An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. The main food of sprat, marine copepods, decreased during the same time period, likely a combined effect of increased predation pressure from sprat and decreasing salinities. This shortage of food for sprat resulted in decreasing quality of sprat as a food source for common guillemots Uria aalge. However, a recent increase in fishing for sprat has again resulted in better feeding conditions for guillemots. Human impacts on this simple food web can be complex. In the early 20th century, marine mammals were abundant and nutrient levels were low in the Baltic Sea. This thesis illustrate that this situation corresponded to lower fish biomass. A reduction of seals early in the century led to reduced top-down control, which resulted in increasing fish stocks. Later, in the 1950s, the largest inflow of salt water during the century mobilized accumulated phosphorus from the deep sediments, which stimulated nitrogen fixation. Combined with increasing anthropogenic nutrient loads, this led to increased primary production and a rapid change from an oligotrophic to a eutrophicated state. This change can be termed a regime shift, which also stimulated fish production. Subsequent over-fishing of cod likely caused a second regime shift, from a cod- to a clupeid- dominated state, which led to the described effects on the common guillemots. Several factors affect the life-history of this long-lived seabird. Bycatches in gillnet fisheries is one factor directly affecting guillemot survival, and the proportion of bycatches increased during a period of increasing fishing effort. Surprisingly, avian cholera, a previously undocumented disease in common guillemots, was found at times to cause considerable adult mortality. Common guillemot life-history information can communicate the diversity of factors influencing marine ecosystems – hopefully this can increase our understanding of how complex even "simple" food webs are.

L’esperienza estetica è un fenomeno complesso e articolato, caratterizzato da un particolare intreccio di processi percettivi, emotivi, cognitivi. Il dibattito sulla definizione del ruolo dei fattori che intervengono nell’esperienza estetica è molto controverso: diverse cornici teoriche enfatizzano o il ruolo dei fattori "bottom-up", riguardanti le caratteristiche visive e strutturali dell'opera d'arte come il colore e simmetria, o il ruolo dei fattori "top-down", relativi al bagaglio di conoscenze ed esperienze personali. Questa tesi presenta due studi volti ad approfondire, attraverso l'analisi dei movimenti oculari, l'influenza dei processi "bottom-up" e "top-down" sul comportamento visivo di adolescenti o adulti non esperti d’arte durante l'osservazione di opere d’arte pittorica. I dati ottenuti suggeriscono che processi intersoggettivi e relazionali giocano un ruolo essenziale nel guidare l’apprezzamento estetico di un quadro. Questi risultati innovativi supportano alcune recenti ipotesi teoriche relative alla natura intrinsecamente intersoggettiva dell’esperienza estetica. / Experiencing art is a complex and articulated phenomenon characterized by a peculiar weaving of perceptive, emotional, and cognitive processes. The debate on the definition of factors that contribute to the surfacing of an aesthetic experience is very controversial, partly because of the different weights assigned to the elements in the competition between “bottom-up” and “top-down” processes. Different theoretical frames emphasize the role of bottom-up factors - concerning the visual and structural characteristics of the artwork such as colour and symmetry - or top-down cognitive processes - concerning the cognitive feedback deriving from everyone’s cultural background and knowledge - in the building up of an aesthetic experience. In this work, two studies aiming at shedding some light on art appreciation are presented. These studies were designed to investigate, by means of the analysis of eye-movements, the influence of bottom-up and top-down processes on visual behavior while adolescents or adults naïve to art criticism were presented with representational paintings. Data suggest that intersubjective and relational processes intervene in first stages of aesthetic experience. These important and novel results support new theoretical proposals, which consider embodied intersubjective processes underpinning aesthetic experience.

Tree series transformations computed by bottom-up and top-down tree series transducers are called bottom-up and top-down tree series transformations, respectively. (Functional) compositions of such transformations are investigated. It turns out that the class of bottomup tree series transformations over a commutative and complete semiring is closed under left-composition with linear bottom-up tree series transformations and right-composition with boolean deterministic bottom-up tree series transformations. Moreover, it is shown that the class of top-down tree series transformations over a commutative and complete semiring is closed under right-composition with linear, nondeleting top-down tree series transformations. Finally, the composition of a boolean, deterministic, total top-down tree series transformation with a linear top-down tree series transformation is shown to be a top-down tree series transformation.

The prevalent view in computer vision since Marr is that visual perception is a data-driven bottom-up process. In this view, image data is processed in a feed-forward fashion where a sequence of independent visual modules transforms simple low-level cues into more complex abstract perceptual units. Over the years, a variety of techniques has been developed using this paradigm. Yet an important realization is that low-level visual cues are generally so ambiguous that they could make purely bottom-up methods quite unsuccessful. These ambiguities cannot be resolved without taking account of high-level contextual information. In this thesis, we explore different ways of enriching early and mid-level computer vision modules with a capacity to extract and use contextual knowledge. Mainly, we integrate low-level image features with contextual information within uni&amp / #64257 / ed formulations where bottom-up and top-down processing take place simultaneously.

A component-oriented tool for hierarchical modeling of instructional designs is developed. The motivation is to show that hierarchical representation of instructional designs is easier, better and more effective for modeling. Additionally a modeling language is developed to provide an effective, flexible and easy to use integration model in which all teaching components are discovered, defined and connected. In order to fulfill the above purposes an abstract notation is developed that is sufficiently general and adapting top-down hierarchic approach to represent Units of Learning (UoL), Operational Knowledge Units (OKU), Learning Objects (LO), and Learning Components (LC) with respect to the common structures found in different instructional models. COSEML, a top-down hierarchic, and component oriented modeling language has been used as a reference and the core concept in developing the Educational Component Oriented Modeling Language (ECOML). The high-level architecture of ECOML provides the means for designing instructional structures. It describes how LOs, UoLs, OKUs and LCs are sequenced in a certain context or knowledge domain. The resulting model can be reused in different contexts and across different educational platforms.

Cette thèse a pour objectif d'éprouver la pertinence d'une approche hybride top-down / bottom-up pour évaluer les projets miniers dans l'optique du développement durable. Avec l'avènement des concepts de responsabilité sociale d'entreprise et de développement durable, de nouvelles attentes sociétales pèsent en effet sur les entreprises qui vont au-delà d'une simple exigence de rentabilité économique. Des réponses doivent être apportées par les entreprises, au risque de perdre leur légitimité sociale. Traditionnellement associée à des risques et des impacts sociaux, environnementaux, économiques et politiques jugés traditionnellement comme importants, l'activité minière est particulièrement concernée par ces nouveaux enjeux. Alors que les besoins en ressources minérales n'ont jamais été aussi élevés, on attend désormais des entreprises qu'elles limitent leurs effets négatifs et prennent en compte les préoccupations de leurs différents publics afin de définir ensemble les termes d'un accord conférant à l'entreprise sa légitimité. Au vu de la diversité des enjeux, des échelles, des contextes et des acteurs concernés, le défi est de taille et nécessite des outils visant à mieux cerner les enjeux et structurer les dialogues. Basé sur l'étude de cas des mines d'uranium d'Arlit au Niger, ce travail montre qu'associer des démarches participatives à des outils de structuration et des propositions issus de la littérature apparaît comme une formule efficace pour mieux organiser la diversité des enjeux associés au projet et construire une négociation structurée entre les entreprises minières et leurs parties prenantes. La Première Partie, (Cadrages), a pour objectif de présenter les contextes théoriques, institutionnels et sectoriels dans lesquels s'ancre la thèse. La Deuxième Partie, (Application de la démarche sur les mines d'Arlit), expose les travaux et les résultats de l'évaluation réalisée au Niger. Enfin, la Troisième Partie, (Recadrages), dresse le bilan des enseignements et des conclusions que l'on peut tirer de ce travail de recherche et présente une proposition de démarche potentiellement applicable à d'autres sites miniers.

<p>The middle management position in the care of the elderly is the focus of this licentiate dissertation. The aim was to develop knowledge about the constraints within which the middle manager is able to act and which freedom of action he/she has. The empirical data consisted of 17 interviews and a vignette study completed by 47 middle managers in social care in the county of Halland. The managers' perceptions of what exerts a control on their work and of the type of control that is exercised was investigated into in the interviews. In the vignette study, using three specific cases, the focus was on the research issue, i.e. how they thought they could act, mainly in terms of their apprehensions of constraints (the formal framework) within which to act and the freedom of action. Further, aspects of loyalty were analysed. It comes down to a view of what can be done and how it can be carried out.</p><p>The middle managers' freedom was violated by control mechanisms that had a disciplinary cognitive orientation as well as mechanisms that constituted a normative control, such as budget issues and legislation. They described, mainly in the interviews, their experiences of being in a vulnerable position and of being trapped between interested parties. On the other hand the vignette study revealed an emphasis on being a manager and conveyed an administrative approach. By adopting this approach the middle managers relinquish to some extent their moral responsibility. A moral indignation is apparent, however, when the consequences for the workplace and the staff become serious as it does in one of the vignettes. Then the indignation in many cases passed on into a deliberation about quitting. The administrative concentration of middle management can, in its extension, lead to the need for an old group to re-enter into the field of the elderly care, namely, the assistant manager. In other words, a new intermediate level emerges that takes care of this dilemma of being trapped between the interested parties from a bottom up perspective. It is possible here to make a comparison with what in modern terms is called shared leadership.</p> / <p>Äldreomsorgens arbetsledare och positionen de befinner sig i, där intressenter från till exempel förvaltning, politik, medarbetare och brukare ställer krav på verksamheten, står i fokus i denna licentiatavhandling.</p><p>Avhandlingens syfte är att utveckla kunskap om och förståelse för arbetsledares handlingsutrymme och handlingsfrihet inom äldreomsorgen. Empirin hämtas från två studier. Den första studien utgörs av 17 intervjuer med första linjens chefer inom äldreomsorgen i Halland. Jag undersöker här hur arbetsledarna uppfattar och tänker om hur formella ramar påverkar arbetet och om sitt mandat att agera som arbetsledare etc. Det handlar till exempel om i vilken utsträckning första linjens chefer uppfattar att de påverkas att fatta beslut, att handla på ett visst sätt och i en viss riktning och vilket utrymme för självständighet som finns i den förvaltning de arbetar i.</p><p>I den andra studien har en enkät som utarbetats utifrån vinjettmetoden använts. Enkäten har besvarats av 47 arbetsledare i Halland. Vinjetterna innebär att informanterna ställs inför beskrivningar av konkreta situationer som är relevanta för deras uppdrag som arbetsledare. Här görs ett försök att gå från arbetsledarens tankar om sina möjligheter att agera till det mer handlingsinriktade. Med hjälp av konstruerade situationer undersöks hur de beskriver sitt agerande, hur handlingsutrymmet och handlingsfriheten formas och hur arbetsledarna lojalitet påverkas av bland annat situationens karaktär. Den första vinjetten består av en organisationsförändring där verkställigheten är delegerad till arbetsledaren. Den andra vinjetten beskriver en situation där omsorgskvaliteten kritiseras och slutligen den sista vinjetten, en situation där arbetsledaren ska verkställa ett kraftigt besparingskrav.</p><p>För att fånga den komplexitet som ledarskapet kännetecknas av har jag valt att ha ett brett angreppssätt. Jag går från teorier som fokuserar likhetsskapande mekanismer på skilda nivåer som nyinstitutionalism och organisationskulturteori, till teori som öppnar upp för möjlighet till variation. Här använder jag teoretisering runt formella och informella regler som öppnar upp för olikheter och handlingsutrymme i organisationen. I den andra studien tas även utgångspunkter i teoretiska perspektiv på beslut utifrån begreppen top down och bottom up, på handlingsutrymme och handlingsfrihet samt på frågan om lojalitet, främst utifrån Albert O Hirschmans teori om individers reaktionsmönster på oacceptabla eller ohållbara situationer som uppkommer.</p><p>I min avhandling gör jag en distinktion mellan handlingsutrymme och handlingsfrihet. Handlingsutrymme identifierar jag som den formella ramen och handlingsfriheten är det som medger eller skapar möjligheter att agera inom ramarna. I verkställandets har arbetsledare stor handlingsfrihet, men till exempel organisationskulturen, värderingar och etiska grundföreställningar inom yrket sätter gränser för vad som är acceptabla beteenden och godtagbara sätt att agera på. Handlingsfrihet i betydelsen att utforma det ”inre” ledarskapet, det som bland annat sker mellan ledaren och medarbetarna på den enskilda enheten medger enligt mina informanter stor frihet att agera utifrån ”egna uppfattningar”.</p><p>Resultaten pekar på att arbetsledarna uppfattar sig ha stor frihet i det konkreta ”nära” arbetet, men att arbetet begränsas av faktorer som de har litet eller inget inflytande över. Det handlar till stor del om regulativa styrningsmekanismer (tvingande/kontrollerande regler), till exempel lagstiftning och politiska beslut som ska verkställas. Arbetsledarna i intervjustudien kände sig mest styrda av Socialtjänstlagen, de arbetsrättsliga lagarna och politiska beslut. Den regulativa styrning har en stark disciplinerande makt, menar arbetsledarna, inte minst när det gäller kontroll av ekonomin. Den ger arbetet på så sätt en inriktning mot administrativa göromål som upptar en stor del av arbetstiden och där också personalfrågor är en viktig del.</p><p>I resultaten finns många exempel på att regler skapas i en process där kollegor på olika sätt och i olika sammanhang har avgörande betydelse. En del av dessa regler är så kallade metaregler. Normativ styrning verkar via värderingar och har i mitt material främst ett kollegialt ursprung och här synes även gemensam utbildningsbakgrund ha betydelse. Institutionaliseringen av regler och rutiner inom arbetsledargruppen har troligen också komponenter som har sin grund i en professionell maktutövning. Det finns anledning att anta att ”starka” professionsgrupper har en sådan normativ kontrollfunktion inom organisationen. I min undersökning är dessa yrkesgrupper bestående av arbetsledare med social omsorgsutbildning eller med sjuksköterskeutbildning.</p><p>Att organisatoriska regelsystem i första hand erbjuder en ram för agerande och att det inom denna ram finns möjlighet för individen till mindre styrda handlingar, visas tydligt i mina studier. Resultaten pekar också på att ett administrativt förhållningssätt breder ut sig i verksamheten vilket har en standardiserande effekt på vad de gör, men också på hur de agerar. Den administrativa orienteringen fungerar via en styrning av både regulativ och normativ art.</p><p>I materialet framstår lojaliteten gentemot förvaltningen som stark. Till viss del skiftar den dock med graden av komplexitet i de situationerna som beskrivs i vinjetterna och med utbildningsbakgrund. I min studie är det framför allt gruppen unga och gruppen med social omsorgsutbildning som i hög grad var lojala gentemot förvaltningen. I denna grupp var det också vanligt att hantera situationerna på ett administrativt sätt. Den tredje vinjetten skiljer sig från de övriga två. I den aktualiserades etiska dilemman och lojaliteten utmanades vilket gav utslag i att det var relativt vanligt att arbetsledarna funderade på att göra sorti.</p><p>I den första delstudien framkommer en bild som visar enhetliga tendenser avseende arbetsledarnas uppfattningar om möjligheter att agera. I den andra delen som tar sin utgångspunkt i mer konkreta situationer, i form av vinjetter, blir bilden mer varierad. Ju mer komplext det specifika fallet ter sig ju mer tenderar variationen att öka. Men vidare och kanske intressantare är att det sammantaget framträder en bild av arbetsledare inom äldreomsorgen som en grupp som har ett administrativt förhållningssätt till sitt uppdrag vilket troligen underlättar hanteringen av situationer som innebär etiska dilemman. Resultaten visar också att det finns tecken på att arbetsledarnas funktion i arbetsorganisationen i sin helhet är under omvandling. Man lämnar i allt högre grad frågor som är verksamhetsanknutna i reell mening till dem som arbetar verksamhetsnära. Arbetsledarnas administrativa uppgifter i termer av chefskap breder ut sig. Det rör sig om budgetansvar och personalansvar. Detta styrks i min vinjettstudie. I den vinjett där störst variation framträder, det vill säga i vinjett nummer tre, är personalfrågan och medarbetarna i hög grad i centrum. I de två tidigare som handlar om verksamheten uppvisar man till min förvåning som områdeskunnig överraskande samstämmighet i hur man tänker sig hantera situationen – en likhet som också uppvisar en stark lojalitetsbindning. Arbetsledarna tycks vara på väg att knytas uppåt i organisationen.</p><p>Utsattheten eller klämsitsen som första linjens chefer sägs befinna sig i framkommer framför allt i intervjustudien. I vinjettstudien handlar det däremot mer om en framtoning som chef, om ett administrativt förhållningssätt och om lojalitet gentemot förvaltningen. I sin förlängning leder detta till i en orientering bort från det verksamhetsnära mot det personalpolitiska området. Genom detta avhänder sig arbetsledarna till viss del ett moraliskt ansvar vilket också kan ses som en strategi för att kunna fortsätta att verka som ledare. En moralisk indignation blir tydlig när konsekvenser för de anställda tar en allvarlig form, så som den gör i den sista vinjetten. Då övergår indignationen i många fall i ett övervägande om sorti. Slutligen kan detta leda till att behovet av att en nygammal grupp gör entré inom äldreomsorgen, det vill säga biträdande föreståndare, alltså en ny mellannivå som får ta hand om klämsitsen mellan intressenterna. Här kan också en parallell dras till det som idag kallas ett delat ledarskap.</p>

Background Research has shown that people need to be pre-informed about the ambiguity in order to perceive both interpretations (reverse) of an ambiguous figure. Children younger than 4 years mostly do not experience reversal even when informed. This suggests that the processes involved in reversal develop at this age. Aim The aim of the studies reported here was to disentangle the cognitive processes (metarepresentation, executive function, mental imagery) and the role of eye-movements involved in reversal. Method Four studies (7 experiments), each involving around sixty 3-, 4- and 5-year-old children, using multiple tasks, were conducted. The primary tasks used were the Ambiguous Figures Production and Reversal tasks. The secondary tasks used were metacognitive, executive function and mental imagery tasks. New tasks were also implemented in order to assess reversal abilities. Results Between the ages of 3 and 4 children develop the basic conceptual understanding for reversal (Study 1), that an ambiguous figure can have two interpretations. This is associated with the understanding of false belief, synonymy and homonymy. Between the ages of 4 and 5 children develop inhibitory (Study 3) and image generation abilities (Study 4). These are key cognitive processes necessary for reversal. Contrary to previous research, when task demands were changed (Reversal Task Revised) children’s reversal is at ceiling by the age of 5 (Studies 3 and 4). Eye-tracking data suggests that appropriate eye-movements, focusing on particular parts of the ambiguous figure, are not a primary causal factor in the development of reversal abilities (Study 4). Conclusion The ability to reverse develops in two stages. During stage 1 (between 3 and 4 years) children develop the necessary conceptual understanding that an ambiguous figure can have two interpretations (top-down knowledge). During stage 2 (between 4 and 5 years) children develop the necessary cognitive processes for reversal to occur (inhibition and image generation).

Le système « plante-ravageur-ennemi naturel » fournit un modèle de base idéal pour comprendre comment les communautés d'arthropodes sont structurées et comment les interactions (directes et indirectes) entre les différents acteurs contribuent à façonner la structure des communautés. Dans les agroécosystèmes, les forces "top-down" correspondent aux effets de contrôle que les organismes arthropodes des niveaux trophiques supérieurs (par exemple, les prédateurs) ont sur les espèces des niveaux inférieurs (par exemple, leurs proies). Les communautés d'arthropodes peuvent également être influencées par des forces "bottom-up" induites par des variations dans les régimes de fertilisation ou d'irrigation ou par des variations de certains traits des plantes (résistance aux herbivores ou adaptations aux stress environnementaux). De plus, les forces "bottom-up" peuvent affecter l'impact "top-down" des ennemis naturels sur les herbivores soit directement (par exemple, les effets sur prédateur omnivore) ou médiées par les insectes herbivores intermédiaires. Dans ce contexte, les objectifs de cette thèse ont été de comprendre comment les variations de l'apport des ressources dans les agroecoécosytsèmes (disponibilité en azote et en eau) peuvent influencer les interactions entre les plantes, les herbivores et les ennemis naturels. Cette question a été étudiée aussi bien à l'échelle individuelle (traits d'histoire de vie des insectes) que populationnelle (dynamique des populations). Les études ont été réalisées sur deux agroécosystèmes basés sur les cultures de la tomate et du coton. / The “Plant-herbivorous insect-natural enemy” system provides an ideal basic model to understand how the plant-inhabiting arthropod communities are structured and how various mechanisms (i.e. direct and indirect interactions) contribute to shape the community structure. In agro-ecosystems, top-down forces encompass the controlling effects that arthropod organisms of the higher trophic level (e.g., predators) have on species at the next lower level (e.g., prey). Arthropod communities may also be influenced by bottom-up forces induced by environmental variations (e.g. fertilization or irrigation regimes) or plant traits (plant insect-resistance or plant-adaptive traits). Furthermore, bottom-up forces may affect top-down forces on herbivores either directly (e.g., effects on omnivorous predator) or mediated by the intermediate herbivorous insects. In this context, the aims of the PhD study were to disentangle how variations in resource inputs (i.e. nitrogen and water availability) affect interactions among plant, herbivores and their natural enemies at both the individual (life-history traits) and population (population dynamic) levels. The studies were carried out on two agrosystems based on tomato and cotton. On tomato, the system 'Solanum lycopersicum L - leafminer Tuta absoluta - omnivorous predator Macrolphis pygmaeus' was used under laboratory and greenhouse conditions in France. We found strong evidence of bottom-up effects of nitrogen and/or water inputs on the herbivore and the omnivorous predator. Feeding ecology of the predator was also strongly influenced by water availability.

O bacterioplâncton é um dos grupos de organismos responsáveis pela remineralização de nutrientes em ecossistemas aquáticos, bem como produtor de biomassa através da alça microbiana. Compreender a dinâmica dessa comunidade em função da variação térmica, disponibilidade de recursos e pressão de predação pode fornecer elementos que auxiliem no gerenciamento dos recursos hídricos, através da aplicação direta desse conhecimento ou como subsídios na interpretação do resultado de simulações através de modelos ecológicos. Este trabalho teve como objetivo verificar a existência de heterogeneidade espacial e temporal na estrutura da comunidade bacteriana, densidade, biomassa e riqueza de morfotipos, na Lagoa Mangueira, bem como identificar as variáveis limnológicas que direcionam esses padrões. Foi evidenciada presença de heterogeneidade temporal, sazonal, e espacial do bacterioplâncton associada a dinâmica das variáveis limnológicas. A temperatura e a disponibilidade de nutrientes foram as principais variáveis que regularam as comunidades planctônicas, biomassa algal, bacterioplâncton e zooplâncton. Observou-se controle lateral, competição por nutrientes, entre as comunidades produtoras. O controle descendente, predação, mostrou ter importante efeito sobre o bacterioplâncton, mais especificamente sobre o morfotipo coccus, durante o verão e o inverno, sendo essa comunidade controlada de forma ascendente durante o outono e a primavera, principalmente por nitrogênio. Durante o inverno, a comunidade bacteriana apresentou significativa redução de densidade e biomassa, sendo que essa resposta pode estar relacionada às baixas temperaturas da água. A forma coccus foi o principal morfotipo produtor de biomassa e de maior densidade na lagoa. Importante heterogeneidade espacial foi observada na Lagoa Mangueira para as variáveis abióticas, visto que as regiões norte e sul apresentaram a maior diferenciação espacial, influenciada pela dimensão da lagoa. Fósforo total e carbono orgânico total regularam a comunidade bacteriana no norte da lagoa, especialmente os morfotipos coccus, curved e outros. Entre as zonas da lagoa, a margem oeste e leste foram as mais distintas em função da disponibilidade de nutrientes, destacando-se o carbono inorgânico total. A densidade bacteriana foi maior durante o verão, outono e inverno na região pelágica e durante a primavera na margem oeste da lagoa. A comunidade fitoplanctônica apresentou uma distribuição espacial caracterizada por maiores densidades nas regiões norte e centro da lagoa e na zona pelágica. O fósforo foi a principal variável limitante para as comunidades produtoras, fitoplâncton e bacterioplâncton, sendo o controle ascendente o principal regulador dessas comunidades, visto que o controle descendente não foi observado. Quanto à dinâmica dos organismos planctônicos e das variáveis limnológicas associados ao perfil de profundidade, a Lagoa Mangueira não apresentou estratificação das variáveis e consequentemente das comunidades planctônicas, resultado relacionado a uma possível característica de mistura completa da massa d’água, mesmo com ventos de baixa intensidade. As comunidades planctônicas apresentaram maior densidade durante o inverno, direcionadas pela maior disponibilidade de nitrogênio e fósforo. / Bacterioplankton is one of the groups of organisms responsible for the remineralization of nutrients in aquatic ecosystems, as well as a producer of biomass through the microbial loop. Understanding the dynamics of this community due to the thermal variation, resource availability and predation pressure may provide data to assist in the management of water resources through the application of that knowledge or direct subsidies in the interpretation of the results of simulations using ecological models. This work aimed to verify the existence of spatial and temporal heterogeneity in bacterial community structure, density, biomass and richness of morphotypes in Mangueira Lake, as well as identify the limnological variables that drive these patterns. We evidenced the presence of temporal heterogeneity, seasonal and spatial dynamics of bacterioplankton associated with limnological characteristics. The temperature and nutrient availability were the main variables that regulated the planktonic communities, algal biomass, bacterioplankton and zooplankton. There was lateral control, competition for nutrients, between the producing communities. The top down control, predation, was shown to have important effects on the bacterioplankton, more specifically on the coccus morphotype during the summer and winter, and this controlled community in bottom up controled during the fall and spring, mainly nitrogen. During the winter, the community had a significant reduction in bacterial density and biomass, and this response may be related to low water temperatures. Morphotype coccus was the main producing biomass and higher density in the lake. Important spatial heterogeneity was observed at Mangueira Lake for the abiotic variables, whereas the northern and southern regions had the highest spatial differentiation, influenced by the size of the lake. Total phosphorus and total organic carbon regulated bacterial community in the north of the lagoon, especially coccus morphotypes, curved and ‘others’. Among the areas of the lake, the west border and east were the most different depending on the availability of nutrients, especially if the total inorganic carbon. The bacterial density was higher during the summer, autumn and winter in the pelagic region and during the spring on the west border of the lake. The phytoplankton community showed a spatial distribution characterized by higher densities in the north and center of the lake and the pelagic zone. Phosphorus was the main variable limiting communities producing, phytoplankton and bacterioplankton, and bottom up control of these communities, since the top down control was not observed. Considering the dynamics of planktonic organisms and limnological variables associated with the depth profile, the Mangueira Lake did not show stratification of variables and consequently the planktonic communities, the result can be related to a characteristic of complete mixing of water mass, even with low wind intensity. The planktonic communities showed higher densities during the winter, driven by increased availability of nitrogen and phosphorus.