Les récifs coralliens hébergent la plus grande biodiversité sur Terre et fournissent la nourriture, le revenu économique, la protection côtière et les valeurs culturelles pour des millions de personnes. L'accessibilité des écosystèmes via les réseaux routiers est un déterminant majeur de leurs conditions, les écosystèmes les plus accessibles étant les plus menacées. Longtemps, l’estimation de l'accessibilité par l’Homme s’est limitée à l'utilisation de la distance linéaire qui ignore l’irrégularité des côtes maritimes et les réseaux routiers, facteurs influençant le temps nécessaire pour atteindre les lieux de pêche. Cette thèse présente un double enjeu : (i) développer des indices d'accessibilité intégrant l’hétérogénéité du milieu marin pour quantifier les impacts humains sur les récifs ; (ii) évaluer l'importance de ces nouveaux indices, en interaction avec les mesures de protection, pour expliquer les variations de la biomasse de poissons. Dans un premier temps, j’ai caractérisé la proximité des hommes aux récifs, en tenant compte des surfaces rencontrées (routes, chemin, eau) qui influencent le temps de trajet jusqu’aux récifs. Le temps de trajet a permis de calculer un indice de gravité, défini comme la population humaine divisée par le temps de trajet au carré, pour évaluer le niveau de pression humaine de n'importe quel récif au monde. J'ai trouvé que le temps de trajet et la gravité sont des déterminants majeurs de la biomasse de poissons à l’échelle globale. Dans un second temps, trois applications utilisant ces nouveaux indices ont permis de montrer que (i) la gravité permet de révéler l’efficacité des actions de conservation : les réserves placées là où les impacts humains sont modérés à forts fournissent des gains de conservation élevés pour la biomasse de poissons, mais elles sont peu susceptibles de protéger les prédateurs supérieurs, qui sont uniquement présent dans les réserves soumises à de faibles impacts humains ; (ii) en utilisant un cas d'étude réalisé dans le Nord-Ouest de Madagascar, j'ai illustré comment la proximité du marché peut affecter les communautés de pêcheurs et, finalement, engendrer des changements dans l'exploitation des ressources marines ; (iii) j’ai développé une nouvelle approche, le Community-Wide Scan (CWS), pour identifier les espèces de poissons qui contribuent de manière significative à la biomasse et à la couverture corallienne des récifs de l’Indopacifique, celles-ci pouvant constituer des espèces cibles à protéger. Dans le contexte de changements globaux et de perte de biodiversité, la mesure d’accessibilité constitue un outil puissant et permet de relancer le défi de gestion durable et efficace des socio-écosystèmes coralliens. / Coral reefs have the greatest biodiversity of any ecosystem on the planet and support ecosystem goods and services to million people who depend directly on them for food, economic income, coastal protection and cultural values. Ecosystem accessibility, through road networks, is the main driver of their conditions, with the most accessible ecosystems being most at risk of resource depletion. To date, measuring accessibility to humans was strictly limited to examining the linear distance which ignores ragged coastlines and road networks that can affect the time required to reach fishing grounds. This thesis presents a double challenge: (i) developing new metrics of accessibility that account for seascape heterogeneity to better assess human impacts on coral reefs; (ii) evaluating the importance of coral reef accessibility, in interactions with their management, to explain variations of fish biomass. First, I developed novel metrics of reef proximity to human populations and markets based on the friction distance which is related to transport surfaces (paved road, dirt road, water) influencing the effective reach of human settlements. Travel time was used to build the gravity index, defined as human population divided by the squared travel time, to assess the level of human pressure on any reef of the world. I found that both travel time and gravity are strong predictors of fish biomass globally. Second, three applications using these new metrics highlighted that (i) gravity identified critical ecological trade-offs in conservation since reserves placed with moderate-to-high impacts may provide substantial conservation gains for fish biomass while reserve locations with low human impacts were more likely to support higher-order predation, (ii) using a study case in Northwest Madagascar, I illustrated how market proximity can affect fishermen communities and, ultimately, trigger changes in marine resources exploitation, and (iii) I implemented a new Community-Wide Scan (CWS) approach to identify fish species that significantly contribute to the biomass and coral cover on Indo-Pacific reefs and which provided tractable conservation targets. Within the context of global changes and biodiversity loss, the thesis challenges the sustainable and efficient management of coral reef socio-ecological systems with accessibility being the cornerstone.

The prevalence of childhood overweight and obesity is increasing at an alarming rate in the United States. Currently more than 1 in 3 children aged 2-19 are overweight or obese. This is of major concern because childhood overweight and obesity leads to chronic conditions such as type II diabetes and tracks into adulthood, where more severe adverse health outcomes arise. In this study I used the premise of the social ecological model (SEM) to analyze the common levels that a child is exposed to daily; the intrapersonal level, the interpersonal level, the school level, and the community level to better understand what risk factors are significantly associated with child weight status. Data came from the 2012 National Survey of Children's Health (NSCH) (n=41,361). Frequencies and confidence intervals were used to describe risk factors at each level. Bivariate analyses were conducted between each risk factor and the outcome variable. Using all risk factors that were significantly associated with overweight and obesity in the bivariate analyses, multinomial logistic regressions were performed for each SEM level. The 4 SEM levels were then analyzed together using stagewise multinomial logistic regression. A significance level cutoff of 0.05 was applied to all analyses. Thirty-three percent of participants were overweight or obese. Child sex, race, age, child physical activity participation, mother’s education and health, the child’s family structure, the child’s participation in extracurricular activities, frequency of family meals at home, safety and engagement in school, the number of amenities and the safety and support within their communities were found to be significantly associated with child weight status. The odds ratios of the covariates in the final stagewise model were similar to those in each individual model. Understanding both the risk factors associated with child overweight and obesity in each individual level and in the complete socio-ecological perspective is important when working toward more effective policy and program creation and the reduction of childhood obesity. Recognizing that all levels of a child's SEM influence his or her likelihood of being overweight or obese can lead to more effective strategies that tackle multiple SEM levels collectively instead of each level independently.

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The present study is one of the first attempts to analyze the societal importance of seagrasses (marine flowering plants) from a Natural Resource Management perspective, using a social-ecological systems (SES) approach. The interdisciplinary study takes place in East Africa (Western Indian Ocean, WIO) and includes in-depth studies in Chwaka Bay, Zanzibar, Tanzania. Natural and social sciences methods were used. The results are presented in six articles, showing that seagrass ecosystems are rich in seagrass species (13) and form an important part of the SES within the tropical seascape of the WIO. Seagrasses provide livelihoods opportunities and basic animal protein, in from of seagrass associated fish e.g. Siganidae and Scaridae. Research, management and education initiatives are, however, nearly non-existent. In Chwaka Bay, the goods and ecosystem services associated with the meadows and also appreciated by locals were fishing and collection grounds as well as substrate for seaweed cultivation. Seagrasses are used as medicines and fertilizers and associated with different beliefs and values. Dema (basket trap) fishery showed clear links to seagrass beds and provided the highest gross income per capita of all economic activities. All showing that the meadows provide social-ecological resilience. Drag-net fishery seems to damage the meadows. Two ecological studies show that artisanal seaweed farming of red algae, mainly done by women and pictured as sustainable in the WIO, has a thinning effect on seagrass beds, reduces associated macrofauna, affects sediments, changes fish catch composition and reduces diversity. Furthermore, it has a negative effect on i.a. women’s health. The two last papers are institutional analyses of the human-seagrass relationship. A broad approach was used to analyze regulative, normative and cultural-cognitive institutions. Cooperation and conflict take place between different institutions, interacting with their slow or fast moving characteristics, and are thus fundamental in directing the system into sustainable/unsustainable paths. Ecological knowledge was heterogeneous and situated. Due to the abundance of resources and high internal control, the SES seems to be entangled in a rigidity trap with the risk of falling into a poverty trap. Regulations were found insufficient to understand SES dynamics. “Well” designed organizational structures for management were found insufficient for “good” institutional performance. The dynamics between individuals embedded in different social and cultural structures showed to be crucial. Bwana Dikos, monitoring officials, placed in villages or landing sites in Zanzibar experienced four dilemmas – kinship, loyalty, poverty and control – which decrease efficiency and affect resilience. Mismatches between institutions themselves, and between institutions and cognitive capacities were identified. Some important practical implications are the need to include seagrass meadows in management and educational plans, addressing a seascape perspective, livelihood diversification, subsistence value, impacts, social-ecological resilience, and a broad institutional approach.

In an increasingly complex, rapidly changing world, the capacity to cope with, adapt to, and shape change is vital. This thesis investigates how natural resource management can be organized and practiced to nurture this capacity, referred to as resilience, in social-ecological systems. Based on case studies and large-N data sets from UNESCO Biosphere Reserves (BRs) and the UN Millennium Ecosystem Assessment (MA), it analyzes actors and social processes involved in adaptive co-management on the ground. Papers I & II use Kristianstads Vattenrike BR to analyze the roles of local stewards and bridging organizations. Here, local stewards, e.g. farmers and bird watchers, provide on-site management, detailed, long-term monitoring, and local ecological knowledge, build public support for ecosystem management, and hold unique links to specialized networks. A bridging organization strengthens their initiatives. Building and drawing on multi-level networks, it gathers different types of ecological knowledge, builds moral, political, legal and financial support from institutions and organizations, and identifies windows of opportunity for projects. Paper III synthesizes the MA community-based assessments and points to the importance of bridging organizations, leadership and vision, knowledge networks, institutions nested across scales, enabling policies, and high motivation among actors for adaptive co-management. Paper IV explores learning processes catalyzed by bridging organizations in BRs. 79 of the 148 BRs analyzed bridge local and scientific knowledge in efforts to conserve biodiversity and foster sustainable development, provide learning platforms, support knowledge generation (research, monitoring and experimentation), and frame information and education to target groups. Paper V tests the effects of participation and adaptive co-management in BRs. Local participation is positively linked to local support, successful integration of conservation and development, and effectiveness in achieving developmental goals. Participation of scientists is linked to effectiveness in achieving ‘conventional’ conservation goals and policy-makers enhance the integration of conservation and development. Adaptive co-management, found in 46 BRs, is positively linked to self-evaluated effectiveness in achieving developmental goals, but not at the expense of conservation. The thesis concludes that adaptive collaboration and learning processes can nurture resilience in social-ecological systems. Such processes often need to be catalyzed, supported and protected to survive. Therefore, bridging organizations are crucial in adaptive co-management.

Cattle ranching in Vermilion Parish is a social-techno-ecological system (STES) that is currently vulnerable due to changing social, technological and ecological conditions. In addressing ways to increase the adaptive capacity of cattle ranching in Vermilion Parish, I used a multiple, mixed method approach grounded in a critical constructivist framework. Constructivism is the idea that our relationship to facts is constructed by our social context. It is these perceptions that shape people’s actions. By looking at these perceptions through an emancipatory frame I was able to understand multiple interpretations of meaning, consciously address them, consider how they may have shaped our actions, and then alter those meanings and power relationships. In an effort to increase the adaptive capacity of cattle ranching in Vermilion Parish, my research focused on actions, why people perform those actions, and how to change them. This research connected the physical landscape of the marshes, the individual landscape of perception, and the conceptual landscape of resilience. If resilience is the ability of a system (cattle ranching in vermilion parish) to recover after a disturbance, adaptive capacity is when the actors within the system can influence that system’s resilience. I explored the history of cattle ranching in Vermilion Parish from three different, but overlapping perspectives – environmental, social, and technological. These perspectives compliment the information from interviews and 3CM sessions. These 15 interviews revealed the perception of 11 types of threats facing cattle ranching in Vermilion Parish. The body of literature surrounding resilience theory identifies traits of highly adaptive systems. The recommendations and suggestions outlined in Chapter 6 exist at the intersection of the actors’ perception of specific threats and the decidedly generalized traits of highly adaptive systems. These suggestions were geared towards increasing the adaptive capacity of cattle ranching in Vermilion Parish. Given these layered landscapes and their complexity, my recommendations were subject to feedback loops and long periods of integration. These recommendations contribute to the theoretical foundation detailed in Chapter 3 by identifying specific ways that the actors of this particular system may be able increase their own adaptive capacity. / text

The approach of conceptualizing biodiversity and ecosystems as goods and services to be represented by monetary values in policy is being championed not just by economists, but also by ecologists and conservation biologists. This new environmental pragmatism is now being pushed forward internationally under the guise of hardwiring biodiversity and ecosystems services into finance. This conflicts with the realisation that biodiversity and ecosystems have multiple incommensurable values. The current trend is to narrowly define a set of instrumental aspects of ecosystems and biodiversity to be associated with ad hoc money numbers. We argue that ecosystem science has more to offer the policy debate than pseudo-economic numbers based on assumptions that do not reflect ecological or social complexity. Re-establishing the ecological discourse in biodiversity policy implies a crucial role for biophysical indicators as policy targets e.g., the Nature Index for Norway. Yet there is a recognisable need to go beyond the traditional ecological approach to create a social ecological economic discourse. This requires reviving and relating to a range of alternative ecologically informed discourses (e.g. intrinsic values, deep ecology, ecofeminism) in order to transform the increasingly dominant and destructive relationship of humans separated from and domineering over Nature. (author's abstract) / Series: SRE - Discussion Papers

Avoiding the negative effects of habitat fragmentation on biodiversity is especially challenging when also the management institutions are spatially and administratively distributed. This doctoral thesis introduces five case studies that investigate ecological, social and social-ecological relations in fragmented landscapes. I present new approaches in which research and governance can detect and manage mismatches between landscape ecology and planning. The case studies include urban and forested landscapes where an intense land-use is limiting the connectivity, i.e., the potential for many species to disperse between the remaining patches of habitat. Graph-theoretic (network) models are applied to map connectivity patterns and to estimate the outcome for dispersing species at the patch level and for the whole study system. In particular, the network models are applied to evaluate the spatial complexity and the potential mismatches between ecological connectivity and geographically distributed management institutions like protected areas and municipalities. Interviews with municipal ecologists complement the spatial analysis; revealing some problems and ways forward regarding the communication and integration of ecological knowledge within local spatial-planning agencies. The results also show that network models are useful to identify and communicate critical ecological and social-ecological patterns that call for management attention. I suggest some developments of network models as to include interactions between species and across governance levels. Finally, I conclude that more effort is needed for network models to materialize into ecological learning and transformation in management processes. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript.</p>

Study 1 - Individual - The purpose was to determine whether a 12-week behavioural risk reduction intervention caused self-reported MVPA to increase and to identify associated Theory of Planned Behaviour (TPB) constructs. Three hundred twenty-four physically inactive (<150 minutes/week moderate-vigorous PA) participants were included. Intervention participants were significantly more likely to meet PA guidelines at 12-weeks (OR=3.54, 95% CI 2.22-5.63, p<.001), which was significantly correlated with increases in TPB constructs. // Study 2 - Family - Semi-structured interviews were conducted with 36 participants to elicit perceptions of factors that influence PA. Interviews were audiotaped, transcribed, coded and analyzed. Spouses were more likely to engage in PA with their spouse after the CHD event; however this may be limited by their partners’ capabilities. The data suggests awareness of an increased susceptibility to CHD is not stimulating participants to increase their own PA to prevent future risk, particularly among offspring, but they may take other actions. The shared family environment can promote PA, although intensity may be limited. // Study 3 - Neighbourhood - Self-reported PA from a prospective behavioural risk reduction intervention was explored in the context of objectively measured Walk Scores and neighbourhood walkability in Ottawa, Canada. Participants in the intervention arm had significantly higher odds of meeting PA guidelines at 12-weeks compared to the standard care control group. This was not influenced by Walk Scores or walkability. This individual-level intervention was effective in assisting participants to overcome potential structural barriers presented by their neighbourhood to meet PA guidelines at 12-weeks.

Active school transport (AST; e.g. the use of non-motorized modes such as walking and cycling to travel to/from school) is an inexpensive, accessible and environmentally-friendly source of physical activity (PA). This dissertation addresses two overarching objectives: 1) to measure the relationships of AST with PA and health-related outcomes; and 2) to examine the correlates of AST immediately before and after the transition from primary to secondary school (the “school transition”). First, a systematic review revealed increasing evidence showing that AST is associated with greater daily PA levels, and that cycling to/from school is associated with higher cardiovascular fitness. Cycling for transportation (not only for school trips) was also associated with lower values for total cholesterol and total cholesterol/HDL cholesterol ratio in the nationally-representative 2007-2009 Canadian Health Measures Survey. Moreover, the present dissertation provides preliminary evidence suggesting that AST may help attenuate the decline in PA across the school transition. However, the relationship between AST and body composition indicators remains unclear. With respect to the correlates of AST, distance was the strongest barrier to AST at both time points, but several road safety concerns, and the perception of having too much stuff to carry were also associated with engagement in motorized travel. At follow-up, AST was more common in children whose parents owned less than 2 cars. In contrast, children were more likely to engage in AST if their parents reported that they chose to live in their current neighbourhood so that their children could walk or bike to school. The associations of neighbourhood walkability (as measured with the Walk Score® application) with AST and PA were generally stronger after the school transition. While AST may improve health among children and youth, an ecological approach targeting multiple levels of influence will likely be needed to alleviate current barriers to AST.