<p> Coyote brush (<i>Baccharis pilularis</i>) is a native shrub common to the coastal sage scrub (CSS) habitat of California and often appears in a complex mosaic with other vegetation types including grasslands. Both CSS and California grasslands are threatened habitats, where restorations of type-converted landscapes are often burdened by the persistent dominance of non-native annual grasses. However, coyote brush has been documented periodically invading grasslands, resulting in a change of state from grassland to shrubland. This study investigates the long-term dynamics of coyote brush invasion in a type-converted landscape of Southern California. Stands of expanding coyote brush were transected to identify species composition along a spatial and temporal continuum. Results show that following initial invasion, non-native species are replaced by not only coyote brush, but also several other noteworthy native species. This study shows that in Southern California, coyote brush invasion of type-converted landscapes leads to increased native diversity that includes native grasses.</p>

<p> Wildfire and subsequent timber salvage harvests are forecasted to increase in the Alaska boreal forest, creating the need to evaluate the effectiveness of forest regeneration practices in light of these interacting disturbances. Silvicultural practices such as site preparation and assisted regeneration are carried out shortly after disturbance in order to ensure satisfactory reforestation. Thirty years after a stand-replacing wildfire and salvage, we sampled an operational-scale (26.7 ha) white spruce (<i>Picea glauca </i> Moench [Voss]) regeneration trial established in a productive upland forest. Regeneration treatments were applied in a split-split plot experimental design on two landform types (LF), four ground scarification treatments (GST) plus a non-scarified control, and five artificial white spruce regeneration treatments (WSRT) plus a natural seedfall control. We analyzed total biomass as well as stand density and basal area for all species, seeking to evaluate the persistence of regeneration silvicultural treatment effects 28 growing seasons after installation. Our results indicate GST had no significant effect on white spruce basal area or stem density. </p><p> However, compared to natural seedfall control plots, white spruce basal area was six times higher in planted seedling plots, and white spruce stem density (dbh &ge; 1.0 cm) was nearly three times greater in broadcast seeding plots. White spruce stem density from natural seedfall averaged 944 stems ha^-1, but density was dependent on both topographic position and distance to wind-dispersed seed sources. Scarification nearly doubled Alaska birch (<i>Betula neoalaskana</i> Sarg.) stem density and basal area compared to non-scarified control plots. Planted white spruce plots supported 19% less birch basal area, except in the most intensive scarification treatments in which birch basal area did not differ. Although quaking aspen (<i>Populus tremuloides</i> Michx.) density and basal area were generally unaffected by the regeneration silvicultural practices in this study, intensive scarification reduced basal area by half on slope plots. These results confirm that regeneration silvicultural practices continue to influence stand development beyond the stem initiation stage, but practices that promote one species may reduce others.</p>

<p> Disturbances such as fire and mowing temporarily increase available resources for plants, opening a window of opportunity for establishment. During the recovery of vegetation after disturbance in remnant prairies, seedling establishment is often negligible compared to vegetative regrowth. It is unclear if this is the case in reconstructions. I tested the contribution of seedlings to diversity after disturbance in two, 25-year-old, low diversity reconstructed prairies by removing seedlings, allowing seedlings, and adding seed in 1 m² plots. Disturbance frequency effects were tested by clipping each treatment zero, one, or multiple times. After two growing seasons, in the wetter field site, seedlings removed plots had the lowest species richness and highest evenness, plots with seedlings from the seed bank were intermediate, and plots with added seed had the highest richness and lowest evenness. In the drier site, only adding seed impacted richness (higher) and evenness (lower). In both sites, the seeds present in the seed bank were over 80% from non-native species. Seedling establishment was quantified along with light, water, and nitrate availability within each seeded plot. In the wetter site, resource levels did not predict seedling numbers, but seedlings were more numerous in more frequently clipped, lighter plots. In the drier site, seedlings were more numerous in less frequently clipped plots which received less light and may have remained moister. Seedling establishment from any source never affected community diversity suggesting that while some seeds establish, reconstructions are primarily maintained by vegetative reproduction. The inconsistent effect of clipping highlights the need for management to adapt to varying precipitation, however, given the non-native dominated seed banks, any management intended to increase seedling establishment could result in increased non-native cover. </p>

<p> To evaluate the success of reestablishing tidal connection to salt marshes as a method of creating new fish habitat, both newly-restored and previously-restored (hereafter termed "reference") habitats within the Huntington Beach Wetlands Complex were monitored over a two year period. Although fish abundance and diversity metrics were generally equivalent between marshes within one year, community composition remained different. Newly-restored habitat generally had higher abundances of planktivores (e.g., <i>Atherinops affinis</i>), and lower abundances of benthic carnivores (e.g., <i>Fundulus parvipinnis </i>) relative to reference habitat. To determine the possible mechanisms driving fish habitat use patterns, trophic support was assessed for juvenile California halibut, <i>Paralichthys californicus,</i> using gut content and stable isotope analyses of wild-caught and caged individuals. Observed differences in the diet of halibut across size classes indicated ontogenetic shifts in feeding behaviors, while similarity in diet among marshes suggested the potential for rapid development of trophic support within restored habitats for this species. </p>

<p>The purpose of this study is to investigate and review literature that examines whether job satisfaction and procedural justice have a positive relationshipwith employees organisational citizenship behaviour in a brick manufacturing industry</p>

Communication is regarded as the lifeblood of any organisation. It plays a vital role in ensuring the smooth functioning of all organisational activities. Communication enables individuals and departments to work together harmoniously to achieve a common goal. It allows leaders to inform, influence and motivate employees towards goal attainment. The survival and profitability of the protection services department studied depends on their leaders ability to effectively communicate with its workforce. Effective communication should be an ongoing process in this organisation. The purpose of this dissertation was to investigate the effectiveness of communication amongst supervisors at the protection services department. The key dimensions that were explored in this study are the defensive scores dimension (namely, evaluation, neutrality, control, superiority, strategy and certainty) and the supportive scores dimension (namely, provisionalism, spontaneity, empathy, problem orientation, equality, and description). The research was conducted at the protection services department in Marianhill, Durban. Cluster sampling was used in this study. Various statistical techniques were used to test the six hypotheses. The results were analysed and a presentation and discussion of the respondents perceptions were presented. From this study, it is evident that there is an immediate need for development in the two key dimensions, namely, the defensive scores dimension (evaluation, neutrality, control, superiority, strategy and certainty) and the supportive scores dimension (provisionalism, spontaneity, empathy, problem orientation, equality and description). The limitations of the study and suggestions for further research are also outlined. Furthermore, a discussion of the possible causes for the findings are included, along with recommendations to improve the effectiveness of communication amongst supervisors in the organisation. / Thesis (M.A.)-University of Durban-Westville, 2003.

<p> <b>Chapter 1:</b> <i>Impending extinction of salmon, steelhead, and trout (Salmonidae) in California. </i> California contains the southernmost native populations of most Pacific Coast salmon and trout, many of which appear to be rapidly headed toward extinction. A quantitative protocol was developed to determine conservation status of all salmonids native to the state. Results indicate that if present trends continue, 25 (78%) of the 32 taxa native to California will likely be extinct or extirpated within the next century, following the bull trout (Salvelinus confluentus), which was extirpated in the 1970s. California's salmonids are adapted to living in a topographically diverse region with a Mediterranean climate, characterized by extreme seasonal and inter-annual variability in streamflow. Consequently, California salmonids have evolved extraordinary life history diversity to persist in the face of stressful conditions that often approach physiological limits. The spatial distributions of California salmonids vary from wide-ranging anadromous forms to endemic inland forms persisting in only a few kilometers of stream. Eighty-one percent of anadromous taxa are threatened with extinction and 73% inland taxa are either threatened or already extinct. Although specific drivers of decline differ across species, major causes of decline are related to increasing competition with humans for water, human degradation of watersheds, and adverse effects of hatchery propagation. Climate change, interacting with the other causes of decline, is increasing the trajectory towards extinction for most populations. Bringing all of California's salmonid fishes back from the brink of extinction may not be possible. If there are bold changes to management policy, however, self-sustaining populations of many species may be possible due to their inherent ability to adapt to changing conditions. </p><p> <b>Chapter 2:</b> <i>Floodplain Farm Fields Provide Novel Rearing Habitat for Chinook Salmon.</i> When inundated by floodwaters, river floodplains provide rich food resources and high quality habitat for many species of wildlife. Globally, many rivers have been leveed and floodplain wetlands drained, primarily for flood control and conversion to agriculture. In the Central Valley of California, USA, where less than 5% of floodplain wetland habitats remain, a critical conservation question is how farmlands located on floodplains can be managed to provide increased habitat benefit to fish and wildlife. In this study agricultural fields located on the Sacramento River floodplain were intentionally inundated after the autumn rice harvest to mimic natural floodplain inundation patterns and determine if they could provide shallow-water rearing habitat for imperiled Sacramento River fall-run Chinook salmon (<i>Oncorhynchus tshawytscha</i>). Approximately 10,000 juvenile fish were reared on two hectares for six weeks when fields were idle between fall harvest and spring planting. Growth rates of juvenile salmon (average 0.76 mm/day) reared in this surrogate floodplain habitat were among the most rapid ever documented in fresh water in California and survival was high (minimum estimated survival 57%). The apparent compatibility of crop production and fish and wildlife habitat on the same ground demonstrates the ecological and economic benefits of reconciling management of agricultural working landscapes with recovery of native species. </p><p> <b>Chapter 3:</b> <i>Managed Inundation of Agricultural Floodplains Produces Record Growth in Juvenile Chinook Salmon.</i> Floodplains are important engines of seasonal productivity in river ecosystems. However, in North America and Europe over 90% of floodplains habitats are no longer hydrologically connected to rivers, representing a significant loss of riverine ecosystem food web productivity. Expanding inundated floodplain area increases the volume of the photic zone, the uppermost portion of the water column, where sunlight is converted to carbohydrates by phytoplankton. Greater extent of shallow floodplain augments overall food availability and provides important aquatic habitats for many species. For example, invertebrates are in greater abundance on floodplains than in adjacent river channels, enhancing foraging success of fish that gain access to these seasonally inundated aquatic habitats. Like many large river valleys globally, the Central Valley of California, USA, (encompassing the Sacramento and San Joaquin River watersheds) has lost the majority of its floodplain habitat, primarily to conversion to agriculture. However, remnant floodplains still exist and are managed as flood bypasses which function in the winter wet season as "pressure relief valves," allowing floodwaters to pass safely around vital infrastructure and urban areas. In the summer dry season, bypasses are actively farmed. Managed inundation of agricultural floodplains may offer a means of regaining some of the ecological benefits of floodplains for native fish and wildlife while continuing to support flood protection and production agriculture, thereby creating a landscape where native species and human uses can coexist. An example of such reconciliation is Yolo Bypass, a farmed floodway where two decades of managed winter inundation of post-harvest rice fields&mdash;in the agricultural off-season when farm fields are idle&mdash;creates wetland habitat for millions of waterfowl using the critically important Pacific Flyway. Recent studies have shown that managed inundation can also provide suitable floodplain foraging habitat for native fish species such as juvenile Chinook Salmon. </p><p> In order to better understand how rice farming practices affect the quality of reconciled winter rearing habitat for juvenile fall run Chinook Salmon (Oncorhynchus tshawytscha), we built and experimentally manipulated nine replicated two-acre rice fields. Fields shared a common layout and water source. Each was randomly assigned to one of three post-harvest farming options generally used in the Yolo Bypass; fallow, leaving standing rice stubble, or tilling to incorporate the stubble into the soil. Each field was stocked with approximately 4,500 juvenile salmon. Weekly sampling for water quality, invertebrate abundance and diversity, and fish growth and survival was conducted for 6 weeks, after which fields were drained and fish counted, measured</p>

<p> MONITOR is an active, automatic extraction sampler that collects daily, integrated extracts of hydrophobic compounds in water. Compounds partition from water, through a polydimethylsiloxane membrane and into hexane. The sampling rate, membrane-water partition coefficients (K_MW) and hexane-water partition coefficients (K_HW) were determined for atrazine and four nonpolar reference compounds. The reference compounds had high effective sampling rates (>10 L/day) while atrazine had a low effective sampling rate (&lt;1 L/day). Atrazine had intermediate hydrophobicity as determined by K_MW and octanol-water partition coefficient (KOW). However, atrazine had a low K_HW, which caused its low sampling rate. In spite of MONITOR's low sampling rate for atrazine, the concentration of atrazine in the drinking water of Syracuse, New York was observed from March - November 2012 using MONITOR. The average concentration was 0.016 &mu;g/L. MONITOR was able to capture fluctuations in the concentration of atrazine at very low levels over several months.</p>

<p> Invasive ants are one of the largest threats to Pacific island ecosystem conservation. I investigated effective ant control options by examining the relative attractiveness of five commercial ant baits to yellow crazy ants (<i>Anoplolepis gracilipes</i>). The results were used to select three baits whose efficacy at reducing <i>A. gracilipes</i> abundance was then tested in experimental treatment plots. The trials failed to identify an obvious preference for any of the baits and none of experimental treatments resulted in decreases in <i>A. gracilipes</i> abundance that differed from untreated plots. Additionally, the impact of <i>A. gracilipes</i> on nest initiation rates of Red-tailed Tropicbirds (<i>Phaethon rubricauda </i>) was explored. The survey found 90% fewer nest occurred in plots containing <i>A. gracilipes.</i> These results demonstrate the negative impacts invasive ants can have on ground-nesting seabirds and suggest that commercial ant baits may be ineffective against controlling <i> A. gracilipes</i> supercolonies.</p>

Habil.-Schrift, Techn. Univ. Braunschweig, 2004.