• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 63
  • 58
  • 12
  • 7
  • 3
  • 1
  • Tagged with
  • 160
  • 160
  • 40
  • 38
  • 35
  • 34
  • 33
  • 17
  • 16
  • 14
  • 14
  • 13
  • 13
  • 13
  • 13
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

La restauration des cours d’eau urbains : regard critique d’un « modèle en circulation » : le cas du projet urbain des Vallées de la vie à Istanbul

Gaillet, Julie 11 1900 (has links)
La restauration écologique des cours d’eau en milieu urbain est pratiquée dans le monde entier (Morandi et al., 2021). Dans les milieux scientifiques et politiques, elle est présentée comme une solution globale associée à de nombreux bénéfices pouvant être appliquée dans divers endroits (Guimarães et al., 2021). Cette pratique peut dès lors être considérée comme l’un des « modèles en circulation » actuels dans le domaine de l’aménagement et de l’urbanisme (Roy, 2011). Pourtant, ce « modèle » promu à l’échelle internationale ne tient pas compte du caractère spécifique des différents contextes urbains, sociaux et politiques dans lesquels il est traduit. En adoptant une vision instrumentale des « modèles en circulation » et en privilégiant une entrée par le territoire et par les acteurs, cette recherche tente de comprendre les modalités de réception à l'échelle locale d’un modèle circulant et de ses effets sur les pratiques locales d’aménagement. En nous penchant sur l’étude de cas d’Istanbul, nous avons effectué une recherche de terrain et mené plusieurs entretiens avec les acteurs locaux pour répondre à cet objectif. Les résultats de l’analyse ont montré que les modalités de l’appropriation à l'échelle locale d’un « modèle circulant » sont bien plus complexes et nuancées que ce qu’un modèle peut contenir, compte tenu des différentes dynamiques et forces à l’oeuvre sur un territoire donné. / Ecological restoration of urban rivers is being practiced all over the world (Morandi et al., 2021). In the scientific and policy literature, it is presented as a global solution associated with many benefits, which can be applied in various locations (Guimarães et al., 2021). This practice can therefore be considered as one of the current “circulating models” in the field of planning and urban studies (Roy, 2011). However, this “model” promoted internationally does not consider the specific character of the different urban, social, and political contexts in which it is applied. By adopting an instrumental vision of “circulating models” and by privileging an entry through the territory and the actors, this research attempts to understand the modalities of reception at the local level of a circulating model and its effects on local planning practices. Based on the case study of Istanbul, we have conducted field research and several interviews with local actors to meet this objective. The results of the analysis showed that the modalities of local appropriation of a 'circulating model' are much more complex and nuanced than what a model can contain, given the different dynamics and forces at work in a given territory.
152

To do or not to do : dealing with the dilemma of intervention in Swedish nature conservation

Steinwall, Anders January 2016 (has links)
Nature conservation is often seen as being primarily about shielding parts of nature from human intervention, e.g. by protecting areas. Over the last decades, however, intervention is increasingly being seen as necessary for nature to regain or retain its values, through ecological restoration and active management. This complicates simple assumptions that ‘nature knows best’ and raises dilemmas which are hotly debated in the scholarly literature around ecological restoration, protected area management, environmental ethics and green political theory. However, how these dilemmas are dealt with in actual policy struggles among the conservation professionals who make management decisions is less studied. This thesis explores how issues regarding active intervention in nature are represented, debated and institutionalized within Swedish nature conservation, and to what effect. The empirical focus lies on policy struggles around the designation and management of protected forests and around efforts to save a nationally threatened bird species, the white-backed woodpecker. My analytical framework is informed by Argumentative Discourse Analysis and Political Discourse Theory, to which I contribute a further elaboration of the notion of discourse institutionalization. Based on documents and interviews with conservation professionals, I identify competing articulations of the ends and means of conservation and relate these to scholarly debates around ecological restoration and interventionist conservation management. The analysis further focuses on how elements of the different policy discourses are institutionalized in rules, routines or official policy documents. Two main competing policy discourses are found: one focused on leaving pristine nature to develop freely, and one focused on active, adaptive management for biodiversity. While the former has previously been said to characterize the Swedish conservation bureaucracy, my analysis shows it is now widely seen as outdated. Arguments which in the scholarly literature are associated with an ethically informed defense of nature’s autonomy are here dismissed as emotional, aesthetic and thus unscientific concerns, delegitimizing them within the rational, science-based public administration for nature conservation. In contrast, biodiversity is broadly forwarded as a self-evident goal for active intervention, in line with both science and policy requirements. Adaptive management for biodiversity is in that sense the dominant discourse. Still, the older discourse is institutionalized in the purposes and management plans of existing nature reserves, and its defenders have also succeeded in strengthening that institutionalization through new and more restrictive guidelines. The findings suggest that this has been possible not only because of the gate-keeping role of a few centrally placed actors, but also because their restrictive stance resonates with the outside threat of exploitation which organizes the common order of discourse. Naturalness, a term described as irrelevant by some proponents of adaptive management for biodiversity, is also shown to remain a shared concern in several ways. The results thus highlight the importance of both entrenched common sense and institutionalization of certain logics or arguments in authoritative documents. The main theoretical contribution of the thesis consists in clarifying the effects of such discourse institutionalization — using the terms durability, legibility and leverage — and showing how the processes of negotiation, re-interpretation and modification of institutions are more dynamic than some accounts of discourse institutionalization suggest. Rather than trying to resolve (and thus remove) the dilemma of intervention, the thesis points to the importance of keeping open discussion of the ultimately unanswerable questions about intervention in nature alive in both theory and practice. / Ecosystem restoration in policy and practice: restore, develop, adapt (RESTORE)
153

Restorative urban design: toward a design method for mitigating human impacts on the natural environment through urban re/development

Toros, Tulu January 1900 (has links)
Doctor of Philosophy / Department of Environmental Design & Planning Program / Lee R. Skabelund / The Restorative Urban Design (RUD) calls for a new urban design and planning approach targeting environmentally responsible re/development of urbanized areas through ecologically responsive impact mitigations. If implemented in a systematic manner, such re/developments can help move urban areas toward the successful restoration of the natural environment of which they are an inseparable part. The RUD model advocates more rigorous assessment and mitigation of urban impacts by carefully evaluating the environmental performance of urban re/developments within five primary dimensions: Atmosphere (emissions, pollutants, ozone depletion); Hydrosphere (stormwater, domestic water, wastewater); Lithosphere (land use, land cover, food and wastes); Ecology (habitat resilience, biodiversity, population and resources); and Energy (renewability, reduction and efficiency, transportation). The model relies on a scenario-comparison process in order to evaluate and optimize the performance of urban re/development projections through four critical scenarios, which are respectively: 1) Natural Baseline (NBASE); 2) Historic Progression (HPROG); 3) Trajectory Forecast (TFORE); and 4) Restorative Projection (RPROJ). The RUD Case Study illustrates how the principles and strategies of Restorative Urban Design can be applied specifically to a typical (densely developed) urban area, namely River North District in Chicago Metropolitan Area. The case study focuses exclusively on mitigation of a single critical human impact on the natural environment: Anthropogenic CO₂ Emissions. The case study focuses on the design assumptions by which the restorative urban re/development scenarios might exceed beyond the full mitigation of emissions into the global remediation by 2040. The restorative projections illustrate that only a certain portion of emissions can be effectively mitigated onsite (5 to 55%), and that the remainder of projected emissions (45 to 95%) need to be mitigated offsite in order to achieve the necessary sequestration and storage. The restorative research suggests that the mitigation of major human impacts on the natural environment – not only CO₂ emissions but also other major impacts – are likely to require significant urban transformations. Moving beyond the strategies of preservation and/or conservation, the restorative approach asserts that comprehensive environmental restoration is achievable if urban impacts are adequately estimated and then entirely mitigated onsite as well as offsite through a systematic process of urban re/development.
154

[fr] IMPACT DE L INTENSIFICATION DES BOVINS DANS LES MUNICIPALITÉS AYANT DES BIOMES DU CERRADO ET DE L AMAZONIE / [en] IMPACT OF BEEF CATTLE INTENSIFICATION IN MUNICIPALITIES WITH CERRADO AND AMAZON BIOMES / [pt] IMPACTO DA INTENSIFICAÇÃO DA PECUÁRIA DE CORTE NOS MUNICÍPIOS COM BIOMAS CERRADO E AMAZÔNIA

GUSTAVO ABREU MALAGUTI 05 May 2022 (has links)
[pt] O processo de ocupação humana no território brasileiro tem provocado, há séculos, profundas alterações no meio ambiente. Desde os primeiros habitantes, a natureza tem sofrido alguma mudança no seu formato, em algum grau de escala. Se os povos tradicionais nativos possuem uma preocupação em conciliar a relação homem-meio ambiente, a invasão europeia inverteu toda essa lógica. Dos processos primitivos até o uso da mecanização moderna, o Brasil pós-1500 mostrou a força humana sobre a natureza e seus consequentes impactos. Apesar dos esforços maiores ou menores, das denúncias propaladas desde do período colonial, avança-se a destruição de ecossistemas de suma importância local e global. Diante desse cenário, o país possui biomas com enorme perigo de perdas irreversíveis se nada for feito. Neste contexto, esta tese tem como objetivo entender essas transformações com olhares histórico, geográfico e econômico, culminando numa análise quantitativa do uso da terra de 2004 a 2019 focada nos municípios dos dois principais biomas brasileiros ameaçados, Cerrado e Amazônia. Por meio de diferentes instrumentos da econometria espacial cujos princípios são as primeiras leis da Geografia, se pretende identificar os fatores que modificaram o uso da terra no período citado e propor medidas para atenuar o impacto do principal vetor de desmatamento direto nos biomas citados: a pecuária. Por meio dessa análise, pretende-se avaliar como a intensificação da bovinocultura de corte altera as emissões, a configuração do uso da terra, pode auxiliar no cumprimento da Lei de Proteção da Vegetação Nativa e gerar ganhos econômicos dentro de uma área com mais de 1.700 municípios. O objetivo final é determinar qual a melhor política de intensificação da atividade de pecuária de corte considerando o trade-off meio ambiente e economia. A escolha permitirá que o país consiga oferecer aos consumidores domésticos e internacionais uma atividade mais sustentável com minimização do impacto ambiental gerado e receitas majoradas. Com isso, a tese mostra que as alterações no uso da terra em quatro diferentes classes – agricultura, pecuária, floresta e outros usos – são fenômenos locais cujo somatório tem um impacto global relevante. Os resultados reforçam a importância de políticas públicas ambientais e agrícolas e observarem as diferenças entre os municípios em sua formulação e implementação. Há, para o Brasil, um imenso potencial tanto de ampliar a área florestal com a intensificação e de restaurar grandes áreas liberadas com o incremento do sistema produtivo de carne bovina. Assim, o país tem nas suas mãos uma chance ímpar de ter uma pecuária sustentável econômica e ambientalmente com uma política governamental que considere a diversidade local. / [en] The process of human occupation in Brazilian territory has caused profound changes in the environment for centuries. Since the first inhabitants, nature has undergone some change in its shape, to some degree of scale. If native traditional peoples have a concern to reconcile the man-environment relationship, the European invasion has reversed all this logic. From primitive processes to the use of modern mechanization, post-1500 Brazil showed human strength under nature and its consequent impacts. Despite the major or minor efforts, the denunciations proposed since the colonial period, the destruction of ecosystems of great local and global importance is advanced. Given this scenario, the country has biomes with enormous danger of irreversible losses if nothing is done. In this context, this thesis aims to understand these transformations in historical, geographical, and economic views, culminating in a quantitative analysis of land use from 2004 to 2019 focused on the municipalities of the two main threatened Brazilian biomes, Cerrado and Amazon. Through different instruments of spatial econometrics whose principles are the first laws of geography, it is intended to identify the factors that modified land use in the period mentioned and propose measures to mitigate the impact of the main vector of direct deforestation in the biomes mentioned: livestock. Through this analysis, it is intended to evaluate how the intensification of beef cattle culture alters emissions, the configuration of land use, can assist in complying with the Native Vegetation Protection Law and generates economic gains within an area with more than 1,700 municipalities. The goal is to determine the best policy of intensification of beef livestock activity considering the trade-off environment and economy. The choice will allow the country to be able to offer domestic and international consumers a more sustainable activity with minimization of the environmental impact generated and increased revenues. Considering all these facts, the thesis shows that changes in land use in four different classes – agriculture, livestock, forest, and other uses – are local phenomena whose sum has a relevant global impact. The results reinforce the importance of environmental and agricultural public policies and the observer in the differences between the municipalities in their formulation and implementation. For Brazil, there is an immense potential for both expanding the forest area with intensification and restoring large areas released with the increase of the beef production system. The country has in its hands a unique chance to have a sustainable livestock economically and environmentally with a government policy that considers local diversity. / [fr] Le processus d occupation humaine sur le territoire brésilien a provoqué de profonds changements dans l environnement pendant des siècles. Depuis les premiers habitants, la nature a subi quelques changements dans sa forme, à un certain degré d échelle. Si les peuples autochtones traditionnels ont le souci de concilier la relation hommeenvironnement, l invasion européenne a inversé toute cette logique. Des processus primitifs à l utilisation de la mécanisation moderne, le Brésil post-1500 a montré la force humaine sous la nature et ses impacts conséquents. Malgré les efforts majeurs ou mineurs, les dénonciations proposées depuis la période coloniale, la destruction d écosystèmes d une grande importance locale et mondiale progresse. Compte tenu de ce scénario, le pays a des biomes avec un énorme danger de pertes irréversibles si rien n est fait. Dans ce contexte, cette thèse vise à comprendre ces transformations avec des vues historiques, géographiques et économiques aboutissant à une analyse quantitative de l utilisation des terres de 2004 à 2019 des municipalités des deux principaux biomes brésiliens menacés, le Cerrado et l Amazonie. A travers de différents instruments d économétrie spatiale dont les principes sont les premières lois de la géographie, il est prévu d identifier les facteurs qui ont modifié l utilisation des terres dans la période mentionnée et de proposer des mesures pour atténuer l impact du principal vecteur de déforestation directe dans les biomes mentionnés : l élevage. Grâce à cette analyse, il est prévu d évaluer comment l intensification de la culture des bovins modifie les émissions, la configuration de l utilisation des terres, peut aider à se conformer à la Loi sur la protection de la végétation native et générer des gains économiques dans une zone comptant plus de 1.700 municipalités. L objectif est de déterminer la meilleure politique d intensification de l activité du bétail en tenant compte de l environnement et de l économie compromis. Ce choix permettra au pays d être en mesure d offrir aux consommateurs domestiques et internationaux une activité plus durable avec une minimisation de l impact environnemental généré et une augmentation des revenus. Avec cela, la thèse montre que les changements dans l utilisation des terres dans quatre classes différentes – l agriculture, l élevage, la forêt et d autres utilisations – sont des phénomènes locaux dont la somme a un impact mondial pertinent. Les résultats renforcent l importance des politiques publiques environnementales et agricoles et regardent les différences entre les municipalités. Pour le Brésil, il existe un immense potentiel à la fois pour l expansion de la zone forestière avec l intensification et la restauration de grandes zones libérées avec l augmentation du système de production de bœuf. Le pays a entre ses mains une chance unique d avoir un élevage durable économique et écologiquement avec une politique gouvernementale qui prend en compte la diversité locale.
155

Restoration of Black Oak (<i>Quercus velutina</i>) Sand Barrens via three different habitat management approaches

Kriska, David J. 03 October 2017 (has links)
No description available.
156

Quels facteurs limitent l’installation de Brachypodium retusum : une espèces clé pour la restauration écologique des steppes méditerranéennes ? / Which factors limit the etablishement of brachypodium retusum : a key species in ecological restoration of Mediterranean steppes ?

Vidaller, Christel 14 December 2018 (has links)
Le brachypode rameux (Brachypodium retusum) est une espèce herbacée pérenne qui domine les pelouses sèches de Méditerranée occidentale. Dans notre zone d’étude du Sud de la France, la recolonisation spontanée est très faible après perturbation du sol. Cette observation ne correspond pas aux résultats d'études menées dans d'autres régions montrant une capacité de colonisation élevée. L'objectif principal de cette thèse était donc de tester les différentes hypothèses pouvant expliquer les différents patrons de colonisation.Dans un premier chapitre, nous avons testé si ces différents patrons de colonisation résultent d'une différenciation génétique entre les populations. Des marqueurs AFLP ont été utilisés pour analyser la structure génétique de 17 populations de Méditerranée occidentale dont la différenciation neutre entre populations. Dans un sous-échantillon de 13 populations françaises, la différenciation de traits phénotypiques sous sélection a été testée dans un jardin commun et comparée à la différenciation neutre. Dans le deuxième chapitre, nous présentons une étude sur la différenciation adaptative des traits phénotypiques et avons testé une potentielle réponse différentielle à la manipulation de facteurs environnementaux clés. Les deux derniers chapitres de la thèse ont analysé les facteurs environnementaux qui limitent la recolonisation in situ, indépendamment du génotype ou de la population. Dans le troisième chapitre, nous avons testé l’effet du pâturage et du feu sur le recouvrement végétatif ainsi que sur la reproduction sexuée de B. retusum installé. Enfin, dans le quatrième chapitre, nous avons mesuré l’effet de l’arrosage initial et du pâturage sur l’installation de plantules transplantées initialement germées en serre et de plantules issues de semis in situ. Nos résultats ont montré que les populations de B. retusum sont génétiquement différenciées pour les marqueurs neutres mais également pour les traits phénotypiques. Cette différenciation est supérieure à la dérive seule et suggère une adaptation aux conditions environnementales, en particulier aux températures estivales et à la fréquence du gel en hiver. Une réponse différentielle à la manipulation expérimentale de facteurs environnementaux (sol, pâturage, humidité du sol) a confirmé le caractère adaptatif de la différenciation génétique. Les expériences in situ ont montré que le feu a un effet positif sur la reproduction de B. retusum et sur la communauté végétale associée, alors que son recouvrement végétatif n’était pas supérieur à la moyenne de la communauté. L'exclusion du pâturage pendant deux saisons n'a eu d'incidence sur aucun des paramètres mesurés chez les populations adultes. L'arrosage initial a affecté l’installation des plantules au cours de la première saison. Au cours de la deuxième saison, l'effet seul de l’arrosage n'était pas significatif, cependant son effet est resté positif sur la survie uniquement dans les parcelles pâturées. Le pâturage, au début du cycle de vie de B. retusum, a eu un effet négatif sur le recrutement et la croissance des plantules. En conclusion, la différenciation adaptative entre les populations peut avoir contribué aux différences régionales en termes de capacité de colonisation et doit être prise en compte lors du ciblage des populations sources pour l'introduction de plantes en restauration écologique. La réponse positive de B. retusum a indiqué que le feu était une force sélective importante dans le passé qui pourrait être utilisée pour favoriser l'espèce et la communauté végétale associée dans des opérations de conservation et de restauration. L'exclusion du pâturage à court terme est tolérée par les populations adultes de B. retusum, mais l'abandon à long terme entraîne une diminution de son recouvrement par rapport aux graminées pérennes à croissance rapide. / Ramose false brome (Brachypodium retusum) is a perennial herbaceous species that dominates dry grasslands of the Western Mediterranean. In our southern French study area, spontaneous re-colonisation is very low after soil disturbance. This observation does not correspond to the results of studies from other regions showing a high colonisation capacity. The major objective of this PhD thesis was to test different hypotheses potentially explaining the different colonisation patterns.In the first chapter, we tested whether these different colonisation patterns are the result of genetic differentiation among populations. AFLP markers were used to analyse genetic structure including neutral population differentiation in 17 Western Mediterranean populations. In a sub-sample of 13 French populations, differentiation in phenotypic traits under selection was tested in a common garden and compared to neutral differentiation. In the second chapter, we present a study on adaptive differentiation in phenotypic traits testing a potentially differential response to the manipulation of key environmental factors. The last two chapters of the PhD analysed environmental factors that limit re-colonisation in the field independent of genotype or population. In the third chapter, we tested the effect of grazing and fire on vegetative recovery as well as on sexual reproduction of established B. retusum and in the fourth chapter we measured the effect of initial watering and grazing on the establishment of transplanted seedlings pre-grown in a greenhouse and of field-sown seedlings.Our results showed that populations of B. retusum are genetically differentiated in neutral markers but also in phenotypic traits. This differentiation is superior to drift alone and suggests adaptation to environmental conditions, particularly to summer temperature and winter frost frequency. A differential response to experimental manipulation of environmental factors (soil, pasture, soil moisture) confirmed the adaptive character of genetic differentiation. The field experiments showed that fire has a positive effect on B. retusum reproduction and on the associated community whereas vegetative recovery was not higher than community average. Two seasons of grazing exclosure did not affect any of the measured parameters in adult populations. Initial watering affected seedling establishment in the first season. In the second season, the watering main effect was not significant but interestingly the effect remained positive on survival in grazed plots whereas no such effect was observed in exclosures. Grazing in early life cycle stages of B. retusum had a negative effect on seedling recruitment and growth.In conclusion, adaptive differentiation between populations may have contributed to regional differences in colonisation capacity and needs to be taken into account in targeting source populations for plant introduction in ecological restoration. The positive response of B. retusum indicated that fire was an important selective force in the past which may be used to favour the species and its associated plant community in current conservation and restoration management. Short-term grazing exclosure is tolerated by mature B. retusum populations but long-term abandonment results in a decrease of cover relative to high-growing perennial grasses. In early stages of seedling establishment grazing should be avoided to guarantee introduction success - or grazing stress needs to be compensated by watering.
157

Counting on their migration home: an examination of monitoring protocols and Saanich First Nations’ perspectives of Coho (Oncorhynchus kisutch), Chinook (O. tshawytscha) and Chum (O. keta) Pacific Salmon at Goldstream River and Saanich Inlet, Southern Vancouver Island, British Columbia

Paul, Roxanne 20 August 2007 (has links)
Records of abundance of salmon that return to their natal spawning stream (escapements) are important indices that can assist with monitoring, conservation, and management of a salmon population over time. On their own, however these data reveal very little about the habitat, ecosystem and human communities that salmon encounter on their journey from freshwater to sea and back again. This research examines monitoring protocols for Goldstream River salmon stocks (coho, chinook and chum Pacific salmon). It includes and reaches beyond biostatistics from stream surveys to gauge First Nations’ artisanal fishing activities at Goldstream River and Saanich Inlet as well as their commercial chum fishing endeavours in Saanich Inlet on south Vancouver Island, British Columbia. Methods included summations of major themes from interviews on traditional ecological knowledge (TEK) shared by local Saanich First Nation fishers whose families have lived in the communities around Goldstream River and Saanich Inlet for more than 200 years. Analyses of Goldstream salmon escapements for the period 1932 to 2004 and native harvest statistics of chum caught from Saanich Inlet between 1982 and 2004 are integrated with results from analysis of TEK research undertaken for this project. Key recommendations arising from the results of this research are: stream habitat restoration in response to loss and degradation of salmon-bearing streams; modification of stream survey procedures to measure for morphological and physiological attributes including indicators of the health of Goldstream salmon; monitoring and eliminating sources of pollution to Saanich Inlet waters; implementing precautionary measures to ensure that overfishing of Goldstream salmon and shrimp in Saanich Inlet does not recur; and safeguarding naturally abundant Goldstream chum populations at the river. Under current management of the Goldstream chum fishery, the maximum carrying capacity (K) or target escapement of chum that the Goldstream River spawning grounds sustain is 15,000. Based on population assessments as well as physiography and ecosystem dynamics, I infer that Goldstream River’s K for its natural chum population is between ~16,000 and 18,000; ~1,500 for the mixed stocks of natural and hatchery enhanced coho; and ~50 for chinook (based on the river’s naturally occurring populations between 1932 and 1973) or ~385 enhanced chinook (based on the returning population from 1975 to 2002 since hatchery enhancement took place). A co-management relationship exists between Fisheries and Oceans Canada (DFO) resource managers and the Saanich First Nations bands (Saanich Tribal Fisheries councilors). Improvements to communication, collaboration and information sharing between DFO resource managers, Goldstream hatchery operators and Saanich First Nations with regards to decisions made about Goldstream salmon stocks are, however, necessary. In this thesis, I propose a model with recommendations for compatible fisheries management goals and techniques including adaptive management and ecosystem-based management to address this problem.
158

Counting on their migration home: an examination of monitoring protocols and Saanich First Nations’ perspectives of Coho (Oncorhynchus kisutch), Chinook (O. tshawytscha) and Chum (O. keta) Pacific Salmon at Goldstream River and Saanich Inlet, Southern Vancouver Island, British Columbia

Paul, Roxanne 20 August 2007 (has links)
Records of abundance of salmon that return to their natal spawning stream (escapements) are important indices that can assist with monitoring, conservation, and management of a salmon population over time. On their own, however these data reveal very little about the habitat, ecosystem and human communities that salmon encounter on their journey from freshwater to sea and back again. This research examines monitoring protocols for Goldstream River salmon stocks (coho, chinook and chum Pacific salmon). It includes and reaches beyond biostatistics from stream surveys to gauge First Nations’ artisanal fishing activities at Goldstream River and Saanich Inlet as well as their commercial chum fishing endeavours in Saanich Inlet on south Vancouver Island, British Columbia. Methods included summations of major themes from interviews on traditional ecological knowledge (TEK) shared by local Saanich First Nation fishers whose families have lived in the communities around Goldstream River and Saanich Inlet for more than 200 years. Analyses of Goldstream salmon escapements for the period 1932 to 2004 and native harvest statistics of chum caught from Saanich Inlet between 1982 and 2004 are integrated with results from analysis of TEK research undertaken for this project. Key recommendations arising from the results of this research are: stream habitat restoration in response to loss and degradation of salmon-bearing streams; modification of stream survey procedures to measure for morphological and physiological attributes including indicators of the health of Goldstream salmon; monitoring and eliminating sources of pollution to Saanich Inlet waters; implementing precautionary measures to ensure that overfishing of Goldstream salmon and shrimp in Saanich Inlet does not recur; and safeguarding naturally abundant Goldstream chum populations at the river. Under current management of the Goldstream chum fishery, the maximum carrying capacity (K) or target escapement of chum that the Goldstream River spawning grounds sustain is 15,000. Based on population assessments as well as physiography and ecosystem dynamics, I infer that Goldstream River’s K for its natural chum population is between ~16,000 and 18,000; ~1,500 for the mixed stocks of natural and hatchery enhanced coho; and ~50 for chinook (based on the river’s naturally occurring populations between 1932 and 1973) or ~385 enhanced chinook (based on the returning population from 1975 to 2002 since hatchery enhancement took place). A co-management relationship exists between Fisheries and Oceans Canada (DFO) resource managers and the Saanich First Nations bands (Saanich Tribal Fisheries councilors). Improvements to communication, collaboration and information sharing between DFO resource managers, Goldstream hatchery operators and Saanich First Nations with regards to decisions made about Goldstream salmon stocks are, however, necessary. In this thesis, I propose a model with recommendations for compatible fisheries management goals and techniques including adaptive management and ecosystem-based management to address this problem.
159

Le principe de solidarité écologique / The principle of ecological solidarity

Danna, Charlotte 07 September 2018 (has links)
Adopté par l’article 2 de la loi n°2016-1087 de reconquête de la biodiversité, de la nature et des paysages du 8 aout 2016, le principe de solidarité écologique appelle « à prendre en compte, dans toute prise de décision publique ayant une incidence notable sur l’environnement des territoires concernés, les interactions des écosystèmes, des êtres vivants et des milieux naturels ou aménagés ». Ce principe général du droit de l’environnement inscrit à l’article L110-1 du code de l’environnement est destiné à conserver les interactions écosystémiques et les processus écologiques ainsi qu’à améliorer la gestion environnementale des territoires. La dualité de son objet en fait un principe d’une grande richesse, qui devrait concerner de nombreuses décisions. Divers fondements supranationaux, au sein de la jurisprudence et dans les textes internationaux et européens peuvent ainsi lui être attribués. Dans un contexte d’interdépendance écologique, l’évolution de la dimension internationale et européenne du principe reste essentielle pour juger de ses effets au regard de la conservation de la biodiversité. Au niveau du droit interne, son ancrage au cœur de l’équilibre de l’environnement lui apporte un rayonnement particulier. Il conforte le droit à un environnement équilibré et prolonge les principes constitutionnels de prévention et de développement durable. Face à la crise d’extinction mondiale de la biodiversité menaçant notre survie, le principe de solidarité écologique se présente comme cette ultime chance de la conserver. Deux grands ensembles de dispositifs permettent de mesurer la dynamique du principe de solidarité écologique : la trame verte et bleue et la gestion intégrée de la mer et du littoral. Ils constituent une base pour concevoir la solidarité écologique et représentent ainsi le commencement d’un droit nouveau. Le principe de solidarité écologique appelle à les renforcer et, de manière plus générale, à faire évoluer l’ensemble des décisions concernées par le principe. / Adopted by article 2 from act nr 2016-1087 concerning the reconquest of biodiversity, nature and landscape of August 8th 2016, the principle of ecological solidarity calls “for taking into consideration the interactions of ecosystems, living creatures and natural or developed environments in all public decisions having a notable impact on the environment of the territories concerned”.This general principle of environmental law inscribed in article L110 1 of the environmental code is designed to preserve the interactions of ecosystems and ecological processes as well as to improve the environmental management of the territories. The duality of its objective renders it a highly valuable principle which should be applied to numerous decisions. Various supranational foundations, within jurisprudence and in international and European laws, can thus be assigned to it. In the context of ecological interdependence the evolution of the international and European dimension of the principle remains essential in order to see the benefits concerning the safeguarding of biodiversity. It is greatly enhanced, as regards internal law, by the fact that it is at the very center of the environment's equilibrium. It justifies the right to a balanced environment and extends the constitutional principles of prevention and sustainable development. Confronted with the crisis of world-wide biodiversity extinction that threatens our survival, the principle of ecological solidarity emerges as the last chance to preserve it. Two major groups of systems allow us to measure the dynamics of the principle of ecological solidarity: the green and the blue line belt network and the Ocean and coastline Governance Framework. They constitute a basis on which to develop ecological solidarity and represent the beginnings of new legislation. The principle of ecological solidarity requires them to be reinforced and more generally to advance all decisions concerned by the principle.
160

Multispectral imaging of Sphagnum canopies: measuring the spectral response of three indicator species to a fluctuating water table at Burns Bog

Elves, Andrew 02 May 2022 (has links)
Northern Canadian peatlands contain vast deposits of carbon. It is with growing urgency that we seek a better understanding of their assimilative capacity. Assimilative capacity and peat accumulation in raised bogs are linked to primary productivity of resident Sphagnum species. Understanding moisture-mediated photosynthesis of Sphagnum spp. is central to understanding peat production rates. The relationship between depth to water table fluctuation and spectral reflectance of Sphagnum moss was investigated using multispectral imaging at a recovering raised bog on the southwest coast of British Columbia, Canada. Burns Bog is a temperate oceanic ombrotrophic bog. Three ecohydrological indicator species of moss were chosen for monitoring: S. capillifolium, S. papillosum, and S. cuspidatum. Three spectral vegetation indices (SVIs) were used to characterize Sphagnum productivity: the normalized difference vegetation index 660, the chlorophyll index, and the photochemical reflectance index. In terms of spectral sensitivity and the appropriateness of SVIs to species and field setting, we found better performance for the normalized difference vegetation index 660 in the discrimination of moisture mediated species-specific reflectance signals. The role that spatiotemporal scale and spectral mixing can have on reflectance signal fidelity was tested. We were specifically interested in the relationship between changes in the local water table and Sphagnum reflectance response, and whether shifting between close spatial scales can affect the statistical strength of this relationship. We found a loss of statistical significance when shifting from the species-specific cm2 scale to the spectrally mixed dm2 scale. This spatiospectral uncoupling of the moisture mediated reflectance signal has implications for the accuracy and reliability of upscaling from plot based measurements. In terms of species-specific moisture mediated reflectance signals, we were able to effectively discriminate between the three indicator species of Sphagnum along the hummock-to-hollow gradient. We were also able to confirm Sphagnum productivity and growth outside of the vascular growing season, establishing clear patterns of reflectance correlated with changes in the local moisture regime. The strongest relationships for moisture mediated Sphagnum productivity were found in the hummock forming species S. capillifolium. Each indicator Sphagnum spp. of peat has distinct functional traits adapted to its preferred position along the ecohydrological gradient. We also discovered moisture mediated and species-specific reflectance phenologies. These phenospectral characteristics of Sphagnum can inform future monitoring work, including the creation of a regionally specific phenospectral library. It’s recommended that further close scale multispectral monitoring be carried out incorporating more species of moss, as well as invasive and upland species of concern. Pervasive vascular reflectance bias in remote sensing products has implications for the reliability of peatland modelling. Avoiding vascular bias, targeted spectral monitoring of Sphagnum indicator species provides a more reliable measure for the modelling of peatland productivity and carbon assimilation estimates. / Graduate

Page generated in 0.2012 seconds