The topic concerned - preventive educational activity as an inseparable part of comprehensive fire protection - deals with education of citizens, particularly children. The thesis is based on the fact that readiness of citizens for danger, emergency situations and their management is a public interest issue. The role of citizens and their involvement improve in contemporary society. Various natural disasters, mass catastrophes connected with endangered lives, fires of cars and large fires caused by dry weather make us all seek information that will make management of extraordinary situations easier. The historical description provides the development of education and preparation for safety threats and risks in the Czech environment since the second half of the 19th century until the present time. The main problem of today is growing passivity of the general public who consider the timely arrival of fire brigades a matter of fact. Fires then catch people unawares in situations that may arise. The latter part of the thesis deals with the present state of the issue in the Czech Republic. In order to ascertain current situation I made a survey, which served as a basis for my further work. The positive aspect was that if someone did not know the answer to the questions, he or she were inspired to search and get the relevant information, as he or she were surprised by their (lack of) knowledge in the area of fire protection. At least half of the respondents did so, which I consider a success. It shows that the interest of the public and youth in the possibility of obtaining education and preparation for emergency situations is inspired by the realization of potential threats and subsequent detection and designation of imperfections in their own knowledge and skills

A cooperação em defesa na América do Sul é explicada pela Teoria Realista Ofensiva de Cooperação em Defesa sob a Unipolaridade - aqui introduzida. Identificada uma lacuna significativa nas teorias de Relações Internacionais e nos trabalhos que buscam explicar, de forma ad hoc, a cooperação em defesa em outras regiões do mundo, nossa teoria traz explicações para (1) a motivação dos Estados para cooperar em defesa; (2) as variáveis independentes que afetam a cooperação em defesa; (3) um modelo amplo de cooperação em defesa que possa ser replicado em diferentes regiões do mundo. Demonstramos que cooperar em defesa serve para aumentar a posição relativa dos Estados participantes tanto frente aos demais Estados quanto frente à potência unipolar, sem, contudo, aumentar as pressões do dilema da segurança. Esse suposto reafirma o princípio egoísta dos Estados, de buscarem maximizar o seu poder para melhor garantir a sua sobrevivência, mas mostrando que novos tempos exigem novas formas de maximização de poder. Para tanto, demonstramos a continuidade da unipolaridade dos Estados Unidos na balança de poder global e apontamos, via 15 indicadores diferentes, que a polaridade sul-americana encontra-se em um momento de transição entre uma multipolaridade desequilibrada e uma unipolaridade brasileira, sofrendo pressões sistêmicas de ambas as configurações e corroborando as expectativas de nossa teoria. Conclui-se que o reaparelhamento ou não das Forças Armadas brasileiras levará à definição do sobe e desce das pressões sistêmicas regionais para a cooperação em defesa: se confirmada a unipolaridade, haverá maiores incentivos para as iniciativas em andamento criadas e mantidas pelo protagonismo brasileiro, como a UNASUL e o CDS. Contudo, se configurada a multipolaridade desequilibrada, os incentivos sistêmicos serão para a manutenção de uma integração baixa e instituições fracas na área de cooperação em defesa na América do Sul. / The defence cooperation in South America is explained by the Offensive Realist Theory of Cooperation in Defence under Unipolarity - hereby introduced. After identifying a meaningful gap in international relations theories and in ad hoc works which tryed to explain defence cooperation in other parts of the world, our theory brings explanations for (1) states' motivations to cooperate in defence; (2) the independent variables that affect defense cooperation; (3) a comprehensive model of defense cooperation that can be applied to different regions of the world. We have shown that cooperating in defence works for improving the relative position of the participating states vis-a-vis either the other states or the unipole without increasing the pressures of the security dilemma. This requisite reaffirms the selfish principle of states of maximising their power to better ensure their survival, but showing that new times demand new ways of power maximisation. To do so, we have demonstrated the maintenance of the United States' unipolarity at the global balance of power and shown, through 15 different indexes, that the South-American polarity finds itself in a transitory moment between an unbalanced multipolarity and a Brazilian unipolarity, suffering then pressures from both configurations and thus corroborating our theory's expectations. Our conclusion is that the refitting or not of the Brazilian Armed Forces will lead to the definition of the ups and downs of the sistemic regional pressures on defence cooperation: if it is confirmed the Brazilian unipolarity, there will be greater incentives for the ongoing initiatives created and maintened by Brazil, such as UNASUR and SDC. Nevertheless, if the unbalanced multipolarity is confirmed, the sistemic incentives will be for the maintenance of a low regional integration and weak institutions on the South American defence cooperation field.

A cooperação em defesa na América do Sul é explicada pela Teoria Realista Ofensiva de Cooperação em Defesa sob a Unipolaridade - aqui introduzida. Identificada uma lacuna significativa nas teorias de Relações Internacionais e nos trabalhos que buscam explicar, de forma ad hoc, a cooperação em defesa em outras regiões do mundo, nossa teoria traz explicações para (1) a motivação dos Estados para cooperar em defesa; (2) as variáveis independentes que afetam a cooperação em defesa; (3) um modelo amplo de cooperação em defesa que possa ser replicado em diferentes regiões do mundo. Demonstramos que cooperar em defesa serve para aumentar a posição relativa dos Estados participantes tanto frente aos demais Estados quanto frente à potência unipolar, sem, contudo, aumentar as pressões do dilema da segurança. Esse suposto reafirma o princípio egoísta dos Estados, de buscarem maximizar o seu poder para melhor garantir a sua sobrevivência, mas mostrando que novos tempos exigem novas formas de maximização de poder. Para tanto, demonstramos a continuidade da unipolaridade dos Estados Unidos na balança de poder global e apontamos, via 15 indicadores diferentes, que a polaridade sul-americana encontra-se em um momento de transição entre uma multipolaridade desequilibrada e uma unipolaridade brasileira, sofrendo pressões sistêmicas de ambas as configurações e corroborando as expectativas de nossa teoria. Conclui-se que o reaparelhamento ou não das Forças Armadas brasileiras levará à definição do sobe e desce das pressões sistêmicas regionais para a cooperação em defesa: se confirmada a unipolaridade, haverá maiores incentivos para as iniciativas em andamento criadas e mantidas pelo protagonismo brasileiro, como a UNASUL e o CDS. Contudo, se configurada a multipolaridade desequilibrada, os incentivos sistêmicos serão para a manutenção de uma integração baixa e instituições fracas na área de cooperação em defesa na América do Sul. / The defence cooperation in South America is explained by the Offensive Realist Theory of Cooperation in Defence under Unipolarity - hereby introduced. After identifying a meaningful gap in international relations theories and in ad hoc works which tryed to explain defence cooperation in other parts of the world, our theory brings explanations for (1) states' motivations to cooperate in defence; (2) the independent variables that affect defense cooperation; (3) a comprehensive model of defense cooperation that can be applied to different regions of the world. We have shown that cooperating in defence works for improving the relative position of the participating states vis-a-vis either the other states or the unipole without increasing the pressures of the security dilemma. This requisite reaffirms the selfish principle of states of maximising their power to better ensure their survival, but showing that new times demand new ways of power maximisation. To do so, we have demonstrated the maintenance of the United States' unipolarity at the global balance of power and shown, through 15 different indexes, that the South-American polarity finds itself in a transitory moment between an unbalanced multipolarity and a Brazilian unipolarity, suffering then pressures from both configurations and thus corroborating our theory's expectations. Our conclusion is that the refitting or not of the Brazilian Armed Forces will lead to the definition of the ups and downs of the sistemic regional pressures on defence cooperation: if it is confirmed the Brazilian unipolarity, there will be greater incentives for the ongoing initiatives created and maintened by Brazil, such as UNASUR and SDC. Nevertheless, if the unbalanced multipolarity is confirmed, the sistemic incentives will be for the maintenance of a low regional integration and weak institutions on the South American defence cooperation field.

Although the period between 1926 and 1934 was relatively peaceful, Imperial Defence policy-making in Britain focused on threats along the periphery of the Empire. This included a short-lived, but serious concern over Communist expansion in China and Afghanistan and a fear that American naval construction would undermine the Royal Navy's position in the world. The first threat receded by 1928 and the second was met by negotiating the highly successful London Naval Conference of 1930. Throughout these years, the need to reorient the Imperial Defence system to meet a perceived Japanese threat in the Far East, and the Treasury's opposition to the very idea, remained constants within policy-making circles. The world-wide depression led to serious defence cutbacks which the services met largely by cutting back even further on war reserves and mobilization potential. The Japanese assault on Manchuria in 1931, and then in Shanghai in 1932, exposed the inability of the Imperial Defence system to meet a Far Eastern threat. This led to pressure from the navy, in particular, for an increase in service estimates, but the economic situation and the World Disarmament Conference kept the government from agreeing to any significant change in policy. From 1931-193, Imperial Defence concerns were centred on the Far East, but Hitler‘s rise to power in March 1933 turned attention hack toward Europe. Nevertheless, the first large-scale review of Imperial defence deficiencies, the Defence Requirements Sub-Committee, presented a report which balanced the needs of European and Far Eastern defence. In the spring of l934. however, the Cabinet found itself unable to come to a consensus on the DRC's recommendations and the Chancellor of the Exchequer, Neville Chamberlain, stepped forward with his own defence vision. He discounted the need for Far Eastern defence and re-oriented defence policy toward homeland defence. It was his intervention that set the tone for British rearmament in the 1930s.

Any person studying the history of the Cape Colony in the mid- Victorian years must soon grow aware of the contrast between what the imperial authorities said they intended to do and what they actually did. This is particularly obvious in the treatment of the frontier tribes, who lost their lands (and sometimes their lives) in the name of a policy described by one governor as based on 'morality and religion'. But it is also evident in many other spheres of government, and insistently raises the question of that British intentions really were and how far Ministers managed to achieve them. The evidence available is too vast and amorphous for a gene- ral survey to be attempted. In order to investigate the problem it is necessary to limit its scope. The period from 1846 to 1854 has been chosen because it embraced two frontier wars and a series of major administrative changes, involving prolonged consultation between Government House and Downing Street, and raising matters which affected the vital interests of the colonial population itself. It is also ground covered by other historians, but they have frequently differed as to the aims of the imperial government and the colonial reaction to them. One reason for their differences is plain: they have failed to take a comprehensive view of the sub- ject, such as the imperial government itself might have taken. Frontier policy is described as if it bore no relation to constitutional changes in Cape Town; local politics are discussed as if the British connection had little relevance. Britain's treatment of the Afrikaners led one of their leaders to style the nineteenth century a 'Century of Wrong.‘ But those sympa- thetic to the British approach have seen in it an attempt to infuse the spirit of British tolerance and justice into Cane society. They explain its contradictions by depicting an imperial power those 'high natives and worthy ends were frustrated by the inadequate resources which could be spared for the resolution of Cape problems. The material on which this conclusion rests is predominantly that found in official archives in Cape Town and London. A glance at the bibliographies of works by de Kiewiet, Galbraith, Morrell and Macmillan reveals no systematic attempt to study newspapers or other sources to check the accuracy or discover the undertones of official reporting from the Colony. Furthermore, large collections of private correspondence belonging to prominent politicians have recently been made public in Britain. Although often edited of financial or other sensitive items they still raise similar doubts about the comprehend- siveness of Colonial Office despatches. A new assessment of these sources is therefore required. In 1867 Bagehot differentiated between the 'distinguished' and the 'efficient' parts of the British constitution. The former he described as designed to 'excite and preserve the reverence of the population'; the latter as 'those by which it, in fact, works and rules'. This thesis attempts to show that Colonial Office pronouncements on the Cape likewise fall into two categories. Some were intended (again borrowing Bagehot's words) to 'win the loyalty and confidence of mankind'; others to 'employ that homage in the work of governmental. From this it follows that the statements in despatches are not invariably to be trusted, and that some are of greater significance in the interaction of Cape and British politics than others. The private correspondence helps us to differentiate. It also shows the Colonial Office less as a place where policy was made and more as one where decisions taken by Mini- sters were translated into a form understandable to governors and acceptable to the British public. Continued in thesis ...

The purpose of this essay is to investigate what kind of motives where behind the long term decisions for the Swedish military defense in 2000 and 2004. This leads to the questions that the essay is meant to answer; 1. Were the motives behind the two decisions for the Swedish military defense of economic character or an adjustment of security and defense policy? 2. Was the parliament united in the two decisions and if they were not, why? 3. Were there any differences in motive between the two decisions? To answer these questions I have investigated the government bills, private member bills and the parliament debate concerning the two decisions. The result of the essay is that the decision of 2000 was a compromise between security and state finances. The essay can’t define the motives for the later decision. There was a greater understanding in the parliament in the later decision and the biggest difference between both decisions is that the parties who made the decisions in the parliament were not the same at both events.

Le véritable enseignement de la présente étude réside en ce que, comme déjà évoqué, le poids de l’appareil judiciaire finit par acquérir plus de consistance que le crime lui-même. A « l’aventure criminelle », c’est-à-dire celle, tragique, des faits à réprimer, se substitue « l’aventure judiciaire », celle de la marche de la justice en vue de parvenir au jugement des faits. Qu’il s’agisse du procès pénal français ou anglo-saxon, l’étude démontre que les règles applicables sont d’une telle complexité qu’elles génèrent une logique judiciaire spécifique et presque détachée des faits à traiter. Les praticiens sont souvent surpris du contraste entre les faits à juger, dont les mobiles et les circonstances sont toujours simples, et la solution judiciaire plus et/ou trop élaborée.L’étude démontre encore le caractère immuable et presque immobile de la justice pénale. Qu’il s’agisse de la France ou des pays anglo-saxons, les fondamentaux des deux systèmes judiciaires en concurrence –procédure inquisitoire ou procédure accusatoire- sont les mêmes depuis le Moyen Âge. Certes, des réformes interviennent, le poids du contradictoire s’accroit, les procédures de recours sont organisées, etc. Mais il s’agit toujours en France de faire faire une enquête approfondie avant procès par un organe d’état et, dans les pays anglo-saxons, de voir s’affronter deux thèses avec un avantage pratique à l’accusation.C’est que, comme le démontre aussi l’étude, la philosophie sociale de chacun des deux mondes français et anglo-saxon est différente sur le statut du suspect : objet d’une recherche de la vérité en France et presque coupable chez les Anglo-Saxons.Cette philosophie sociale en recoupe une autre : la philosophie politique. En France, l’individu est assisté car l’Etat est plus grand que lui ; dans les pays anglo-saxons, l’individu est un homme libre et seul responsable de son destin. Dès lors, en France, l’Etat veut forger sa propre opinion sur des faits délictueux ; dans les pays anglo-saxons, l’affrontement des individus (parquetiers et défenseurs) prime le reste. De plus, dans ces pays, la liberté et l’indépendance reconnues à l’individu le rendent davantage responsable de ses faits et gestes, d’où l’importance démesurée accordée à l’aveu. Pour autant, cette philosophie politique d’un citoyen libre et fort est un extraordinaire levier pour l’Histoire de la Liberté et celle aussi de l’Expansion économique. Sans elle, les pays européens du continent n’auraient sans doute pas pu se soustraire à la botte de conquérants. Sans elle, les Etats-Unis ne seraient pas une locomotive du développement.Il ne faudrait pas croire non plus que le monde anglo-saxon n’a fait que peu d’apports positifs au procès pénal. C’est à la loi britannique sur l’Habeas corpus de 1679 que l’on doit l’idée d’un délai raisonnable pour être jugé et, à défaut, le droit à être remis en liberté. C’est encore aux Britanniques que l’on doit l’idée de droits de la défense recensés en tant que tels, d’abord dans certains articles de la Magna Carta de 1212 puis dans le Bill of Rights de 1689. C’est aux Américains que l’on doit l’idée de sacraliser les droits de la défense en leur donnant un contenu constitutionnel par les amendements à la Constitution de 1787, ajoutés à partir de 1789, une idée qui sera reprise bien plus tard dans la Convention Européenne des Droits de l’Homme et des libertés fondamentales.L’étude montre donc que les pays anglo-saxons réputés pragmatiques ont plutôt fait des contributions de principe, sans mesurer que les applications pratiques qu’ils en tirent dénaturent le procès pénal. L’étude montre aussi que la France, réputée pour ses approches dogmatiques et rationnelles mais d’une raison déconnectée des réalités, a une vision bien plus juste du procès pénal.L’étude a enfin montré que, dans le domaine de la justice pénale, les mondes français et anglo-saxons s’ignorent. / This study shows that the criminal process finally acquires more consistency than the crime itself. The “criminal adventure”, namely the tragical story of the crime itself, turns into “the judicial adventure”, namely the path of justice towards the final decision (conviction or dismissal). Whether it deals with the French or with the Anglo-Saxon models, the legal rules are so complicated that they create a judicial logic which is specific and clipped from the facts of the case. In comparison, the motives and the circumstances of a crime are always simple. Accordingly, the judicial issue appears to be more (and often too much) elaborated than the crime itself.The study also shows the unchanging character of the criminal justice. Whether it is in France or in the Anglo-Saxon countries, the fundamentals of the two justices which are concurrent – inquisitorial model and adversary one- are the same that in the Middle Age. Of course, some reforms happened. The importance of the rule of the contradictory increases, etc. However, the main concern of the French justice still deals with a pretrial investigation which is very thoroughly conducted by a state agency. The Anglo-Saxon model always lies in the confrontation of two thesis with a practical advantage given to the prosecution. These different approaches by the two justices are attributable to a different social philosophy. The status of the suspected person greatly differs whether he is prosecuted in France or in the Anglo-Saxon countries: in France, this status is a matter of the search for the truth; in the Anglo-Saxon countries, this status is in practice that of an almost guilty one, even if his guilt must be proved beyond a reasonable doubt.This social and/or ethic philosophy recuts another one: the political philosophy. In France, the individual is assisted since the State is deemed to be “stronger” than him; in the Anglo-Saxon countries, the individual is a free man; accordingly, he is solely responsible for his acts. Therefore, in France, the State wants to fix up its own opinion about the crime; in the Anglo-Saxon countries, the confrontation of the prosecution and the lawyer outdoes all the rest, in particular the truth. Moreover, in these countries, according to the freedom and the independence of the individual, an undue importance is given to confessions.However, the Anglo-Saxon political philosophy is an extraordinary lever for the history and the liberty and also for the economic expansion. Without it, the continental countries would not have been able to be freed from the conquerors of the two world wars and the cold war. Without it, the US would not be a forefront of the progress.We do not consider that the Anglo-Saxon world made few positive contributions to the criminal proceedings. Indeed, this is the famous English Habeas Corpus Act of 1679 which created the idea of a reasonable time to be tried in court and, if not, to be released from prison. From the English comes the idea of an explicit list of rights of the defence, in particular in some articles in the Magna Carta of 1212 and then officially included in the Bill of Rights of 1689. From the Americans comes the idea of making the rights of defence sacred through the amendments of the constitution. We remember that this idea arrived late in Europe with the ECHR.Therefore, the study shows that the Anglo-Saxons countries which benefit from a reputation of pragmatism have rather acted as theoreticians of criminal law. They have provided the world of criminal justice mainly with contributions close to symbols. They have underestimated the consequences of these symbols in the practice of the criminal proceedings. The study shows also that the French, who are often known for their dogmatic approach of problems, have a better understanding of the criminal proceedings.The study shows especially that the Anglo-Saxon world of criminal justice and the French one totally ignore each other.

La ricerca fornisce un’indagine diacronica dell’evoluzione della cooperazione UE-NATO. Lo studio permette di andare oltre le dicotomie “formale/informale” e “stato/burocrazia” che hanno contraddistinto gli studi sulla relazione tra le due organizzazioni. Arricchendo il quadro analitico multilivello con proposizioni teoriche tratte dall'istituzionalismo storico, la ricerca considera la cooperazione formale e informale come istituzioni che si influenzano reciprocamente e dimostra come la complessa interazione tra fattori materiali, istituzionali e l’azione di attori statali e non statali influenzi la cooperazione tra le due organizzazioni. Evidenze empiriche rivelano un andamento ricorrente nel cambiamento della cooperazione formale UE-NATO, in quanto minacce alla sicurezza e integrità territoriale Europea innescano una giuntura critica che facilita una convergenza di preferenze tra gli stati che segnalano interesse per una nuova politica di cooperazione e individui nelle organizzazioni che agiscono come negoziatori. Nonostante tale processo accomuni l’accordo Berlin Plus con la Dichiarazione congiunta UE-NATO, il recente ritorno alla cooperazione formale avanza ambizioni con maggiori sfumature costruttiviste e segnala un ruolo crescente della burocrazia come policy-maker. Lo staff delle due organizzazioni ha sviluppato pratiche di cooperazione informale, che non solo hanno parzialmente compensato gli anni di stallo tra UE e NATO, ma hanno anche influenzato la finalità e il contenuto della recente ripresa della cooperazione formale tra le due organizzazioni. / The research provides a diachronic investigation of the evolution of EU-NATO cooperation. In so doing, the study allows for going past the “formal/informal” and “state/bureaucratic” dichotomies that have characterized EU-NATO studies. Combining the “multilevel framework” of analysis with theoretical insights from historical institutionalism, the research considers formal and informal cooperation as intersecting and mutually influencing institutions and reveals how the complex interplay among material, institutional factors and state and no-state actors’ agency affect inter-organizational cooperation. Our empirical findings reveal a recurring pattern of change in EU-NATO formal cooperation, as threats to European security and territorial integrity trigger a critical juncture facilitating the convergence of actors’ preferences with states showing interest in a new policy of cooperation and individuals acting as policy-brokers. Notwithstanding this commonality between the adoption of the Berlin Plus agreement and the EU-NATO Joint Declaration, the recent upsurge of formal cooperation shows more constructivist nuanced ambitions and a growing role of bureaucrats as policy-makers. Staff have displayed inter-organizational agency by developing informal practices of cooperation that did not only partially counterbalance lack of cooperation in the years of the EU-NATO stalemate, but have also shaped the ratio and content of the recent comeback to formal cooperation.

This thesis deals with the development of the political environment and society in the Union of South Africa between 1939 and 1948. This period is characterized not only by close cooperation with Great Britain during World War II, the temporary suppression of nationalist opposition and the dominance of the United Party led by Jan Smuts in the South African political scene, but also social tensions and escalating conflict between the mainly Afrikaner "white" populations in the Union and non- European ethnic groups. Regardless of the fact that the Union was in World War II on the side of the victors and the sacrifice that had to bring in comparison with many other belligerent countries was relatively small, Smuts and his United Party suffered a fatal defeat in the first post-war elections in 1948. These elections not only meant the actual end of Smuts' political career and departure of United Party to permanent opposition, but also the beginning of the rule of Afrikaner nationalists for more than forty years. This paper aims to analyse the changes in society and the political climate in the Union during World War II and in the first three years after the war and the reasons that led to long-term dominance of nationalists in South Africa. Key Words Union of South Africa, Second World War, Union...

Abstract Grazing by reindeer (Rangifer tarandus L.) affects vegetation and soil microbial processes in tundra ecosystems. It is considered that grazing can induce two alternative vegetation states that differ in plant species composition and the rate of nutrient cycling. I hypothesised that these alternative vegetation states differ in ecosystem responses to climate warming. I tested the hypothesis using a factorial warming and fertilisation experiment on long-term lightly grazed (LG) and heavily grazed (HG) tundra. The reindeer grazing induced vegetation shift from dwarf shrubs to graminoids increased microbial activities for SOM decomposition. The grazer-induced shifts in vegetation and microbial activities in combination with the fertilisation via urine and faeces had important consequences on soil N availability and soil C quality that determined the ecosystem-level consequences of climate warming. Due to higher soil N availability, warming increased plant productivity (GEP) on HG but not on LG tundra, where N limitation prevented the warming-increased plant production. The varying effects of warming on GEP at different grazing intensities determined the effects of warming on ecosystem net C sink, which was unaffected by warming on HG but decreased on LG tundra. Reindeer grazing reduced the soil C quality, as soils under LG stored a higher proportion of carbohydrates vulnerable to microbial decomposition than soils under HG. According to laboratory soil incubations, the grazer-induced reduction in soil C quality mitigated the responses of soil microbial activity to prolonged warming. Warming caused a stronger decrease in concentrations of phenolics, an important means of plant defence against biotic and abiotic stresses, in Empetrum nigrum ssp. hermaphroditum under HG than LG. Grazing history by reindeer, with the associated vegetation shift from dwarf shrubs to graminoids, can significantly alter the ecosystem-level consequences of climate warming. Overall, this thesis highlights that the effects of reindeer grazing on soil properties, soil N availability and C quality, are important determinants of the ecosystem responses to climate warming. Therefore, future research on climate warming should take into account herbivores and aim towards a more holistic approach that includes both aboveground and belowground components of the ecosystem. / Tiivistelmä Tundralla porolaidunnus vaikuttaa kasvillisuuteen ja maaperän mikrobien toimintaan. Porolaidunnus voi aikaansaada kaksi vaihtoehtoista kasvillisuuden tilaa, jotka eroavat toisistaan paitsi kasvilajiston myös ravinnekierron suhteen. Esitin hypoteesin, jonka mukaan ilmaston lämpenemisen vaikutukset eroavat tundratyypeillä, jotka edustavat vaihtoehtoisia kasvillisuustiloja. Testasin hypoteesia faktoriaalisen lämmitys- ja lannoituskokeen avulla tundra-alueilla, joilla poron laidunnuspaine on ollut pitkäaikaisesti joko kevyttä tai voimakasta. Poron aiheuttama kasvillisuusmuutos varpuvaltaisesta heinävaltaiseksi lisäsi maaperän mikrobien hajotusaktiivisuutta. Poron aiheuttamat erot kasvillisuudessa ja mikrobiaktiivisuuksissa yhdessä virtsan ja papanoiden lannoittavan vaikutuksen kanssa muuttivat maaperän typen saatavuutta sekä hiilen laatua. Erot maaperän ominaisuuksissa puolestaan ohjasivat ilmaston lämpenemisen ekosysteemitason vaikutuksia. Lämmitys kasvatti ekosysteemituotantoa ravinteikkaalla voimakkaasti laidunnetulla tundralla mutta ei kevyesti laidunnetulla tundralla, joka oli typpirajoitteinen. Lämmityksen erilaiset vaikutukset ekosysteemituotantoon eri laidunpaineissa määrittivät lämmityksen vaikutuksen ekosysteemin hiilinieluun, joka pysyi muuttumattomana voimakkaasti laidunnetulla tundralla mutta pieneni kevyesti laidunnetulla tundralla. Porolaidunnus alensi maaperän hiilen laatua, ja kevyesti laidunnetulla tundralla maaperässä oli enemmän mikrobien hajotukselle alttiita hiilihydraatteja kuin voimakkaasti laidunnetulla tundralla. Laboratoriossa suoritetun inkubaatiokokeen perusteella maaperän hiilen alhaisempi laatu lievensi mikrobien hajotusaktiivisuuden vastetta pitkäaikaiseen lämmitykseen. Lämmitys vähensi pohjanvariksenmarjan fenoliyhdisteiden, jotka ovat tärkeä osa kasvien puolustusta bioottisia ja abioottisia stressitekijöitä vastaan, pitoisuuksia enemmän voimakkaasti kuin kevyesti laidunnetulla tundralla. Poron laidunnushistoria yhdessä kasvillisuusmuutoksen kanssa voi merkittävästi vaikuttaa ilmaston lämpenemisen ekosysteemitason seurauksiin. Tämän väitöstyön tulokset osoittavat, että poron vaikutukset maaperän typpeen ja hiileen määrittävät lämpenemisen vaikutukset ekosysteemissä. Tulevaisuudessa ilmastonmuutostutkimuksen pitäisikin kokonaisvaltaisemmin huomioida sekä herbivorian että ekosysteemin eri osien merkitys.