Astragalus filipes Torrey ex. A. Gray (Fabaceae) is being studied and propagated for use in rangeland restoration projects throughout the Great Basin. Restoration forbs often require sufficient pollination services for seed production and persistence in restoration sites. Knowledge of a plant's breeding biology is important in providing pollination for maximal seed set. Reproductive output from four manual pollination treatments (autogamy, geitonogamy, xenogamy, and distant xenogamy) was examined in a common garden. Pod set, seed set, and seed germination were quantified for each of the treatments. Seed set from four wild populations was compared to that of an openly visited common garden array. A. filipes was found to be self-compatible, but to benefit greatly from outcrossing. Less seed germinated from distantly outcrossed treatments than for any other treatment, indicating possible outbreeding depression. Common garden plants set less seed per pod than any wild population, possibly due to a depauperate pollinator guild in the common garden. Bees were surveyed at wild A. filipes populations to identify common pollinators. Solitary and social bee species were observed visiting A. filipes to estimate aspects of their pollination efficacies, particularly foraging tempo and frequency of stigmatic contact. The nesting biologies of bees that visit A. filipes were considered as a component of bee manageability. Bees in the genus Osmia (Megachilidae) dominated this pollinator guild. Bombus nevadensis queens were the fastest foragers; honey bees and native solitary bees did not differ in foraging tempo. Megachilid bees consistently contacted the stigma during foraging, but honey bees exhibited sideworking behavior, contacting stigmas far less frequently than any other bee species observed. Two solitary bee species (Osmia bruneri and Hoplitis hypocrita) are recommended as prospective pollinators for management in association with Great Basin rehabilitation efforts.

Managing Wyoming Big Sagebrush (Artemisia tridentata ssp. wyomingensis) systems biologically with grazing can potentially reduce costs and increase both biodiversity and understory production as well as rejuvenate Wyoming Big Sagebrush (ARTRWY). Sheep were provided a protein-energy supplement to facilitate use of the secondary metabolites found in ARTRWY forage. Phytomass ( ) was estimated for the following plant categories: total phytomass, current annual growth (CAG) of ARTRWY, the woody portion of ARTRWY, CAG of other shrubs, the woody portion of other shrubs, grasses, forbs, litter, and standing dead material. I also measured plant species richness and abundance, as well as estimates of the age class structure of sagebrush. One year following grazing, total phytomass decreased by 43%, due primarily to the reduction of ARTRWY. The CAG of ARTRWY decreased by 66%, while grasses increased by 43%, forbs increased 60%, and the number of species encountered in the grazed plots increased 42%.

Large fires (400 ha +) occur about every seven to ten years in the vegetation types located at US Army Garrison Camp Williams (AGCW) practice range located near South Jordan, Utah. In 2010 and 2012, wildfires burned beyond the Camp’s boundaries into the wildland-urban interface. The political and public reaction to these fire escapes was intense. Researchers at Utah State University were asked to organize a system of fuel treatments that could be developed to prevent future escapes. The first step of evaluation was to spatially predict fuel model types derived from a random forests classification approach. Fuel types were mapped according to fire behavior fuel models with an overall validation of 72.3% at 0.5 m resolution. Next, using a combination of empirical and semi-empirical based methods, potential fire behavior was analyzed for the dominant vegetation types at AGCW on a climatological basis. Results suggest the need for removal of woody vegetation within 20 m of firebreaks and a minimum firebreak width of 8 m in grassland fuels. In Utah juniper (Juniperus osteosperma (Torr.) Little), results suggest canopy coverage of 25% or less while in Gambel oak (Quercus gambelii Nutt.) stands along the northern boundary of the installation, a fuelbreak width of 60 m for secondary breaks and 90 m for primary breaks is recommended.

This study aims to find out major factors acting on steppe biodiversity of Inner Anatolia by focusing on one million hectares of mountainous land. Quantitative data on common plants, breeding birds and butterflies as well as environmental and land use data were collected at 33 sites determined by environmental stratification. Data has been analyzed with Spearman&rsquo / s rank correlation, canonical correspondence analysis, detrended correspondence analysis, two-way indicator species analysis and hierarchical partitioning. Results show that elevation, current grazing intensity, distance to woodlands and arable lands are the main determinants of richness and diversity. Other important factors are soil Magnesium and organic matter for plants / local heterogeneity and shrub/tree density for birds / plant richness and mud-puddling sites or wind shelters attracting butterflies. Altitude and grazing intensity have negative effects on biodiversity whereas soil Magnesium and proximity to other vegetation types have positive effects. In sites with more than 90% herbaceous coverage, shrub/tree density is a good indicator for the richness patterns of all groups. The richest sites are low mountain shrubby steppes close to woodlands and arable lands, ploughed 30-100 years ago but then abandoned and experienced light or no grazing afterwards. Six major plant communities are distinguished by gypsum bedrock, altitude and years since land abandonment. Four main bird assemblages are differentiated with landscape and local heterogeneity and composition and wood density of the sites. Various factors act on richness and diversity patterns on steppes, differing for species groups and assemblages. Conservation actions should encompass conservation priority species, represent different species assemblages, consider all major factors mentioned above especially landscape and local heterogeneity including different seral stages and sustaining conservation through nature-friendly land use. Planning afforestation in the way not to destroy rich steppes and building awareness on steppes as a value are important conservation actions.

The Russian people and the steppe nomads have maintained a symbiotic relationship for 2600 years that was undeniably fluid; however, for the most part mental and sometimes physical barriers have been erected in Russian society and historiography in an attempt to deny or suppress many aspects of Russia’s “Asian” features or historical past. This thesis aims to bring to light the fluidity and cross-cultural exchanges of this relationship, the substantial influences of steppe societies on Russian society and history, as well as to examine the motives and ideologies behind Russia’s anti-nomadic sentiments that ultimately shaped and censored Russian national history. The invaluable benefits of nomadic and steppe customs in Russian society and on Russian identity have previously been ignored, dismissed or downplayed in Russian historiography, and revisionist historians hope to reverse this and introduce the concept that the rise of the Russian nation would not have been possible without the influence of steppe nomadic societies.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 46-55). Also available on the World Wide Web.

nÃo hà / Esta pesquisa tem como objetivo analisar a questÃo da identidade nacional angolana em obras de Pepetela, com Ãnfase para o romance O planalto e a estepe, publicado em 2009. A hipÃtese que serve como horizonte de trabalho à a de que Pepetela, atravÃs de suas obras, demonstra que qualquer modelo que tome a identidade nacional angolana como algo fixo e acabado està condenado ao fracasso, pois, assim como sua histÃria, a identidade dessa naÃÃo à dinÃmica e mÃvel, ou seja, està em constante processo de reconfiguraÃÃo. Com o fim de verificarmos tal premissa, elegemos como corpus de pesquisa quatro obras de Pepetela em que a discussÃo sobre a identidade angolana fica claramente evidenciada: o conto âEstranhos pÃssaros de asas abertasâ (extraÃdo da obra Contos de morte, de 2008) e os romances Yaka (1980), Mayombe (1985) e O planalto e a estepe (2009). Para a consecuÃÃo do trabalho, recorremos a alguns conceitos importantes ligados tanto à questÃo da identidade quanto Ãs marcas da produÃÃo ficcional de Pepetela, merecendo destaque a) a elipse do herÃi, tese atravÃs da qual Robson Dutra demonstra que Pepetela, com o fim de criticar os discursos hegemÃnicos e autoritÃrios, intencionalmente evita construir personagens à imagem e semelhanÃa dos herÃis clÃssicos; b) literatura insubmissa, conceito desenvolvido pelo professor Roberto Pontes e que se refere Ãs obras de autores africanos lusÃfonos que, mesmo antes da independÃncia de seus paÃses, se insurgiram contra as formas de literatura colonial que predominavam na ex-colÃnias africanas de Portugal; c) memÃria identitÃria, expressÃo cunhada por Janine Ponty e que à utilizada por JÃel Candau (2012) em um estudo sobre as relaÃÃes estreitas entre memÃria e identidade; e d) naÃÃo como narraÃÃo, argumento desenvolvido por Homi Bhabha, e que diz respeito ao fato de que a naÃÃo, como a literatura, à tambÃm uma narrativa, tendo em vista que se desenvolve a partir de um arranjo de sÃmbolos, acontecimentos, formulaÃÃes mÃticas e personagens que visa atribuir sentidos para a trajetÃria dos membros de uma dada naÃÃo. AtravÃs desses e de outros construtos teÃricos, mostramos que as diferentes Angolas que surgem das pÃginas da obra de Pepetela abrigam uma diversidade de identidades individuais que impossibilitam qualquer projeto de construÃÃo de uma identidade nacional angolana que se baseie na fixidez e na homogeneidade. / This research aims to analyze the Angolan national identity in Pepetelaâs literary works, with emphasis on the novel O Planalto e a estepe [The Plateau and the steppe], published in 2009. The hypothesis that guides this dissertation is that Pepetela, in his works, argues that any model that takes the Angolan national identity as something fixed and finished is doomed to failure because, as well as its history, the identity of Angola is dynamic and mobile, i.e., it is in a constant process of reconfiguration. In order to verify this assumption, we choose as research corpus four Pepetelaâs works in which the discussion of Angolan identity is clearly evident: the short story âEstranhos pÃssaros de asas abertasâ ["Strange birds with open wings"] (from the book Contos de morte [Tales of Death], 2008) and the novels Yaka (1980), Mayombe (1985) and O Planalto e a estepe (2009). To the development of this work, we turn to some important ideas linked to identity discussion and to Pepetelaâs fiction, being more important the following concepts: a) the ellipse of the hero, a thesis by which Robson Dutra shows that Pepetela, in order to criticize the authoritarian and hegemonic discourses, intentionally avoids to build characters inspired in classic heroes; b) the concept of unsubmissive literature developed by professor Roberto Pontes and that is linked with some works written by African Portuguese speakers who, even before the independence of their countries, rebelled against colonial literature forms prevailed in the former Portugal colonies in Africa; c) memory identity, an expression created by Janine Ponty and that is used by JÃel Candau (2012) in a study on the close relationship between memory and identity; and d) the understanding of nation as narration, argument developed by Homi Bhabha, and that has its origin in the fact that the nation, like literature, is also a narrative, given that it is developed from an arrangement of symbols, events, formulations and mythical characters that give meaning to the trajectory of the members of a given country. Through these and other theoretical constructs, we demonstrate that the different Angolas arisen from the Pepetelaâs works shelter a diversity of individual identities that preclude any construction project of an Angolan national identity based on fixity and homogeneity.

Planting native species after a major disturbance is a critical tool land managers use to stabilize soils, restore ecosystem processes, and prevent weed invasion. However, within the sagebrush steppe and other arid and semi-arid environments the percentage of sown seeds that produce an adult plant is remarkably low. Applying fertilizers at the time of planting may improve native plant establishment by increasing the ability of the seedlings to cope with environmental stresses. However, traditional fertilizer applications are often economically infeasible and may be counterproductive by encouraging weed invasion. Seed coating technology allows for the efficient application of fertilizers within the microsite of the seeded species. The objective of our research was to determine the optimal rate of fertilizer to apply to the seed to improve seedling emergence and plant growth. We applied a phosphorus (P) rich fertilizer (0.13 g P g-1) to bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) Á. Löve) seeds in a rotary coater at rates ranging from 0 to 50 g of fertilizer 100 g-1 seed. Three separate studies were conducted to test germination, biomass, relative growth rate, and tissue nutrient uptake. Study one showed decreasing root and shoot biomass and increasing time to 50% germination as fertilizer rates increased. Study two showed no difference in relative growth rate between the controls and fertilizer treatments. Study three showed no difference in root and shoot biomass or nutrient concentration between treatments except in the lowest fertilizer treatment (10 g fertilizer 100 g-1 seed), which was significantly lower in root and shoot biomass than all other treatments but had higher P tissue concentrations than all other treatments. Collectively these results showed no evidence that a P fertilizer coating could aid in bluebunch wheatgrass seedling establishment. Because bluebunch wheatgrass and similar late-seral plants have evolved with low nutrient requirements they may not be physiologically capable of handling increased nutrient supply, which may explain the results of our studies. Continued studies and fieldwork need to be performed to evaluate the potential of fertilizer seed coatings in restoration efforts.

Understanding the relative importance of density-dependent and density-independent factors in driving population dynamics is one of the oldest challenges in ecology, and may play a critical role in predicting the effects of climate change on populations. We used long-term observational data to describe patterns in plant population regulation for 57 forb and grass species from three different ecosystems (arid desert grassland, semiarid sagebrush steppe, and subhumid mixed-grass prairie). Using a hierarchical partitioning approach, we (i) quantified the relative influence of conspecific density, heterospecific composition, and climate on temporal variation in population growth rates, and (ii) asked how the relative importance of these drivers depends on site aridity, species growth form and life expectancy, and abundance and spatial patterns. The data from one of the sites in this analysis are presented in one of the chapters of this thesis. We found that density-dependence had the strongest effect on species. Climate often had a significant effect, but its strength depended on growth form. Community composition rarely explained significant variation in growth rates. The relative importance of density, composition, and climate did not vary among sites, but was related to species' life histories: compared to forbs, grasses were more sensitive to climate drivers. Abundance and spatial clustering were negatively correlated with the importance of density dependence, suggesting that local rarity is a consequence of self-limitation. Our results show that interspecific interactions play a weaker role than intraspecific interactions and climate variability in regulating plant populations. Forecasting the impacts of climate change on populations may require understanding how changes in climate variables will affect the strength of density-dependence, especially for rare species.

Forecasting the effects of climate change on plant and animal populations is a high priority in ecology. We studied the effects of climate on plant populations through the use of observational and experimental data, as well as analytical models. Our research questions were: (1) Do the effects of interannual climate variation on the population growth rates of widespread species show a coherent pattern across gradients of mean annual climate? (2) How well can population models fit to observational data predict the response of populations to field experiments that manipulate climate? And (3) does niche overlap between competitors predict the magnitude of competition-mediated indirect effects in mechanistic resource competition models? To test the first question, we assessed how interannual variation in climate affected the abundance of big sagebrush (Artemisia tridentata) at 131 monitoring sites across its range. We found that years of above average temperature increased sagebrush abundance at cold sites, but decreased sagebrush abundance at hot sites. This pattern indicates that sagebrush distribution may be limited by hot and cold temperatures at the extremes of its distribution. We addressed iv our second research question by fitting statistical models to over 25 years of observational data on the performance of four dominant plant species in a sagebrush steppe community. We then experimentally manipulated soil moisture in this community and tested how well the statistical models fit to observational data could predict species’ responses to the experimental treatments. In two out of four species, we found that including climate effects in our models helped us predict the population-level responses to the experiment. Moreover, effects of historical soil moisture variation on vital rates were generally consistent with the effects of drought and irrigation treatments. Our results provide some evidence that observational data can be used to predict species’ responses to climate change in the future. We addressed our third question by simulating environmental change in analytical models of resource competition and quantifying the size of direct and competition-mediated indirect effects that resulted. We showed that the magnitude of indirect effects increased as the niche overlap between competitors increased.