ecology and Range Management Group, PS Dr. Anja Linstädter, University of Cologne, Germany.
2010 - 2014
Scientific Staff / Cooperative Researcher in the DFG funded research-group 'Resilience, Collapse and Reorganisation in Social-Ecological Systems of African Savannas' (www.fg1501.uni-koeln.de), Range Ecology and Range Management Group, Dr. Anja Linstädter, University of Cologne & Crop Science Group, Prof. Dr. Frank Ewert, University Bonn, Germany. (www.lap.uni-bonn.de)
Scientific Staff at the Department of Ecological Modelling at the Helmholtz-Centre for Environmental Research, PD Dr. Karin Frank and Dr. Birgit Müller, UFZ Leipzig, Germany. (www.ufz.de)
2007 - 2010
Research Student at Range Ecology and Range Management Group, Dr. Anja Linstädter, University of Cologne, Germany.
Scholarships and Grants
2015 - 2017
UoC PostDoc Grant, "You get what you pay for? Putting inexpensive Remote Sensing Technologies to the test in Vegetation Ecology", awarded by the University of Cologne.
2011 - 2013
Full, merit-based PhD-scholarship of the Foundation of German Business (Stiftung der Deutschen Wirtschaft, sdw; www.sdw.org)
2011 - 2014
Fellow of the Theodor-Brinkmann-Graduate-School, University Bonn (www.tbgs.uni-bonn.de).
Publications (Peer Reviewed)
Ruppert, J.C., Harmoney, K., Henkin, Z., Snyman, H.A., Sternberg, M., Willms, W., Linstädter, A., 2015. Quantifying drylands’ drought resistance and recovery: The importance of drought intensity, dominant life history and grazing regime. Global Change Biology 21(3): 1258-1270. dx.doi.org/10.1111/gcb.12777
Linstädter, A., Schellberg, J., Brüser, K., Moreno-García, C., Oomen, R.J., du Preez, C., Ruppert, J.C. & F. Ewert, 2014. Are There Consistent Grazing Indicators in Drylands? Testing Plant Functional Types of Various Complexity in South Africa’s Grassland and Savanna Biomes. PLoS ONE 9(8): e104672. dx.doi.org/10.1371/journal.pone.0104672 (Open Access)
Ruppert, J.C. & A. Linstädter. 2014. Convergence between ANPP estimation methods in grasslands - a practical solution to the comparability dilemma. Ecological Indicators, 36:524-531. dx.doi.org/10.1016/j.ecolind.2013.09.008 [Download PrePrint]
Brüser, K., Feilhauer, H., Schellberg, J., Linstädter, A., Oomen, R.J., Ruppert, J.C., Ewert, F. 2014. Discrimination and Characterization of Management Systems in semi-arid Rangelands of South Africa using RapidEye Time Series. International Journal of Remote Sensing, 35:1653-1673. dx.doi.org/10.1080/01431161.2014.882028
Moreno García, C.A., Schellberg, J., Ewert, F., Brüser, K., Canales-Prati, P., Linstädter, A., Oomen, R.J., Ruppert, J.C., Perelman, SB. 2014. Response of community-aggregated plant functional traits along grazing gradients: insights from African semi-arid grasslands. Applied Vegetation Science, 17:470-481. dx.doi.org/10.1111/avsc.12092
Moreno García, C.A., Schellberg, J., Ewert, F., Linstädter, A., Ruppert, J.C., Perelman, SB. 2013. Functional Responses of South African Rangelands in Contrasting Tenure Systems. Conference Proceedings of the 22nd International Grassland Congress, 15th - 19th September 2013, Sydney, Australia. [Download Proceedings]
Ruppert, J.C., Holm, A., Miehe, S., Muldavin, E., Snyman, H.A., Wesche, K., Linstädter, A. 2012. Meta-analysis of rain-use efficiency confirms indicative value for degradation and supports non-linear response along precipitation gradients. Journal of Vegetation Science 23(6): 1035-1050. dx.doi.org/10.1111/j.1654-1103.2012.01420.x [Download PrePrint]
Conference Contributions & Invited Talks
Ruppert, J.C., Linstädter, A. 2015. Is „good“ rainfall as good as „bad“ is bad? Drylands‘ stability towards positive and negative rainfall anomalies. Conference of the Ecological Society of Germany, Austria and Switzerland (GfÖ), 31st August - 4th September 2013, University of Goettingen, Germany. [Abstract, page 96]
Ruppert, J.C., 2014. Quantifying drylands’ drought resistance and recovery: The importance of drought intensity, dominant life history and grazing regime. Evolution and Ecology Seminar Series, Host: Prof. Dr. Katja Tielbörger, University of Tübingen, Germany (http://www.uni-tuebingen.de)
Ruppert, J.C. & A. Linstädter, 2013. Savanna or Grassland - Which biome is more resilient to anomalies in precipitation? A data fusion study in arid and semi-arid Africa. Conference of the Ecological Society of Germany, Austria and Switzerland (GfÖ), 9th August - 13th September 2013, University Potsdam, Germany.
Ruppert, J.C., 2013. Rangeland Productivity in Drylands - Insights from a Global Database of Long-Term Studies. Meteorological Colloquium, Host: Prof. Dr. Ulrich Cubasch, Freie Universität Berlin, Germany (http://www.geo.fu-berlin.de/en/met/ag/klimod/index.html).
Ruppert, J.C., Ewert, F., Linstädter, A. 2012. Drivers of dryland productivity – Insights from a global meta-analysis. EcoSummit 2012, Sept 30th - Oct 5th 2012, Columbus OH, USA. [Abstract, page 345]
Moreno García, C.A., J. Schellberg, F. Ewert, A. Linstädter, J.C. Ruppert, S.B. Perelman, 2012. Response of Communities Plant Functional Traits Along Grazing Gradients on South African Rangelands. Tropentag, Sept 19th - 21th 2012, Göttingen - Kassel/Witzenhausen, Germany.
Ruppert, J.C.& A. Linstädter, 2011. Aboveground Net Primary Production and Rain-use Efficiency in Drylands - Results and Insights from a Meta-analytical Perspective. Tropentag, Oct 5th - 7th 2011, Bonn, Germany. [Abstract]
Ruppert, J.C., A. Linstädter, 2010. Rain-use efficiency: A concept revisited. Recent challenges and possible approaches. 40th Anniversary Conference of the Ecological Society of Germany, Austria and Switzerland (GfÖ), 30th August - 3rd September 2010, Gießen, Germany.
Ruppert, J.C., A. Linstädter, 2010. Analyzing the rain-use efficiency: New insights by meta-analysis and quantile regression. 95th Annual Meeting of the Ecological Society of America (ESA), Aug 1st - 6th 2010, Pittsburgh PA, USA. [Abstract]
Joe DeCapua interviews Jan Ruppert about drylands’ vulnerability to climate change on the Voice of America.
Ruppert, J.C., A. Linstädter, 2013. Convergence between ANPP estimation methods in grasslands - a practical solution to the comparability dilemma (Poster). Poster presentation at the Bastheva de Rothschild Seminar on "Coordinated approaches for studying long-term ecosystem responses to global change" in Ramat Hanadiv Park, Israel. [Download Poster]
Advancing Functional Understanding of Primary Production in Drylands: Insights from a Data-Integration Approach [Download]
Dryland ecosystems are highly vulnerable and degradation-prone regions, especially under the premises of global change. Since drylands are preponderantly used as rangelands for livestock production, reliable provision of natural resources and basic ecosystem services, such as forage, are indispensable for local livelihoods. Even though climate projections for drylands still exhibit considerable variation and uncertainty across scenarios and regions, there is a general trend that most dryland regions are facing unbeneficial changes. In particular, climatic aridity and variability are projected to increase even above the already high level of today. Simultaneously, population growth will further increase the demand for ecosystem services from drylands, with negative feedbacks on ecosystem functioning. Given the high natural variability in drylands, as well as future projections, the assessment of drylands’ current and future provision of ecosystem services is challenging, yet essential. The most common estimate for a major ecosystem service of dryland ecosystems (i.e. forage) is aboveground net primary production (ANPP).This cumulative dissertation aimed at advancing our understanding of dryland ecosystems’ functioning and ecosystem service provision, taking a global perspective. Particularly, data integration and standardization techniques were used to derive new insights from available data on drylands’ primary production. With this innovative approach, it could be shown that dryland primary production is mainly driven by precipitation and grazing, not only locally but also on a global scale (Chapter 2.1). Another important outcome was that effects of grazing and rainfall are not merely additive, but could mask each other (Chapter 2.1) or interact in complex ways (Chapter 2.3). Similarly, drought severity may influence primary production either linearly or non-linearly, depending on vegetation characteristics (Chapter 2.3). These findings underline the complex dynamics of dryland ecosystems. Besides these general findings, the established methodological toolbox as well as the assembled global database of dryland primary production are among the main merits of this dissertation. The combination of a large global database, the normalization of ANPP and precipitation data (Chapter 2.2), and the collection of additional site- or study-based information allowed the assessment of ecosystem functioning and stability on a global scale, which thus far could only be done on a theoretical or anecdotal basis.