Por apresentar elevada capacidade de produção e por ser uma das poucas cultivares adaptadas à produção de "chips", a cultivar de batata 'Atlantic' responde por cerca de 80% do mercado brasileiro formal de batata consumida desta forma. Com os objetivos de determinar as curvas de crescimento de massa de material seco, o acúmulo máximo e a exportação de nutrientes, em lavouras comerciais, em duas safras, pela cv. 'Atlantic', realizou-se este trabalho nos períodos de setembro a dezembro de 2001(safra das águas) e de fevereiro a março de 2002 (safra da seca) em Itapetininga-SP, localizada na latitude 23 o 35'08" S, longitude 48 o 02'50" W e com 636 m de altitude. Para isso, foram delimitadas quatro parcelas de 100 m X 17 m em lavouras comerciais, das quais foram realizadas coletas semanais das plantas a partir de 20 dias após o plantio. As plantas coletadas foram separadas em raízes, caules, folhas e tubérculos e secas e pesadas para a obtenção da massa de material seco nos diferentes estádios de desenvolvimento, sendo posteriormente moídas, e submetidas à análise para a obtenção da extração de nutrientes ao longo do ciclo. A análise estatística dos parâmetros avaliados foi feita considerando-se as épocas de plantio e quatro repetições. Os resultados permitiram as seguintes conclusões: a safra das águas produziu mais massa de material seco que a safra da seca. O acúmulo de massa da planta foi influenciado pelos estádios da cultura e pela safra: vegetativo (2,2 e 5,2%) < tuberização (13 e 20%) < enchimento de tubérculos (90 e 95%) < maturação (100 e 100%) para a safra das águas e da seca, respectivamente. A seqüência de acúmulo máximo na safra das águas foi: nitrogênio > potássio > cálcio > fósforo > magnésio > enxofre > ferro > manganês > zinco > boro > cobre. Na safra da seca, o potássio trocou de posição com o nitrogênio e o fósforo com o cálcio. O acúmulo máximo dos nutrientes depende da safra e do nutriente: nitrogênio (140 e 119); fósforo (17,6 e15,2); potássio (134 e 139); cálcio (21,7 e 14,6); magnésio (14,3 e 6,9); enxofre (10,8 e 14,6) em kg ha -1 ; boro (107 e 84,3); cobre (43,5 e 38,9); ferro (1.229 e 790); manganês (250 e 130); zinco (156,6 e 124,6) em g ha -1, para as safras das águas e da seca, respectivamente. A seqüência de exportação de nutrientes pelos tubérculos na safra das águas foi: nitrogênio > potássio > fósforo > enxofre > magnésio > cálcio > ferro > zinco > boro > manganês > cobre. Na safra da seca, potássio trocou de posição nitrogênio e cobre com manganês. / By presenting a high yield potencial and being one of the few cultivars adapted for chipping, Atlantic potatoes are responsible for approximately 80% of the brazilian formal potato chips market. With the objective of determining the growth curves, maximum nutrient accumulation and nutrient exportation, this study was carried out in Itapetininga, São Paulo State, at 23o 35'08" S of latitude, 48o 02'50" W of longitude and 636 meters above sea level, in two commercial areas of Atlantic potatoes from September to December 2001 (wet season), and from February to March 2002 (dry season). Four plots with 100 m X 17 m were set in each experiment and plants were collected weekly, after 20 days from planting. The collected plants were separated in roots, stems, leaves and tubers, dried and weighted, to obtain the dry-matter at different stages of growth. Samples were ground and analized to obtain nutrients concentration and to calculate nutrients accumulations. Statistical analysis considered the season and four replications. Results showed that wet season potatoes had higher dry-matter production than those of dry season. Nutrient accumulation was influenced by growth stage and season: vegetative (2.2 and 5.2%) < tuberization (13 and 20%) < tuber bulking (90 and 95%) < maturation (100 and 100%) for wet and dry season, respectively. The maximum nutrient accumulation in the wet season was: nitrogen > potassium > calcium > phosphorus > magnesium > sulphur > iron > manganese > zinc > boron > copper. During dry season, potassium changed position with nitrogen, and phosphorus with calcium. Maximum accumulation of nutrients (kg ha-1 for macronutrients and g ha-1 for micronutrients) depended on the season and on the nutrient: nitrogen (140 and 119); phosphorus (17.6 and 15.2); potassium (134 and 139); calcium (21.7 and 14.6); magnesium (14.3 and 6.9); sulphur (10.8 and 14.6); boron (107 and 84.3); copper (43.5 and 38.9); iron (1229 and 790); manganese (250 and 130); zinc (156.6 and 124.6), for wet and dry season, respectively. The nutrient exportation by the tubers in the wet season was: nitrogen > potassium > phosphorus > sulphur > magnesium > calcium > iron > zinc > boron > manganese > copper. In the dry season, potassium changed position with nitrogen, and copper with manganese.

This study investigated the effects of a seasonally variable forage resource on herbivore population dynamics. This involved estimating the relative importance of environmental conditions, and the accessible and used forage resources, at different stages of the seasonal cycle to herbivores in different life-stages and at different points in the reproductive cycle. This study was carried out in the Richtersveld region in South Africa, using goats kept by semi-nomadic Nama pastoralists. In the main study site, the Richtersveld National Park (RNP), herd movements follow a general seasonal migratory pattern: herds are based in the riparian zone of the Orange River during the dry season, and on plains away from the river in the wet season. Over 800 uniquely marked female goats in three life-stages (adults, yearlings and kids) were monitored over a three year period (2007 to 2009). These goats were weighed at 2 - 3 month intervals to provide an estimate of body condition. Browse availability in the riparian zone was estimated using measurements at an individual branch-level and a whole tree-level. FPAR satellite imagery was used to estimate forage abundance outside the riparian zone. Goat density was mapped for each week of the study using census data and the herd positions. Goat body condition, survival rates and fecundity rates for each life-stage were modelled as a response to forage availability, density and climatic conditions. The riparian zone in the RNP was found to function as the key resource of the RNP goat population. Forage depletion by goat browsing resulted in a negative feedback on goat body condition. This decline in body condition was directly related to lower adult survival over the dry season. Fecundity was also most influenced by dry season conditions through the negative effect of poor body condition on pregnancy rates and birth rates. Asymmetric competition between life-stages, resulting from the riparian browse profile being depleted from the bottom-up, was predicted to have a strong effect on goat demography by contributing to differences in body condition and survival rates between life-stages. Wet season conditions appeared to have little effect on goat population dynamics, either through increased neonate survival or through a mass carry-over effect influencing dry season survival. Goat body condition and vital rates were compared between the RNP and the neighbouring Kuboes rangeland, which does not have access to the Orange River, to assess the impact of differences in their dry season forage resource. The long-term size and variability of the livestock population in the RNP was also compared with livestock dynamics in Paulshoek, a rangeland 250 km south east of the RNP. The a priori predictions of relative population dynamics in each region, based on perceived differences in the nature of the key resource in each region, were largely supported.

PURPOSE: Examine the effect that a competitive season has on performance characteristics in male soccer players. METHODS: 17 Division I National Collegiate Athletic Association (NCAA) male soccer players participated in this study. As part of an ongoing athlete monitoring program, each player completed two maximal effort countermovement jumps each with a PVC pipe, 11kg bar, and 20kg bar during pre- and post-season testing sessions. Jump height (JH), allometrically-scaled peak power (PPa), and reactive strength index-modified (RSImod) were compared using a series of 2 (season) x 3 (load) repeated measures ANOVA. RESULTS: Statistically significant main effect differences existed for season for JH (p = 0.003) and RSImod (p = 0.016), but not for PPa (p = 0.081). Statistically significant main effect differences existed for load for JH and RSImod (both p < 0.001), but not for PPa (p = 0.369). CONCLUSIONS: A soccer season appears to negatively affect the explosive and reactive strength performance characteristics of Division I male soccer players, namely JH and RSImod. In contrast, the relative peak power of male soccer players remained unchanged following the completion of a season. The high volume and intensity of matches and practice experienced over the course of a collegiate season may negatively affect the explosive characteristics of Division I male soccer players, which indicates a need to consistently monitor and alter training loads to maintain performance levels.

The direct effects of chemically- induced reduced transpiration on soil moisture were studied in a sub -watershed of the greater Logan River drainage. No statistically significant differences occurred among the total amounts of water transpired by the treated and control units. The seasonal low points of soil moisture, in September, showed no significant differences in final moisture retention for the two years studied, either for the control or the treated portions of the study site . The 1967 season showed a lag in soil moisture depletion compared to the 1966 season. Although a later spring in 1967 may have aided in the explanation of this lag, there was good reason to believe that the antitranspirant treatment incurred a significant delay in water use. There was evidence that more effective application of chemicals might have given more positive results.

In 1993, to determine if wild-strain mallard releases could be used as a management practice to increase local mallard breeding populations, I released 2,344,4.5- week-old mallard ducklings (1,200 females and 1,144 males) to wetlands on 12,10.4-km2 sites (approximately 200 per site, 100 females, 100 males) in the North Dakota Prairie Pothole Region. I monitored the release sites to determine if any relationship existed between site characteristics and time of release to duckling survival estimates. I conducted breeding pair surveys during 1994 and 1995 on treatment and paired control sites to compare post-release population levels. Lastly, I analyzed return data and habitat use, and conducted behavioral experiments to determine if wild-strain mallards experienced higher mortality rates and if any observed differences could be explained by behavior. In 1994,1 observed 55 of the nasal saddled ducklings returning as adult fem ale to the release sites. In 1995, only 5 nasal saddled females were observed, both on treatment and control sites. No difference was observed hi breeding pair populations on treatment and control sites in 1994 (P = 0.18) and 1995 (P = 0.59). Hard-released wild-strain mallard females had lower survival rates than wild (P = 0.01) and modified gentle-release wild-strain females (P = 0.05). Ail wild-strain females were virtually eliminated from the population by year 4. This suggests that these buds may have been more vulnerable to predation and other mortality factors than wild females. Breeding wild and wild-strain mallard females reacted similarly to human approach, but when flushed, wild females flew farther than wild-strain females (P = 0.0002). Wetlands used by wild-strain females differed from wild females during breeding by type (P < 0.0001) and cover (P = 0.0003) classification. Wild-strain females selected larger, more permanent wetlands exhibiting less emergent vegetation than did wild counterparts. These differences may help to explain why wiki-strain mallard releases did not increase local breeding populations. The lack of band recoveries for wild-strain females during the latter years when viewed in the context of the observed behavioral differences suggests that these birds were unable to adapt to conditions in the wild.

Sport events and attractions which encourage both participants and spectators are seen as significant contributors to the tourism economy (Delpy, 1998; Glyptis, 1991; Standeven & DeKnop, 1999). Further, Gratton and Taylor (2000) note that sport related travel accounts for 7% of total expenditure on sport. To date, the main focus of event sport tourism research has been on the economic impact of large-scale sport events (Burgan & Mules, 1992; Crompton, 1995; Mules & Faulkner, 1996; Walo, Bull, & Breen, 1996). However, Higham (1999) posits that smaller scale events such as regular season games may be of greater benefit to the host community as these events are hosted within existing infrastructure and therefore limit the need for public expenditure. However, fans who travel to regular season competition are a market segment that has been largely ignored by both sport and tourism marketers. Sport marketers have focused on home game attendance, media viewership and product purchases, while tourism marketers have focused on leveraging the destination. Anecdotal evidence suggests that fans who travel organise a substantial proportion of their discretionary time and income around this activity. Recent research by Gibson, Willming and Holdnak (2002, 2003) has begun to understand the behaviours of sport fans who travel to home games. This study seeks to understand the behaviours and experiences of those who travel to attend away games. In particular the study asks: What motivates fans to travel to follow professional sport teams, what experiences fans have and seek during the travel, and what place does travelling to follow a sport team have in the overall consumption behaviour of sport fans. This study examined the motives and experiences of six fan groups travelling interstate to follow their Australian Football League (AFL) team in the 2001 season. As the behaviours and experiences of those who travel to follow sport teams have not previously been explored, exploratory analysis using an iterative process of constant comparison between data colleted from the research setting and the existent literature. Using this method the researcher was able to describe the social world under investigation without preconceived hypotheses. The researcher travelled interstate with each fan group, and collected data via participant observation and interviews with key informants. Data were coded using standard protocols for analysis of qualitative data (Spradley, 1980). The researcher read through the transcripts and field notes and coded all phrases and opinions from the manuscript. Data were analysed through the process of data reduction, selective sampling of the literature, and selected sampling of the data (Stern, 1980). From the initial codes, data reduction identified core variables and emergent themes. Through this grounded theory methodology, a conceptual model was developed which illustrates the motives and experiences of those who travel to follow professional sport teams. Three distinct types of groups were identified, each garnering a distinctive sport tourism experience. The groups identified were: supporter groups, long-term travel groups, and temporary travel groups. While travel to follow the team is the stated rationale for all three groups, the game experience for each is substantially different, four major themes emerged which distinguished the groups and the experiences that they had. These were: (1) group structure, (2) trip characteristics, (3) socialisation, and (4) game experience and reaction to game outcome. Each type of group was found to have a distinct group structure, communication pattern, but differed in terms of the objects to which they identified. Findings suggest that sport fans do not necessarily identify with the team or related object, but can identify with a smaller social group, which has a shared interest in the team. These elements of group structure and point of identification were found to have a reciprocal relationship with various travel elements that were utilised by each group including the mode of transport, temporal elements, choice of destination, and activities at the destination. In particular, the travel elements were chosen so that each group type could best express and experience that which is core to each group. Further analysis suggested that the experience of each of the groups was influenced by the continual development of the group both before and during the travel experience. For the supporter groups and long-term travel groups, rituals, symbols, and folklore played a key role in the experience. These elements of performance were used to continually shape and interpret the travel experience. One would expect that the game would have elevated importance, as it is the activity that legitimates each group. However, the on-field game did not have prime importance. Instead the different points of identification of each group were used as a basis through which the game was experienced. Key implications for sport and tourism marketing suggest that the sport tourism experience is more than an experience of place or an experience of watching the sport. Identification with a small social group is sufficient to generate travel to follow a team. By providing a setting which immerses participants in a particular identity for a prolonged period of time, the act of travelling itself can create a social climate that encourages participants to undertake the trip week after week, and form deep connection to the team. Implications for practice and future research directions are also discussed.

Studies described in this thesis were performed to investigate associations among season, diet, pituitary pars intermedia dysfunction (PPID) and blood concentrations of adrenocorticotropic hormone (ACTH), insulin, glucose, and leptin in horses. In the first study, higher ACTH concentrations were detected in horses affected with PPID. A seasonal increase in plasma ACTH concentration was detected in the late summer and early fall, but PPID did not affect the timing or duration of this increase. Pasture grazing raised glucose and insulin concentrations with a peak in September, at the same time that horses had higher ACTH concentrations, and this convergence of risk factors may raise the risk of laminitis. All of the horses included in this study were from the same farm. The second study was performed to determine whether horses from different locations within the same region exhibited the same seasonal increase in ACTH concentrations. Results of this study indicate that the seasonal increase in plasma ACTH concentrations occurs in horses from different farms with varying management practices. The third study investigated the effects of season on plasma leptin concentrations in the horses from the first study. We hypothesized that higher leptin concentrations would be detected in advance of the seasonal increase in plasma ACTH concentrations. Results did not support our hypothesis because leptin concentrations increased after ACTH concentrations peaked in September. Our findings suggest that the seasonal increase in ACTH concentrations induced leptin resistance, which might facilitate weight gain in the autumn. Alternatively, leptin concentrations increased as a result of weight gain or change in body fat composition. In summary, season appears to signal upregulation of the hypothalamic-pituitary-adrenal axis in horses, in an effort to prepare for winter. This upregulation is retained in horses with PPID, a disorder associated with loss of dopaminergic inhibition to the pars intermedia of the pituitary. The seasonal rise in plasma ACTH concentrations is followed by an increase in leptin concentrations, which suggests the development of leptin resistance or an increase in adiposity.

Grassland birds have declined more than any other guild of birds in North America, largely due to loss and degradation of native grasslands. The Conservation Reserve Program (CRP) has restored some native warm-season grasses (NWSG), but grassland birds continued to decline (-1.1% annually) partly due to the limited acreage converted (1% of southeastern US). Using NWSG in production settings provides profit incentive to landowners while reducing dependency on government programs. Studies examining these production practices and their effect on grassland birds east of the Great Plains are limited. During 2009 – 2010, I surveyed 102 NWSG fields in Kentucky and Tennessee being used for production purposes (control, biofuel, seed, hay, and pasture treatments) to assess bird use and vegetation characteristics. Landscape cover around each field (250, 500, and 1000 m) was digitized from aerial photography. Using analysis of variance (ANOVA), I compared bird (relative abundance, species diversity, and species richness) and vegetation (average height, litter depth, vertical cover, litter cover, and vegetation cover) metrics across the five treatments. Relative abundance for all species, species diversity, and species richness were all greater for seed production fields (P <0.05); other treatments did not differ. Field sparrows (Spizella pusilla) were less abundant (P <0.05) in biofuel than control, hay and graze treatments, whereas eastern meadowlarks (Sturnella magna) and dickcissels (Spiza americana) were more abundant in seed fields. Average vegetation height, vertical cover, percent litter, percent forbs and percent woody plants differed (P <0.05) among treatments. Using Program Mark, I modeled occupancy for field sparrow, red-winged blackbird (Agelaius phoeniceus), eastern meadowlark, and northern bobwhite (Colinus virginianus) using vegetation and landscape cover as covariates. Treatment was influential in field sparrow and eastern meadowlark models, but not those for red-winged blackbird and northern bobwhite. Occupancy for field sparrow and northern bobwhite were affected by woody cover (+), for red-winged blackbird by vegetation height (-), and for eastern meadowlark by litter depth (+) or percent NWSG (+). All four species were negatively affected by forest within 250-m. Use of NWSG in production could increase the amount of available habitat and thus, help conservation efforts for grassland birds.

<p>Recent changes in the timing of annual events are a sign that climate change is already impacting ecosystems. Carbon sequestration by forests increases with longer growing seasons. Biodiversity can be affected by mis-timing of events through shading interactions and frost damage. Projecting forests' ability to provide these ecosystem services in the future requires an understanding of trees' phenological responses to a new climate. I begin by proposing a first order definition of an `optimal' phenological response to warming: that the mean temperature following budburst should remain essentially constant. Analogously, the temperature preceding senescence can serve the same role. </p><p>To understand which environmental cues will drive future changes in phenology, I assimilate clues from observational and experimental literature. For budburst in woody plants, spring warmth, over-winter chilling and light drive nearly all behavior, but species' responses vary widely. Species using chilling or light as safety mechanisms against budburst during mid-winter thaws are thought to be less able to phenologically track a warming climate. However, I show that even species cued solely by spring warmth are likely to under-track temperature changes. Fall cues are more idiosyncratic, and a plant's driver of senescence is likely to vary from year to year. </p><p>Models are a tempting method to untangle species budburst cues and forecast phenology under warmer climate scenarios. I tested two models' ability to recover parameters used to simulate budburst data. The simpler model was cued only by spring warmth while the complex one modulated warmth requirements with chilling exposure. For the simple model, parameters could be recovered consistently from some, but not all, regions of parameter space. The complex model's parameters were largely unrecoverable. To understand the consequences of parameter uncertainty, I applied both models to an 18 year phenological record of 13 deciduous tree species. While a few species fell into identifiable regions of the simple model's parameter space, most did not, and projected budburst dates had wide parameter-derived uncertainty intervals. These bands were wider still under a 5°C warming scenario. Even greater uncertainty resulted from the complex model.</p><p>To better understand plants' potential for growing season extension I subjected seedlings to warmer climates in a series of open-topped chambers in sites at each end of the eastern deciduous biome. Soil and air were heated to 3 or 5°C above ambient, or left unheated. For nearly all species, warming hastened budburst and germination and delayed senescence. However, these events failed to track temperature changes, happening at warmer temperatures in hotter chambers. Individual species showed a remarkable variability of all events' dates within treatments, and even within chambers. Because phenological traits are heritable, this offers a potential for evolutionary response to climate change.</p><p>This research has shown that while individual trees extend their growing seasons under warmer temperatures, they typically under-respond to the magnitude of warming, suggesting forests' capacity for increased carbon sequestration may reach a limit. However, within populations, trees vary substantially in their phenological responses, forming a possibility for evolutionarily adaptation to changing cues.</p> / Dissertation

<p>This research investigated the nature, source and the spatial variation of the salinity of the water used for irrigation in the urban farming area of Philippi, which lies in the Cape Flats region of the Cape Town Metropolitan Area, South Africa. The irrigation water is mainly drawn from the Cape Flats aquifer, and pumped into ponds for eventual crop irrigation. Water samples were collected in summer and in winter from fifteen selected sites using standard water sampling procedures. Each site consisted of one borehole and one pond. The samples were routinely analyzed for salinity levels, and concentrations of major and minor ions. From the same boreholes and ponds, water was sampled in summer for isotope analysis to assess effects of evaporation on the water quality and salinity. Descriptive statistics were used to display the variation in range of specific ions in order to compare them with the recommended ranges. Geographical Information Systems analysis described the spatial distribution of the salinity across the study area, and hydrogeochemical analysis characterized the various waters and detected similarities between the water samples in the study area and other waters found in the Cape Flats region. In addition, the US salinity diagram classification of irrigation water developed by Richards (1954) was used to assess the current suitability of groundwater and pond water samples collected during the entire sampling period for irrigation activities. The research indicated that the concentrations of some ions such as chloride, nitrate, potassium and sodium exceeded in places in the study area, the target range values set by the Department of Water Affairs and Forestry (DWAF, 1996) and the Food and Agriculture Organization (Ayers and Westcot, 1985). It revealed that borehole and pond water were mostly brackish across the area regarding their total dissolved salts content, and fresh water was only found in the middle part of the study area. The research found that sea water does not intrude into the aquifer of the study area, and the accumulation of salts in groundwater and soil in the study area is mainly due to the agricultural activities and partially due to the natural movement of water through the geological formation of the Cape Flats region. The conceptual model of the occurrence of the salinization process supported these findings. From this investigation it is understood that the groundwater and pond water in the study area were generally suitable for irrigation purposes but they have to be used with caution as the vegetables are classified as sensitive and moderately sensitive to salt according to DWAF Irrigation water guidelines (1996). The quality of these waters was mainly affected by the land use activities.</p>