29 research outputs found
Gaming and simulation to explore resilience of contested agricultural landscapes
Keywords: Complex systems, resilience thinking theory, communal decision-making, agent-based modeling, serious games Over the past decades, smallholder farming communities have become increasingly affected by an ever larger number of (unexpected) non-local economic and institutional drivers. At the same time, also environmental consequences of past and current agricultural activities have become more apparent. Consequently, farmer’s decision-making is now part of a complex social-ecological system in which stakeholders from various scales and levels exert power to influence smallholders’ decision-making. The capacity of rural communities to adapt to this fast-changing environment is key in securing the continuation of livelihoods in rural parts of the world. Improving the adaptive capacity of rural communities has been proposed as the largest challenge of the century, especially in contested areas were the interests of non-local stakeholders often strongly conflict with those of local communities. Although the attributes that underpin adaptive capacity are widely agreed upon in literature, (i) empirical evidence on how rural communities can construct trajectories of change based on adaptation, and (ii) tools that can facilitate the development of adaptive capacity are still lacking. This PhD thesis addressed both these issues. This research was based on extensive fieldwork in a usufruct community in the buffer zone of a Biosphere Reserve in Chiapas, Mexico, where objectives to conserve nature and produce food make completing claims on land and on a series of gaming and simulation workshops including a variety of stakeholders. Data showed that communities can strengthen their resilience to the sometimes strong negative effects of changes in legislation and markets. Improved local organization, diversification of land use and cooperation among farmers proved essential in this process. Four gaming and simulation tools were developed and applied with various stakeholders within this thesis. Results showed that the understanding of difficult concepts and processes among participants improved as a result of the gaming and simulation tools and that the workshops provided an opportunity to share ideas.</p
Reconstruction of the Arctic Ocean environment during the Eocene Azolla interval using geochemical proxies and climate modeling. Geologica Ultraiectina (331)
With the realization that the Arctic Ocean was covered with enormous quantities of the aquatic floating fern Azolla 49 Myrs ago, new questions regarding the Eocene conditions facilitating these blooms arose. This dissertation describes the reconstruction of paleo-environmental conditions facilitating the large-scale occurrence of the freshwater fern Azolla in the Early/Middle Eocene Arctic and how this bloom might have affected global climate. Comparison of organic geochemical analyses of Eocene Arctic sediments and extant Azolla filiculoides resulted in the discovery of unique biomarkers for both Azolla and its nitrogen fixating cyanobacterial symbiont Anabaena azollae. Lipids identified as 1,?20 C30–C36 diols and structurally related mid-chain hydroxy compounds can now serve as palaeo-environmental indicators for the Arctic Azolla interval and as markers for past occurrences of Azolla in general. The finding of heterocyst glycolipids in the Eocene sediments indicates that diazotrophic cyanobacteria played a major role in adding newly fixed nitrogen to surface waters in the past-stratified Arctic. Moreover, the similar distribution of heterocyst glycolipids in the Eocene Arctic sediments and extant Azolla suggests that the symbiotic relationship between Azolla and diazotrophic cyanobacteria of the family of Nostocaceae was already established in the Early/Middle Eocene and that Azolla arctica production mainly depended on phosphorus supply. Through analyses of the hydrogen isotopic composition (?D) of the novel biomarkers for Azolla and isotope modeling the water sources for and the salinity of the Eocene Arctic basin could be constrained. Model simulations using an isotope-enabled atmospheric general circulation model were validated using ?D values of paleo-precipitation obtained through ?D analyses of terrestrially derived n-alkanes found in sediments from the Azolla interval. The Eocene simulation accurately predicted the occurrence of less depleted precipitation, with ?D values ranging only between 0 and -140‰ (compared to Present-day 0 to -300‰), supporting the prevalence of a strongly reduced meridional temperature gradient during the Azolla interval. The hydrogen isotopic composition of the biomarkers for Azolla encountered in Eocene Arctic sediments fell in the same range as precipitation ?D reconstructed using n-alkanes extracted from the same sediments. This indicates that virtually no mixing could have occurred between deeper saline waters (isotopically heavy) and the freshwater (isotopically light), thus showing that the Arctic surface waters freshened considerably (salinity: 0 to 6) as a result of enhanced moisture transport to Northern high latitudes. Using trace metal budgets also the inflow of saline deepwater into the Arctic was constrained. Combining sedimentary phosphorus data, modeled freshwater fluxes and the reconstructed deepwater inflow in a new mass balance box model showed that a combination of enhanced regeneration of phosphorus and upwelling of phosphorus-rich deepwater is needed to explain the sustained growth of Azolla in the Eocene Arctic. Sustained production and subsequent burial of organic matter during a period of 160.000 to 1.000.000 yrs led to storage of 0.9 – 3.5 1018 g carbon in the Arctic, which resulted in a 55 to 470 ppm drawdown of atmospheric pCO2. This indicates that the Arctic Azolla blooms likely contributed to lowering atmospheric pCO2 levels in the Early/Middle Eocen
Agrodiversity v.2: An educational simulation tool to address some challenges for sustaining functional agrodiversity in agro-ecosystems
Functional agrodiversity can be useful and even essential for, i.e., the long-term sustainability of agriculture. However, still many aspects of this concept are not well understood. The interplay between species in diverse agro-ecosystems is based on processes as, i.e., competition, facilitation, and predator–prey relations. The net-effect of these processes on crop growth is not static and can change over time as the relative density of species change. The equilibrium state of a diverse agro-ecosystem might be far from optimum or even unproductive. This makes agrodiveristy a concept which is not easily grasped nor obtained or maintained. We believe that an agent-based model can facilitate learning on the topic of functional agrodiversity. In this paper, we present the agent-based simulation model, Agrodiversity v.2, developed in Netlogo 3.1.5. The model simulates a virtual diverse agro-ecosystem with four ecological agents. The user is challenged to explore ecological parameters and design a productive sustainable system. The model's “simplest playing level” shows that a proper balance between the co-existing species is necessary so that their ecological interactions allow the multi-species system to become self-organized and persist over time. It demonstrates the transient nature of profitable functional agrodiversity. Our analysis on the effects of using Agrodiversity v.2 on actual learning shows that the learning took place. Students increased the quality of their answers to paper-based individual questions on the topic from 29% during passive/conceptual teaching to 86% after the simulation session. On average students stated to have learnt 55% of their current knowledge through the workshop of which 76% was learnt by using the simulation
An educational simulation tool for negotiating sustainable natural resource management strategies among stakeholders with conflicting interests
Biotic communities subject to productive transformation - and social relations among stakeholders involved in their management - are complex, nonlinear, adaptive processes. The inner workings and potential behaviors of such processes are not always easily grasped. It is important to help people understand the dynamic nature of sustainability attributes and to better address the issues, tradeoffs and conflicts associated with sustainable management of natural resources. We have developed a number of graphic, interactive simulation tools - coupled with role-playing games - that allow stakeholders to explore scenarios and negotiate collective decisions regarding such management. The free-ware tool described here is called "Negotiated Design of Sustainable Production Systems among Social Agents with Conflicting Interests" (www.ecosur.mx/sustentabilidad). It is an interactive drama in three acts. In act 1, users play the role of slash-and-burn farmers compelled by the government to leave a biodiversity reserve zone and to intensify maize production in a smaller area using nitrogen fertilizer. Users simulate production under different fertilization scenarios and decide if they can sustain their families under the government's proposal. In act 2, other users play the role of rural families who depend on ecotourism in a clear lake downhill and who anticipate that their livelihood could be threatened by lake eutrophication caused by nitrogen runoff. As part of the negotiations with uphill farmers, they need to know how much N can lixiviate from the fields before the lake becomes murky. Time series, coupled with parameter-sensitive cup and marble models that run as real-time animations, allow the user to better understand the dynamics of this bi-stable lake ecosystem. In act 3, stakeholders negotiate possible solutions, combining computer use and group dramatization. They search for nitrogen management strategies based on maize monocrop and maize-leguminous shrub systems. Technical decisions change output variables that are monitored through a graphical multi-criteria analysis of environmental and social sustainability attributes. Results from 12 workshops show that participants usually come up with creative solutions that meet the biodiversity conservation and rural livelihood interests of all stakeholders involved. Through these dynamical modeling games, users better grasp the meaning of productivity, stability, resistance, resilience, reliability, adaptability and equity. They also understand concepts such as bi-stability, thresholds, risk, catastrophic shift, hysteresis and restoration. Ultimately, they get an opportunity to become familiar with more creative and open-minded attitudes when defending interests and making collective decisions in a multi-stakeholder environmen