986 resultados para Ecological recovery


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The objective of this monitoring project was to determine the baseline condition for a 960-m long stream reach and its associated streamside zone, which terminates at the confluence with the Deschutes River. This stream reach had been damaged heavily in the February 1996 flood and had also received many years of overuse by livestock grazing. The monitoring project was conducted in July 1997 just after installation of riparian exclosure fencing. Future resurvey of the study area will allow determination of progress made in ecological recovery.

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本文从种群、群落、景观等水平研究了浑善达克沙地退化状况,发现浑善达克沙地生态系统退化严重。运用“以地养地”模式,建立自然保护地,能恢复浑善达克退化生态系统,同时能实现社区的经济发展。通过对自然保护区恢复潜力和可行性的分析,发现将“以地养地”模式推广到全旗,可实现全旗的可持续发展。运用自然保护区设计理论,对拟建自然保护区进行了设计,并对自然保护区-社区的区域可持续发展能力进行了分析,提出了可持续发展战略。有以下主要内容: 1)浑善达克沙地榆树疏林种群在人为干扰下处于衰退期。本研究表明,浑善达克沙地中部榆树疏林种群是一个数量处于下降的种群。中老龄龄级榆树较多,而年幼龄级榆树较少。种群静态生命表表明,幼苗库严重不足,种群进入中老龄期后,外界干扰(例如直接砍伐等)导致了个体较高的死亡量。按照一次平均推移法预测各龄级在未来20年、40年、60年及100年后的株数,老龄龄级株数将有所增加,而中幼年株数则下降。目前蓝旗榆种群中老年个体仍保持着比较旺盛生殖能力,应该充分利用这一特征,采取适度放牧、严禁超载过牧、严禁滥砍滥伐等措施,促进天然更新。 2)浑善达克沙地沙丘植物群落退化严重。浑善达克沙地中部典型固定沙丘调查表明,阴坡植物群落种类复杂,主要为耐阴乔木半乔木+灌木+柳灌丛类,群落较为稳定。阳坡主要以褐沙蒿、雾冰藜和虫实为主,种类组成较为简单,沙脊为沙蒿+半旱生杂草类,腰地形成木岩黄芪+半灌木半旱生杂草类。落沙地形成虫实+狗尾草优势群落,风蚀坑形成狗尾草+虫实+褐沙蒿优势群落。顶部则形成虫实单优势群落。固定沙丘退化严重,有活化的可能,需要加强保护,控制放牧强度。 3)浑善达克沙地榆树疏林在景观水平上破碎化严重。研究发现榆树疏林斑块在全旗分布不均匀,斑块集中分布于北部苏木。其中有20个嘎查所含疏林斑块面积较多,占该旗疏林斑块总面积的86%,是主要分布区。榆树疏林斑块密度较低,斑块边界割裂严重,斑块之间分离度高,大斑块较少,小斑块数量多。 4)建立保护区可恢复浑善达克退化生态系统。运用以地养地模式,将大部分退化沙地围封保护,进行自然恢复;在小面积土地上建立了高产高效饲料基地,以向上一营养级提供足够的能量。结果表明,牲畜的压力逐步向小范围的土地集中,而大面积的退化草地借助自然力逐步恢复。群落生物量、平均高度和总盖度2年后均显著增加。植被组成方面,优质牧草比例提高。生态恢复不仅使自然生态系统得以恢复,而且带动了社会经济的发展,项目中的正蓝旗巴音胡舒嘎查牧民,在实验示范以后,年人均收入提高了32%。在全旗自然保护区建成后,大量居民将从保护区内迁移到城镇中去,有利于提高城市化水平,有利于调整产业结构,对于当前逐渐发展的二、三产业有促进作用;同时,自然保护区面积扩大有利于城市人口增长,能为城市发展提供消费食物来源、水源保障、环境保障。 5)拟建自然保护区设计。按照景观规划理论、Diamond自然保护区设计原则,选择榆树疏林斑块集中分布区,作为潜在核心区,运用ArcGIS的缓冲区分析功能,设计不同的宽度。同时调查斑块外不同距离样方与疏林斑块的群落相似度。由此而初步确定的核心区分布在正蓝旗23个嘎查,面积1 531 km2,约占全旗总面积的15%。根据核心区边界的生态、经济社会发展等因素,以及保护核心区所需要的最小宽度、当地土地利用所能规划的最大宽度,确定了不同区域的缓冲区宽度。由此而确定的缓冲区面积为1140km2,占保护区总面积的11.2%。其他地区均设置为过渡区,面积为7514km2,占保护区总面积的73.8%。 6)浑善达克自然保护区-社区的可持续发展。按照区域可持续发展理论,对浑善达克自然保护区-社区的各个苏木、镇、牧场、示范区,按照环境、经济、社会三个子系统进行了综合评价。发现可以按照区域可持续发展原则将正蓝旗划分为四个区域、两条畜产品产业带,简称“四区两带”战略:北部景观保护区、西部生态功能恢复区,以自然保护和生态恢复为主;中部社会经济服务区,以经济社会发展为主,集中建设好三个小城镇,发展集约化畜牧业、生态旅游产业;南部低山丘陵农业区,以及沿国道、省道的畜产品产业带。

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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil

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Abandoned mine land cleanups are limited by restrictive regulations, inconsistent and unavailable funds, and a lack of adequate protections for stakeholders attempting to improve site conditions. This study evaluated examples of two cleanup mechanisms: an EPA-lead CERCLA cleanup and a state-lead, stakeholder-funded approach. The case studies showed that CERCLA provides the most comprehensive funding mechanism for abandoned mine cleanups while offering very little flexibility. State-lead programs allow for more flexibility, yet states are bound by federal laws and are hampered by lack of funding. Case analysis determined that any new approach should provide adequate funding, be flexible in its cleanup criteria, and minimize liability for those undertaking cleanups. It must also protect human health and promote natural ecological recovery.

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The goal of mangrove restoration projects should be to improve community structure and ecosystem function of degraded coastal landscapes. This requires the ability to forecast how mangrove structure and function will respond to prescribed changes in site conditions including hydrology, topography, and geophysical energies. There are global, regional, and local factors that can explain gradients of regulators (e.g., salinity, sulfides), resources (nutrients, light, water), and hydroperiod (frequency, duration of flooding) that collectively account for stressors that result in diverse patterns of mangrove properties across a variety of environmental settings. Simulation models of hydrology, nutrient biogeochemistry, and vegetation dynamics have been developed to forecast patterns in mangroves in the Florida Coastal Everglades. These models provide insight to mangrove response to specific restoration alternatives, testing causal mechanisms of system degradation. We propose that these models can also assist in selecting performance measures for monitoring programs that evaluate project effectiveness. This selection process in turn improves model development and calibration for forecasting mangrove response to restoration alternatives. Hydrologic performance measures include soil regulators, particularly soil salinity, surface topography of mangrove landscape, and hydroperiod, including both the frequency and duration of flooding. Estuarine performance measures should include salinity of the bay, tidal amplitude, and conditions of fresh water discharge (included in the salinity value). The most important performance measures from the mangrove biogeochemistry model should include soil resources (bulk density, total nitrogen, and phosphorus) and soil accretion. Mangrove ecology performance measures should include forest dimension analysis (transects and/or plots), sapling recruitment, leaf area index, and faunal relationships. Estuarine ecology performance measures should include the habitat function of mangroves, which can be evaluated with growth rate of key species, habitat suitability analysis, isotope abundance of indicator species, and bird census. The list of performance measures can be modified according to the model output that is used to define the scientific goals during the restoration planning process that reflect specific goals of the project.

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During recent decades anthropogenic activities have dramatically impacted the Black Sea ecosystem. High levels of riverine nutrient input during the 1970s and 1980s caused eutrophic conditions including intense algal blooms resulting in hypoxia and the subsequent collapse of benthic habitats on the northwestern shelf. Intense fishing pressure also depleted stocks of many apex predators, contributing to an increase in planktivorous fish that are now the focus of fishing efforts. Additionally, the Black Sea's ecosystem changed even further with the introduction of exotic species. Economic collapse of the surrounding socialist republics in the early 1990s resulted in decreased nutrient loading which has allowed the Black Sea ecosystem to start to recover, but under rapidly changing economic and political conditions, future recovery is uncertain. In this study we use a multidisciplinary approach to integrate information from socio-economic and ecological systems to model the effects of future development scenarios on the marine environment of the northwestern Black Sea shelf. The Driver–Pressure–State-Impact-Response framework was used to construct conceptual models, explicitly mapping impacts of socio-economic Drivers on the marine ecosystem. Bayesian belief networks (BBNs), a stochastic modelling technique, were used to quantify these causal relationships, operationalise models and assess the effects of alternative development paths on the Black Sea ecosystem. BBNs use probabilistic dependencies as a common metric, allowing the integration of quantitative and qualitative information. Under the Baseline Scenario, recovery of the Black Sea appears tenuous as the exploitation of environmental resources (agriculture, fishing and shipping) increases with continued economic development of post-Soviet countries. This results in the loss of wetlands through drainage and reclamation. Water transparency decreases as phytoplankton bloom and this deterioration in water quality leads to the degradation of coastal plant communities (Cystoseira, seagrass) and also Phyllophora habitat on the shelf. Decomposition of benthic plants results in hypoxia killing flora and fauna associated with these habitats. Ecological pressure from these factors along with constant levels of fishing activity results in target stocks remaining depleted. Of the four Alternative Scenarios, two show improvements on the Baseline ecosystem condition, with improved waste water treatment and reduced fishing pressure, while the other two show a worsening, due to increased natural resource exploitation leading to rapid reversal of any recent ecosystem recovery. From this we conclude that variations in economic policy have significant consequences for the health of the Black Sea, and ecosystem recovery is directly linked to social–economic choices.

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This study explores, from an ecological perspective, the relationship between perceived housing quality and the perception of choice, and between perceived choice and recovery of 45 Housing First Lisbon participants. For this purpose, we used a quantitative method and applied three instruments that report perceived housing quality, perceived choice and severe mental illness recovery. The findings reveal a significant and positive association between perceived housing quality and perceived choice, and between perceived choice and recovery, with choice being predicted by housing quality and recovery predicted by choice. These results reinforce the scientific evidence regarding the success of housing first models as a consumer choice-driven intervention, addressing pertinent environmental factors that contribute to housing stability. The study demonstrates that recovery processes can be maximized through services that empower their consumers by allowing them to choose and control the priority and order of the support services received.

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This paper analyzes effects of different practice task constraints on heart rate (HR) variability during 4v4 smallsided football games. Participants were sixteen football players divided into two age groups (U13, Mean age: 12.4±0.5 yrs; U15: 14.6±0.5). The task consisted of a 4v4 sub-phase without goalkeepers, on a 25x15 m field, of 15 minutes duration with an active recovery period of 6 minutes between each condition. We recorded players’ heart rates using heart rate monitors (Polar Team System, Polar Electro, Kempele, Finland) as scoring mode was manipulated (line goal: scoring by dribbling past an extended line; double goal: scoring in either of two lateral goals; and central goal: scoring only in one goal). Subsequently, %HR reserve was calculated with the Karvonen formula. We performed a time-series analysis of HR for each individual in each condition. Mean data for intra-participant variability showed that autocorrelation function was associated with more short-range dependence processes in the “line goal” condition, compared to other conditions, demonstrating that the “line goal” constraint induced more randomness in HR response. Relative to inter-individual variability, line goal constraints demonstrated lower %CV and %RMSD (U13: 9% and 19%; U15: 10% and 19%) compared with double goal (U13: 12% and 21%; U15: 12% and 21%) and central goal (U13: 14% and 24%; U15: 13% and 24%) task constraints, respectively. Results suggested that line goal constraints imposed more randomness on cardiovascular stimulation of each individual and lower inter-individual variability than double goal and central goal constraints.

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Land-change science emphasizes the intimate linkages between the human and environmental components of land management systems. Recent theoretical developments in drylands identify a small set of key principles that can guide the understanding of these linkages. Using these principles, a detailed study of seven major degradation episodes over the past century in Australian grazed rangelands was reanalyzed to show a common set of events: (i) good climatic and economic conditions for a period, leading to local and regional social responses of increasing stocking rates, setting the preconditions for rapid environmental collapse, followed by (ii) a major drought coupled with a fall in the market making destocking financially unattractive, further exacerbating the pressure on the environment; then (iii) permanent or temporary declines in grazing productivity, depending on follow-up seasons coupled again with market and social conditions. The analysis supports recent theoretical developments but shows that the establishment of environmental knowledge that is strictly local may be insufficient on its own for sustainable management. Learning systems based in a wider community are needed that combine local knowledge, formal research, and institutional support. It also illustrates how natural variability in the state of both ecological and social systems can interact to precipitate nonequilibrial change in each other, so that planning cannot be based only on average conditions. Indeed, it is this variability in both environment and social subsystems that hinders the local learning required to prevent collapse.

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This thesis by creative work explores relationships among human beings, the nonhuman natural world and language. It addresses the central research question: 'How can a novel embody a narrative of recovery from psychological trauma in which recovery is primarily a function of the character's subjective interaction with nature?' The novel, 'The Child Pose', tells the story of a woman's recovery from psychological trauma. The thesis draws on the psychoanalytic theory of Jacques Lacan, who saw the human subject as fundamentally split and alienated, and therefore inherently vulnerable to being destabilised by trauma. Situating the narrative of recovery within the emerging fields of ecocriticism and ecopsychology, the research constructs psychological recovery through interaction with nature as a transformation of subjectivity: the creation of a new, more stable and connected kind of subject, which Jordan (2012) has called 'the ecological subject'.

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Successful biodiversity conservation requires safeguarding viable populations of species. To work with this challenge Sweden has introduced a concept of Action Plans, which focus on the recovery of one or more species; while keeping in mind the philosophy of addressing ecosystems in a more comprehensive way, following the umbrella concept. In this paper we investigate the implementationprocess of the ActionPlanfor one umbrella species, the White-backed Woodpecker (WBW) Dendrocopos leucotos. We describe the plan's organisation and goals, and investigate its implementation and accomplishment of particular targets, based on interviewing and surveying the key actors. The achievement of the targets in 2005-2008 was on average much lower than planned, explained partially by the lack of knowledge/data, experienced workers, and administrative flexibility. Surprisingly, the perceived importance of particular conservation measures, the investment priority accorded to them, the money available and various practical obstacles all failed to kg? explain the target levels achieved. However qualitative data from both the interviews and the survey highlight possible implementation obstacles: competing interests with other conservation actions and the level of engagement of particular implementing actors. Therefore we suggest that for successful implementation of recovery plans, there is aneed for initial and inclusive scoping prior to embarking on the plan, where not only issues like ecological knowledge and practical resources are considered, but also possible conflicts and synergies with other conservation actions. An adaptive approach with regular review of the conservation process is essential, particularly in the case of such complex action plans as the one for the WBW.

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Instantaneous natural mortality rates and a nonparametric hunting mortality function are estimated from a multiple-year tagging experiment with arbitrary, time-dependent fishing or hunting mortality. Our theory allows animals to be tagged over a range of times in each year, and to take time to mix into the population. Animals are recovered by hunting or fishing, and death events from natural causes occur but are not observed. We combine a long-standing approach based on yearly totals, described by Brownie et al. (1985, Statistical Inference from Band Recovery Data: A Handbook, Second edition, United States Fish and Wildlife Service, Washington, Resource Publication, 156), with an exact-time-of-recovery approach originated by Hearn, Sandland and Hampton (1987, Journal du Conseil International pour l'Exploration de la Mer, 43, 107-117), who modeled times at liberty without regard to time of tagging. Our model allows for exact times of release and recovery, incomplete reporting of recoveries, and potential tag shedding. We apply our methods to data on the heavily exploited southern bluefin tuna (Thunnus maccoyii).

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This two-year study examined the impacts of feral pig diggings on five ecological indicators: seedling survival, surface litter, subsurface plant biomass, earthworm biomass and soil moisture content. Twelve recovery exclosures were established in two habitats (characterised by wet and dry soil moisture) by fencing off areas of previous pig diggings. A total of 0.59 ha was excluded from further pig diggings and compared with 1.18 ha of unfenced control areas. Overall, seedling numbers increased 7% within the protected exclosures and decreased 37% within the unprotected controls over the two-year study period. A significant temporal interaction was found in the dry habitat, with seedling survival increasing with increasing time of protection from diggings. Feral pig diggings had no significant effect on surface litter biomass, subsurface plant biomass, earthworm biomass or soil moisture content.

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This work will progess and extend recommendations and guidelines for use of integrated wet season spelling in Queenslands savannahs and woodlands. The research will generate a greater ecological and pasture production understanding of pastures and soils that exist in C land condition areas (major landtypes), and their recovery. Practical, cost-effective spelling regimes will be developed. Research will be conducted on-property with small plot exclosures and plots with controlled utilisation levels, examining ecological responses to different spelling regimes. This information will improve bio-economic modelling capacity. Industry consultations with producers and field staff will drive implementation of the recommendations arising.

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Fermentable components of municipal solid wastes (MSW) such as fruit and vegetable wastes (FVW), leaf litter, paddy straw, cane bagasse, cane trash and paper are generated in large quantities at various pockets of the city. These form potential feedstocks for decentralized biogas plants to be operated in the vicinity. We characterized the fermentation potential of six of the above MSW fractions for their suitability to be converted to biogas and anaerobic compost using the solid-state stratified bed (SSB) process in a laboratory study. FVW and leaf litter (papermulberry leaves) decomposed almost completely while paddy straw, sugarcane trash, sugarcane bagasse and photocopying paper decomposed to a lower extent. In the SSB process between 50-60% of the biological methane potential (BMP) could be realized. Observations revealed that the SSB process needs to be adapted differently for each of the feedstocks to obtain a higher gas recovery. Bagasse produced the largest fraction of anaerobic compost (fermentation residue) and has the potential for reuse in many ways.