NamTip: Understanding and Managing Desertification Tipping Points in Dryland Social-Ecological Systems – A Namibian Perspective

 

NamTip is one of seven projects in the "BioTip" funding line. Within the framework of this programme, worldwide research is being conducted into how critical thresholds can be recognised at an early stage and thus how countermeasures can be initiated in good time. The initiative is funded by the Federal Ministry of Education and Research (BMBF, duration 02/2019 - 02/2023).

Tipping points play an important role in dryland ecosystems. When pastures are heavily overgrazed and droughts occur in addition, they can "tip" into a desert-like state. Perennial forage grasses are then often permanently lost, leaving behind barren soils. Desertification is a pressing problem in Namibia.

Please have a look on the official website for more details.

 

Mission

In the NamTip project, scientists and stakeholders are working closely together to gain a better understanding of "desertification tipping points" and their impact on the livelihoods of Namibian farmers. At the same time, they are exploring ways to avoid such undesirable impacts - for example, through appropriate early warning systems. To this end, a wide variety of interdisciplinary studies are being conducted on the semi-arid pastureland of farms in the Greater Waterberg Landscape.

The aims of NamTip are:

  • Improving the understanding of ecological and social factors influencing desertification tipping points in arid regions
  • Identification and evaluation of potential early warning indicators
  • Research and communication of management interventions

 

In the NamTip project we are entrusted with the scientific-technical coordination work and the vegetation related ecological studies. We study plant populations and communities as well as forage quantity and quality using a comparative as well as an experimental research approach.

 

 

vegetation surveys

Vegetation surveys at one of the observational plots located at a grazing gradient.

Photo: K. Zimmer

removal of a rain-out shelter

Removal of a rain-out shelter roof to conduct hyperspectral measurements of the vegetation canopy.

Photo: L. Schwarz

 

 

demonstration of the tipping point experiment

Demonstration of the Tipping Point Experiment to local farmers.

Photo: V. Amputu

knowledge dissemination Nambian Rangeland Forum

Knowledge dissemination at the Namibian Rangeland Forum.

Photo: Rangeland Forum

 

 

 

(1) Comparative analysis of ecosystems along a Desertification Tipping Point gradient and (2) Experimental studies of Desertification Tipping Points

 

In the comparative approach, we investigate ecosystem structure and function along grazing gradients using a space-time substitution where we assume that gradients stretch from tipped to non-tipped conditions.

In terms of experimental studies, we are setting up the central research platform "TipEx", which experimentally pushes a savanna area in Namibia beyond a Desertification Tipping Point by combining two triggers for catastrophic change - heavy grazing and severe drought.

 

Aims

Within the comparative approach we aim to identify patterns in plant populations, plant communities and forage quality that enhances our understanding of tipping points or can even serve as early-warning indicators.

The experimental approach shall complement the comparative approach with mechanistic information.

Approach

Comparative approach: We installed observational plots along grazing gradients located at different communal and commercial farms. There we conduct plant inventories, perennial grass species counts, collect plant and biomass samples.

Experimental approach: We established an experiment with a full-factorial design combining 3 clipping treatments with ambient and reduced rainfall. We examine the effects on permanent observation quadrats via plant inventories, perennial grass species counts and biomass collections.

Expected Outcome

We hypothesise that a Desertification Tipping Point will cascade through ecosystem compartments and that this will have negative impacts on biodiversity and the ecosystem service of forage provision.

Persons involved

 

 

 

 

 

 

 

 

Project head

Prof. Dr. Anja Linstädter

 

PhDs

Florian Männer

Lisa-Maricia Schwarz

 

Coordinator (contact person)

Eike Kiene

namtip@uni-bonn.de

Cooperation partners

Agri-Ecological Services, Namibia

EduVentures Trust, Namibia

Helmholtz Centre for Environmental Research (UFZ), Germany

Institute for Social-Ecological Research (ISOE), Germany

Namibia University of Science and Technology, Namibia

University of Bonn, Germany

University of Cologne, Germany

University of Namibia, Namibia

University of Tübingen, Germany

Outreach                                                                                                                                                   

Männer, F.A., Amputu, V., Knox, N., Tielbörger, K, Linstädter, A., (2022), Exploring capabilities of modelling forage quality and quantity using field spectroscopy and UAV imagery in a semi-arid rangeland, Living Planet Symposium 2022, Bonn, https://doi.org/10.13140/RG.2.2.12739.89124

 

Männer, F.A., Dubovyk, O., Ferner, J., Freyaldenhoven, A., Muro, J., Schmidtlein, S., Linstädter, A., (2022). Forage quality predicted by hyperspectral reflection readings across climate zones. In: Grassland Science in Europe, Vol. 27 – Grassland at the heart of circular and sustainable food systems. Proceedings of the 28th European Grassland Federation General Meeting, France, ISBN: 978-2-7380-1445-0, p. 656 – 658

 

Männer, F.A., Ferner, J., Freyaldenhoven, A., Schmidtlein, S., Linstädter, A., (2021). Predicting grassland forage provision from spectral canopy reflection for different climate zones. The Joint International Grassland and International Rangeland Congress 2021, 25-29 October 2021. Nairobi, Kenya, https://doi.org/10.13140/RG.2.2.23756.08320

 

Männer, F.A., Schwarz, L.-M., Menestrey Schwieger, D., Amputu, V., Bilton, M.C., Brinkmann, K., Dressler, G., Hamunyela, N., Heita, H., Heshmati, S., Liehr, S., Mbidzo, M., Munyebvu-Chambara, F., Nesongano, W.C., Rauchecker, M., Sandhage-Hofmann, A., Tielbörger, K., Zimmer, K., Linstädter, A., (2022). An integrated framework to study ecological tipping points in social-ecological systems, in: National Organizing Committee of 2021 IGC/IRC Congress (Ed.), International Grassland Congress Proceedings. Kenya Agricultural and Livestock Research Organization, Online Conference Oct 2021, https://uknowledge.uky.edu/igc/24/1-2/2

 

Munyebvu-Chambara, F., Nesongano, W.C., Bilton, M.C., Linstädter, A., (2022). Utilizing perennial grass species’ population patterns to detect looming desertification tipping points in semi-arid regions, in: National Organizing Committee of 2021 IGC/IRC Congress (Ed.), International Grassland Congress Proceedings. Kenya Agricultural and Livestock Research Organization, Online Conference Oct 2021, https://uknowledge.uky.edu/igc/24/5-2/21/

 

Munyebvu-Chambara, F., Nesongano, W.C., Bilton, M.C., Linstädter, A., (2021). Grass species dynamics assist to detect rangeland transitions. GfÖ Virtual Annual Meeting 2021, 30 August – 1 September 2021, https://doi.org/10.13140/RG.2.2.33843.71205

 

Schwarz, L.-M., Bilton, M., Munyebvu-Chambara, F., Behn, K., Linstädter, A., (2022). Functional diversity as an indicator of rangeland degradation - insights from a Namibian grazing gradient study. Tropentag 2022, 14-16 September 2022. Prague, Czech Republic, https://doi.org/10.13140/RG.2.2.33843.71205

 

Schwarz, L.-M., Männer, F.A., Menestrey Schwieger, D.A., Amputu, V., Bilton, M.C., Brinkmann, K., Dressler, G., Hamunyela, N., Heita, H., Heshmati, S., Liehr, S., Mbidzo, M., Munyebvu-Chambara, F., Nesongano, W.C., Rauchecker, M., Sandhage-Hofmann, A., Tielbörger, K., Zimmer, K., Linstädter, A., (2021). An integrated framework to study ecological tipping points in social-ecological systems. The Joint International Grassland and International Rangeland Congress 2021, 25-29 October 2021. Nairobi, Kenya, https://doi.org/10.13140/RG.2.2.19509.35040

 

Schwarz, L.-M, Männer, F.A., Zimmer, K., Sandhage-Hofmann, A., Linstädter, A., (2020). Wenn der Sand kommt. Südzeit, 84, 11.

 

Interview with Prof. Dr. Anja Linstädter (2022). "Warum die Wüsten weltweit wachsen". Deutschlandfunk 10.05.2022. https://www.deutschlandfunkkultur.de/warum-die-wuesten-wachsen-und-was-wir-dagegen-tun-koennen-dlf-kultur-da61e3a5-100.html
 

Interview with Prof. Dr. Anja Linstädter (2019). "Wenn das Ökosystem kippt, hilft auch kein Regen mehr". Süddeutsche Zeitung 08.08.2019. https://www.sueddeutsche.de/wissen/klimawandel-wueste-landfaechen-ernaehrungssicherheit-1.4555951