Resilienz aus der ressourcenökonomischen Perspektive
Zusammenfassung der Projektergebnisse
The project aimed to quantify the resilience of the two socio-ecological systems; communal rangelands in South Africa and the agricultural system of the Naivasha Lake Basin. The communal rangeland systems are characterized by an institutional collapse after the sudden dismantlement of Apartheids’ long-term, top-down interventions. The economics of these rangeland systems shifted from the highly subsidized goal of agricultural self-sustainability towards a high dependence on state grants which are not related to land use. According to canonical economic reasoning, resource appropriation of the communal rangelands would result in a tragedy of the commons leading to ecological collapse and a decoupling of systems due to externalities created by individuals. Another strand of literature suggests that formal institutions governing resource use can lead to a successful and sustainable management by cooperative agents. However, both could not be observed for the communal rangeland system. This observation was the starting point to ask two research questions: (1) Are there relevant informal institutions preventing the prediction of a tragedy of the commons and how can the dynamics behind them be quantified in a socio-ecological system setting? (2) How are the resiliencies of the coupled system and of the social system subject to shocks, stresses and interventions related to each other and how can both resiliencies be quantitatively measured? Research in resource economics investigated this question both using hydro-economic modeling as well as analyzing surveys among small-scale farmers in the upper catchment of Lake Naivasha. (3) How does volatility of water supply impact upon the viability of water management institutions? (4) Can soil conservation practices generate private benefits in-terms of higher crop productivity? (5) How do social institutions affect the diffusion of technologies to mitigate negative externalities? The socio-ecological system modelling exercise for South Africa has shown (1) the ability of the approach for accounting for complexity arising from human-nature feedbacks, (2) the need to look beyond the prevailing dichotomic debates of a tragedy of the commons vs. “good” governance, (3) how to approach the endogenization of norm guided behaviour and (4) measurement of multi-scale resilience in SES models. Moreover, it showed that (5) resilience research must not constrain itself by only asking the question “who is resilient towards what?” but must include interaction effects between resilience scales. Results from the River-Basin model shows (1) increasing human water use raises the likelihood of low lake levels in coming decades so proliferation of permits should be prevented, (2) Regulations of water use - however strict or smart - will not completely prevent low lake levels, but can make a difference when properly enforced, (3) Therefore, non-compliance should be made costly (by law, with an uncertainty element, and not per cubic meter), (4) Voluntary agreements are unlikely to work under water stress as long as they make non-compliance cheap.
Projektbezogene Publikationen (Auswahl)
-
(2012) ‘Can hydro-economic river basin models simulate water shadow prices under asymmetric access?’ Water Science & Technology 66, 879
Kuhn, A., Britz, W.
-
(2013) ‘Modeling water allocating institutions based on Multiple Optimization Problems with Equilibrium Constraints’ Environmental Modelling & Software 46, 196–207
Britz, W., Ferris, M., Kuhn, A.
-
(2013) ‘Social influence and collective action effects on farm level soil conservation effort in rural Kenya’, Ecological Economics 90, 94–103
Willy, D.K., Holm-Müller, K.
-
(2014) ‘Estimating the joint effect of multiple soil conservation practices: A case study of smallholder farmers in the Lake Naivasha basin, Kenya’, Land Use Policy 39, 177–187
Willy, D.K., Zhunusova, E., Holm-Müller, K.
-
(2016) ‘Cooperation and collapse in a communal livestock production SES model – A case from South Africa’, Environmental Modelling & Software, vol. 75, pp. 402-413
Rasch, S, Heckelei, T, Oomen, R, Naumann, C.
-
(2016) ‘Reorganizing resource use in a communal livestock production socio-ecological system in South Africa’, Land Use Policy, vol. 52, pp. 221-231
Rasch, S, Heckelei, T, Oomen, R.
-
(2016) ‘Simulating the viability of water institutions under volatile rainfall conditions – The case of the Lake Naivasha Basin’ Environmental Modelling & Software 75, 373–387
Kuhn, A., Britz, W., Willy, D.K., van Oel, P.
-
(2017) ‘Multi-scale resilience of a communal rangeland system in South Africa’, Ecological Economics, vol. 131, pp. 129-138
Rasch, S, Heckelei, T, Oomen, R, Naumann, C.
