The variation that exists in both time and space in riparian plant communities was explored in five streams within the Salmon National Forest and surrounding Bureau of Land Management (BLM) lands of central-eastern Idaho that are managed for cattle grazing. In this study, we evaluated the ability of commonly used vegetation metrics (live vegetation cover, species richness, % forb, litter, bare ground, wetland indicator rating, % graminoid, bank alteration, soil compaction, and % native) and different plot types (static or dynamic) to assess changes in plant communities over time and in areas grazed by cattle. We were particularly interested in evaluating the stability of metrics over time and the responsiveness of metrics to cattle grazing. We found that the metrics wetland indicator rating, % graminoid, and % native were stable across the season, while live vegetation cover, species richness, % forb, litter, bare ground, bank alteration, and soil compaction were affected by seasonal variation. The metrics that responded to grazing similarly at all streams and sites were live vegetation cover, litter, bare ground, and bank alteration, while species richness, % forb, wetland indicator rating, % graminoid, soil compaction, and % native responded differently to cattle grazing at individual streams. The metrics that were most sensitive to cattle grazing within the season were live vegetation cover, species richness, % forb, litter, and bare ground. Plot type did not have an effect on the majority of the metrics at the majority of the streams. This information can be used by land managers to determine which metrics are suitable for short- and long-term monitoring, and which ones are appropriate for monitoring the effects of cattle grazing.

No description available.

Background: Suicide rates among Alaska Natives in rural Alaska are almost 16 times higher than the national average. Some studies in northern latitudes have shown seasonal variation among suicide rates, with differences in patterns by age and sex, reasons for this variation and contributing factors are unclear. We modeled our hypotheses based on the assumption that vitamin D deficiency influences seasonal variation of suicide. We assessed the relationship between age, sex and seasonal variation of suicidal behavior in a rural region of Alaska. Methods: We utilized data from 804 individuals who exhibited lethal and nonlethal suicidal behavior (1990-2009). Information on age, sex, and potential contributing factors were recorded via a case report. We used multivariable logistic regression to identify the association between age, sex, and seasonality of suicide. Results: Among women, we observed a significant 41% increase in odds during season two compared to season one (OR=1.41, CI=1.06, 1.90); women had a significant 48% increase in odds during season two using data collected between 2002-2009 (OR=1.48, CI=1.04, 2.11). We did not observe any significant findings of seasonality with respects to age. The observed seasonal variation of suicide did not support vitamin D deficiency as an underlying cause, as increased incidence of suicide continued into the summer months when vitamin D deficiency would be less prevalent. Conclusion: We observed evidence of seasonal variation of suicidal acts by sex. Future studies of physiologic mechanisms influencing seasonality of suicide are important to target those at highest risk throughout the year.

The Greenland ice sheet is an area of great interest to the scientific community due to its role as an important bellwether for the global climate. Satellite-borne scatterometers are particularly well-suited to studying temporal changes in the Greenland ice sheet because of their high spatial coverage, frequent sampling, and sensitivity to the presence of liquid water. The dry snow zone is the largest component of the Greenland ice sheet and is identified as the region that experiences negligible annual melt. Due to the lack of melt in the dry snow zone, backscatter was previously assumed to be relatively constant over time in this region. However, this thesis shows that a small seasonal variation in backscatter is present in QuikSCAT data in the dry snow zone. Understanding the cause of this seasonal variability is important to verify the accuracy of QuikSCAT measurements, to better understand the ice sheet conditions, and to improve future scatterometer calibration efforts that may use ice sheets as calibration targets.This thesis provides a study of the temporal behavior of backscatter in the dry snow zone of the Greenland ice sheet focusing on seasonal variation. Spatial averaging of backscatter and the Karhunen-Lo`eve transform are used to identify and study the dominant patterns in annual backscatter behavior. Several QuikSCAT instrumental parameters are tested as possible causes of seasonal variation in backscatter in the dry snow zone to verify the accuracy of QuikSCAT products. None of the tested parameters are found to be related to seasonal variation. Further evidence is given that suggests that the cause of the seasonal variation is geophysical and several geophysical factors are tested. Temperature is found to be highly related to dry snow backscatter and therefore may be driving the seasonal variation in backscatter in the dry snow zone.

Floods is a serious concern across Europe due to the enormous material damage and death toll. Of alltypes of floods, flash floods and large-scale river floods have become major natural hydrological hazardsin most countries. The city of Halmstad was chosen due to its placement on the southern west coast ofSweden, a region for which climate projections have indicated more precipitation and potential forflooding. In recent years a number of floods have also been observed with associated damages. Usingextreme value analysis on observed data these events can be interpreted in terms of return level valuesand their frequency of occurrence. The seasonal variation of the precipitation and discharge of thecatchment were analyzed based on 43-year precipitation and 25-year discharge observation data and therelationship to NAO index was investigated to give a preliminary overview of the hydrologicalconditions in Halmstad and its causes. The results showed that Halmstad was seasonally characterizedby high discharge in winter and lower discharge in summer with the highest rainfall. The effect of stormtracks represented by the NAO index on the precipitation and discharge in winter months was evident.This study focused on the analysis of extreme data of precipitation and discharge. The return levels forup to 50-year return period were estimated by GEV fitting. The estimated return level of discharge fora 50-year return period is 250 m³/s, and the return levels of precipitation for a 50-year flood was foundto be 68 mm/day. Two cases were selected from a compiled annual maxima discharge data set foranalyzing and comparing their weather conditions based on ERA5 data. The results showed that differentweather conditions do have an impact on the total rainfall, and there were similar patterns but largedifferences between ERA5 reanalysis data and observed SMHI data was also shown emphasizing theneed for long-term observational data sets and further evaluation of reanalysis data.

A própolis é uma substância resinosa coletada pelas abelhas de diversas partes das plantas, como brotos, botões florais e exudados resinosos, conhecida por do ácido cinâmico e ácido benzócio, foram ainda encontrados o ácido pimárico, várias atividades biológicas como antimicrobiana, anti-inflamatória, antiproliferativa e antioxidante. Sua composição química depende de vários fatores, como a localização geográfica, vegetação e clima. A própolis brasileira com certificação de produto orgânico, proveniente do sul do Brasil, foi coletada e avaliada em diferentes estações do ano. Essa própolis é produzida em florestas nativas e áreas de reflorestamento, locais livres de contaminação por insumos agrícolas, metais pesados e poluição industrial. O objetivo deste trabalho foi avaliar a composição química e atividade antioxidante, considerando a variação sazonal das estações de verão, outono e primavera. Foram coletadas ao todo 78 amostras provenientes de 14 apiários distintos. O teor de compostos fenólicos totais e flavonoides foram feitos por métodos colorimétricos, a atividade antioxidante foi avaliada pelos métodos de sequestro dos radicais livres DPPH•, ABTS+, sendo a capacidade antioxidante contra os radicais peroxila, determinado pelo método ORAC. O perfil químico do extrato de etanólico da própolis (EEPO) foi avaliado por cromatografia de camada delgada em fase reversa (CCDAE-FR), varredura no ultravioleta-visível (UV-vis) e cromatografia gasosa acoplada com espectrometria de massas (CGEM). A composição de voláteis foi analisada por CG-EM. Os teores de flavonoides variaram de não detectado até 4,76 mg.g-1 e de 6,80 a 72,55 mg.g-1 para fenólicos totais. Em relação à atividade antioxidante, a variação encontrada foi de 1,01 a 384,60 mg Trolox.g-1 para ABTS+, de 4,50 a 148,10 µmol Trolox.g-1 para DPPH• e de 0,20 a 1,25 µmol Trolox.g-1 de amostra para o ORAC. Em relação às estações, o verão apresentou maior teor de flavonoides (p=6%) e o outono, maior teor de DPPH• (p=7%). Com base no perfil químico pela técnica de CCDAE, foi possível classificar as 78 amostras em sete variantes distintas. Dentre os compostos presentes e derivados dos ácidos cinâmico e benzóico, analisados pela técnica CG/MS, identificou-se os compostos ácido pimárico, norolean-12 ene, alfa bisabolol e metil comate A. Também foram identificados oito compostos voláteis em grande quantidade como α-pineno (54,77%), β- pineno (14,83%), α-limoneno (3,78%), β- mirceno (9,29%), ?-candineno (2,11%), γ -muroleno (1,86%), β-felandreno (4,79%) e α-selineno (8,40%). Uma correlação estatística foi encontrada entre o teor de fenólicos totais e o método DPPH•, p=0,78, diferentemente do teor de flavonoides que não apresentou correlação com a atividade antioxidante. Os resultados obtidos demonstraram que a própolis orgânica possui atividade antioxidante, embora apresente baixos teores de flavonoides. Não existe correlação entre os flavonoides e atividade antioxidante. Os compostos fenólicos e a atividade antioxidante foram influenciados pela sazonalidade, sendo o outono, a estação que apresentou teores maiores de fenólicos e atividade antioxidante. / Propolis is a resinous substance collected from plant buds, flowers, and exudates by Apis mellifera bees widely known for its biological activities such as antiviral, antimicrobial, anti-inflammatory, antiproliferative and antioxidant activities. Its chemical composition depends on many factors as geographic location, vegetation, and climate. A certified Brazilian propolis, originated from South Brazil, was collected and evaluated in different seasons. This kind of propolis is produced in native forest and in reforestation areas, where contamination derived from agricultural inputs, heavy metals, and factory fumes is found. Hence, the aim of this work was to evaluate the chemical composition and the antioxidant activity during seasonal variation in summer, autumn and spring. Seventy-eight samples were collected from 14 different apiaries. The phenolic compound content and flavonoids were performed by colorimetric methods. The antioxidant activity was evaluated by free radical scavenging methods such as DPPH• and ABTS+. The antioxidant capacity against peroxil radicals was assessed by ORAC method. The chemical profiles of the organic propolis ethanolic extracts were evaluated by reversed-phase thin-layer chromatography (RP-TLC), ultraviolet (UV) scanning, and gas chromatography-mass spectrometry (GC-MS). Flavonoid content varied from non - detected to 4.76 mg. g-1 and 6.80 to 72.55 mg.g-1 for phenolics. The antioxidant activity varied from 1.01 to 384.60 mg Trolox.g-1 for ABTS+ and 4.50 to 148.10 µmol Trolox.g-1 for DPPH. Considering the seasonal variation, summer presented the highest compound content for flavonoids (p=6%), meanwhile autumn presented the highest compound content for DPPH• (p=7%). Thus, considering the chemical profile presented by RP-TLC, seven different variances of propolis were classified. Compounds such as pimaric acid, norolean-12-ene, alpha bisabolol, and methyl commate A were found by GC-MS technique on these seven variances. Eight volatile compounds were also identified as follow: α-pinene (54,77%), β- pinene (14,83%), α-limonene (3,78%), β-myrcene (9,29%), .-candinene (2,11%), γ - muurolene (1,86%), β-phellandrene (4,79%), and α-selinene (8,40%). In conclusion, the results demonstrated that autumn showed higher antioxidant activity by DPPH• method than those produced in other seasons. A statistical correlation was found between phenolic compound and DPPH•, p=0.78, differing from the flavonoid content which did not demonstrate a correlation with antioxidant activity. The results obtained showed that organic propolis presents antioxidant activity, although its flavonoid content is extremely low. On extent, there was no correlation between flavonoid content and antioxidant activity. Moreover, the seasonal variation showed its influence on phenolic compounds as well as on antioxidant activity, in which autumn presented the highest phenolic content and antioxidant activity.

As lagoas de estabilização compõem sistemas de tratamento de águas residuárias sujeitos à variação de eficiência decorrente, dentre outros fatores, das variações climáticas. A variação de eficiência e da estratificação em lagoas de estabilização, localizadas em ambiente subtropical, em diferentes épocas do ano, foi o principal objetivo dessa pesquisa. Para essa finalidade, a eficiência de dois sistemas de lagoas de estabilização localizadas no Vale do Ribeira de Iguape (SP) - nas cidades de Jacupiranga e Pariquera-Açu - foi determinada, em período sazonal (quatro épocas do ano) e semanal (três dias consecutivos), assim como perfis de temperatura, condutividade elétrica, pH e oxigênio dissolvido e aspectos ambientais (temperatura do ar, radiação solar, direção e velocidade do vento e precipitação) foram mensurados. Além disso, aspectos operacionais, tais como, volume de lodo, de água, vazão e tempo de detenção teórico foram mensurados a fim de caracterizar apenas as lagoas facultativas. Alterações no comportamento sazonal destas variáveis e padrões de similaridade entre eficiência de cada lagoa e estratificação térmica foram analisadas através da ferramenta estatística análise do componente principal (PCA). Observou-se, principalmente, que a variação sazonal de eficiência foi relevante, sendo que, em julho/06 a qualidade do afluente e do efluente foi diferente das outras épocas do ano, ou seja, houve variação sazonal de variáveis físicas e químicas. Variação diária foi observada em janeiro/06, época de maiores precipitações e maior homogeneidade térmica. Na PCA, a estratificação térmica foi significativa, ou seja, esteve relacionada com outras variáveis. A vazão e tempo de detenção, nas lagoas facultativas, estiveram dentro de faixas observadas em outras lagoas de estabilização e o volume de lodo não ultrapassou 3% do volume das lagoas. / Stabilization ponds compose systems of wastewater treatment citizens to the variation of efficiency decurrent, amongst other factors, of the climatic variations. The variation of efficiency and stratification in stabilization ponds, located in subtropical environment, at different seasons, was the main objective. For this purpose, the efficiency of two stabilization ponds systems located in the Vale do Ribeira de Iguape (SP) - in cities as Jacupiranga and Pariquera-Açu - was determined, in sazonal period (four seasons) and weekly (three days consecutive), as well as temperature, electric condutivity, pH and dissolved oxygen profiles and environment aspects had been measured (air temperature, solar radiation, direction and speed of the wind and precipitation). Moreover, operational aspects, such as, volume of sludge, volume of water, outflow and theoretical detention times had been measured in order to characterize only the facultative ponds. Alterations in sazonal behavior of these variables and standards of similarity between efficiency and thermal stratification had been analyzed through the tool statistics análise do componente principal (PCA). It was observed, mainly, that the sazonal variation of efficiency was important, so, in July/06 the quality of the affluent and effluent was different to the other seasons, in other words, it was observed sazonal variation of physical and chemical variable. Daily variation happened in January/06, time of more precipitations and thermal homogeneity. In other analysis with PCA, the thermal stratification was significant and it was related with other variable. The outflow and detention times, in the facultative ponds, had been similar others facultatives ponds and the volume of sludge did not exceed 3% of the volume of water in the ponds.

A área de estudo do presente trabalho é parte integrante da barreira holocênica do estado do Rio Grande do Sul. Apresenta seus limites entre o balneário de Itapeva (município de Torres) ao norte e, ao sul, o balneário de Dunas Altas (município de Palmares do Sul). Este trabalho teve por objetivo obter novas informações referentes às variações sazonais (inverno e verão) morfológicas e sedimentológicas (granulometria e morfoscopia) do sistema praia-duna frontal no Litoral Norte do Rio Grande do Sul, Brasil. Para isso, foram coletadas e analisadas por difração a lazer (granulometria) 26 amostras de sedimentos das dunas frontais (face marinha) e 26 da praia (nos limites instantâneos da zona de espraiamento), bem como as suas características morfológicas através de medição, observação e descrição em campo. Os resultados obtidos demostraram nítida relação sedimentológica entre a praia e a duna frontal quando observados na mesma estação. No ambiente praial, os sedimentos foram caracterizados como areia fina com tendência granocrescente para o norte, bem selecionados, aproximadamente simétricos e mesocúrticos no verão, com tendência a leptocúrticos no inverno. Nas dunas frontais os sedimentos foram classificados como areia fina, com tendência granocrescente para o norte no inverno e um sutil decréscimo no verão, bem selecionados a muito bem selecionados e aproximadamente simétricos, mesocúrticos com tendência leptocúrticos nas duas estações. No inverno, a praia apresentou areias com maior valor de diâmetro médio em relação ao verão, da mesma forma que as a dunas frontais. Quanto à morfoscopia (verão/inverno), os grãos foram classificados como angulosos com média esfericidade. Com relação à análise das variáveis morfológicas, a largura da praia e a pista de vento não apresentaram relação com a altura das dunas frontais. As mesmas tendem a um decréscimo de sul para norte. As maiores alturas de dunas foram encontradas ao sul, onde há maior velocidade dos ventos e em função da orientação da linha de costa que determina uma incidência com maior valor angular do vento dominante proveniente de nordeste. / The study area of this work corresponds to the beach-foredune system of the Holocene barrier of the Rio Grande do Sul state. It presents its boundaries between Itapeva (Torres municipality) to the north and Dunas Altas (Palmares do Sul municipality) to the south. The objective of this work was to obtain new information regarding seasonal (winter and summer) morphological and sedimentological variations (granulometry and morphoscopy) of the beach-foredune system in the northern coast of Rio Grande do Sul, Brazil. For this, 26 samples of sediments of the foredunes (marine face) and 26 of the beach (at the instantaneous limits of the swash zone) were collected and analyzed by laser diffraction (granulometry), as well as their morphological characteristics through the measurement, observation and field description. The results obtained showed a clear sedimentological relationship between the beach and the foredune when considered the same season. At the beach the sediments were characterized as fine sand with a tendency to a northward increase on grain size. These sands are well selected, approximately symmetrical and mesocurtic in the summer, with tendency to leptocurtic in the winter. In the foredunes the sediments were classified as fine sand, with a tendency to a northward increase on grain size in the winter, and a subtle decrease in the summer. These sands are well selected to very well selected and approximately symmetrical, mesocurtic with a leptocurtic tendency in the two seasons. In winter the beach and the foredune presented sands with a higher value of average diameter in relation to the summer. In regard of morphoscopy (summer/winter), the grains were classified as angular with moderate sphericity. Regarding the analysis of the morphological variables, the width of the beach and the wind fetch were not related to the height of the foredunes. They tend to decrease from south to north. The highest heights of dunes were found to the south, where there is higher wind velocity, due to the orientation of the coastline that determines a higher angular value of incidence of the dominant wind coming from the northeast.

Objetivos: O comportamento alimentar de trabalhadores em turnos fixos pode variar segundo a estação do ano e o horário de trabalho. Neste sentido realizou-se estudo com o objetivo de verificar a variação entre inverno e verão do comportamento alimentar e do estado nutricional de trabalhadores em turnos fixos. Também se verificou a distribuição circadiana da quantidade de calorias e macronutrientes da dieta e a ritmicidade circadiana das calorias da dieta dos trabalhadores. Metodologia: Foram estudados 28 trabalhadores de três turnos fixos (matutino, vespertino e noturno) de uma companhia de transporte de São Paulo. O consumo alimentar foi verificado pelo inquérito diário alimentar de três dias e o estado nutricional foi avaliado pelo índice de massa corporal, tanto no inverno quanto no verão. Testes paramétricas e não-paramétricas foram utilizados para comparar os grupos de trabalhadores e as estações. O Cosinor foi utilizado para verificar a ritmicidade circadiana das calorias da dieta dos trabalhadores. Resultados: A dieta dos trabalhadores forneceu uma quantidade maior de calorias (p=0,00), carboidratos (p=0,00) e lipídeos (p=0,03) no inverno. O índice de massa corporal dos trabalhadores, ao contrário, não variou de uma estação para outra (p=0,33). Comparando-se os grupos de trabalhadores não foram observadas diferenças quanto a quantidade de calorias (p=0,44), proteínas (p=0,78), carboidratos (p=0,59) e lipídeos (p=0,24) em nenhuma das estações, assim como não houve diferenças no índice de massa corporal no inverno (p=0,35) e no verão (p=0,35). Foi encontrado ritmo de calorias da dieta dos trabalhadores do turno matutino (p<0,05) e vespertino (p<0,05) nas duas estações. Conclusão: O comportamento alimentar de trabalhadores em turnos fixos variou de uma estação para outra, o que não se refletiu no índice de massa corporal. Os turnos de trabalho parecem não estar correlacionados com as mudanças sazonais observadas. No entanto, a distribuição do consumo alimentar ao longo das 24 horas pode ser um reflexo do turno ao qual o trabalhador está submetido. / Objectives: The eating habits of workers may vary according to the season of the year and the corresponding work schedule. A study aiming at verifying the variations occurring in their diet in summer and in winter, as well as the nutritional status of those who work in fixed shifts was carried out. The 24-hour distribution of the amount of calories and macronutrients ingested and the circadian rhythmicity of the calories contained in their diet were also analyzed. Methodology: The study was carried out with 28 workers subject to three fixed work shifts (morning, afternoon, and night) at a transport company in São Paulo. The food consumption was checked by using the 3-day dietary record, and their nutritional status was evaluated through the body mass index, both in winter and in summer. Parametric and non-parametric tests were performed so as to compare the different groups of workers and the seasons. The Cosinor method was utilized to verify the circadian rhythmicity of the calories included in their diet. Results: In winter, the workers typical diet contained a larger amount of calories (p=0,00), carbohydrates (p=0,00) and lipids (p=0,03). Their body mass index, on the other hand, did not show any variation from one season to another. The comparison carried out among the groups of workers did not show differences as to the amount of calories (p=0,44), proteins (p=0,78), carbohydrates (p=0,59) and lipids (p=0,24) in none of the seasons, and no differences as to the body mass index were observed, that is, the same index (p=0,35) was registered both in summer and winter. On both seasons a circadian rhythmicity of the calories was found in the workers belonging to the morning shift (p<0,05) and those belonging to the afternoon shift (p<0,05). Conclusion: The eating habits of workers subject to fixed shifts varied from one season to another, but the variation did not reflect upon their body mass index. In view of this, we might conclude that the work schedule (morning, afternoon, or night) do not seem to be related to the seasonal changes observed. Nevertheless, a 24-hour distribution of food intake may reflect upon the shift the worker is subject to.

Vernonia herbacea, Asteraceae, possui órgãos subterrâneos de reserva ramificados, os rizóforos, que acumulam frutanos do tipo inulina como carboidratos de reserva. Os frutanos são polímeros de frutose que são sintetizados pelas enzimas SST (sacarose: sacarose frutosiltransferase) e FFT (frutano:frutano frutosiltransferase) e despolimerizados pela FEH (frutano exohidrolase). Plantas desta espécie entram em dormência no final do outono, quando perdem os ramos aéreos e rebrotam na primavera seguinte; subseqüentemente ocorre a floração e o crescimento vegetativo no verão; ocorrem variações no teor e na composição dos frutanos durante o ciclo fenológico das plantas. O rizóforo apresenta crescimento geotrópico positivo, cujo ápice apresenta tecidos mais jovens em crescimento e a rebrota dos novos órgãos aéreos se dá pelo desenvolvimento das gemas situadas na região proximal do rizóforo, localizada próximo à superfície do solo. Considerando estas variações este trabalho visou à análise da distribuição espacial das atividades da SST, FFT, Invertase e FEH, bem do teor e composição dos frutanos nas regiões proximal, mediana e distal dos rizóforos de plantas de Vernonia herbacea, em diferentes fases de desenvolvimento e em plantas induzidas à brotação pela remoção dos órgãos aéreos. Também foram analisados esses parâmetros em plantas na fase vegetativa com os órgãos aéreos intactos ou excisados, mantidas em condições ambientais naturais ou em baixa temperatura. De maneira geral, as enzimas SST e FFT apresentaram atividades mais elevadas em plantas na fase vegetativa, enquanto a FEH apresentou atividade mais elevada em plantas na fase de brotação natural ou induzida e nos tratamentos sob baixa temperatura. Com relação à distribuição espacial das atividades enzimáticas, a SST e FFT apresentaram atividade mais elevada na região distal, que diminuiu no sentido proximal dos rizóforos. A FEH por sua vez apresentou atividade mais elevada na região proximal, diminuindo no sentido distal. Em geral, o conteúdo de fruto-oligossacarídeos foi mais elevado na região distal e diminuiu em direção à região proximal dos rizóforos. Os tratamentos com baixa temperatura levaram a uma maior proporção de frutooligossacarídeos, enquanto nas plantas induzidas à brotação, a proporção de fruto-polissacarídeos foi superior. Os menores valores de grau de polimerização médio (GP) das cadeias de frutanos foram detectados na região distal, sugerindo que as cadeias de frutanos nesses tecidos não apresentam o GP característico da espécie. Valores elevados de GP foram detectados na região proximal, e valores mais elevados ainda, em plantas na fase de brotação e sob baixa temperatura, coincidindo com atividades mais elevadas de FEH. Estes resultados sugerem que o mecanismo de ação da FEH em V. herbacea seja do tipo "single chain", pelo qual uma molécula da enzima se liga à cadeia de frutano degradando-a até a molécula de sacarose. Os experimentos realizados possibilitaram algumas deduções a respeito do mecanismo de ação das enzimas envolvidas no metabolismo de frutanos, e um maior conhecimento sobre a dinâmica de variação temporal e espacial destes carboidratos, em diferentes fases de desenvolvimento das plantas e em condições adversas ao desenvolvimento vegetal. / Vernonia herbacea, Asteraceae, bears branched underground reserve organs, rhizophores, that accumulate inulin-type fructans as reserve carbohydrates. Fructans are fructose polymers, that are synthesized by SST (sucrose: sucrose fructosyltransferase) and FFT (fructan:fructan frutosyltransferase) and mobilized by FEH (fructan exohydrolase). Plants of this species enter dormancy at the end of autumn, with senescence and abscission of the aerial organs and sprout in the following spring; flowering occurs subsequently followed by a period of vegetative growth in the summer. The concentration and composition of fructans vary during the phenological cycle of the plants. Considering this variation in fructans, and the positive geotropic growth of the rhizophores, with the apex presenting younger tissues (distal region) and the resprouting of the new aerial organs occurring in the opposite end of the organ (proximal region), close to the soil surface, the aim of this work was to analyze the spatial distribution of fructans and fructan metabolizing enzymes in the different regions of the rhizophores (distal, median and proximal) in plants of Vernonia herbacea in different developmental phases and plants induced to sprouting by the excision of the aerial organs. These parameters were also analyzed in intact plants in the vegetative phase and in excised plants, kept in natural environmental conditions or in low temperature. In general SST and FFT presented higher activities in plants in the vegetative phase, while FEH presented higher activity during sprouting, either under natural or induced sprouting and in plants under low temperature. Concerning the spatial distribution of the enzyme activities, SST and FFT presented higher activity in the distal region, decreasing towards the proximal region of the rhizophores. The FEH, on the other hand, presented higher activity in the proximal region, decreasing towards the distal region. In general, the content of fructo-oligosaccharides in the phenological phases studied was higher in the distal region and decreased towards the proximal region of the rhizophores. Low temperature led to a higher proportion of fructo-oligosaccharides, while in plants induced to sprouting the proportion of fructo-polysaccharides was higher. The lower values of average degree of polymerization (DP) of fructans chains were detected in the distal region. This indicates that fructan chain length in younger tissues is shorter then that characteristic of the species. Higher values of mean DP were detected in the proximal region and even higher DP was detected in this region in sprouting plants and in plants under low temperature, coinciding with the higher FEH activity detected in these conditions. These results suggest a mechanism of action for the FEH in V. herbacea of the "single chain" type, in which a molecule of the enzyme binds to the fructan chain degrading it completely before binding to the next fructan molecule. These studies allowed us to draw several conclusions regarding the mechanism of action of enzymes involved in the metabolism of fructans in Vernonia herbacea and regarding the dynamics of distribution of these carbohydrates and the related enzymes in different phases of development and in adverse conditions for plant development.