Forestry Best Management Practices (BMPs) include guidelines, recommendations, and protocols utilized to protect forest water quality from nonpoint source pollutants (NPSP). Sediment is the most common NPSP associated with forest operations, and BMPs are implemented primarily to reduce erosion and potential sediment delivery to streams. Skid trails, stream crossings, forest roads, decks, and harvest areas are major forest operational features that have the potential to erode and deliver sediment to streams. These five features are also common BMP categories evaluated by states across the southeastern U.S. Although BMPs are designed to minimize erosion and sediment delivery, the exact relationship between BMP implementation rates, erosion rates, and potential sediment delivery is largely unexamined. Specifically, the inherently intuitive but unverified concept that increasing levels of BMP implementation decreases erosion and sediment delivery associated with forest harvesting. This hypothesis was tested in this project at five operational features located within three physiographic regions, including the Mountains, Piedmont, and Coastal Plain, across clearcut harvest sites in the southeastern U.S. First, BMP implementation rates, audit questionnaires, and state guidelines were compared across 13 states in the southeastern region at 116 clearcut harvest sites. Overall, BMPs were implemented at an average rate of 90.1% in the southeastern United States, thus demonstrating that BMPs are currently being implemented consistently at high levels throughout the region. Across all regions, average BMP implementation rates were highest at harvest areas (95.6%), followed by decks (92.7%), haul roads (91.9%), stream crossings (88.2%), and skid trails (82.9%). Average BMP implementation rates for Mountain stream crossings (83.9%) and skid trails (76.1%) were significantly lower than rates calculated in the Piedmont and Coastal Plain, and had the lowest implementation rate for any feature in any region. These findings indicate that skid trails and stream crossings, especially in the Mountains, may benefit the most from enhanced BMP implementation and resources. In the second manuscript, the relationship between BMP implementation, estimated erosion, and potential sediment delivery were examined in three regions of Virginia and North Carolina. This study is one of the only forestry studies that have presented sediment delivery ratios by operational feature and physiographic region. BMP implementation rates and sediment delivery ratios were poorly correlated, however, a significant inverse relationship existed between BMP implementation and the total sediment mass delivered to streams (Spearman ρ = -0.2206, p-value = 0.0027). Generally, as BMP implementation increased, erosion rates and the amount of sediment delivered to streams also decreased. Additionally, this study demonstrated that most of the erosion generated by clearcutting operations in the southeast is trapped in either the harvest area or in Streamside Management Zones (SMZs) prior to reaching the stream. In the third manuscript, BMP implementation rates and erosion estimates were categorized into three BMP levels (BMP−, BMP-standard, BMP+) which represent low, moderate, and high levels of BMP implementation, respectively. Skid trails and haul roads generally had the highest erosion estimates, regardless of BMP level and physiographic region. Non-parametric correlation analyses indicated that significant inverse relationships existed between BMP implementation rates and erosion estimates at skid trails (Spearman ρ = -0.589, p-value < 0.0001), haul roads (Spearman ρ = -0.388, p-value < 0.0001), and harvest areas (Spearman ρ = -0.2305, p-value = 0.0169), while decks and stream crossings were more poorly correlated with erosion estimates. This reinforces the need for BMP audit questions that specifically address ground cover and bare soil, water control structures, gradients, and stabilization to better address potential erosion and sedimentation. Clearcut areas, erosion and sediment estimates, and sediment removal efficiencies were presented for the Mountains, Middle/Lower Coastal Plain, and Piedmont/Upper Coastal Plain for the fourth, fifth, and sixth manuscripts, respectively. Regardless of BMP level and physiographic region, a combination of harvest areas, skid trails, and haul roads were responsible for over 95% of potential sediment delivery. Increasing site-wide BMP implementation from BMP− to BMP+ could reduce sediment delivery by 70% in all physiographic regions. High levels of BMP implementation were most effective at reducing potential erosion and sediment delivery from skid trails and haul roads throughout the southeast. Findings from these studies demonstrate that current BMPs are highly effective at mitigating sediment. In the southeastern U.S., increasing levels of BMP implementation effectively reduce both potential erosion and sedimentation associated with forest harvesting. Generally, both estimated erosion and sedimentation associated with clearcutting in the region is much lower than rates associated with other land uses such as development or agriculture, especially when BMPs are implemented at standard or high levels. However, several opportunities exist to improve the effectiveness of BMPs in the southeastern U.S. Skid trails, haul roads, and stream crossings consistently had the lowest BMP implementation rates and highest estimated erosion rates and sediment delivery ratios. While these features only represent a small proportion of total clearcut area in the southeast, they are responsible for a disproportionate amount of sediment delivery and should receive more attention and resources during the pre-harvest planning and closure processes. Conclusively, this project addresses several knowledge gaps pertaining to water quality impacts resulting from harvesting operations in the southeastern U.S. For instance, this is only the third project that has presented sediment delivery ratios associated with forest operations in the southeastern U.S., and the first to do so for the Mountains and Coastal Plain regions. On average, SMZs and harvest areas trap 66-96% of sediment on-site before it can be deposited into streams. Additionally, this project provides one of the first and most comprehensive regional comparisons of state BMP manuals, audits, and programs in-field using a third-party approach. Several significant differences existed among state BMP programs and protocol, and states may need to design specific BMP guidelines and audit protocol for major physiographic regions to address the challenges and variation of on-site conditions inherent of each region. Additionally, this project presents one of the only regional-scale estimates of sediment and efficiencies of increased levels of BMP implementation at mitigating sediment associated with forest operations in the southeastern U.S. Conclusively, this project provides forest managers, state and federal agencies, and policymakers with a robust assessment on the effectiveness of forestry BMPs in the southeast. / Doctor of Philosophy / Forestry Best Management Practices (BMPs) are used throughout the southeastern U.S. to minimize the impacts that harvesting has on soil and water resources. Eroded soil that is eventually deposited into streams as sediment is the most important pollutant that BMPs address in forestry. Common BMP guidelines utilized to minimize sediment include leaving riparian buffers along streams, providing ground cover, minimizing slopes on roads, and using water control structures to divert runoff from road systems. The exact relationship between forestry BMPs, erosion, and sediment delivery is largely unexamined. Objectively, this study was designed to provide a better understanding of this relationship, and to present estimates of erosion and sediment delivery resulting from clearcut harvesting on over 100 harvest sites across 13 states with diverse conditions and topography in the southeastern U.S. Forestry BMPs are being implemented at an average rate of 90.1% across the southeast. BMPs are implemented at higher rates in the Coastal Plain, followed by the Piedmont and Mountains. Generally, harvest areas had the highest BMP implementation rates, followed by decks, haul roads, stream crossings, and skid trails, respectively. This relationship was consistent across most regions and states. Logging decks, which are areas where wood was transported for processing and loading onto logging trucks, were generally located distantly from streams and followed most state-approved BMPs. Whereas skid trails, which are low-standard temporary roads trafficked during primary transport and require water diversion structures such as waterbars, occupied a much larger area and were generally located on much steeper slopes. Mountain skid trails leading to stream crossings are concerning because of their low BMP implementation rates and high erosion potential. These features would greatly benefit from increased ground cover and water control structures. Forestry BMPs reduce both erosion and sedimentation associated with clearcutting. The highest level of BMP implementation reduces potential sediment by over 70% in all regions, and the highest BMP level is most effective at reducing sediment from skid trails and forest roads. Average sedimentation rates, especially at the highest BMP level, calculated for Mountains, Piedmont, and Coastal Plain clearcuts are considerably lower than sedimentation rates associated with agricultural and developmental land uses. Clearcut forestland, which is generally the most erodible time period during a forest's cycle, only makes up 1-2% of total forestland in the southeast annually. Both erosion and sedimentation rates should decrease further in the years following harvesting as the site revegetates and trees begin to reestablish. This study verifies that BMPs are highly effective at reducing erosion and sediment while subsequently providing estimates of erosion and sediment delivery based on ranges of BMP implementation that state forestry agencies can use to better quantify the effectiveness of their BMPs.

Climate change impacts hydrology, nutrient cycling, agricultural conservation practices, and greenhouse gas (GHG) emissions. The Chesapeake Bay and its watershed are subject to the largest and most expensive Total Maximum Daily Load (TMDL) ever developed. It is unclear if the TMDL can be met given climate change and variability (e.g., extreme weather events). The objective of this dissertation is to quantify the impact of climate change and climate on water resources, nutrient cycling and export in agroecosystems, and agricultural conservation practices in the Chesapeake Bay watershed. This is accomplished by developing and employing a suite of modelling tools. GHG emissions from agroecosystems, particularly nitrous oxide (N2O), are an increasing concern. To quantify N2O emissions a routine was developed for the Soil and Water Assessment Tool (SWAT) model. The new routine predicts N2O and di-nitrogen (N2) emissions by coupling the C and N cycles with soil moisture, temperature, and pH in SWAT. The model uses reduction functions to predict total denitrification (N2 + N2O production) and partitions N2 from N2O using a ratio method. The SWAT nitrification routine was modified to predict N2O emissions using reduction functions. The new model was tested using GRACEnet data at University Park, Pennsylvania, and West Lafayette, Indiana. Results showed strong correlations between plot measurements of N2O flux and the model predictions for both test sites and suggest that N2O emissions are particularly sensitive to soil pH and soil N, and moderately sensitive to soil temperature/moisture and total soil C levels. The new GHG model was then used to analyze the impact of climate change and extreme weather conditions on the denitrification rate, N2O emissions, and nutrient cycling/export in the 7.4 km2 WE38 watershed in Pennsylvania. Climate change impacts hydrology and nutrient cycling by changing soil moisture, stoichiometric nutrient ratios, and soil temperature, potentially complicating mitigation measures. To quantify the impact of climate change we forced the new GHG model with downscaled and bias-corrected regional climate model output and derived climate anomalies to assess their impact on hydrology, nitrate (NO3-), phosphorus (P), and sediment export, and on emissions of N2O and N2. Model-average (± standard deviation) results indicate that climate change, through an increase in precipitation, will result in moderate increases in winter/spring flow (2.7±10.6 %) and NO3- export (3.0±7.3 %), substantial increases in dissolved P (DP, 8.8±19.8 %), total P (TP, 4.5±11.7 %), and sediment (17.9±14.2 %) export, and greater N2O (63.3±50.8 %) and N2 (17.6±20.7 %) emissions. Conversely, decreases in summer flow (-12.4±26.7 %) and the export of P (-11.4±27.4 %), TP (-7.9±24.5 %), sediment (-4.1±21.4 %), and NO3- (-12.2±31.4 %) are driven by greater evapotranspiration from increasing summer temperatures. Increases in N2O (20.1±29.3 %) and decreases in N2 (-13.0±14.6 %) are also predicted in the summer and driven by increases in soil moisture and temperature. In an effort to assess the impact of climate change at a regional level, the model was then scaled-up to the entire Susquehanna River basin and was used to evaluate if agricultural best management practices (BMPs) can offset the impact of climate change. Agricultural BMPs are increasingly and widely employed to reduce diffuse nutrient pollution. Climate change can complicate the development, implementation, and efficiency of BMPs by altering hydrology, nutrient cycling, and erosion. We select and evaluate four common BMPs (buffer strips, strip crop, no-till, and tile drainage) to test their response to climate change. We force the calibrated model with six downscaled global climate models (GCMs) for a historic period (1990-2014) and two future scenario periods (2041-2065) and (2075-2099) and quantify the impact of climate change on hydrology, NO3-, total N (TN), DP, TP, and sediment export with and without BMPs. We also tested prioritizing BMP installation on the 30% of agricultural lands that generate the most runoff (e.g., critical source areas-CSAs). Compared against the historical baseline and excluding the impact of BMPs, the ensemble model mean (± standard deviation?) predictions indicate that climate change results in annual increases in flow (4.5±7.3%), surface runoff (3.5±6.1%), sediment export (28.5±18.2%) and TN (9.5±5.1%), but decreases in NO3- (12±12.8%), DP (14±11.5%), and TP (2.5±7.4%) export. When agricultural BMPs are simulated most do not appreciably change the overall water balance; however, tile drainage and strip crop decrease surface runoff generation and the export of sediment, DP, and TP, while buffer strips reduced N export substantially. Installing BMPs on critical source areas (CSAs) results in nearly the same level of performance for most practices and most pollutants. These results suggest that climate change will influence the performance of BMPs and that targeting BMPs to CSAs can provide nearly the same level of water quality impact as more widespread adoption. Finally, recognizing that all of these model applications have considerable uncertainty associated with their predictions, we develop and employ a Bayesian multi-model ensemble to evaluate structural model prediction uncertainty. The reliability of watershed models in a management context depends largely on associated uncertainties. Our Objective is to quantify structural uncertainty for predictions of flow, sediment, TN, and TP predictions using three models: the SWAT-Variable Source Area model (SWAT-VSA), the standard SWAT model (SWAT-ST), and the Chesapeake Bay watershed model (CBP-model). We initialize each of the models using weather, soil, and land use data and analyze outputs of flow, sediment, TN, and TP for the Susquehanna River basin at the Conowingo Dam in Conowingo, Maryland. Using these three models we fit Bayesian Generalized Non - Linear Multilevel Models (BGMM) for flow, sediment, TN, and TP and obtain estimated outputs with 95% confidence intervals. We compare the BGMM results against the individual model results and straight model averaging (SMA) results using a split time period analysis (training period and testing period) to assess the BGMM in a predictive fashion. The BGMM provided better predictions of flow, sediment, TN, and TP compared to individual models and the SMA during the training period. However, during the testing period the BGMM was not always the best predictor; in fact, there was no clear best model during the testing period. Perhaps more importantly, the BGMM provides estimates of prediction uncertainty, which can enhance decision making and improve watershed management by providing a risk-based assessment of outcomes. / Ph. D.

For over 30 years, federal and state governments have been engaged in a collective effort to improve the water quality and living resources in the Chesapeake Bay (CB), focusing particularly on reducing delivered nitrogen and phosphorus loads. However, achievement of water quality objectives remains elusive. In Virginia, agriculture represents the single largest source of nutrient loads to the Chesapeake Bay. Despite aggressive regulatory efforts in other nutrient source sectors, state authorities rely on educational programs and voluntary financial assistance programs to induce landowners to adopt best management practices (BMPs) that reduce agricultural nutrient loads. This study explores two economic aspects of efforts to reduce agricultural nonpoint source (NPS) pollution in the Virginia portion of the CB watershed. Firstly, current and possible future transactions costs associated with specific aspects of agricultural NPS participation in water quality trading (WQT) programs are examined in Chapter 1. A case study approach is used to consider the possible cost consequences of expanding the use of NPS credits from agricultural 'working lands' BMPs in Virginia. Findings indicate that overall transactions costs for nutrient trades involving agricultural NPS in Virginia are currently relatively low, due to the type of activities being credited: simple land conversions. Based on best available evidence, the administrative transactions costs of creating credits on agricultural 'working lands' using management and structural BMPs will be 2 to 5 times more costly on a per project basis than for credits generated from land conversions. Compliance monitoring protocols were found to be a significant driver of costs for credits generated from working agricultural lands. These results suggest an important cost/risk tradeoff between verification cost and compliance certainty for program designers to consider. The second study (Chapter 2) considers the economic cost of meeting pollution reduction targets for the Virginia portion of the CB Watershed. Existing cost models are based on simplifying behavioral assumptions about public transactions costs, conservation adoption rates, and implementation costs of agricultural BMPs. This study builds on the existing literature and uses the estimates of transactions costs from Chapter 1 together with information on producer BMP adoption rates to examine the implications of including transactions costs and differential BMP costs and adoption rates when estimating the minimum costs of achieving specified nutrient reduction goals in Virginia. The paper uses a cost-minimizing mathematical programming approach and models a number of different cost scenarios. Results indicate that inclusion of transactions costs substantially affects estimates of total costs of meeting nutrient reduction goals; on average total costs increased by 44 percent, but ranged between 19 and 81 percent depending on the scenario analyzed. Analysis of the modelled scenarios shows that those BMPs that account for the most implementation costs do not necessarily account for the most transactions costs (and vice versa). This suggests that transactions costs should be acknowledged to vary with the type of practices being implemented, rather than being approximated as either a fixed amount or a fixed proportion of implementation costs. In addition, the analysis highlights the disproportionate costs associated with achieving nutrient reductions via high-cost adopters, and suggests there may be a role for education or extension to assist landholders to lower opportunity costs of participating in conservation. / Master of Science

Stream crossings are an integral component of forest road systems that provide access for timber harvesting and silvicultural activities. Stream crossings and their associated approaches are often the most critical point of concern for water quality along forest roads. Several types of crossings are used for extracting timber, but limited studies actually compare different types of stream crossings with regard to their effect on water quality. The objectives of this study were to examine four different stream crossing structures: 1) steel bridges, 2) pole bridges (pipe with poles), 3) standard culverts, and 4) re-enforced fords (with GeoWeb or Geotextile) to determine the influence of stream crossing type on water quality and to evaluate erosion associated with stream crossing approaches. We also evaluated each site at four different time intervals to determine if water quality was more affected during different stages of the operations. Prior to operational timber harvests, we identified six replications for each type of crossings (4 fords) and collected data at four time intervals: 1) prior to reopening or installation of crossing, 2) after crossing installation, 3) during harvest operation, and 4) after road closure. Potential erosion rates from approaches to the crossings were estimated by collecting the road/site information necessary to estimate erosion with the Water Erosion Prediction Project for forest roads (WEPP) and the forest version of the Universal Soil Loss Equation (USLE). In-stream water samples were collected at fixed locations above and below each crossing and were evaluated for total dissolved solids (TDS), pH, conductivity, water temperature, and total suspended solids (TSS) or sediment concentration. Steel bridge crossings generally caused the least amount of water quality disturbance. Model-generated estimates of erosion demonstrated that culvert crossings were associated with the highest average soil loss potential. Although steel bridge crossings had the best overall results, pole bridges proved to be a viable option for ephemeral or intermittent streams due to low potential of soil loss. Ford crossings were found to impact water quality indicators, but showed a decrease in total dissolved solids (TDS) after installation, prior to harvest. Overall, the steel skidder bridges were generally the best crossing type, but any of the crossings can be used effectively with minimal impact under specific site conditions and with judicious installation, use, and closure. Road/skid trail location and adherence to existing road grade, water control, cover, and closure best management practices are critical for protection of water quality at stream crossings. / Master of Science

In this research study, triangulation is employed utilizing quantitative and qualitative methods, including content analysis, a perception survey, and expert interviews to find key themes and patterns in management and digital strategies for ESG reporting. The primary focus centered on sequential research, applying the emerging themes from the content analysis to the survey and interview creation. The research questions address organizational challenges with ESG reporting (1), the influence of digital strategies on reporting reliability (2), and management practices that impact stakeholders’ perception of quality, credibility, and transparency in ESG reporting (3). The findings reveal that organizations need to prepare and restructure to meet intensifying ESG reporting requirements. Digital strategies and solutions emerged as fundamental variables that influence the success and quality of ESG reporting practices. To achieve this, data streamlining, normalization, assurance, and verification processes are crucial for enhancing data traceability and credibility across the value chain. Additionally, the empirical findings found that management and communication practices influence stakeholder perception significantly. Therefore, organizations must improve their disclosure practices in transparency and openness to ultimately impact stakeholder perception of organizational communication. The research findings suggest organizations adopt a holistic approach to integrating ESG practices into business models and operational activities. The findings emphasize the urgent need for any organization to comply with ESG reporting practices and continuously improve ESG performance. In conclusion, this study advocates for proactive management practices to maintain a competitive advantage through improving environmental and social business practices.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Lee R. Skabelund / Stormwater management is typically approached from different perspectives by practicing professionals. As such, stormwater planning/design is not always completed as a multi-disciplinary coalition of experts using holistic and synergistic methods. For a number of years, engineers and design professionals, particularly landscape architects, have been employing various strategies and techniques to address on-site stormwater management in terms of water quality and quantity. There is increasing awareness that in order to create solutions that are effective over both the short and long-term a landscape architect’s approach needs to account for the health, safety and welfare perspectives carried by engineers, the unique aspects of particular project sites, their surroundings and bio-regional context, as well as the perceptions of clients, other key stakeholders, and the broader public. This research investigates the various criteria integral to developing an analytic framework for ecologically-appropriate stormwater planning/design (Sustainable Stormwater Evaluation and Site Assessment or SSWESA). SSWESA is proposed as a type of decision-tree for site analysis of sustainable systems pertaining to stormwater. Using the SSWESA process is expected to help researchers and professionals make better planning and design decisions as they select and implement appropriate best management practices (BMPs) for a given site and context. My intent in developing SSWESA is to help designers assess existing and potential stormwater functions at the site scale in order to promote sustainable planning and design based upon the important principle: “First, do no harm”. It is also my intent to promote further research related to sustainability by providing references and sources from experts in the various fields related to ecologically-based stormwater management. A review of the literature related to ecological factors relevant to low impact stormwater management assisted in the development and refinement of the criteria for stormwater assessment and evaluation. In this report, the SSWESA framework is tested on a public school property in Manhattan, Kansas to demonstrate how the framework is applied and to understand the questions and issues that arise from its use.

Using data envelopment analysis with principal components, we calculate an adoption-intensity index for herbicide-resistance best management practices (BMPs). Empirical results for over 1,100 farmers in twenty-two U.S. states suggest that many farmers could improve their herbicide resistance BMP adoption. Two-limit truncated regression results show that higher yields and a greater proportion of acres planted with Roundup Ready (R) seeds motivate weed BMP adoption. While soybean and corn farmers have lower adoption intensity than cotton farmers, farmer educational attainment and greater concern for herbicide effectiveness and for human and environmental safety are found to help increase the adoption of weed BMPs.

A comprehensive literature review was undertaken in order to define and assess the sustainability and resiliency characteristics associated with grass-based and confinement dairy farming. Primarily as a result of reduced input costs, grass-based dairy farming often enhances profitability over confinement systems, especially on small farms. Further, conversion of tilled soil to permanent pasture has been shown to significantly reduce harmful sediment and nutrient transport into waterways. Perennial forage also acts as a carbon sink, curtailing or even negating a grass-based farm's carbon footprint. Finally, social benefits derived from enhanced nutrition and higher quality of life are also associated with grass-based dairy farming. Given that policy goals of the State of Vermont include both bolstering farm viability and reducing farm-related runoff, two questions are then raised. What is the most effective way to incentivize the adoption of rotational grazing in Vermont? And what types of farms are best suited to its use? A series of interviews with dairy experts and farmers was conducted as a preliminary investigation into these questions. This qualitative evidence suggested that farmers generally adopted grass-based dairying after observing a peer's success with the method, suggesting that a key leverage point may be peer-based learning. A behavioral economics game was developed to evaluate the role of peer networks in facilitating decision-making under conditions of uncertainty. A computerized game platform simulated networks of small dairy farm enterprises, with participants acting as farm managers. Treatments varied the size of peer networks, as well as the inclusion of a perfectly-performing automated 'seed player.' Participants could base their decisions upon the successes of their peers. They received a cash incentive based on their farms' performance. Results indicated that players with higher numbers of peers made better economic decisions on average. The inclusion of a 'seed player' within a network, which modeled the ideal behavior, also facilitated better decision-making. Both of these correlations were statistically significant. Furthermore, the shape of the 'diffusion curve' of new adoptees confirmed literature on the dynamics of innovation diffusion. Public policy implications from this work include an increased focus on facilitating peer-to-peer learning among farmers where Best Management Practice adoption is a policy goal. To further evaluate the potential for peer learning to facilitate positive change, the Dairy Farm Transitions Agent Based Model (DFTABM) was developed. The model was calibrated using existing datasets along with the qualitative and quantitative results described above. It forecasts effects on farm profitability, attrition, and soil loss arising from varying assumptions about peer network connectivity, peer emulation, macroeconomic trends, and agri-environmental policy. Nine experimental treatments were assessed. Overall, it was found that high rates of emulation coupled with high rates of connectivity'especially targeted connectivity among smaller farms'yielded the best balance of farm viability and reduction in soil loss. The establishment of a performance-based tax credit had no clear correlation with the resulting soil loss figures predicted by the model. Policy implications from this study include the finding that direct payment schemes for reduction in environmental harm may not always have their intended effects, whereas policies that enhance peer-to-peer learning opportunities, especially among the proprietors of smaller farms, may present an effective and relatively affordable means by which to bolster farm profitability while also reducing environmental degradation.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Les difficultés économiques qui affectent les systèmes de protection sociale, l’évolution des politiques publiques sous l’affirmation des principes du nouveau management public, et l’évolution des savoirs médicaux et soignants font peser sur de nombreux établissements de santé des menaces importantes pour leur survie ou à tout le moins sur la continuation de leur projet originel. Cette thèse s’intéresse à la question des facteurs de pérennité des organisations de santé. Elle repose sur l’étude de cas longitudinale d’un établissement psychiatrique privé fondé en 1943 qui assure la responsabilité de la psychiatrie publique du secteur de l’Est vaudois, alors qu’il pratique une politique de soins qui se réfère à la psychanalyse, à contre-courant des références actuelles en psychiatrie qui relèvent plutôt des neurosciences et des traitements cognitivo-comportementaux (TCC). Suivant les principes de la démarche clinique, une approche globale de l'organisation est réalisée pour comprendre la dynamique de fonctionnement de cette institution et son faire-ensemble particulier. Dans cet perspective, l’analyse se focalise sur les pratiques du quotidien, tant du point de vue des soins (les pratiques cliniques) que du management (les pratiques de gestion), en prenant également en compte la dimension historique de l’institution mais aussi de l’environnement et de la psychiatrie. Il ressort de cette analyse que 3 éléments fondent la pérennité de cet établissement dans une dynamique récursive :- une philosophie des soins affirmée et ancrée sur des valeurs humanistes,- l’homologie entre pratiques cliniques et pratiques de gestion,- La gestion de l’interstitiel, c’est-à-dire les espaces de marge de manœuvre et d’autonomie des acteurs instaurés en dehors de toute structure et de regards hiérarchiques dans des relations de confiance.Ces 3 éléments constituent l’esquisse d’un modèle organisationnel de pérennité qui devra être testé à plus grande échelle. / The economic difficulties affecting social protection systems, the evolution of public policies under the affirmation of the principles of the new public management, and the evolution of medical and nursing knowledge pose major threats to the survival of many health establishments or at least to the continuation of their original project. This thesis addresses the issue of sustainability factors in health organizations. It is based on the longitudinal case study of a private psychiatric establishment founded in 1943 which is responsible for public psychiatry in the eastern sector of the Canton of Vaud, while it practices a policy of care which refers to psychoanalysis, against the current references in psychiatry which are rather neurosciences and cognitive-behavioural treatments (CBT). Following the principles of the clinical approach, a global approach of the organization is realized to understand the dynamics of the functioning of this institution and its particular make-together. In this perspective, the analysis focuses on everyday practices, both from the point of view of care (clinical practices) and management (management practices), also taking into account the historical dimension of the institution but also of the environment and psychiatry. 3 inter-related elements emerge from this analysis as the basis of the sustainability of this establishment in a recursive dynamic:- an affirmed philosophy of care rooted in humanist values,- the homology between clinical and management practices,- Interstitial management, i.e. the spaces of autonomy of the actors that are set up outside any structure and hierarchical and are based on relationships of trust.These 3 elements constitute the outline of an organizational model of sustainability that will have to be tested on a larger scale.