By means of a hypergraph, we study the resilience and the connectivity of a socio-ecological system (SES), which takes the form of a concentric diagram reflecting strong sustainability. The structure ...is subjected to dynamics of spread of a global reform. The model outcomes reveal that, in the concentric representation of sustainability, the environmental layer is endowed with the maximum magnitude of efficiency of the knock-on effect. The existence of risk of reform abrogation prevents the equilibrium density of reformed nodes from reaching stationarity. The numerical simulation results confirm that the environmental layer is the most efficient when it comes to launching a reform through a small number of nodes. They also show that connectivity between all types of elements is most fairly valued from the environmental perspective.
The paper models the maintenance of ecological networks in forest environments, built from bioreserves, patches and corridors, when these grids are subject to random processes such as extreme natural ...events. It also outlines a management plan to support the optimized results. After presenting the random graph-theoretic framework, we apply the stochastic optimal control to the graph dynamics. Our results show that the preservation of the network architecture cannot be achieved, under stochastic control, over the entire duration. It can only be accomplished, at the cost of sacrificing the links between the patches, by increasing the usage of the control devices. This would have a negative effect on the species migration by causing congestion among the channels left at their disposal. The optimal scenario, in which the shadow price is at its lowest and all connections are well-preserved, occurs at half of the course, be it the only optimal stopping moment found on the stochastic optimal trajectories. In such a scenario, the optimal forestry management policy has to integrate agility, integrated response, and quicker response time.
We unify evolutionary dynamics on graphs in strategic uncertainty through a decaying Bayesian update. Our analysis focuses on the Price theorem of selection, which governs replicator(-mutator) ...dynamics, based on a stratified interaction mechanism and a composite strategy update rule. Our findings suggest that the replication of a certain mutation in a strategy, leading to a shift from competition to cooperation in a well-mixed population, is equivalent to the replication of a strategy in a Bayesian-structured population without any mutation. Likewise, the replication of a strategy in a Bayesian-structured population with a certain mutation, resulting in a move from competition to cooperation, is equivalent to the replication of a strategy in a well-mixed population without any mutation. This equivalence holds when the transition rate from competition to cooperation is equal to the relative strength of selection acting on either competition or cooperation in relation to the selection differential between cooperators and competitors. Our research allows us to identify situations where cooperation is more likely, irrespective of the specific payoff levels. This approach provides new perspectives into the intended purpose of Price’s equation, which was initially not designed for this type of analysis.
Deconstructing the Doughnut Dragicevic, Arnaud Z
Current opinion in environmental sustainability,
June 2024, 2024-06-00, Letnik:
68
Journal Article
Recenzirano
This review paper contributes to understanding and interpreting the widely adopted Doughnut model by investigating the mathematical objects underpinning its creation. While the model has gained ...popularity as a geometrical representation of sustainability, little attention has been given to the nature and properties of its components. By analyzing the visuals of the model and using mathematical tools such as sets and hypergraphs, this work provides a new perspective on the pathways to sustainability. The deconstructive methodology reveals a paradox within the model that distinguishes weak sustainability from strong sustainability. This paper adds value by extending the range of ideas and implications associated with the Doughnut model and providing a more nuanced understanding of its implications for sustainability.
•We study the dynamics of stochastic closed-loop input-output forest systems.•We introduce a negative feedback mechanism, where an element contained in the system behaves as a negative input toward ...elements to which it is connected.•The monofunctional-zoning mode of forest governance performs robustly against invasive biological threats at all levels of outbreak probability.•The multifunctional mode of forest governance is mainly sturdy when the probability of invasion verges into certainty.
In order to take account of the negative effects of invasive species and pathogens on networked forest areas, we study the dynamics of stochastic closed-loop input-output systems faced with the risk of external random perturbations. The extension of previous works on robustness is carried out by introducing a negative feedback mechanism, such that the output from an element contained in the system behaves as a negative input toward elements to which it is connected. Through the study of an overall network divided into compartments barely connected to one another, we first consider the pathway pertaining to monofunctional zoning. By looking at a single aggregated structure, we then move our focus to the pathway proper to multifunctionality. Our results show that, at significant time scales, the monofunctional-zoning mode of forest governance, generally applied in Australasia, performs robustly against invasive biological threats at all levels of outbreak probability. The multifunctional mode of forest governance, further practiced in Western Europe, is mainly sturdy when the probability of invasion verges into certainty. Should this not be the case, robustness is ensured would disturbers and perturbations be uncorrelated. Accordingly, the monofunctional pathway can afford adopting control strategies for outbreak avoidance, which is only acceptable in case the expected invasion can be halted. For the sake of maintaining low likelihood of invasion, the multifunctional pathway is compelled to applying preventive strategies.
In order to address the topic of the tragedy of the commons, more specifically that of tropical forest ecosystems explored as common-pool resources endowed with public-good features and exposed to ...deforestation risks, we consider game-theoretic population dynamics contingent on various differential equations. We propose an evolutionary model handed down to the Price theorem of selection. In a set of model-players evolving in strategic uncertainty and subject to certain mutation toward cooperation, the Price equation evens out unstructured and structured population replicator dynamics. According to the model outputs, avoiding the tragedy of the commons can be achieved on condition that half of the population temporarily exhibits a cooperative behavior. Furthermore, cooperative model-players ought to be rewarded at a level equivalent to the joint selection of cooperators and competitors issued from the unifying Price identity.
Through the consideration of a stochastic matching model dependent on a probability function built from the Heron’s formula, we analyze the emergence and the dynamics of short agrifood sale circuits ...in form of time-evolving random hypergraphs. These marketing circuits, which are used as a supportive policy for promoting local food consumption, typify short distribution channels. Although bipartite matching can be easily derived from the framework, we move our focus on the matching of triplets of players representing buyers, retailers and sellers. Their conditional pairings with respect to standard and social preferences are both taken into consideration. Our results show that the emergence of short food supply chains is triggered by a three-dimensional stochastic matching mechanism. Their time evolution is found to be governed by both stable and unstable dynamics, the latter being subject to bounded antiperiodic oscillations. Via the use of a Poisson process, we then redirect our interest toward spatial randomness and the number of circuits attainable in a defined territory. The model unveils a restricted spread of short circuits over the entire territory, which, in expectation, can only be a partial substitute for long supply chains. The outcomes show consistency with the agribusiness patterns currently observable in France.
This work aims at modeling the economics of the sylvo-cynegetic equilibrium in commercial forests, as defined by forestry authorities, with respect to uncertain damages to plantation stands caused by ...the overabundance of ungulate species. After presenting the stochastic optimal control framework, in which the dynamics of forest resources and the population dynamics of big game species are both considered, we apply the stochastic control to an updated version of the well-known Gordon-Schaefer bioeconomic model. Our results show that the equilibrium can be achieved through the use of a joint control divided between regeneration works and hunting regimes. Furthermore, we find that, in equilibrium, the investment in forestry works ought to be equal to the willingness to undertake the resource stock stabilization in uncertainty. The investment should amount no more than 20% of total costs engaged in a forestry management plan.
•We model the economic aspect of the sylvo-cynegetic equilibrium in uncertainty.•The uncertainty is modeled via the Fokker-Planck equations of order two.•We apply the stochastic optimal control to the Gordon-Schaefer bioeconomic model.•We find strategic substitutability between regeneration works and hunting activities.
Abstract This paper examines the effectiveness of climate pledges and eco-taxation as strategies for mitigating climate change within a networked agricultural supply chain organisation. We utilise ...variational inequality techniques within a multicriteria decision-making framework and validate our theoretical findings through numerical simulations using a machine learning augmented algorithm. By employing this approach, we position the Agricultural Sector Roadmap, aimed at capping global warming at 1.5°C, within the wider agricultural sector’s climate action framework. Our results demonstrate that environmental taxation emerges as the most effective approach for addressing climate change. Eco-taxation leads to a 57.87 per cent reduction in global emissions, whereas climate pledges only account for a 20.59 per cent reduction at the same level of production. Furthermore, eco-taxation results in a 45.68 per cent greater reduction in emission intensity compared to climate pledges. In contrast to climate commitments, an eco-fiscal policy is capable of achieving the objectives established by the European Union.
