This paper demonstrates the utility of small area estimation (SAE) of poverty methods for researchers that wish to conduct a detailed welfare analysis as part of a larger survey of a small geographic area of interest. Researchers studying context-specific technologies or interventions can incorporate the survey-based SAE of poverty approach to conduct detailed poverty analyzes of their specific area of interest without the expense of collecting household consumption data. This study applies SAE methods as part of an impact assessment of a locally adapted conservation agriculture production system in Uganda's Tororo District. Using SAE, I assess the Tororo District's Foster-Greer-Thorbecke (FGT) rural poverty indices, estimate the effects of per acre farm profit increases to poor households on the district's rural poverty indices, and compare the findings to current estimates of the net returns from conservation agriculture in the Tororo District. The SAE results suggest that increasing the farm profits of the bottom 30% of households by two U.S. dollars per acre per season could reduce the district's rural poverty incidence by one percentage point. The available data on the net returns to conservation agriculture in the Tororo District, however, indicate that these modest increases may only be achievable for adopting households that face high land preparation costs. / Master of Science

Klimatförändringar kommer att få en ökad påverkan på Ölands jordbruk genom en ökad medeltemperatur och fler extremväder som torka och skyfall. Jordbruket är dessutom en av de sektorer som bidrar mest till övergödningen av Östersjön.   Conservation Agriculture bygger på de tre principerna minimal plöjning, direktsådd i ett permanent växttäcke och varierad växtföljd på grödor. Detta ger ofta fördelar såsom en ökad infiltration av regnvatten och minskad avrinning, samt minskat läckage av gödnings- och bekämpningsmedel. På lång sikt är metoden ofta ekonomiskt lönsam, men under omställningsperioden kan den ge lägre avkastning på grödor och ett större behov av bekämpningsmedel (om det används).   Syftet med undersökningen är att undersöka hur Ölands jordbrukare ser på jordbruksmetoden, och hur villigheten att prova metoden skulle kunna ökas. Detta gjordes genom en enkätundersökning med tretton respondenter. Denna grupp kan inte ses som representativ för alla jordbrukare på Öland, men indikerar att förbättringar i spridningen av information skulle behöva göras om en ökad tillämpning önskas.   Klimatförändringar, tillgång till vatten, minskade dieselkostnader och erosion visades vara troliga potentiella drivkrafter för en ökad tillämpning. Omställningskostnader, ogräshantering och att grödrester kan behövas till foder kan istället ses som troliga utmaningar för en tillämpning av metoden på Öland. Detta behöver dock styrkas med vidare studier. / Climate change will have an increasing impact on the farmlands of Öland, the average temperature will rise and extreme weathers such as drought and downpour will be more common. It would also be desirable to lessen the leakage of nutrients from farmlands to the Baltic Sea.   Conservation Agricultures fundamentals are reduced tillage, permanent crop coverage and plant rotation. It provides benefits like increased water infiltration, reduced runoff and reduced leakage of fertilizers and pesticides. The method is normally financially profitable in the long run, but will during the transition period result in a lower yield and a higher use of pesticides, if it’s used.   The study’s purpose  is to investigate the farmers perception of the method, and how they could be made more willing to try it. This was done through a questionnaire with thirteen respondents. The group can not be seen as representative for all farmers on Öland, but it indicates that the spread of information needs to improve if a higher adaptation is desired.   Climate change, access to water, fuel costs and erosion was shown to be potential motivations for an increased adaptation. Transition costs, weed control and the need for straw as animal feed were probable challenges. This needs to be confirmed through further studies.

<p> The state and federally endangered California clapper rail (<i> Rallus longirostris obsoletus</i>) has declined in abundance and been reduced in range and now occupies fragmented intertidal saltmarsh only within San Francisco Bay. Historically extensive salt marsh habitats existed in San Francisco Bay and today, remnants are largely restricted to the water's edge with dikes and levees separating marshland from modified habitats unsuitable for clapper rails. Clapper rail population abundance has roughly tracked a series of positive and negative impacts including market hunting at the turn of the 20th century, widespread habitat reduction and fragmentation, and invasive species introduction and eradication programs. Despite these changes, rail populations have been subject to the ebb and flow of the tides, which regularly inundate salt marsh habitats. The influence that tides have on vertebrate species living in intertidal saltmarsh should be substantial, but the relationship between tide and California clapper rails is poorly understood. This research identified important ways in which tides influenced demographic processes, space use, and resource selection in California clapper rails. Tidal inundation in San Francisco Bay saltmarshes creates zonation in plant communities, typically with tall monocots in the low marsh (<i>Spartina </i> sp.), short pickleweed (<i>Sarcocornia pacifica</i>) in mid-elevation ranges, and gumplant (<i>Grindela humilis</i>) in the high marsh. Invasive Spartina (<i>Spartina foliosa x alterniflora </i>) grows taller and thicker than native Pacific cordgrass (<i> Spartina foliosa</i>). Invasive Spartina also grows lower onto mudflats, further up into pickleweed areas, and provided both nesting habitat and tidal refuge for clapper rails. In Chapter 1, I examined survival rates of California clapper rails. Specifically, I investigated whether seasonal patterns observed in the early 1990s were still evident and assessed the influence that Invasive Spartina and the degree of tidal inundation on weekly survival rates in four South San Francisco Bay salt marshes. Between January 2007 and March 2010, California clapper rail annual survival was 73% greater in Spartina-dominated marshes (&Scirc; = 0.482) than in a control marsh dominated by native vegetation (&Scirc; = 0.278). Lower survival also occurred during periods when tide height was greatest and during the winter. Survival patterns were consistent with Invasive Spartina providing increased refuge cover from predators during tidal extremes which flood native vegetation, particularly during the winter when the vegetation senesces. Tide heights also strongly influenced selection for artificial habitats provided adjacent to one marsh during the winters of 2010-2011 and 2011-2012. Ten floating islands equipped with canopies providing cover were monitored using time-lapse cameras for evidence of clapper rail use. Clapper rails regularly used artificial islands once tides reached heights equal to the average surface elevation of the marsh. When tides had inundated the marsh plan, observed use of the artificial islands was more than 300 times expected use based on the surface area provided. Probability of use varied among the islands and low levels of use were observed at night. Endemic saltmarsh species are increasingly at risk from habitat change resulting from sea-level rise and development of adjacent uplands. Escape cover during tidal inundation may therefore need to be supplemented if species are to survive. I developed a new method to estimate space use accounting for individual movement phases within non-stationary relocation datasets using simulated radio-telemetry data. To define movement phases I used a nonparametric, multivariate test to detect change points in the mean or variance of a sequence of x,y coordinates. Once all phases (change points) were identified, Gaussian kernel density analysis was used to estimate space use during each phase, which I termed change-point utilization distributions (CPUDs). One advantage of this technique is that the location of change points can subsequently be tested for relationships with conditions that might trigger a change in how individuals use space. Change points in clapper rail movement were associated with a variety of environmental and biotic variables including high tides, nesting activity, intrusion by neighboring clapper rails, and transient movements outside the home range. Change points occurred more than twice as frequently during the highest observed tides relative to all other tide heights. Another use of CPUDs is that space use patterns of adjacent individuals can be evaluated for joint overlap only during specific time periods when overlap occurs. I used CPUDs developed for California clapper rails and identified the point within overlapping space-use estimates where each individual had priority access to the resources within its utilization distribution (i.e. the lowest kernel density isopleth that was common to two overlapping individuals). This provided an estimate of the spatial region at which individuals exhibited territoriality. During the breeding season, space use distributions overlapped less and average territory size increased relative to the non-breeding seasons. Population density implied by these territory sizes (1.38 birds/ha) is comparable to density estimates during the 1970s and 1980s. Together these findings show the great degree to which clapper rail behavior and demography can be influenced by the tides that populations experience. It is my hope that conservation efforts for this species, particularly in the arena of habitat restoration may benefit from this research.</p>

<p> Within Mediterranean ecosystems, conservation and restoration action is becoming increasingly necessary to preserve biological diversity within these working landscapes. Many of these systems have been managed to increase forage production through the removal of canopy trees and shrubs, resulting in understories dominated by herbaceous species. In California, woody plant regeneration can be constrained by exotic annual grasses, particularly in the presence of grazing. <i>Quercus douglasii</i> and other oak species are known to indirectly facilitate and provide spatial refuges to native plants through competitive suppression of herbaceous productivity. Mature trees can also compete with understory recruits and shrub species, limiting their occurrences to interstitial canopy gaps and resulting in reduced competition for resources. This study surveyed the overstory composition of 34 study plots at the Sierra Foothill Research and Extension Center to determine the effects of tree canopies on the occurrence and distribution of native woody species in the undergrowth. Because other studies have shown safesites, which include rock outcroppings, woodpiles, and nurse plants to facilitate woody plant establishment in this system, the microsites containing individual plants were recorded to determine the distribution of different woody species. Multivariate regressions showed that understory plant richness and abundance increased with higher levels of canopy cover, suggesting that mature trees play a role in maintaining understory diversity. The majority of stems were found growing directly underneath the canopy, with only one species established primarily in interstitial areas. Restoration strategies can utilize the natural distributions of woody species in the understory in order to increase the survival of plantings while continuing to manage these systems for multiple ecosystem services.</p>

<p> After nearly being extirpated from the state, black bears in Maryland have rebounded to a point where recreational harvest has now become an important management tool. Having a better understanding of bear population parameters, movements, and harvest vulnerability allows managers to implement hunting more effectively and responsibly. To estimate demographics of the Maryland bear population, we implemented noninvasive genetic sampling of bear hair during summer 2011. We used a model-based sampling design that allowed us to collect samples more efficiently. We used presence-only maximum entropy (Maxent) modeling to classify the study area based on predicted probability of bear occurrence, and allocated the majority of our hair snares to areas with high or medium probabilities. Using microsatellite analysis and mark-recapture methods, we estimated the bear population at 701 individuals. This represents a nearly doubling of the population since the previous estimate in 2005. Our density estimate (0.25 bears/km²) is comparable to other estimates from southeastern and mid-Atlantic states. Our sampling approach did lead to more efficient sample collection, with more hair samples collected at snares located in areas with predicted high or medium probability of bear occurrence than those in low probability areas. However, in the eastern portion of our study area, where bear occurrence is presumed to be much lower, our sampling effort seemed insufficient to collect enough samples for reliable abundance estimation. As a first step toward quantifying harvest vulnerability, we used Global Positioning System (GPS) units to record movements and spatial behaviors of 108 bear hunters during the 2005&ndash;2007 Maryland bear hunting seasons. Median values showed that hunters traveled 2.9 km per hunting event, but only 0.6 km from their starting point. Hunters did not seem to show any preferential use of areas based on the landscape metrics we examined (e.g., elevation, distance from nearest road) except cover type, where 81% of locations were in deciduous forests. We found few differences between spatial behaviors of groups of hunters based on harvest success, residency, and previous bear hunting experience, as classified using post-hunt mail surveys. One notable difference is that successful hunters used steeper slopes than unsuccessful hunters. We also found that hunter perceptions of total distance traveled and distance from nearest roads were often highly inaccurate, showing that hunter surveys are not a useful tool for collecting those data. For Garrett County, Maryland, we used the hunter locations to create a Maxent model of the spatial distribution of harvest pressure. We also created a model using fall telemetry locations of female bears and compared the models to identify areas of high (i.e., high hunter and high bear occurrence) and low (i.e., low hunter and high bear occurrence) harvest vulnerability. Both models showed higher probability of occurrence on public lands. Both high and low vulnerability areas comprised small portions of the county. The low vulnerability areas included 9 larger blocks (>1 km²), which were 2.3 times steeper, 2.0 times farther from roads, and 1.5 times farther from streams than the medians for the study area. Those characteristics may limit hunter access to and use of the areas. Our predicted high vulnerability areas did not correspond to most previous bear harvest locations, indicating that our definition of harvest vulnerability often does not translate to actual harvest. Finally, we used GPS collars to track female bear locations in Garrett County and examine home range dynamics. Fixed kernel estimates for annual, spring, summer, and fall home ranges were 10.40 km², 8.93 km², 16.08 km², and 19.35 km², respectively. Fall and summer home ranges were larger than spring home ranges, but summer and fall ranges were similar. Solitary females had mean spring home ranges 6.9 times larger than females with cubs-of-the-year, but ranges did not differ during other seasons. Bears exhibited high levels of home range fidelity, with home range centroids shifting little among seasons or years. Intraspecific overlap of home ranges occurred during all 3 seasons, but was most common in summer. The results of this study provide Maryland bear biologists and managers with essential information about the state&rsquo;s bear population. Home range estimates represent important baseline information to determine appropriate spatial scales of management. The abundance estimates will be used to set proper harvest quotas with the goal of slowing the bear population growth. The hunter movement analysis and harvest vulnerability modeling may be used by managers to adjust harvest regulations to increase the efficacy of the hunting seasons.</p>

<p> The Golden-winged Warbler (<i>Vermivora chrysoptera</i>) is an imperiled migratory songbird that nests in young forest habitats of eastern North America. As such, this species has recently been the focus of an intensive multi-year, range-wide, breeding ecology study. A major focus of this research involved spot-mapping color banded males to examine relationships between nesting success and territory-scale habitat variables. I compared differences in space and habitat use of individual male Golden-winged Warblers that were monitored using both spot mapping and radio telemetry. An individual's telemetry delineated use area was on average 3.6 times larger than its spot-mapped territory. Almost half (46%) of all telemetry locations were located outside their respective male's spot-mapped territory. Number of saplings was higher in telemetry use areas (22.49 &plusmn; 2.14) than spot-mapped territories (11.80 &plusmn; 1.86). Although the exact motive for extra-territorial movements is unknown, foraging and/or suggestive observations of extra-pair copulation are likely motivating factors. The results of my study suggest Golden-winged Warblers are seeking resources outside their spot-mapped delineated territories. Furthermore, Golden-winged Warblers were found to have more telemetry locations in mature forest than found through spot-mapping. Ultimately, spot mapping alone does not accurately reflect Golden-winged Warbler space use and habitat needs.</p>

<p> My research was focused on greater sage-grouse (<i> Centrocercus urophasianus</i>; hereafter "sage-grouse") nest-site selection, nest success, and hen survival in relation to avian predators. The trade-off between using habitat and avoiding predators is a common decision for prey species including sage-grouse. In Chapter 2, I compared avian predator densities at sage-grouse nest and brood locations to random locations. Sage-grouse were located where densities of small, medium, and large avian predators were 65-68% less than random locations. </p><p> The effects of anthropogenic and landscape features on habitat use of sage-grouse hens have not been evaluated relative to avian predator densities. In Chapter 3, I compared anthropogenic and landscape features and avian predator densities among sage-grouse locations (nest, early-brood, late-brood) and random locations. I found sage-grouse hens chose locations with lower avian predator densities compared to random locations, and selected locations farther away from anthropogenic and landscape features. </p><p> Depredation of sage-grouse nests can be an influential factor limiting their productivity. Predator removal has been simultaneously proposed and criticized as a potential mitigation measure for low reproductive rates of sage-grouse. In Chapter 4, I hypothesized that sage-grouse nest success would be greater in areas where Wildlife Services lowered common raven (<i> Corvus corax</i>: hereafter "raven") density. I found that Wildlife Services decreased raven density by 61% during 2008&ndash;2011 but I did not detect a direct improvement to sage-grouse nest success. However, sage-grouse nest success was 22% when ravens were detected within 550 m of a sage-grouse nest and 41% when no raven was detected within 550 m. In Chapter 5, I assessed interactive effects of corvid densities relative to anthropogenic and landscape features on sage-grouse nest success. I found that sage-grouse nest success was positively correlated with rugged habitat. </p><p> Survival of breeding-age birds is the most important demographic parameter driving sage-grouse abundance. In Chapter 6, I evaluated the effect of raptor densities, proximity to anthropogenic and landscape features, and hen behavior on survival of sage-grouse hens. I found that sage-grouse hen survival was negatively correlated with golden eagle (<i>Aquila chrysaeto</i>s) density, proximity to anthropogenic and landscape features, and hen parental investment (nesting and brood-rearing).</p>

<p>Rice not collected by harvesters and natural seeds are important foods for waterfowl. Estimation of abundance of these seeds is necessary for calculating waterfowl habitat conservation needs in the Louisiana Chenier Plain (LCP) and Texas Mid-Coast (TMC). My objectives were to quantify dry mass of rice and other seeds from August-November 2010, and estimate waterbird abundances on farmed and idle ricelands in these regions from December 2010-March 2011. Rice abundance in farmed ricelands ranged from 159.7 kg/ha (CV = 66.6%) to 1,014.0 kg/ha (CV = 8.3%). Natural seed abundance in idle ricelands ranged from 99.7 kg/ha (CV = 32.9%) to 957.4 kg/ha (CV = 17.2%). Greatest waterbird densities occurred in shallowly flooded disked ricelands (mean = 7.35 waterbirds/ha, 90%; CI = 2.37-19.70). Ratoon, disked, and shallowly flooded ricelands are important habitat for non-breeding waterbirds but variable estimates of seed and waterbird abundances warrant continuation of this study.

<p> What drives invasive species success? My research consists of four studies aiming to answer this question for <i>Ligustrum sinense</i>. The four projects are: (1) Synthesis of invasion literature within passenger-driver-backseat driver frameworks; (2) hydrochory investigation of water as a dispersal mechanism for invasion; (3) ecohydrology investigation of inundation effects on seed viability of <i>L. sinense</i>; (4) dendrochronology study of the effects of stream channelization and <i>L. sinense</i> invasion on bottomland oak tree growth. Results suggest that <i>L. sinense</i> initially invaded habitats that were hydrologically altered, resulting in drier conditions and a "novel niche." Dispersal <i>via</i> hydrochory allowed <i>L. sinense</i> to quickly colonize the novel niches. Once established, <i>L. sinense</i> competed with native oak species contributing to reduced growth rates, an "invasion meltdown." Control strategies should aim to remove <i>L. sinense</i> and return natural hydrologic regimes, or should consist of human-assisted re-establishment of native species that can thrive in altered conditions.</p>

<p> West Texas, especially the Trans-Pecos region, mainly consists of desert shrubs and grasslands with patches of higher elevation (1,500 &ndash; 2,000 m) mountain ranges. Black bears (<i>Ursus americanus</i>) were extirpated from this area by the 1940s because of predator control and over hunting. In the 1980s, black bears returned to west Texas in a natural recolonization movement from Mexico, where they had survived. The black bear populations of the Trans-Pecos region and northern Mexico fit a mainland-island metapopulation model. Based on previously published research on this recolonization event, I identified several likely habitat recolonization sites and corridor routes for use in predicting possible black bear dispersal throughout the area. Then, using these corridor and recolonization scenarios, I produced a black bear metapopulation model for the Trans-Pecos region.</p><p> The possible habitat recolonization site map was created by combining 2 habitat suitability index (HSI) maps and using these HSI maps to define 'core' and 'useable' black bear habitat within the Trans-Pecos region. Using these locations, along with dispersal probabilities and black bear demographic parameters, I created a corridor dispersal map of the area using the program Circuitscape.</p><p> The metapopulation model was created using STELLA modeling software. Each recolonization location in the Trans-Pecos region (Big Bend National Park, Black Gap Wildlife Management Area, and the Davis Mountains) has its own black bear subpopulation. The metapopulation model is a stochastic compartment model based on a yearly time step (&Delta;<i>t</i> = 1 yr). This model was tested for the effects of: carrying capacity per site, immigration rates from Mexico, rates of dispersal from Black Gap Wildlife Management Area to the Davis Mountains, and the recovery time for the area after complete extirpation from the Trans-Pecos. This information will help local biologists conserve and manage these returning black bears in the Trans-Pecos region. </p>