Ecology of Semi-arid Regions

Festuca pallescens Parodi steppes in Patagonia. The degradation due to overgrazing was not recognized due to the higly variable rainfall. Picture: Sandro Pütz.

(Semi-) Arid regions are characterised by highly variable and unpredictable rainfall. The livelihood of at least one billion people depends on the use of this land. However, understanding patterns and processes of vegetation dynamics in (semi)-arid plant communities is an inherently difficult task due to several factors such as the mismatch in time scales between observation and vegetation change, the occurrence of complex event-driven dynamics, spatial heterogeneities, and non-equilibrium ecosystem dynamics. With the help of modelling, we aim to improve the general understanding how processes such as spatially and temporally variable rainfall and interactions between species and land use influence the dynamics of (semi-)arid regions (e.g. in South Africa, Namibia, Argentina (Patagonia), Morocco, China (Eastern Tibetan Plateau), Australia). In particular our research focuses on:

  • The structure and long-term dynamics of vegetation in (semi-)arid grasslands and savannas subject to variable rainfall and grazing.
  • Upscaling of the local dynamics at the individual plant level to the management relevant scales of hundreds of hectares
  • Emergence of spatial patterns such as fairy circles in (semi)-arid communities
  • Emergence of patterns and resilience in savannas.
  • Developing a mechanistic understanding of degradation and desertification processes by exploring the interactions among climatic drivers and human impacts on demographic processes of key species in (semi-)arid ecosystems.
  • Ecological and economic strategies for risk management in and long-term sustainable use of semi-arid lands in the face of highly stochastic environmental conditions and global change.

Selected Publications

  • Müller, B., Johnson, L., Kreuer, D., (2017):
    Maladaptive outcomes of climate insurance in agriculture
    Glob. Environ. Change 46 , 23 - 33
    full text (url)
  • Cipriotti, P.A., Wiegand, T., Pütz, S., Bartoloni, N.J., Paruelo, J.M., (2016):
    Nonparametric upscaling of stochastic simulation models using transition matrices
    Methods Ecol. Evol. 7 (3), 313 - 322
    full text (url)
  • Dressler, G., Müller, B., Frank, K., Kuhlicke, C., (2016):
    Towards thresholds of disaster management performance under demographic change: exploring functional relationships using agent-based modeling
    Nat. Hazards Earth Syst. Sci. 16 (10), 2287 - 2301
    full text (url)
  • Martin, R., Linstädter, A., Frank, K., Müller, B., (2016):
    Livelihood security in face of drought – Assessing the vulnerability of pastoral households
    Environ. Modell. Softw. 75 , 414 - 423
    full text (url)
  • Getzin, S., Wiegand, K., Wiegand, T., Yizhaq, H., von Hardenberg, J., Meron, E., (2015):
    Adopting a spatially explicit perspective to study the mysterious fairy circles of Namibia
    Ecography 38 (1), 1 - 11
    full text (url)
  • Getzin, S., Wiegand, K., Wiegand, T., Yizhaq, H., von Hardenberg, J., Meron, E., (2015):
    Clarifying misunderstandings regarding vegetation self-organisation and spatial patterns of fairy circles in Namibia: a response to recent termite hypotheses
    Ecol. Entomol. 40 (6), 669 - 675
    full text (url)
  • Müller, B., Schulze, J., Kreuer, D., Linstädter, A., Frank, K., (2015):
    How to avoid unsustainable side effects of managing climate risk in drylands - The supplementary feeding controversy
    Agric. Syst. 139 , 153 - 165
    full text (url)
  • Cipriotti, P.A., Aguiar, M.R., Wiegand, T., Paruelo, J.M., (2014):
    A complex network of interactions controls coexistence and relative abundances in Patagonian grass-shrub steppes
    J. Ecol. 102 (3), 776 - 788
    full text (url)
  • Jakoby, O., Grimm, V., Frank, K., (2014):
    Pattern-oriented parameterization of general models for ecological application: towards realistic evaluations of management approaches
    Ecol. Model. 275 , 78 - 88
    full text (url)
  • Martin, R., Müller, B., Linstädter, A., Frank, K., (2014):
    How much climate change can pastoral livelihoods tolerate? Modelling rangeland use and evaluating risk
    Glob. Environ. Change 24 , 183 - 192
    full text (url)
  • Cipriotti, P.A., Aguiar, M.R., Wiegand, T., Paruelo, J.M., (2012):
    Understanding the long term spatial dynamics of a semiarid grass-shrub steppe through inverse parameterization for simulation models
    Oikos 121 (6), 848 - 861
    full text (url)
  • Rayburn, A.P., Wiegand, T., (2012):
    Individual species–area relationships and spatial patterns of species diversity in a Great Basin, semi-arid shrubland
    Ecography 35 (4), 341 - 347
    full text (url)