O clado de Passeriformes denominado, atualmente, Furnariida é endêmico da região Neotropical e muito diversificado; ele é representado por cerca de 623 espécies alocadas em 134 gêneros, distribuídas nas seguintes famílias: Furnariidae, Dendrocolaptidae, Thamnophilidae, Formicariidae, Conopophagidae e Rhinocryptidae. As aves deste grupo são, em geral, encontradas em bandos mistos de espécies e/ou podem seguir formigas de correição, fenômenos que são conspícuos entre aves de florestas tropicais. Os representantes de Furnariida são considerados insetívoros, embora possam consumir, ocasionalmente, pequena quantidade de frutos ou sementes e pequenos vertebrados. Este trabalho teve como objetivo descrever a dieta de espécies representantes dos Furnariida que ocorrem em diferentes regiões da Amazônia, além de estimar o número de presas e de biomassa bruta consumida. Para tal, foi analisado o conteúdo estomacal de 476 espécimes de aves Furnariida, dos quais 51 pertencem à família Furnariidae, 139 à Dendrocolaptidae, 280 à Thamnophilidae, 3 à Formicariidae e 3 à Conopophagidae. Foram utilizados dois métodos diferentes para avaliar a contribuição da biomassa de presas consumidas pelos Dendrocolaptidae. O método da biomassa parcial apresentou-se muito incerto e, neste estudo, considerou-se a biomassa estimada como o método mais confiável para comparar o número total de itens e sua biomassa correspondente. As principais presas consumidas por estes pássaros foram Coleoptera, Orthoptera e Araneae. No entanto, Orthoptera foi o item que contribuiu com a maior biomassa ingerida, seguido de Coleoptera e Vertebrata. A alta biomassa de Orthoptera no ambiente poderia explicar o maior consumo, ou preferência desses insetívoros por tal item. Os vertebrados foram consumidos por alguns espécimes de Dendrocolaptidae e de Thamnophilidae e a maior parte do material ingerido pelos dendrocolaptídeos corresponde a Gonatodes humeralis, um pequeno lagarto escansorial; já os vertebrados consumidos pelos tamnofilídeos não foram identificados. A predação de vertebrados pode ser ocasional e, em geral, é considerada oportunística. Nas famílias de Furnariida, com número representativo de espécimes, Orthoptera e Araneae tiveram maior frequência de ocorrência em Furnariidae, enquanto Coleoptera e Orthoptera em Thamnophilidae e Coleoptera em Dendrocolaptidae, o que pode estar relacionado aos hábitos de forrageamento das espécies nelas incluídas / The clade Furnariida of the Passeriformes is endemic to the Neotropical region, and is very diverse: it is represented by around 623 species in some 134 genera distributed in the following families: Furnariidae, Dendrocolaptidae, Thamnophilidae, Formicariidae, Conopophagidae e Rhinocryptidae. Commonly the birds of this group are found in mixed-species flocks and/or as army-ant-followers, features that are common amongst birds of the tropical forests. Members of the Funariida are considered to be insectivores although they may occasionally eat small quantities of fruit or seeds, or small vertebrates. The objective of this study was to describe the diet of representative species of the Funariida that occur in different Amazonian regions, and also estimate the numbers of prey and total biomass consumed. To do this the stomach contents of 476 specimens of the Furnariida were analyzed, of which, 51 belonged to the family Funariidae, 139 to the Dendrocolaptidae, 280 to the Thamnophilidae, and 3 each to the Formaricariidae and Conopophagidae. Two methods were used to evaluate the contribution of the biomass of the preys consumed by the Dendrocolaptidae. The partial biomass method was found to be very unreliable and so, in this study, the estimated biomass method was found to be the most appropriate to compare the total number of items in the corresponding biomass. The main types of prey eaten by these birds were Coleoptera, Orthoptera and Araneae. Nevertheless, Orthoptera were the group that made the biggest contribution to the ingested biomass, followed by Coleoptera and Vertebrata. The high biomass of Orthoptera in the environment would explain the high consumption and preference for these insects as prey. The vertebrates were consumed by some specimens of Dendrocolaptidae and Thamnophilidae, and in the case of the dendrocolaptids these were all the small scansorial lizard Gonatodes humeralis; those consumed by the thamnophilids were not identified. Predation on vertebrates seems to be occasional and is probably opportunistic. In the families of the Furnariida, represented by numbers of specimens, Orthoptera and Aranae had the highest frequency of occurrence in the Funariidae, with Coleoptera and Orthoptera in the Thamnophilidae, and Coleoptera in the Dendrocolaptidae, which can be related to the foraging habits of the species in these families

Os artrópodes constituem o grupo mais diverso do Reino Animal, apresentando uma distribuição muito ampla nos ecossistemas e habitats. O fato de esses animais terem mudado muito pouco durante sua evolução e estarem bem adaptados aos ambientes inóspitos e com uma alta presença de microorganismos patogênicos, torna interessante a realização de estudos sobre o seu sistema imunológico. Parte importante deste sistema são os peptídeos antimicrobianos, que controlam a invasão dos diferentes patógenos. Estas moléculas não só podem fornecer informação sobre o sistema imune e o funcionamento deste, como também pode ajudar a buscar alternativas nas lutas contra as doenças infecciosas. Sendo assim, se torna interessante a purificação e a caracterização dos peptídeos antimicrobianos presentes nesses animais como também o conhecimento do funcionamento de seu sistema imune. Neste trabalho foram utilizadas duas espécies da ordem quilópoda: Scolopendra viridicornis e Otostigmus cavalcanti como modelo experimental. Foi avaliada a presença de moléculas bioativas na hemolinfa (plasma e hemócitos) e no extrato total do corpo, bem como a produção destas moléculas após o animal receber um estímulo ou injúria. Foi observada a presença de diferentes frações com atividade antimicrobiana na hemolinfa (plasma e hemócitos) e no extrato total de animais desafiados e não desafiados em Otostigmus cavalcanti, apresentando um aumento na atividade antimicrobiana nos animais do grupo estimulado. O que pode significar que algumas das moléculas antimicrobianas estão presentes constitutivamente no animal enquanto outras precisam de um estímulo para ser expressas. No plasma de S. viridicornis foram observadas diferentes frações com atividade antimicrobiana, observando-se atividade contra a bactéria Gram-negativa E coli e contra a levedura C. albicans. No entanto, nos hemocitos, diferentes frações apresentaram atividade somente contra a bactéria Gram-positiva M. luteus. Na porção hidrofóbica do extrato total do corpo de S. viridicornis também foram observadas diferentes frações com atividade antimicrobiana. No material eluído em 5% de ACN, por análise de ESI-MS de uma fração com atividade contra M. luteus foram observadas duas moléculas com massa molecular baixa (848,49 e 861,94 Da). Ainda no extrato total da fração hidrofóbica foram observadas duas moléculas que se apresentaram puras. A primeira destas mostrou uma massa molecular de 1,7 kDa mas ainda não foi caracterizada. Enquanto a segunda evidenciou um peptídeo de 925,4658 Da e cuja estrutura primaria apresentou um composto de 8 resíduos de aminoácidos (RYPAVGYT). Esta molécula foi nomeada Lacraina. Entretanto na porção hidrofílica do extrato total de S. viridicornis e de Otostigmus cavalcanti foram observadas frações de baixa massa molecular com atividade antiparasítica contra Leishmania amazonensis e Trypanosoma brucei e antibacteriana contra E. coli e M. luteus. Também nesta fração foi observada uma molécula semelhante à Gomesina um peptídeo antimicrobiano da aranha caranguejeira Acanthoscurria gomesiana. A análise e caracterização desta molécula ainda esta em progresso. / Arthropods constitute the most diverse group in the Animal Kingdom, representing a very wide distribution in different ecosystems and habitats. The fact that these animals have changed very little during their evolution and that theyre well adapted to harsh environments with a high presence of pathogenic microorganisms, makes it interesting to conduct studies on their immune system. An important part of these systems are antimicrobial peptides that control the invasion of various pathogens. These molecules not only provide us with information on their immune system and its functioning, but can also help us find alternatives in the struggle against infectious diseases. Therefore, the purification and characterization of antimicrobial peptides present in these animals becomes important, as well as gaining knowledge on how their immune systems work. In this work two specimens of the Chilopoda order, Scolopendra viridicornis and Otostigmus cavalcanti, were used as an experimental model for the characterization of bioactive molecules present in the hemolymph and total body extract as well as the production of these molecules after stimulating or injuring the animal. The presence of different fractions with antimicrobial activity in the hemolymph (plasma and hemocytes) and the total body extract of defied and not defied animals in Otostigmus cavalcanti was observed. Presenting an increase in the antimicrobial activity in the stimulated group of animals, this could mean that some of the antimicrobial molecules are constitutively present in the animal, while others need to be induced to be expressed. In the plasma of S. viridicornis different fractions with antimicrobial activity and with activity against the Gram-negative bacteria E coli and against the C. albicans yeast were observed. Notwithstanding, in the hemocytes, there are different fractions that presented activity only against the Gram-positive M. luteus bacteria. In the hydrophobic portion of the total extract of the S. viridicorniss body, different fractions with anti-microbial activity were also observed. In the 5% ACN eluted material, by an ESI-MS analysis of a fraction with activity against M. luteus two molecules with low molecular mass (848.49 and 861.94 Da) were present and two pure molecules were observed in the total extract of the hydrophobic fraction. The first one presented a molecular mass of 1.7 kDa that remains to be characterized. The second one was a 925.4658 Da peptide, whose primary structure presented a compound of 8 amino acid residues (RYPAVGYT). This molecule was named Lacrain. However, in the hydrophilic portion of the total extract of S. viridicornis and O. cavalcanti low molecular mass fractions with antiparasitic activity against Leishmania amazonensis and Trypanosoma brucei as well as antibacterial activity against E. coli and M. luteus were observed. Also in this fraction a molecule similar to Gomesin, an antimicrobial peptide from the spider Acanthoscurria gomesiana. was present. The analysis and characterization of this molecule is still in progress.

Human activities have being responsible for the global environmental changes, resulting in an increase number of incident of vector- and rodent-borne diseases worldwide. Rodents and arthropods-borne viruses are important globally emerging and re-emerging viruses and most of them are RNA viruses. Efficient and early diagnosis of these infections are very important to prevent their spread, to improve clinical management of the patients, as wells to protect livestock and domestic animals. Currently, available diagnostic methods such as immunoassays, polymerase chain reaction and virus isolation can detect only one or few viruses in a single assay. The DNA microarray platform has emerged as diagnostic tool suitable for high throughput screening of pathogenic agents. The aim of this study was to develop a DNA microarray platform (RoboArboVirusChip) for detecting rodent- and arthropod-borne viruses, which belong to seven families: Bunyaviridae (genera Orthobunyavirus, Nairovirus and Phlebovirus), Flaviviridae (genus Flavivirus), Togaviridae (genus Alphavirus), Reoviridae (genera Orbivirus, Seadornavirus and Coltvivirus), Rhabdoviridae (genera Vesiculovirus and Ephemerovirus), and Asfarviridae (genus Asfarvirus). Specific oligonucleotide probes of 60-mer (n=4209) targeting 412 virus species and generic probes of 25-35-mer (n=87) targeting viruses at the genus level were designed. A total of 17 reference viruses belonging to the Bunyaviridae, Flaviviridae, Rhabdoviridae and Togaviridae families were used to standardize RoboArboVirusChip. All reference viruses were specifically detected without any cross hybridization; however, the generic probes were not able to identify the viruses at the genus level. The RoboArboVirusChip was able to specifically identify four viruses contained in three different mixtures: i) virus of different families, ii) virus of the Flavivirus genus, and iii) the Dengue virus (DENV) serotypes. The four DENV serotypes were use to evaluate the sensitivity of the RoboArboVirusChip, which was able to detect a minimum of 25 RNA copies/mL of the viruses, confirming its high sensitivity. The applicability of the RoboArboVirusChip to detect viruses in clinical samples was tested with serum samples obtained from dengue suspected cases (four positive cases and 40 negative cases). DENV was detected in the four positive serum samples, while in the 40 negative serum samples, it was not detected any virus. The results obtained in this study suggest that the RoboArboVirusChip platform could be a useful tool for early diagnosis of robovirus and arbovirus infections during epidemic outbreaks, helping in the rapid implementation of disease containment strategies / As atividades humanas têm sido responsável por mudanças ambientais globais, resultando num aumento do número de casos de doenças transmitidas por vetores e roedores em todo o mundo. Os vírus transmitidos por roedores e artrópodes são vírus emergentes e re-emergentes de importância global, sendo que a maioria deles são vírus de RNA. O diagnóstico eficiente e precoce dessas infecções são muito importantes para evitar a sua propagação, para melhorar o manejo clínico dos pacientes e também, para proteger o gado e os animais domésticos. Atualmente, os métodos de diagnóstico disponíveis, tais como os imunoensaios, a reação em cadeia da polimerase e o isolamento viral podem detectar apenas um ou poucos vírus em um único ensaio. A plataforma de microarranjo de DNA tem surgido como uma ferramenta de diagnóstico apropriada para o monitoramento em larga escala de agentes patogênicos. O objetivo deste estudo foi desenvolver uma plataforma de microarranjo de DNA (RoboArboVirusChip) para a detecção de vírus transmitidos por roedores e artrópodes, os quais pertencem a sete famílias: Bunyaviridae (gêneros Orthobunyavirus, Nairovirus e Phlebovírus), Flaviviridae (gênero Flavivirus), Togaviridae (gênero Alphavirus), Reoviridae (gênero Orbivirus, Seadornavirus e Coltvivirus), Rhabdoviridae (géneros Vesiculovirus e Ephemerovirus), e Asfarviridae (gênero Asfarvirus). Sondas oligonucleotídicas de 60-mer (n=4209) específicas contra 412 espécies virais, e sondas genéricas de 25-35-mer (n=87) para detecção de vírus a nível do gênero foram desenhados. Um total de 17 vírus de referência, pertencentes às famílias Bunyaviridae, Flaviviridae, Rhabdoviridae e Togaviridae foram utilizados para padronizar o RoboArboVirusChip. Todos os vírus de referência foram detectados especificamente sem apresentação de hibridação cruzada, porem as sondas genéricas não foram capazes de detectar os vírus a nível do gênero. O RoboArboVirusChip foi capaz de identificar especificamente quatro vírus contidos em diferentes misturas: i) vírus de diferentes famílias, ii) vírus pertencentes ao gênero a Flavivirus, e iii) os sorotipos do vírus da dengue (DENV). Os quatro sorotipos do DENV foram utilizados para determinar a sensibilidade do RoboArboVirusChip, o qual foi capaz de detectar um mínimo de 25 copias de RNA/mL. A aplicabilidade do RoboArboVirusChip para detectar vírus em amostras clínicas foi avaliada testando amostras de soro de pacientes com suspeita de dengue (quatro casos positivos e 40 casos negativos). Os resultados obtidos neste estudo sugerem que o RoboArboVirusChip poderá ser uma ferramenta útil para o diagnóstico precoce da infecção causada por robovírus e arbovírus, auxiliando na rápida implementação de estratégias de contenção das doenças causadas por esses vírus

Para conseguirem se alimentar com sucesso, os mosquitos hematófagos possuem componentes em sua saliva capazes de regular a hemostasia e modular a imunidade dos hospedeiros. Entretanto, a avaliação das atividades biológicas dessas moléculas no hospedeiro ainda carece de estudos mais aprofundados. No presente projeto, propomos caracterizar as atividades biológicas do produto do transcrito AET-7393, uma serpina presente nas glândulas salivares de fêmeas do mosquito Aedes aegypti. Nossos dados mostram que a serpina AET-7393 recombinante provoca um aumento no sangramento quando inoculada em camundongos, mas aparentemente esse efeito não está ligado à interferência com a cascata de coagulação. Mostramos ainda que a AET-7393 é capaz de inibir a proteinase 3 e aumentar a produção de IL-1b. Por fim, observamos a ausência de capacidade moduladora sobre a ativação de macrófagos ou sobre a inflamação, e que presença de anticorpos específicos contra a serpina no hospedeiro não interfere no ciclo de vida do mosquito. / In order to successfully feed, hematophagous mosquitoes possess salivary components capable of regulating hemostasis and modulate the host immunity. However, the evaluation of the biological activities of the salivary molecules in the host still needs further investigation. In this study, we intend to characterize the biological activities of the AET-7393, a serpin that is present in the saliva of the females Aedes aegypti mosquitoes. Our data show that the recombinant AET-7393 serpin increases bleeding when inoculated in mice, but apparently this effect is not due to its interference on the coagulation cascade. In addition, AET-7393 is able to inhibit proteinase 3 and enhance the production of IL-1b. Finally, we observed the absence of modulatory effect on macrophage activation or inflammation, and that the presence of host anti-AET-7393 antibodies does not interfere in the life cycle of the mosquitoes.

The heterogeneity in species assemblages of epigeal spiders was studied in a natural forest and in a managed forest. Additionally the effects of small-scale microhabitat heterogeneity of managed and unmanaged forests were determined by analysing the spider assemblages of three different microhabitat structures (i. vegetation, ii. dead wood. iii. litter cover). The spider were collected in a block design by pitfall traps (n=72) in a 4-week interval. To reveal key environmental factors affecting the spider distribution abiotic and biotic habitat parameters (e.g. vegetation parameters, climate parameters, soil moisture) were assessed around each pitfall trap. A TWINSPAN analyses separated pitfall traps from the natural forest from traps of the managed forest. A subsequent discriminant analyses revealed that the temperature, the visible sky, the plant diversity and the mean diameter at breast height as key discriminant factors between the microhabitat groupings designated by the TWINSPAN analyses. Finally a Redundant analysis (RDA) was done revealing similar environmental factors responsible for the spider species distribution, as a good separation of the different forest types as well as the separation of the microhabitat groupings from the TWINSPAN. Overall the study revealed that the spider communities differed between the forest types as well as between the microhabitat structures and thus species distribution changed within a forest stand on a fine spatial scale. It was documented that the structure of managed forests affects the composition of spider assemblages compared to natural forests significantly and even small scale-heterogeneity seems to influence the spider species composition. / Um die Anpassungsfähigkeit von Organismen, bei sich ändernden Umweltbedingungen, sicher zu stellen, spielt die Erhaltung der Biologischen Vielfalt auf allen ökosystemaren Ebenen eine entscheidende Rolle. Eben diese Anpassungsfähigkeit kann durch waldbauliche Maßnahmen einschränkt werden, und zur Instabilität des Systems führen. Daher kommt der Untersuchung von aus der Nutzung genommenen Naturwaldzellen eine immer größere Bedeutung zu. Einerseits um die potentiell natürliche Diversität in Naturwäldern mit der in Wirtschaftswäldern zu vergleichen, andererseits um die ökologischen Zusammenhänge in einer natürlichen Waldentwicklung zu verstehen. Ziel diese Studie war es eben diese natürlichen Waldynamiken auf das Artengefüge von Spinnen (Araneae) zu untersuchen. Dabei sollte Mithilfe eines experimentellen Fangdesigns, auch der kleinräumige Einfluss von Strukturheterogenität untersucht werden.

Arthropods have a rich fossil record spanning the Phanerozoic. Biomineralized forms such as the extinct trilobites are particularly common and are proven index fossils for biostratigraphy. Forms with an unmineralized cuticle are more rare, preserved only in so called konservat lagerstätten. Cambrian strata of Greenland have yielded rich trilobite faunas with potential for intercontinental correlation of Cambrian strata, but also an exceptionally preserved fauna, the Sirius Passet Lagerstätte. The first part of this thesis is concerned with trilobite biotratigraphy of the provisional Cambrian Series 2 in Greenland. The second part is concerned with exceptionally preserved arthropods from the Sirius Passet Lagerstätte, but also from 'Orsten' deposits from the Cambrian of Sweden. Perissopyge phenax occurs in the Henson Gletscher and Paralleldal formations spanning the Series 2 and 3 boundary interval in North Greenland. It also occurs in the Sekwi Formation of Yukon Territory, demonstrating that the species may hold potential for correlation within Laurentia. An indeterminate species of Perissopyge is shown to occur in the Ella Island Formation of North-East Greenland together with Olenellus cf. hanseni, which is similar to Olenellus cf. truemani described from the Henson Gletscher Formation. If this correlation is further corroborated it would offer a first tie-point for the An t'Sron Formation of North-West Scotland which yields Fritzolenellus lapworthi, herein reported for the first time from the Bastion Formation which underlies the Ella Island Formation. Oelandocaris oelandica from ‘Orsten’ deposits in the Cambrian series 3 and 4 boundary interval in Sweden is an early representative of the Crustacean stem lineage. Kiisortoqia avannaarsuensis is a new arthropod from the Sirius Passet Lagerstätte with robust antennulae strikingly similar to the 'raptorial' limb of the problematic anomalocaridids. The ventral morphology of the 'bivalved' Isoxys volucris is described for the first time and compared with other species assigned to Isoxys from Cambrian lagerstätten around the world. Finally, Siriocaris trolla, is a new arthropod that similarities with trilobites and certain ‘trilobitomorphs’ but seems to lack important synapomorphies of these taxa, though this may be due to preservational limitations in the material at hand.

The projected increase of shrubs across the Arctic is expected to alter patterns of snow cover, which may affect the phenology and survival of arthropods such as spiders. In this study, we simulated shrub encroachment on a series of tundra plots and examined the effects on the spider assemblages during the following growing season. Our simulated shrub treatment did not affect the abundance or composition of spider communities over the season; however, adults from the dominant genus Pardosa (Lycosidae) had significantly higher body mass on treatment plots. This difference in mass was observed following snow melt and persisted until halfway through the growing season. Given the importance of spiders as arthropod predators and as food sources for breeding birds, such a change in summer body mass could represent a shift in spiders’ functional contributions to Arctic ecosystems.

The projected increase of shrubs across the Arctic is expected to alter patterns of snow cover, which may affect the phenology and survival of arthropods such as spiders. In this study, we simulated shrub encroachment on a series of tundra plots and examined the effects on the spider assemblages during the following growing season. Our simulated shrub treatment did not affect the abundance or composition of spider communities over the season; however, adults from the dominant genus Pardosa (Lycosidae) had significantly higher body mass on treatment plots. This difference in mass was observed following snow melt and persisted until halfway through the growing season. Given the importance of spiders as arthropod predators and as food sources for breeding birds, such a change in summer body mass could represent a shift in spiders’ functional contributions to Arctic ecosystems.

As discussed in Chapter 1, although our understanding of the ecology and evolution of carnivorous plants has greatly improved in recent years, many fundamental questions remain unanswered. Unfortunately, at the present time, many carnivorous plants are increasingly threatened by anthropogenic activities. Indeed, over half of the carnivorous plant species assessed by the International Union for the Conservation of Nature (IUCN) are listed as `threatened', but the threats to carnivorous plants have not previously been quantified. In Chapter 2, I quantified the conservation threats to carnivorous plant taxa worldwide by searching peer-reviewed literature, and found data on the threats to 48 species of carnivorous plants from nine genera. The most common threat was habitat loss from agriculture, followed by the collection of wild plants, pollution, and natural systems modifications. As I found in Chapter 2, while agrochemical pollution is thought to be an important conservation threat to carnivorous plants, the effects of insecticides in particular on these taxa have not previously been quantified. Therefore in Chapter 3 I tested the effects of commercial and technical grades of three widely used insecticides (carbaryl, lambda-cyhalothrin, and malathion) on survival and the expression of traits associated with carnivory of pink sundews (Drosera capillaris) and Venus flytraps (Dionaea muscipula) using a combination of lab- and field-based experiments. Commercial grades were generally more harmful than technical grades under lab and field conditions, but all three insecticides were capable of causing negative effects on the plants within recommended application rates. Pink sundews appeared to be more susceptible to insecticides than Venus flytraps, perhaps because of larger numbers of digestive glands on the leaf surfaces. Given the effects observed, I suggest that the use of insecticides should be carefully managed in areas containing vulnerable carnivorous plant species. For Chapters 4 and 5, I explored the ecological role of carnivorous plants, specifically if they could compete with animals for shared prey resources. In Chapter 4 I characterized the ground-surface spider and arthropod assemblages of two mesic flatwood habitats in Florida, to resolve what the most likely animal competitor was for pink sundews. I identified 31 spider species from 27 genera in 12 families, with wolf spiders (Lycosidae) being the dominant spider family at both sites. Based on their abundance and the behavioral traits they exhibited, I determined that the funnel-web-building wolf spider Sosippus floridanus was the most likely potential competitor with pink sundews. Collembola and Formicidae were the most abundant arthropod taxa present, but ground-surface spiders were not strongly associated with any typical prey groups, suggesting that environmental factors might also be important in structuring this community. Subsequently, in Chapter 5 I examined the potential for competition between carnivorous plants and animals by studying dietary and microhabitat overlap between pink sundews and wolf spiders in the field, and by conducting a lab experiment examining the effects of wolf spiders on sundew fitness. In the field, I found that sundews and spiders had high dietary overlap with each other and with the available arthropod prey. Associations between sundews and spiders depended on spatial-scale: sundews and spiders were both found more frequently in quadrats with more abundant prey, but within quadrats spiders constructed larger webs and located them further away from sundews as the total sundew trapping area increased. Spiders also constructed larger webs when fewer prey were available. In the lab, my experiment revealed that spiders can significantly reduce sundew fitness. All of these results suggest that members of the plant and animal kingdoms can and do compete. These findings provided inspiration for Chapter 6, where I explored if phylogenetic distance was a good predictor of the strength of competition between taxa, using a meta-analytical approach. I collected data from studies published from 1998-2008 in eight ecology journals using the keyword `interspecific competition', gathering a total of 191 effect sizes. I found no significant relationship between phylogenetic distance and the strength of competition, contrary to the long-standing assumption that it should be greatest in strength between closely related species. However, these findings could presently be limited by publication bias, and I suggest several directions for future research.

Οι έντονες εναλλαγές σχετικά ακραίων συνθηκών και η συνεξέλιξη των μεσογειακών οικοσυστημάτων με τη φωτιά αποτελούν τα βασικά στοιχεία που προσδίδουν τη μεγάλη ετερογένεια που χαρακτηρίζει τα οικοσυστήματα αυτά. Τα δάση χαλεπίου πεύκης έχουν αναπτύξει προσαρμογές για σύντομη αποκατάσταση έπειτα από πυρκαγιά. Η συνήθης διαδοχή περιλαμβάνει την εμφάνιση αρχικά ποώδους βλάστησης (που σε περίπτωση έντονης υποβάθμισης μπορεί να γίνεται φρύγανα), κατόπιν θαμνώδους (μακκίας) βλάστησης σε διάφορα στάδια ανάπτυξης, και εντέλει νέου πευκοδάσους. Το μωσαϊκό πρότυπο στη βλάστηση, το οποίο δημιουργείται από τη δράση παραγόντων όχλησης, είναι δυνατό να έχει σημαντικές συνέπειες στη δυναμική των πληθυσμών των ζώων. Με τη χρήση παγίδων παρεμβολής, μελετήθηκαν οι βιοκοινότητες των εδαφικών αρθροπόδων σε μια τέτοια σύγχρονη εμφάνιση των σταδίων διαδοχής στις παρυφές της Πάρνηθας. Τα χερσόβια Ισόποδα μελετήθηκαν σε επίπεδο είδους, ενώ οι λοιπές ζωικές ομάδες μακροαρθροπόδων, με την εξαίρεση των Αραχνών και των Κολεοπτέρων, μελετήθηκαν σε επίπεδο τάξης. Συμπερασματικά, τα αρθρόποδα σε επίπεδο τάξης και τα Ισόποδα σε επίπεδο είδους, μπορούν να εμφανίζουν το μέγιστο της δραστηριότητάς τους είτε το καλοκαίρι είτε την άνοιξη ή/και το φθινόπωρο. Επιπλέον, η παρατηρούμενη διαφοροποίηση στη σύνθεση της κοινότητας των εδαφικών αρθροπόδων (τόσο σε επίπεδο τάξης όσο και σε επίπεδο είδους για τα Ισόποδα) είναι σύμφωνη με τα στάδια διαδοχής της βλάστησης (CA, PCA). Η βιοκοινότητα των φρυγάνων εμφανίζει σαφή διαφοροποίηση και μεγαλύτερη ποικιλότητα από τις υπόλοιπες βιοκοινότητες, ενώ τα Ισόποδα εμφανίζονται ιδιαίτερα άφθονα στα φρύγανα. Μεταξύ των κοινοτήτων εδαφικών αρθροπόδων στους έξι βιοτόπους (στάδια διαδοχής), παρατηρούνται αλλαγές στη σχετική αφθονία των τάξεων των αρθροπόδων και των ειδών Ισοπόδων, ενώ παρατηρούνται ακόμη και αλλαγές κυριαρχίας μεταξύ τάξεων αρθροπόδων και ειδών Ισοπόδων. Το πρότυπο αυτό, ενδεχομένως οφείλεται στην προσαρμογή των εδαφικών αρθροπόδων στις οχλήσεις, οι οποίες είναι χαρακτηριστικές των μεσογειακών οικοσυστημάτων. / Climatic extremes and coevolution with fire make the Mediterranean-Type Ecosystems to appear highly heterogeneous. Aleppo pine forests have developed adaptations for rapid restoration after fire. A typical successional sequence includes herbaceous formations (turned into phrygana in case of severe deterioration) followed by sclerophyllous shrubland (maquis) in various stages of progressive succession to forest. Mosaic patterns in vegetation generated by disturbance are likely to have a profound effect on the population dynamics of animals. The communities of soil arthropods in a mosaic of sites in different succesional stages on the slopes of mountain Parnitha, were studied using pitfall traps. Terrestrial isopods were analysed at species level, whereas the rest of the macroarthropods, with the exception of Araneae and Coleoptera, were analysed at ordinal level. In conclusion, macroathropods at ordinal level and Isopoda at species level have activity peaks either in summer or in spring and/or autumn. In addition, the observed differences between edaphic macroarthropod communities (even at ordinal level as well as species level for Isopoda) are consistent with the successional stages (CA, PCA). The macroarthropod community in phrygana shows marked differentiation and highest diversity in comparison with the communities in the rest successional stages. The abundance of Isopoda is remarkably high in phrygana. Differences in relative abundance and distribution of dominance among the orders of macroarthropods and species of Isopoda were found between communities of different successional stages. It is likely that the observed pattern is a result of the adaptation of soil arthropods over evolutionary time to the characteristic disturbance regimes of the Mediterranean-Type Ecosystems.