SALLnet is one out of nine collaborative projects of the new German–South African research collaboration on global change under the SPACES2 programme, funded by BMBF.
Enhancing the food security, multi-functionality and resilience of South African Limpopo landscapes under global change, through:
Aims: We focus on the ecology and on adaptive management options of Limpopo’s multifunctional landscapes, in particular on rangelands and agroforestry systems. Our ultimate goal is to help farmers achieve resilience in their livelihoods, and to cope better with future climatic conditions.
Approach: To generate results on spatial and temporal scales relevant for decision-making, we combine (a) experiments with (b) field observations, and (c) synergetic analysis.
(a) Experiments: At the heart of our activities is our field experiment DroughtAct, located on the Experimental Farm of the University of Limpopo (see map). This experiment has been set up to evaluate land-use options under (post-)drought conditions. By combining grazing and drought treatments, we address two main research questions: (1) What determines rangelands’ stability (buffering capacity) in face of drought? (2) What are suitable management interventions to avoid degradation (shifts to undesirable states)? After four years of grazing and drought treatments, we will implement a bush encroachment add-on. To this end, nutrient addition and tree seeding treatments will be added.
(b) Field observations: To assess climate change effects on multiple ecosystem services provided by rangelands and agroforestry systems, we will concentrate on SALLnet's 15 target villages along the steep gradient of climatic aridity in Limpopo. Plots will be established in villages’ rangelands and homegardens. Soil- and vegetation mediated ecosystem services will mainly be assessed via a Rapid Ecosystem Functioning Assessment (REFA) while ecosystem services provided by higher trophic levels will mainly be evaluated with a functional trait approach.
(c) Synergies and Upscaling: Field data from the 15 target villages will be used for an integrated assessment of ecosystem services delivered by Limpopo’s multifunctional landscapes. We aim at addressing interactions (synergies and trade-offs) of multiple ecosystem services within and across land-use types, and under future climate conditions. In a first step, ecosystem service bundles will be identified and trade-offs will be quantified. We will then explore direct and indirect effects of environmental conditions (including changing climate and land-use) on ecosystem multifunctionality.
There are options to participate as a student volunteer or for MSc/BSc level theses. Applications should be sent to Anja Linstädter.
08/2018 - 07/2021
SPACES2 Call of the Federal Ministry of Education and Research (BMBF)
Pfeiffer, M., Langan, L., Linstädter, A., Martens, C., Gaillard, C., Ruppert, J., Higgins, S., Mudongo, E. and Scheiter, S. (2019). Grazing and aridity reduce perennial grass abundance in semi-arid rangelands – Insights from a trait-based dynamic vegetation model. Ecological Modelling, 395, pp. 11-22. Available at: URL.
The DroughtAct experiment addresses two main research questions:
(1) What determines rangelands’ stability in the face of drought?
(2) What are suitable management interventions to avoid degradation?
DroughtAct t is located at the experimental farm of the University of Limpopo, South Africa (Figure 1). It combines rainfall and grazing treatments (Figures 2 & 3), simulating realistic climate conditions under future climate change regimes in conjunction with potential management interventions. The experiment is part of the International Drought Experiment (IDE), initiated by Drought-Net, a global network to assess terrestrial ecosystem sensitivity to drought.
Details on the experiment
A pilot study for a network experiment on joint grazing and drought effects
The DroughtAct experiment is also a pilot study for an extension of the International Drought Experiment (IDE). With this grazing add-on, it will be possible to study combined grazing and drought effects over a broad range of terrestrial ecosystems to better understand their potentially interactive effects on ecosystems functioning and ecosystem service provision.
The grazing add-on also allows transferring the IDE approach (that requires undisturbed sites) to ecosystems which are subject to herbivory by wild or domestic herbivores. The sampling procedures of DroughtAct are fully compatible with the core IDE protocol. You can download our sampling protocol with the grazing add-on to Drought-Net [here].
If you are interested in the DroughtAct approach, contact Anja: linstaedter[at]uni-potsdam.de
Figure 2: Temporal grazing exclosure-cage with soil moisture probe. Cages allow for accurate estimation of aboveground net primary production (ANPP) under grazing conditions. The scattered soil moisture probes (white cap in foreground) allow for mid- to high-resolution monitoring of temporal and spatial patterns of plant available water.