Predator harvesting in stage dependent predation models: insights from a threshold management policy

Stage dependent predation may give rise to the hydra effect - the increase of predator density at equilibrium as its mortality rate is raised. Management strategies that adjust predator harvest rates or quotas based on responses of populations to past changes in capture rates may eventually lead to a catastrophic collapse of predator species. A proposed threshold management policy avoids the hydra effect and its subsequent danger of predator extinction. Suggestions to extend the application of threshold policies in areas such as intermediate disturbance hypothesis, density-trait mediated interactions and non-optimal anti-predatory behavior are put forward.     

Dynamical stabilization of grazing systems: An interplay among plant-water interaction, overgrazing and a threshold management policy

In a plant-herbivore system, a management strategy called threshold policy is proposed to control grazing intensity where the vegetation dynamics is described by a plant-water interaction model. It is shown that this policy can lead the vegetation density to a previously chosen level under an overgrazing regime. This result is obtained despite both the potential occurrence of vegetation collapse due to overgrazing and the possibility of complex dynamics sensitive to vegetation initial densities and parameter uncertainties.     

Exploitation of a single species by a threshold management policy

Continuous time models of single exploited populations usually generate outcomes expressing a dependence of yield and economic items on harvest intensity. In this work it is shown that a known threshold policy is able to generate yield and related economic items that do not depend on harvest intensity, but rather on the values of the population threshold itself and the species intrinsic parameters. It is argued that since this result can be carried over to other models of single species dynamics, it may have significant implications in the management and conservation of exploited populations.     

Realistic threshold policy with hysteresis to control predator–prey continuous dynamics

This paper introduces a threshold policy with hysteresis (TPH) for the control of one-predator one-prey models. The models studied are the Lotka–Volterra and Rosenzweig–MacArthur two species density-dependent predator–prey models and the Arditi–Ginzburg nondimensional ratio-dependent model. The proposed policy (TPH) changes the dynamics of the system in such a way that a bounded oscillation is achieved confined to a region that does not allow extinction of either species. The policy can be designed by a suitable choice of so called virtual equilibrium points in a simple and intuitive manner.

Conflictive management of small mammals considered as pests: A long way to evidence-based policy making

This paper discusses the controversial management decisions made by policy-makers worldwide regarding poisoning campaigns aimed to control small mammal populations,often considered harmful economic pests.Aside from considerations regarding the biological consequences of these campaigns,we argue that when society rejects all values of science and expertise then only badly supported and negligent decisions will be made about conservation and management issues.The extermination of small mammal species,some of which play crucial ecological roles in several regions of the world,is just an example of such discredit and misinformation.Without a strong commitment towards evidence-based policy-making,economic investments in research and development could be entirely compromised [Current Zoology 58 (2):353-357,2012].     

Threshold policies control for predator-prey systems using a control Liapunov function approach

The stability of predator-prey models, in the context of exploitation of renewable resources, subject to threshold policies (TP) is studied in this paper using the idea of backstepping and control Liapunov functions (CLF) well known in control theory, as well as the concept of virtual equilibria. TPs are defined and analysed for different types of one and two species predator-prey models. The models studied are the single species Noy-Meir herbivore-vegetation model, in a grazing management context, as well as the Rosenzweig-MacArthur two species predator-prey model, in a fishery management context. TPs are shown to be versatile and useful in managing renewable resources, being simple to design and implement, and also yielding advantages in situations of overexploitation.     

The impact of environmental fluctuations on structured discrete time population models: resonance, synchrony and threshold behaviour

External forcing of a discrete time ecological system does not just add variation to existing dynamics but can change the dynamics. We study the mechanisms that can bring this about, focusing on the key concepts of excitation and suppression which emerge when analysing the power spectra of the system in linear approximation. Excitation, through resonance between the system dynamics and the external forcing, is the greater the closer the system is to the boundary of the stability region. This amplification means that the extinction of populations becomes possible sooner than expected and, conversely, invasion can be significantly delayed. Suppression and the consequent redistribution of power within the spectrum proves to be a function both of the connectivity of the network graph of the system and the way that external forcing is applied to the system. It is also established that colour in stochastic forcing can have a major impact, by enhancing resonance and by greater redistribution of power. This can mean a higher risk of extinction through larger fluctuations in population numbers and a higher degree of synchrony between populations. The implications of external forcing for stage-structured species, for populations in competition and for trophic web systems are studied using the tools and concepts developed in the paper.     

Making parks make a difference: poor alignment of policy,planning and management with protected-area impact,and ways forward

Policy and practice around protected areas are poorly aligned with the basic purpose of protection, which is to make a difference. The difference made by protected areas is their impact, defined in program evaluation as the outcomes arising from protection relative to the counterfactual of no protection or a different form of protection. Although impact evaluation of programs is well established in fields such as medicine, education and development aid, it is rare in nature conservation. We show that the present weak alignment with impact of policy targets and operational objectives for protected areas involves a great risk: targets and objectives can be achieved while making little difference to the conservation of biodiversity. We also review potential ways of increasing the difference made by protected areas, finding a poor evidence base for the use of planning and management ‘levers’ to better achieve impact. We propose a dual strategy for making protected areas more effective in their basic role of saving nature, outlining ways of developing targets and objectives focused on impact while also improving the evidence for effective planning and management.     

Challenges in genetic resources policy making: some lessons from participatory policy research with a special reference to Ethiopia

It is widely recognized that developing countries lack technical and institutional capacity to effectively implement genetic resources policy. This has led Bioversity International (the then IPGRI) to initiate a project called Genetic Resources Policy Initiative (GRPI) in six countries (Ethiopia, Egypt, Zambia, Peru, Vietnam and Nepal). Drawing from the literature and experiences of this project, this paper has attempted to document some of the lessons from the project and present the issues and challenges that need to be addressed for effective genetic resources policy. Recognizing its cross-cutting nature, the paper has argued that genetic resources policy has to be part of the broader development agenda to effectively deal with trade-offs and harmonize the conflicts. Essentially, the important policy question is to strike the balance and simultaneously promote the diversity of genetic resources and welfare outcomes. The major thrust of GRPI has been the multi-disciplinary, -sectoral, and -stakeholder (3M) approach. Despite all its theoretical merits, its implementation has been a serious challenge in practice. This has, among others, been due to ‘‘A project for all is a project for none’’ dilemma. Engaging decision makers in 3M deliberations has revealed that many of them tend to think that maintaining genetic diversity promotes traditional farming and retards agricultural development. Clearly, addressing each of these challenges and policy loopholes requires innovation in a diversity of institutions.     

Linking reductionist science and holistic policy using systematic reviews: unpacking environmental policy questions to construct an evidence-based framework

1. There is a mismatch between broad holistic questions typically posed in policy formation and narrow reductionist questions that are susceptible to scientific method. This inhibits the two-way flow of information at the science-policy interface and weakens the impact of applied ecology on environmental policy.
2. We investigate the approaches to building policy in the health services as a model to help establish a framework in applied ecology and environmental management by which reductionist science can underpin decision making at the policy level.
3. A comparison of policy documents in the health and environmental sectors reveals many similarities in identifying approaches and specific interventions that might achieve policy objectives. The difference is that in the health services, information on the effectiveness of potential interventions is far more readily available through the collaborative process of systematic review.
4. Synthesis and applications . Decision makers are increasingly looking to produce policies that are shaped by evidence through evidence-based policy making. The approach that we outline here provides a framework for structuring systematic reviews to deliver the evidence on key policy issues in a way that will see a faster return and provide better use of the systematic review methodology in environmental management.     

Rehabilitation of degraded forests in Thailand: policy and practice

Thailand has suffered from severe deforestation during the last century. Forest cover has declined drastically both in terms of area and quality, mostly due to the expansion of human activities. Much of the deforested area has been used for agricultural purposes, but much has also been left in a degraded condition. In late 1980s, the forest declined to a point where the nation decided that the remaining forest should be kept for conservation rather than further exploitation. Consequently, forest policy has shifted its focus from exploitation to sustainable management and protection. Thailand has set a goal of increasing its forest area to 40% of the total land area, while at present, forests occupy around 28.9% of the land. With the intention to retain most of the remaining forest as protected areas and, at the same time, achieve the goal set, several reforestation and rehabilitation initiatives have been implemented, especially on those lands in a degraded condition. This paper focuses on the significant issues affecting both the policy and practice of forest rehabilitation. Given that the large number of people whose livelihood depends on the forests for subsistence and other purposes normally has been excluded from the decision-making process in forest management, most important among these issues are the integration of the socio-economic and environmental needs into rehabilitation initiatives together with the active participation of local communities in the rehabilitation program. Case studies of reforestation and rehabilitation initiatives are also discussed.     

Farm characteristics and the vegetative diversity of grasslands in the North of England: a policy perspective

A survey of 36 fields across 11 farms in the North of England was conducted to record the plant species diversity of grassland communities under various base conditions. Data pertaining to topographical advantage, farm management strategy and soil type were also collected for each field site. The relationship between management inputs and base environmental conditions and the resultant diversity of flora were identified through ordination techniques. The results show a total of 111 species being observed across the sample and some expected relationship emerge, but they also suggest that complementary management techniques can have opposing or conflicting effects on species prevalence. The study argues that provision or use of such information should be paramount within environmental policy formulation where site-specific management plans are used to produce environmental goods.     

A model of a myelinated nerve axon: threshold behaviour and propagation

A model of a myelinated nerve axon is developed on the basis of FitzHugh-Nagumo dynamics under the assumption that the nodes of Ranvier are of small but finite width. It is shown that a periodic excited state may not exist if the width of the nodes is too small and the leakage across the myelin sheath is too great. The propagation of a super threshold pulse is prevented in the absence of nodes. Global stability of the resting equilibrium state is investigated as well as the propagation of wave front, type solutions.     

Stochastic fluctuations in frequency-dependent selection: a one-locus, two-allele and two-phenotype model

Stochastic fluctuations in a simple frequency-dependent selection model with one-locus, two-alleles and two-phenotypes are investigated. The steady-state statistics of allele frequencies for an interior stable phenotypic equilibrium are shown to be similar to the stochastic fluctuations in standard evolutionary game dynamics [Tao, Y., Cressman, R., 2007. Stochastic fluctuations through intrinsic noise in evolutionary game dynamics. Bull. Math. Biol. 69, 1377-1399]. On the other hand, for an interior stable phenotypic or genotypic equilibrium, our main results show that the deterministic model cannot be used to predict the expectation of phenotypic frequency. The variance of phenotypic frequency for an interior stable genotypic equilibrium is more sensitive to the expected population size than for an interior stable phenotypic equilibrium. Furthermore, the stochastic fluctuations of allele frequency and phenotypic frequency can be considered approximately independent of each other for these genotypic equilibria, but not for phenotypic.     

Plans of mice and men: from bench science to science policy

The transition from bench science to science policy is not always a smooth one, and my journey stretched as far as the unemployment line to the hallowed halls of the U.S. Capitol. While earning my doctorate in microbiology, I found myself more interested in my political activities than my experiments. Thus, my science policy career aspirations were born from merging my love of science with my interest in policy and politics. After receiving my doctorate, I accepted the Henry Luce Scholarship, which allowed me to live in South Korea for 1 year and delve into the field of science policy research. This introduction into science policy occurred at the South Korean think tank called the Science and Technology Policy Institute (STEPI). During that year, I used textbooks, colleagues, and hands-on research projects as my educational introduction into the social science of science and technology decision-making. However, upon returning to the United States during one of the worst job markets in nearly 80 years, securing a position in science policy proved to be very difficult, and I was unemployed for five months. Ultimately, it took more than a year from the end of the Luce Scholarship to obtain my next science policy position with the American Society for Microbiology Congressional Fellowship. This fellowship gave me the opportunity to work as the science and public health advisor to U.S. Senator Harry Reid. While there were significant challenges during my transition from the laboratory to science policy, those challenges made me tougher, more appreciative, and more prepared to move from working at the bench to working in the field of science policy.     

Tackling the threat of antimicrobial resistance: from policy to sustainable action

Antibiotics underpin all of modern medicine, from routine major surgery through to caesarean sections and modern cancer therapies. These drugs have revolutionized how we practice medicine, but we are in a constant evolutionary battle to evade microbial resistance and this has become a major global public health problem. We have overused and misused these essential medicines both in the human and animal health sectors and this threatens the effectiveness of antimicrobials for future generations. We can only address the threat of antimicrobial resistance (AMR) through international collaboration across human and animal health sectors integrating social, economic and behavioural factors. Our global organizations are rising to the challenge with the recent World Health Assembly resolution on AMR and development of the Global Action plan but we must act now to avoid a return to a pre-antibiotic era.     

LCA in Japan: policy and progress

A summary of the current Japanese activities related to Life Cycle Assessment are presented with a specific comparison of Life Cycle Impact Assessment in relation to European tendencies. Japanese organizations involved in LCA, recent legislation impacting LCA activities and LCA case studies are also tabulated. The LCA priorities of policy makers and industrialists are discussed in comparison and compared to those in the United States. Projects within the Life Cycle Assessment Society of Japan and the Man-Earth Project are highlighted including the construction of a public LCI data base and the prediction of 21st century environmental crises.     

Cultivating participatory policy processes for genetic resources policy: lessons from the Genetic Resources Policy Initiative (GRPI) project

The purpose of the paper is to draw lessons and document experiences from the Genetic Resources Policy Initiative (GRPI) project, a project which has been underway in six countries and two sub-regions during the last 5 years. Its focus has been to experiment an approach to participatory policy processes, coined by the project, called the multi-stakeholder, multi-disciplinary and multi-sector or in short the 3M. This approach, which was demand-driven due to the nature of the policy problems being examined, aims to create a platform to address competing interests inherent in genetic resources issues from multiple perspectives. It is meant to enable different stakeholders to balance issues they diverge and/or converge upon in genetic resources management, thereby harmonizing trade-offs, objectives and strategies. Experiences from the project in applying the 3M in Egypt, Nepal, Vietnam Peru and Zambia highlight several lessons in participatory policy processes. The experiences show that the success or otherwise of participatory policy making processes is dependent on various factors that have to do with stakeholder capacities, process orientation, shared understanding versus vested interests and institutional functions. They highlight that the most effective approach to stakeholder engagement in policy processes is to construct them around an actively engaged ‘process leader’ that possesses, or has the potential to champion the process by mobilising the required cognitive knowledge and institutional engagement. They further suggest that since genetic resources policy issues are cross-cutting, they will demand a more holistic approach with a clear identification of impact pathways through which policy changes can be expected to influence the outcome variables. Since policy making processes are perpetual, the question of sustaining project ideas and recommendations beyond the life of a project has to be part of the planning exercise in any participatory genetic resources policy research and formulation.

Structuring policy problems for plastics,the environment and human health: reflections from the UK

How can we strengthen the science–policy interface for plastics, the environment and human health? In a complex policy area with multiple stakeholders, it is important to clarify the nature of the particular plastics-related issue before trying to understand how to reconcile the supply and demand for evidence in policy. This article proposes a simple problem typology to assess the fundamental characteristics of a policy issue and thus identify appropriate processes for science–policy interactions. This is illustrated with two case studies from one UK Government Department, showing how policy and science meet over the environmental problems of plastics waste in the marine environment and on land. A problem-structuring methodology helps us understand why some policy issues can be addressed through relatively linear flows of science from experts to policymakers but why others demand a more reflexive approach to brokering the knowledge between science and policy. Suggestions are given at the end of the article for practical actions that can be taken on both sides.