491 |
ECOLOGICAL IMPLICATIONS OF INTERNATIONAL PATENT REGIMES: A COMPARATIVE ANALYSIS OF LAWS AND CASES FROM THE UNITED STATES, INDIA, AND BRAZILLeary, Alyssa 26 June 2014 (has links)
Patents spur technological innovation; often, patented technologies have helped diminish the impact of some of the worlds most pressing concerns: from population growth, to world hunger, to global warming. A more contentious side of patents has emerged within the last several decades as more information is gathered on the sources and origins of biotechnological patents, evidencing misappropriation of traditional knowledge and resources, biopiracy. Biopiracy has been studied in detail for the social justice implications of wrongfully acquiring property of indigenous and traditional groups, but the literature is nearly void of the ecological implications of different patent regimes. International treaties and discussions have addressed the need to combat biopiracy and enable appropriate mechanisms of benefit sharing, but the implementation and success of laws and regulations guided by the treaties on a national level have been varied and inadequately quantified. This comment explores the international agreements governing intellectual property and access to natural resources, and examines how such agreements have been enacted in three countries: the United States, India, and Brazil. This comment then draws connections between the laws and policies of each country and their ecological environment. The goal of this comment is to draw attention to the direct ecological impact of patent laws in each country and the different national approaches to combat biopiracy. This comment will highlight the strengths and weaknesses of the variety of approaches and suggest ways to move forward with patent law and alternative mechanisms that are more conducive to balancing private property rights and technological innovation with biodiversity conservation and social justice.
|
492 |
Analyzing the error structure and simultaneous nature of multi-dimensional, density dependent growth models for ponderosa pineFurlaud, James 26 June 2014 (has links)
A precommercial thinning study for ponderosa pine (Pinus ponderosa) was initiated by the U.S. Forest Service, the Nez Perce Tribe, and the Spokane Tribe of Indians in 1997/98. The agencies ran plot inventories and measured tagged trees before thinning and then at 1, 3, and 5 years post-thinning. In 2011, at 13/14 years after the original thinning, the Inland Northwest Growth and Yield Cooperative returned to the site to re-measure the tagged trees. This dataset presented an opportunity to quantify the effect of precommercial thinning on ponderosa pine growth in the Inland Northwest, where the effects of this treatment have yet to be rigorously documented.
I used this dataset to build density dependent growth models in an attempt to quantify the precise effects of density management on three dimensions of individual tree growth. I first estimated these models using nonlinear least-squares. These models confirmed the results of previous precommercial thinning studies in other regions, that changing densities significantly impact diameter growth and crown dimensions at the individual tree level, and that density management does not significantly affect height. These models captured the mean trends in growth variation quite well, yet because the data exhibited heteroskedasticity and autocorrelation, nonlinear least-squares coeffi- cient estimates were inefficient, and coefficient standard error estimates were biased.
I therefore attempted to model the heteroskedasticity and autocorrelation of the data, and reestimated the coefficients, using generalized nonlinear least-squares. These models confirmed the existence of heteroskedasticity and autocorrelation in the data by parameterizing statistically significant parameters for these two conditions. Parame- terizing the covariance structure also resulted in a clarification of residual trends, which led to the addition of another explanatory variable to the basal area increment models. In the height increment and height to crown base models, parameterizing the variance did not appreciably alter the models descriptions of mean growth trends, within the context of my analyses.
Lastly, I performed parametric bootstrapping simulations to investigate the poten- tial for coefficient biases due to the simultaneous nature of the basal area growth, height growth, and height to crown base models. Simulated data were generated using six different error structures to investigate the consequences of ignoring contemporaneous cross-correlation. I found that ignoring a level of contemporaneous cross-correlation consistent with the empirical levels in this dataset did not result in substantial simul- taneity bias in the model coefficient estimates. However, if the level of contemporaneous cross-correlation between the height and basal area increment residuals was increased, the potential simultaneity bias grew substantial enough to result in meaningful changes in expected predictions.
|
493 |
Long-term effects of base cation fertilization on nutrient cycling and species composition of a sugar maple stand in southern Québec: application of the Rb/K reverse tracerMcMillan, Chloé January 2014 (has links)
To improve the understanding of the long-term effect of forest potassium (K)-fertilization, I revived a 23-year-old base cation fertilization experiment in a sugar maple stand in southern Quebec (45°59.6'N 73°59.9'W). My main objectives were to determine (i) the long-term percent of K derived from fertilizer in the soil-plant system using the rubidium (Rb)/K reverse tracer method, (ii) if fertilization had altered the diversity of the understory plant community, and (iii) if there was still an effect on the growth and nutrient status of the sugar maple trees. In 1988, six 40 m × 40 m plots were delineated in a sugar maple stand. In June 1989, three of these plots received 500, 250, and 250 kg•ha-1 of K2SO4, CaMg(CO3)2, and CaCO3, respectively as fine particulate matter, and the other three were left as control. Mid-canopy leaves of sugar maple trees were sampled annually in August from 1988 to 1991 and 2011 to 2012. In 2012, understory species were surveyed using the Braun-Blanquet method and ten of the most abundant and ubiquitous species were sampled for leaf chemistry. Leaves of both understory and canopy sugar maple trees were digested for nutrient concentrations using trace metal grade HNO3. In 2012, two soil pits were dug in each plot and individual horizons were sampled. Soil was extracted with 1 M NH4Cl. K, Ca, Mg, and Rb concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) for both digested and extracted samples. Growth of sugar maple trees was assessed using tree cores taken in 2012. Fertilization increased sugar maple leaf K two years following fertilization, but the effect was no longer detectable in 2011/2012. Only Ca and Mg showed increased concentrations in the leaves the fall of the year of fertilization. The percent of leaf K derived from fertilizer in 2011/12 is nearly what it was in the fall of 1989, two months after fertilization. There was no significant difference between control and fertilized plots in the concentration of K in the sapwood of the sugar maple trees, but there was 27 ± 2 % of K derived from fertilizer in the wood in 2012. There was no difference in relative growth of sugar maple, or understory vegetation diversity or species richness in fertilized plots. Nutrient analysis of understory vegetation showed no differences in concentrations of leaf K between treatments, but percent K from fertilizers amounted to over 25 % in several species. There was no effect of treatment on soil chemistry but there was a large proportion of the original fertilizer recovered in the soil profile. The total amount of K from fertilizer held in the soil-plant system was 54 kg•ha-1 or 24 % of the original 225 kg•ha-1 of fertilizer K applied. Overall, these results suggest: (i) a short-term improvement of K status following fertilization, (ii) efficient recycling of K fertilizer in the soil-plant system of maple forests, and (iii) no obvious long-term change in understory species composition following forest fertilization. / Pour améliorer notre compréhension de l'effet de la fertilisation en potassium (K) des forêts à long terme, nous avons remis en fonction une expérience de 23 ans de fertilisation en cations basiques dans un peuplement d'érable à sucre dans le sud du Québec (45°59.6'N 73°59.9'W). Nos objectifs étaient de déterminer (i) le pourcentage de potassium (K) provenant d'engrais dans le système sol-plante 23 ans après la fertilisation en utilisant méthode de traçage inverse du rubidium (Rb) / K, (ii) si la fertilisation a modifié la biodiversité de la communauté végétale des strates arbustives et herbacées, et (iii) s'il y avait encore un effet sur la croissance et l'état nutritionnel des érables à sucre.En 1988, six 40 x 40 m parcelles ont été délimitées dans un peuplement d'érable à sucre. En juin 1989, trois de ces parcelles ont reçu 500, 250 et 250 kg•ha- 1 de K2SO4, CaMg(CO3)2 et CaCO3, respectivement, sous forme de particules fines, et les trois autres parcelles n'ont pas été fertilisées (contrôle). Les feuilles en périphérie de la couronne d'érables à sucre ont été échantillonnées annuellement en août de 1988 à 1991 et 2011 à 2012. En 2012, les espèces du sous-étage ont été échantillonnés selon la méthode de Braun-Blanquet et dix espèces les plus communes ont été analysées pour la chimie des feuilles (digestion humide au HNO3). En 2012, deux pédons ont été creusés dans chaque parcelle et les horizons ont été échantillonnés jusqu'à une profondeur de 70 cm. Les sols ont été extraits au NH4Cl (1 M). Les concentrations de Rb, K, Ca, et Mg dans les feuilles et les sols ont été déterminées par spectrométrie de masse à plasma inductif (ICP-MS). La croissance des érables à sucre a été évaluée en utilisant des carottes d'arbres récoltées en 2012.La fertilisation a augmenté le K des feuilles d'érable à sucre deux ans après la fertilisation, mais l'effet n'était plus détectable en 2011/ 2012. Les concentrations en Ca et Mg ont augmenté à l'automne de l'année de la fertilisation. Le pourcentage du K foliaire provenant des engrais en 2011/12 est à peu près ce qu'il était à l'automne 1989. La fertilisation n'a pas augmenté la concentration de K de l'aubier des arbres d'érable à sucre, mais 27 ± 2% du K provenait des engrais en 2012. La croissance relative de l'érable à sucre, et la diversité et la richesse en espèces de la végétation du sous-étage dans les parcelles fertilisées n'ont pas été affectées par la fertilisation. L'analyse des éléments nutritifs de la végétation du sous-étage n'a montré aucune différence dans les concentrations en K des feuilles entre les traitements, mais le pourcentage en K dérivé des engrais s'élevaient à plus de 25% chez plusieurs espèces. Il n'y avait aucun effet du traitement sur la chimie du sol, mais il y avait une grande proportion de l'engrais récupéré dans le profil du sol. La masse totale de K dérivé des engrais dans le système sol-plante était de 54 kg•ha-1 ou 24 % des 225 kg•ha-1 d'engrais K appliqué. Ces résultats suggèrent: (i) une amélioration à court terme de la nutrition en K suivant la fertilisation, (ii) un recyclage efficace des engrais en K dans le système sol-plante de cette érablière, et (iii) aucun changement évident à long terme de la composition en espèces du sous-étage suivant la fertilisation du peuplement.
|
494 |
Problems and improvements in reindeer’s habitataskelund, sara January 2013 (has links)
No description available.
|
495 |
Understanding aspen in the James Bay area of Québec at multiple scalesWhitbeck, Kristen January 2014 (has links)
Understanding tree species distributions and dynamics in northern boreal forests is necessary for appropriate societal action and response to critical issues such as climate change, increased economic development of northern natural resources, and the collateral damage to cultures of indigenous communities. Northern tree species are expected to be sensitive to ongoing and anticipated climate change. Due to their remoteness and lack of a history of management-oriented research, information that is available for temperate areas, such as species distribution maps, soils, and climatology is often poorly quantified in the North. Consequently, our understanding of the factors controlling tree species northern distributional limits (NDL) and our ability to predict how future environmental change will affect their range distributions is limited. Moreover, very little attention has been devoted to understanding the dynamics of the few broadleaf tree species, such as trembling aspen, which are important components of northern boreal forest systems, from both an ecological and an economical perspective.This thesis was inspired by observations of aspen growing in uncharacteristic abundance near the extremes of its NDL in Quebec in conjunction with the pressing need to answer questions regarding how individual boreal tree species may respond to current and future environmental change. Here, I investigate the factors driving the variation in observable patterns of aspen distribution and abundance at regional and landscape scales in the James Bay area of northwestern Quebec, as well as the influence of a range of ecological conditions on aspen growth. The four specific objectives of this research were: (i) to map aspen's regional distribution and abundance using a combination of field, GIS, and remote sensing techniques, (ii) to determine how aspen height growth responds to change in environmental conditions across a broad latitudinal gradient from 46° to 54°N latitude, (iii) to determine the factors organizing vegetation community composition in and around aspen-dominated communities at the landscape scale, and (iv) to explore the influence of specific environmental factors on aspen abundance at the landscape scale near aspen's NDL.The key scientific merits of this thesis are: (i) creation of baseline data characterizing aspen's geographic range and associated land cover in northwestern Quebec to allow for more accurate comparative and quantitative studies now and in the future, (ii) development and application of a new method for rapid extraction of land cover classification data in remote areas, (iii) demonstration that the regional scale pattern of aspen occupancy in the James Bay area of QC appears influenced by anthropogenic driven disturbance, (iv) demonstration that aspen's NDL in QC is not predominately governed by harsh climate, thus highlighting the need for more in depth species specific research on determinants of range limits, and the subsequent factors most appropriate for use in predictive modelling of future tree species' distributions, and (v) demonstration that gradients related to soil moisture and soil fertility best characterize forest composition and structure at the landscape scale in the study area, while aspen abundance, in particular, is associated with soils high in K, and inland areas where fire events are more frequent than those on the coast. Together these tools and findings suggest that identifying and understanding species' distribution and abundance patterns is complex and a further grasp of change in species specific patterns across their entire ranges is necessary to make informed forest management decisions and predict future outcomes. / Une meilleure compréhension de la dynamique et de la répartition des espèces d'arbres en forêt boréale permettra d'intervenir socialement de façon plus appropriée face aux pressions exercées par les changements climatiques et par le développement accru du Nord, en plus de limiter les effets néfastes de ces pressions sur les communautés autochtones. Les espèces d'arbres nordiques peuvent s'avérer sensibles aux changements climatiques. Or, les données sur la répartition des espèces, la climatologie et les sols sont souvent manquantes en milieux nordiques étant donné l'isolement et le manque de recherche sur la gestion de ces milieux. En conséquence, notre compréhension des facteurs contrôlant les limites nordiques de répartition des espèces ligneuses et notre capacité à prédire les effets des changements environnementaux sur leurs aires de répartition sont limités. Les dynamiques des essences d'arbres feuillus tels que le peuplier faux-tremble ont été très peu étudiées malgré la très grande importance écologique et économique de ces espèces pour l'écosystème forestier boréal.Ce projet, initié suite à l'observation de quantités surprenantes de peupliers à la limite nordique de répartition de l'espèce au Québec, vise à améliorer les connaissances sur la réponse possible des espèces d'arbres boréales face aux changements environnementaux présents et futurs. J'étudie les facteurs contrôlant la répartition du peuplier dans la région de la Baie James du nord-ouest québécois et j'évalue l'influence d'un nombre de conditions écologiques sur la croissance du peuplier. Les objectifs de cette étude étaient de (i) cartographier, avec l'aide d'un SIG, la répartition et l'abondance régionale du peuplier en utilisant des données de terrain et de télédétection, (ii) déterminer de quelle façon la croissance du peuplier varie en fonction d'un large gradient de latitude (de 46° à 54°N), (iii) au niveau du paysage, déterminer les facteurs responsables de l'organisation et de la composition des communautés végétales dominées par le peuplier, et des communautés environnantes, (iv) explorer l'influence de facteurs environnementaux spécifiques au niveau du paysage sur l'abondance du peuplier près de la limite nordique de sa répartition. Les contributions scientifiques principales de cette thèse sont : (i) l'obtention de données sur la répartition géographique et la couverture terrestre du peuplier dans le nord-ouest du Québec qui pourront servir de base à des études comparatives et quantitatives plus précises, (ii) le développement et l'application d'une nouvelle méthode pour l'extraction rapide de classification de la couverture terrestre dans des régions éloignées, (iii) la démonstration que les patrons de répartition du peuplier à l'échelle régionale dans la région de la Baie James sont influencés par des perturbations anthropiques, (iv) la démonstration que la limite nord de répartition du peuplier au Québec n'est pas contrôlée principalement par le climat. Cette observation met en évidence le besoin d'effectuer des recherches plus approfondies sur les facteurs déterminant les limites de répartition, et d'évaluer lesquels permettront de prédire de façon précise la répartition future des espèces d'arbres, (v) la démonstration que les gradients liés à l'humidité et à la fertilité du sol caractérisent la composition et la structure de la forêt à l'échelle du paysage. De façon particulière, le peuplier est associé à des sols avec des teneurs élevées en potassium et à des sites éloignés des côtes où les feux sont moins fréquents. La mise en commun de ces outils et de ces résultats suggère que l'identification et la compréhension des patrons d'abondance et de répartition des espèces sont complexes. Plus de connaissances sur les patrons complets des aires de répartition spécifiques à chaque espèce sont nécessaires afin de prendre de meilleures décisions relatives à l'aménagement forestier et pour prédire les impacts futurs de ces décisions.
|
496 |
Roles of maladaptive behaviour and evolutionary traps in the decline of a threatened woodpeckerFrei, Barbara January 2014 (has links)
The Red-headed Woodpecker (Melanerpes erythrocephalus) is a widespread, once common but increasingly rare North American bird species. Consistent long-term population declines have resulted in the species' threatened status in Canada and several states in the United States. Throughout most of its range, Red-headed Woodpeckers occupy habitats that have been heavily influenced by human presence and activities. Yet, there is little research quantifying the potential drivers of the species' population decline, which constrains conservation or policy action. The overall objective of this research is to determine why the Red-headed Woodpecker, a once common, widespread species with apparently a high flexibility in habitat use is undergoing such large population declines. I hypothesize that rapid anthropogenic changes and ecological novelties are causing Red-headed Woodpecker fitness and its behavioural choices to have become disjointed. The specific objectives include: (1) to determine if Red-headed Woodpecker habitat use is adaptive or maladaptive, (2) to determine the influence of a non-native interference competitor, the European Starling (Sturnus vulgaris), on Red-headed Woodpecker breeding success, and (3) to compare the efficacy of global and local models of the relationships between Red-headed Woodpeckers and two possible competitor species over space and time, and explore local variations of these relationships. To test my hypothesis, I investigated Red-headed Woodpecker multi-scale habitat use and associations, and nest survival near the northern edge of the species range in southern Ontario, where populations are rapidly declining. In addition, I modelled interspecies abundance relationships across southern Canada and east-central United States using 45 years of survey data from the Breeding Bird Survey (BBS) for Red-headed Woodpeckers, European Starlings, and Red-bellied Woodpeckers (M. carolinus). Field-based results demonstrated that Red-headed Woodpeckers exhibit maladaptive habitat use at multiple scales, suggesting the potential for an ecological trap for the species. Specifically habitat characteristics that promoted feeding potential such as canopy openness and greater limb length were consistently associated with Red-headed Woodpecker occupancy from nest tree to woodlot scales, despite correlations with lower reproductive success. Further investigation into Red-headed Woodpecker nest survival by modelling a suite of abiotic, biotic, temporal, and habitat-based drivers showed that European Starling abundance near active woodpecker nest sites was the strongest factors influencing woodpecker nest survival. Logistic-exposure nest success assuming constant survival dropped significantly from 68% to 13% when starling abundance was considered. When interspecies abundance relationships were investigated at a larger spatial scale, they were found to be spatially structured, and suggested evidence for interspecific competition between Red-headed Woodpeckers and starlings, and niche differentiation between Red-headed and Red-bellied Woodpeckers. This research demonstrates the importance of multi-scale, multi-factor studies when determining threats for species-at-risk and will help in the development of conservation, management, and policy-making decisions for the species. / Le Pic à Tête Rouge (Melanerpes erythrocephalus) est une espèce d'oiseau répandue en Amérique du Nord, autrefois commune mais maintenant de plus en plus rare. Un déclin constant de la population dans les dernières décennies a mené l'espèce à être désignée menacée au Canada et dans plusieurs États américains. Dans la plupart de son aire de répartition, le Pic à Tête Rouge occupe des habitats fortement influencés par la présence et les activités humaines. Il y a cependant peu de recherche quantifiant les causes possibles du déclin de la population de l'espèce. Par conséquent, il manque d'information pour la conservation et l'action politique. L'objectif général de cette recherche est de déterminer pourquoi le Pic à Tête Rouge, une espèce autrefois commune et répandue avec une grande souplesse d'utilisation de l'habitat, connaît-il une diminution dramatique de ses populations. J'émets l'hypothèse que de rapides changements anthropiques et des nouveautés écologiques ont mené la valeur sélective et les choix comportementaux du Pic à Tête Rouge à être devenus disjoints. Les objectifs spécifiques incluent : (1) de déterminer si l'utilisation de l'habitat par le Pic à Tête Rouge est adaptatée ou mésadaptée, (2) de déterminer l'influence d'un compétiteur par interférence exotique, l'Étourneau Sansonnet (Sturnus vulgaris), sur le succès de reproduction du Pic à Tête Rouge, et (3) de comparer l'efficacité des modèles global et local du Pic à Tête Rouge versus deux compétiteurs potentiels pour l'espace et le temps, et explorer les variations locales des relations interspecifiques. Pour tester notre hypothèse, nous avons étudié l'utilisation et les associations multiéchelles de l'habitat du Pic à Tête Rouge, et la survie au nid près de la frontière nord de sa distribution dans le sud de l'Ontario, où les populations sont en rapide déclin. De plus, nous avons modélisé l'abondance interspécifique à travers le sud du Canada et le centre-est des États-Unis en utilisant 45 ans de données de recherche du Relevé des oiseaux nicheurs (BBS) pour le Pic à Tête Rouge et deux potentiels compétiteurs (Étourneau Sansonnet et Pic à Ventre Roux (M. carolinus). Des résultats basés sur la recherche sur le terrain ont démontré que le Pic à Tête Rouge présente une utilisation multiéchelles de l'habitat mésadaptée, ce qui suggère la possibilité d'un piège écologique pour l'espèce. De façon spécifique, les caractéristiques de l'habitat qui promouvaient le potentiel alimentaire tels que l'ouverture de la canopée et des membres plus longs étaient systématiquement associés à l'occupation de l'habitat à l'échelle de l'arbre du nid et du boisé par le Pic à Tête Rouge, malgré des corrélations avec un plus faible succès de reproduction. Une étude plus poussée de la survie au nid du Pic à Tête Rouge en modélisant une suite de pilotes abiotiques, biotiques, temporels et basés sur l'habitat a démontré que l'abondance de l'Étourneau Sansonnet près des sites de nids de pic actifs était le plus fort facteur influençant la survie au nid du pic. L'exposition logistique survie des nids en supposant une survie constante (68%) a chuté de façon significative lorsque l'abondance de l'Étourneau était considérée (13%). Lorsque les relations d'abondance interspécifiques ont été examinées à une plus grande échelle spatiale, elles se sont trouvées être structurées spatialement, et suggéraient une preuve de la compétition interspécifique entre le Pic à Tête Rouge et l'Étourneau et de la différentiation de niche entre les Pics à Tête Rouge et à Ventre Roux. Cette recherche démontre l'importance des études multiéchelles et à facteurs multiples lors de la détermination des menaces pour les espèces en péril, et aidera au développement de décisions relatives à la conservation, la gestion et l'élaboration des politiques pour cette espèce.
|
497 |
SECURING FOOD AND LIVELIHOODS: OPPORTUNITIES AND CONSTRAINTS TO SUSTAINABLY ENHANCING HOUSEHOLD FOOD PRODUCTION IN SANTA FAMILIA VILLAGE, BELIZELozada, Siobhan B. 03 June 2014 (has links)
Rural households play an active role in reorganizing their livelihood strategies to respond to external stresses and shocks. What is unclear is the extent to which rural households can remain resilient in the face of continued external stresses and how policy actions at larger scales can more effectively encourage rural food and livelihood sustainability. Economic and ecological stresses and shocks have negatively impacted livelihood security and wider economic stability in Belize. This has increased the number of people below the poverty line to 41.3 percent, who remain disproportionately located in rural areas. With a high degree of import dependency, global food price surges have resulted in direct pass through effects on domestic prices, creating food price inflation of up to 22.8 percent between 2006 and 2009. Within this context, this study assesses the state of livelihood security in a village of the Cayo district by assessing the quality of household capital assets, including human, financial, natural and social capital. Semi-structured face-to-face interviews were conducted in 2012 using a random sample of 64 households. Participant observation, key-informant interviews, the use of secondary sources and extra-local interviews with government officials were also employed to gain deeper insight into the complexity of the rural environment and institutional policies related to food security and sustainable agricultural development.
Results show high levels of livelihood diversification among both grain farmers and non-farming households. No significant difference existed between total household median incomes. However, the median income of non-grain male household heads is significantly greater than that of grain farmer male householders (U = 1393, n1 = 43, n2 = 16, p < .05). Part-time farming households maintained the highest number of livelihood strategies compared to non-grain households, with a median of 4 to 3 respectively (U = 506, n1 = 11, n2 = 48, p < .0005). Compared to non-farmers, part-time farmers are disproportionately engaged in day labor as a primary income strategy, where pay is lower and work is less reliable (Chi = 57, df = 1, p < .01). Human capital is low among both household types, with 65 percent of non-farming male householders receiving no education above the primary school level, while all grain farmers received no education above the primary school level (Chi = 59, df = 1, p < .01). Domestic and foreign remittances did not impact the majority of participants, as only 28 percent reported they received, or would receive, some amount of extra-household monetary support. Yet, the median value of out-country remittances were significantly greater for non-farmers compared to grain farmers (U = 21.00, n1 = 4, n2 = 3, p < .05). Despite these strategies, financial capital remains constrained, as over 75% of households are unable to save money, and the large majority of working females worked out of necessity. In addition, nearly two thirds of households have reduced meal size in recent years, with no significant difference between household types.
Nearly three quarters of all householders valued home gardens as a mode to adding diversity to the diet and improving health or reducing purchasing costs. Among grain farmers, 94 percent stated that grain farms provided their family with food, where 62.5 percent indicated risk management, specifically, as their reason for farming. This proportion rises to 83.3 percent when looking at white corn producers exclusively. When asked if farming has become more difficult, less difficult, or the same compared to the past, 62.5 percent of grain farmers stated that agriculture in Belize has become more difficult (Chi = 6.5, df = 2, p < .05). Biophysical constraints among both household types include vulnerability to waterlogging and drought, soil fertility and pest problems. Input costs are also of concern, while grain farmers faced additional transaction risk. Furthermore, land tenure insecurity is widespread. To compound the problem, social capital is also weak given disillusionment with formal organizing, where exclusionary policies by the local cooperative further restrict access to relevant low-cost and low-input technologies. Expanding access to sustainable technologies through participatory research and extension is recommended. However, greater access to technology alone is insufficient for sustaining intensification that can ensure resilient food and livelihood strategies. Reducing costs and risk through secure access to productive resources, markets, and financial services in a manner that accounts for heterogeneity in farming systems and local food security priorities are also essential. To this end, and with attention to national-level social and economic conditions, a pro-poor agricultural growth strategy is considered within a dynamic food sovereignty framework.
|
498 |
Escape probability: an alternative risk metric to support and evaluate wilderness fire management decisionsBarnett, Kevin Matthew 03 June 2014 (has links)
Inside many U.S. federally designated wilderness areas, fire suppression is the dominant management strategy largely due to the risk that fires pose to resources adjacent to the wilderness boundary. Opportunities to exploit the fuel treatment and risk-mitigation benefits of allowing wilderness fires to burn are foregone when ignitions are suppressed. Existing risk-based metrics (e.g. burn probability) produced from wildfire simulation models were not designed to inform management of wilderness fires. They focus on the management of fuels, or on suppression resource allocation, not managing ignitions through monitoring strategies for resource benefits. The purpose of this research was to develop a risk-based decision support metric to support wilderness fire management. The metric, escape probability, was developed using the Bob Marshall Wilderness Complex, Montana, USA, (BMWC) as the case study landscape, and applied to evaluate previous management decisions to suppress ignitions within the BMWC. The outputs from two wildfire simulation models, FARSITE (Finney, 1998) and FSim (Finney et al., 2011), were used to map escape probability for two different landscape scenarios in 2007: (1) an observed landscape reflecting fuel conditions as a result of actual wildfire management strategies; and (2) a treated landscape that reflects hypothetical fuels and vegetation assuming suppressed ignitions in 2007 had been allowed to burn. First, wildfire spread and behavior for suppressed ignitions in 2007 were retrospectively simulated using FARSITE. Hypothetical fuels layers were created for each retrospectively simulated fire by modifying the observed pre-fire fuels conditions within the simulated perimeter based on modeled burn severity. The observed and hypothetical fuels layers were then used as inputs in FSim, a large wildfire modeling system commonly used in quantitative wildfire risk analyses. Differences in the likelihood of future wilderness fire escape between the observed and treated landscape scenarios were examined for both inside the simulated area burned by the suppressed ignitions (i.e. the treated area) and the area within several kilometers of the simulated wildfire perimeters (i.e. the off-site effects). Results suggest that larger treated areas arising from ignitions closer to the wilderness boundary had the greatest effect on reducing the likelihood of wilderness fire escape within the treated area. The relationship between ignition location, fire size, and reduction in escape probability outside the treated area was variable. Fire and fuels managers can use escape probability information during strategic decision-making and pre-season planning to allow natural fires to burn absent of suppression, as well as to evaluate the effectiveness of different risk-mitigation strategies based on how the strategies affect future opportunities to allow natural ignitions to burn.
|
499 |
Effects of Disturbance on Tree Community Dynamics in Whitebark Pine EcosystemsAmberson, Jeremy Travis 03 June 2014 (has links)
Whitebark pine (Pinus albicaulis), a keystone species of high-elevation ecosystems of western North America, is warranted for listing under the Endangered Species Act due to the combined threats of fire exclusion, white pine blister rust (Cronartium ribicola), and increased pressure from insects due to climate warming. Despite widespread knowledge of the potential causes of the trees decline, there is limited understanding of its ecology, including successional dynamics in forests disturbed by white pine blister rust and mountain pine beetle. Specifically, there is a need for more information on successional replacement by subalpine fir and whitebark seedling regeneration dynamics. I assessed changes in forest composition and structure and seedling regeneration dynamics over a 22-year period (1990-2012) at 19 sites in the Cascade Mountains of Washington State (USA). Over the two decades analyzed, 26% of sites experienced wildfire, 58% were disturbed by mountain pine beetle, and 68% were infected by white pine blister rust. Only one of 19 sites showed no evidence of disturbance by these agents. Tree community composition changed significantly during the study period, primarily due to a significant decline in mature (≥20-cm DBH) whitebark pine . Despite loss of mature whitebark pine, I found little evidence of successional replacement by other tree species. I also found insignificant correlation between whitebark seedling density and basal area of mature whitebark pine. Seedling density was positively correlated with herb and shrub cover. These observed regeneration dynamics appear to contradict the conventional view that seedling establishment is contingent on local seed production and microsites free of competing vegetation. Additional, long-term studies are needed to comprehensively quantify the effects of novel disturbances on successional trajectories in whitebark pine ecosystems.
|
500 |
AN EMPRIRICAL TEST OF THE EFFECTIVENESS OF AN INDIRECT MANAGEMENT TOOL IN INCREASING OPTIONAL SHUTTLE USE AT GLACIER NATIONAL PARKWeinberg, Alex Benjamin 03 June 2014 (has links)
Glacier National Park instituted an optional, free shuttle system on the Going-to-the-Sun Road in 2007.It was recently discovered that the shuttle system was having an adverse impact on parking congestion at the Logan Pass parking lot. This was occurring because visitors were able to park at Logan Pass all day while they performed a looped hike from the Highline trailhead to the Loop trailhead. Upon completion of their hike, visitors would take the shuttle back to their vehicles. A variety of data suggests that the shuttle system may be inadvertently adding 40-60 day-long passenger vehicles to the Logan Pass parking area as a result of this phenomenon.
In order to alleviate management issues in protected areas, managers typically employ two types of management techniques: indirect or direct management. Direct management typically calls for placing direct constraints on visitor behavior while indirect management employs a more subtle approach which typically consists of persuasive messaging. Visitors typically prefer indirect management because it preserves a sense of freedom.
This study tested the effectiveness of indirect management in increasing optional shuttle use among St. Mary Campground and Rising Sun Campground occupants. It was surmised that if the technique was shown to be effective at increasing shuttle use among a target population it could be useful at alleviating the problem described above. The present study constructed a persuasive message that was guided by the theory of planned behavior, elaboration likelihood model of persuasion, research pertaining to alternative transportation in National Parks, and research pertaining to the effectiveness of indirect management in recreation settings.
Results suggested that the brochure was ineffective at increasing shuttle use and the researcher concludes by recommending that the park use a direct form of management to alleviate the problem described in this paper. Furthermore, contrary to suggestions provided in prior research, this study suggests that providing messages to increase shuttle use will not be effective at increasing optional shuttle ridership. The researcher suggests that if managers want to increase use on park shuttles they should first examine constraints, incentives and disincentives pertaining to shuttle use in order to understand the barriers concerning shuttle ridership.
|
Page generated in 0.0558 seconds