Medusahead is a harmful weed that is invading public lands in the West. The invasion is a serious concern to the public because it can reduce forage for livestock and wildlife, increase fire frequency, alter important ecosystem cycles (like water), reduce recreational activities, and produce landscapes that are aesthetically unpleasing. Invasions can drive up costs that generally require taxpayer’s dollars. Medusahead seedlings typically spread to new areas by attaching itself to passing objects (e.g. vehicles, animals, clothing) where it can quickly begin to affect plants communities. To be effective, management plans need to be sustainable, informed, and considerate to invasion levels across large landscapes. Ecological remote sensing analysis is a method that uses airborne imagery, taken from drones, aircrafts, or satellites, to gather information about ecological systems. This Thesis strived to use remote sensing techniques to identify medusahead in the landscape and its changes through time. This was done for an extensive area of rangelands in the Channel Scabland region of eastern ashington. This Thesis provided results that would benefit land managers that include: 1) a dispersal map of medusahead, 2) a time line of medusahead cover through time, 3) “high risk’ dispersal areas, 4) climatic factors showing an influence on the time line of medusahead, 5) a strategy map that can be utilized by land managers to direct management needs. This Thesis shows how remote sensing applications can be used to detect medusahead in the landscape and understand its invasiveness through time. This information can help create sustainable and effective management plans so land managers can continue to protect and improve western public lands threatened by the invasion of medusahead.

Diffuse knapweed (Centaurea diffusa) is an introduced annual or short-lived perennial from Eurasia that has become a threat to native rangelands in the Pacific Northwest. Military training activities on the Yakima Training Center (YTC) increase the likelihood that knapweed will expand its range at YTC. This study, conducted in a major watershed at YTC, focused on: 1) how a variety of environmental variables influences knapweed distribution, 2) the use of Landsat Thematic Mapper (TM) imagery to map existing knapweed populations, and 3) the use of a logistic regression model and geographical information systems (GIS) to create a potential knapweed habitat map. Topographic and climatic factors had the greatest influence on knapweed distribution. Knapweed has a competitive advantage over those which may have some water stress due to increased temperatures (i.e., lower elevations and south slopes). Lower shrub density, greater percent bare ground, and lower percent perennial aerial cover also made for ideal knapweed habitat. Knapweed density decreased as slope steepness, pH, and percent rock cover increased. Using TM imagery to define existing knapweed populations was unsuccessful because most knapweed stands were less than 30 m X 30 m and had little effect on the TM image values. However, the TM imagery was useful in defining potential knapweed habitat along with other variables. Sixty percent of the Selah watershed has the potential to support knapweed. Approximately 68 % of the potential knapweed habitat was infested with knapweed. Denser patches (> 1 plant per m2) were limited to 21% of the potential habitat.

To develop a sustainable future for the rangelands, partnerships are needed — partnerships between scientists, policy makers, visitors, and most significantly, the various communities of people who live and work in the rangelands. The views of these people are as variable as the country about which they care; rangeland communities are not homogeneous. The power relations between these people are at the base of many conflicts. How we handle the relationships between these groups, and manage these conflicts, are crucial for success in land management. ¶ The first part of this thesis reviews the history of both community participation and power theory. While participatory approaches are part of the rhetoric in Australian land management, proponents are generally naïve about the complexities of power and power relations. The philosophical literature highlights that power is a contested concept; and these divisions are epitomised by the works of Habermas and Foucault. Their writings are compared and contrasted to provide a rich understanding of power relations in community participation. ¶ Power relations influence whose voices are heard: those who exercise power, and the sets of rules that define what is seen as true or false at any given time in history. Power relations also determine whose knowledge is incorporated in land management policy and practice. The model proposed in this thesis demonstrates that power relations interact with every dimension of community participation: context, goals, scale, stage, who is involved, the capacity of those involved, and the methods used. ¶ Research was undertaken within agricultural and natural resource management programs and projects in south-west Queensland. A variety of participatory approaches are used by government agencies to encourage grazier participation and the adoption of more sustainable practices, such as Landcare, Bestprac and the regional groups, such as the South West Strategy. While government staff in south-west Queensland purport to share decision-making power with landholders, landholders tend to have different perspectives about the level of power that is being shared. ¶ One of the key findings of this research is that power is not static within any project. Rather, power is ultradynamic, fluid, and highly dependent on context. In terms of land management programs, the levels of power sharing fluctuate over time and between actors. The micro-physics of power, or the power relations among individuals, are often invisible to, or neglected by, the facilitators of land management programs. ¶ Government agencies tend to focus on the processes used, and on finding the best participatory methods, rather than on the individuals who implement the process or the individuals who participate. Greater flexibility is needed in approaches to land management; correspondingly, greater responsibility is needed from all individuals who have a stake in it. To find sustainable solutions for the rangelands and its people, all involved in participatory land management projects need to better understand the dynamics of power, so as to manage any negative effects.

There is concern that the communal rangelands of Botswana are overstocked with cattle, and that this has led to unwanted ecological changes. These changes are assumed to be most prominent around boreholes. This study describes vegetation and soil piospheres around boreholes in Eastern Botswana and investigates factors associated with their development. The classical range succession model and its modifications, the bush encroachment theories and the soil-nutrient transfer model, have been applied here to explain changes in vegetation and soil variables with distance from artificial water points. Data on soil texture, soil nutrients, vegetation species composition and cover, dung weight and bare ground were collected from boreholes of different ages, with different numbers of cattle using them. Piosphere patterns were observed. However, some of the patterns were not in accordance with the classical range succession model and the bush encroachment theories. The frequent occurrence of palatable grasses (Panicum maximum, Setaria verticiliata and Digitaria milanjiand) nearer to water points where the grazing pressure is highest, and of unpalatable ones (Aristida congesta and Eragrostis rigidior) further away, where the grazing pressure is minimal, contradicts the classical range succession model. Total tree cover along the gradient did not show any changes, which contradicts bush encroachment theory (two-layer soil moisture model). The concentration of soil nutrients and dung weight close to boreholes was well predicted by the soil-nutrient transfer model. The frequency of Acacia tortilis and Dicrostachys cinerea and bare patches, increased towards boreholes. Grass cover, occurrence of Terminalia sericea, Boscia albitrunca and Combretum apiculatum increased with distance from water points. The results suggest that the range succession model and its modification, the twolayer soil moisture model, cannot satisfactorily explain vegetation changes with distance from water points. Species composition at a point may be affected by the growth, survival, recovery and reproductive strategies of different species, fire, selectivity of browsers and nutrients status, as well as grazing disturbance. Therefore, the 'state and transition' model is recommended, as it considers factors that are ignored by the classical range succession model, and is appropriate for analysing vegetation change under highly variable rainfall. The adverse impacts of grazing around boreholes could be reduced by controlling cattle distribution on the range as a whole.

Over time the impact of human interactions upon the natural environment has revealed changes to the condition and structure of the landscape. Practices which were once deemed to be suitable to natural conditions have since been recognised as having caused degradation to land, water, soils, and impacted upon floral and faunal biodiversity. In response to evidence of ecological declines, a range of institutional and management responses have been implemented, evolving to become a complex and fragmented environmental legal and management system. The purpose of this study was to examine the effectiveness of institutional responses as solutions to environmental problems. It did this through a case study exploration of the development, implementation, and administration of regulatory changes to the management of native vegetation in Queensland. These reforms were introduced to meet electoral commitments to address the high land clearing rates in light of scientific evidence of the association between this activity and the symptoms of degradation. Specifically, the study investigated whether these reforms would achieve their designed objectives without perverse impacts upon the ecological, economic, or social sustainability in semi-arid rangelands of south-west Queensland. The Pressure-State-Response (PSR)/ Driving Force-Pressure-State-Impact-Response (DPSIR) Models and the principles of Ecologically Sustainable Development (ESD) provided the foundation for the formation of the case study research questions to examine this complex real world environmental problem, and the attempts made to achieve its resolution. These questions focused upon each element of the Models. Hence, five research questions guided this investigation: 1. What is the condition of the environment in south-west Queensland? 2. What are the major pressures upon the condition of the environment? 3. How effectively have institutional responses to address the environmental problem been implemented? 4. What are the social, economic, and environmental impacts of the response in the case study region? 5. Was the response designed to maximise its potential effectiveness without unintended consequences (impacts)? Five research cycles were employed to gather and verify data required to explore these questions. Firstly, published knowledge, science, and best-practice approaches to decision making were highlighted through literature examinations. Focus groups then identified priority issues for further exploration. Interviews facilitated the in-depth investigation of problems and the testing of assumptions. Practical and on-ground conditions, practices, and issues were subsequently detailed in ethnographic studies, and emerging research and system changes reviews presented the context to the matters being explored. Through this process of data collection, triangulation, and verification, collectively, this case study investigation found that: • despite extensive research and investment into science and knowledge, environmental problems in the case study area persist, due to the combined impacts of natural and induced pressures; • the introduction of domestic grazing and permanent waters into an area ill-equipped to handle it led to the transformation of the semi-arid landscape, whilst the changes which have become apparent have been attempted to be resolved by the landholders who inherited them; • the on-ground responses to degradation are influenced by an evolving, multifaceted, and multi-jurisdictional framework of policies, laws, and strategies which comprise the environmental legal system, and are implemented at international, national, jurisdictional, local, and property levels; • Queensland’s native vegetation framework is one of the more recent additions to this system, and whilst well intended, its design and implementation has been criticised as poorly reflecting best practice approaches; • regulatory deficiencies have the potential to limit the effectiveness of native vegetation reforms and the achievement of desired legislated objectives, and have the potential to compounding environmental, social, and economic problems in the case study region. However, it is argued that had a best practice approach to institutional response design and implementation been followed, this would have provided the opportunity to anticipate future problems, and allowed them to be addressed through the development and implementation of complementary tools and strategies. Furthermore, where institutional responses anticipate and address perversities as they occur, this can ensure that potential solutions to complex problems are capable of maximising the achievement of desired objectives without unacceptable impacts. Consequently, in order to identify and prevent the undesired outcomes predicted for the case study region, and to maximise the effectiveness of policy and institutional responses, problems need to be correctly defined, and appropriate responses generated. Hence, the thesis is: Where institutional reforms to solve environmental problems are not designed,implemented, and administered effectively, they will create negative ecological,economic, and social impacts. Policy design must be capable of conceptualizing and responding to possible and probable outcomes. However, and despite the knowledge, science, and information to do this already being available to guide decision making processes, the exploration of the case study demonstrated that institutional responses can still be potentially ineffective. This may be due to the complexity of issues needing to be considered, and the lack of guiding processes and tools to assist decision makers undertake this multidisciplinary activity. To resolve this dilemma, an adapted model has been created. The “Anticipatory, Sustainable, and Precautionary Institutional Response Evaluation (ASPIRE) Model” incorporates the findings and lessons from this study, and the elements which need to be considered in decision making. Through the utilisation of this model as a framework for examining complex problems, and developing and evaluating proposed solutions, the replication of the negative and perverse impacts of institutional responses which are anticipated for the case study can be prevented in the future. This will be achieved where the model is utilised by decision makers to guide the process for policy development and solution design in all sectors which attempt to address complex problems in multifaceted management environments.

Two studies were conducted to determine the factors influencing distribution of cattle on northeastern Oregon mixed-conifer forested rangelands. The objective of the first study was the quantification of differences in distribution of cattle of different ages. Beginning in 1991, and continuing through 2001, radio telemetry collars were placed on a minimum of 30 cattle per year, prior to turnout. Cattle graze the forest from approximately 15 Jun until 15 Oct each year, and were grouped into four age classes: two and three year old cattle (group 1), four and five year old cattle (group 2), six and seven year old cattle (group 3), and cattle eight years of age and older (group 4). The objective of the second study was to determine differences in landscape thermal regimes between riparian and upland areas. Ambient and "black body" thermal probes were placed in a grid pattern in riparian and upland areas at a height of one meter (mid height of a cow), to encompass the entire pasture. For study 1, all groups of cattle preferred areas with shallow slopes (P<0.05), westerly aspects (P<0.05). All age classes of cattle also preferred areas farther from water than the mean distance to water in the pasture (P<0.05) as well as areas with higher quantities of forage (kg/ha) than the mean value of forage production for the pasture (P<0.05). Cattle in age classes two, three and four selected areas with lower percent canopy closure of trees greater than 12 cm diameter, breast height (dbh), than the mean value for the pasture (P<0.05) Cattle in age class one selected for areas of lower elevation and slightly steeper slopes than cattle in age class four (P<0.05). Cattle in age class two were not affected by slope or elevation in their distribution (P<0.05). Cattle in age class three were not influenced by elevation in their distribution, but selected areas of the pasture with shallower slopes (P<0.05). For the second study, the trial was conducted from 5 Aug to 25 Sep in 2001, and from 15 Jul to 1 Sep in 2002. Year was found to be significant (P<0.0001), therefore results from each year were analyzed separately. Each six week grazing period was divided into three-week intervals, and deemed early and late season for each year. Season was found to be highly significant (P<0.0001), and therefore analyzed separately within each year. Least significant means were utilized to determine differences in temperatures. Differences were considered significant at the P<0.05 level for all analysis. Thermal probes were divided into two types within two areas; ambient and blackball, within riparian and upland areas. Analysis conducted examined the differences between riparian and upland ambient and blackball thermal probes. Area and type of probe were both highly significant (P<0.0001) for all classifications, however, there was not an area by type interaction. / Graduation date: 2004

The objectives of this research were to 1) evaluate the establishment and peak standing crop of Berber Orchardgrass (Dactylis glomerata var. "Berber"), Palestine Orchardgrass (Dactylis glomerata var. "Palestine"), and Sheep Fescue (Festuca ovina var. "Covar") ; 2) to assess establishment and production changes resulting from environmental gradients (elevation, slope, aspect, soil texture, precipitation, and resident annual community) across the foothill landscape; 3) develop a mathematical model that predicts site potential for restoration; and 4) evaluate the utility of Geographic Information Systems for creation and analysis of spatial data which identify site production potential. Sixteen sites were chosen which reflect the general character of the foothill rangelands in southwestern Oregon. A Randomized Complete Block design was used to select treatment arrangement on each site. Seeded treatments received both chemical (Glyphosate, Hoelon, and 2,4-D) and mechanical (residue removal) disturbance. Test species were seeded into three replications at each site. Each replication also included a non-treatment control. Standing crop data for test species and resident exotics were collected after three growing seasons. Berber orchardgrass did not establish at most sites and where establishment did take place production was less than 132 kgDM/ha. Palestine orchardgrass established on on a majority of the study sites and produced most aboveground phytomass at mid-elevations where coarser soil textures and deeper soil depths were common. Sheep fescue was the most successful of the three test species and did best on low elevation high clay sites. There was significantly (P=0.001) more phytomass produced by annual exotics on seeded plots than on undisturbed controls at most sites. Both Palestine orchardgrass and sheep fescue treatments significantly suppressed the annual exotics when compared to the Berber treatments. Generally, "Covar" sheep fescue can establish and successfully compete with exotics on heavier textured soils at low elevations. "Palestine orchardgrass is adapted to mid-elevation coarser soils. / Graduation date: 1995

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