Os principais objetivos deste trabalho foram conhecer a distribuição da riqueza dos Hymenoptera parasitoides Diapriidae Belytinae ao longo de um gradiente latitudinal da Mata Atlântica e explicar as causas do padrão de riqueza encontrado por comparação com os padrões descritos para outros grupos. Os Belytinae exercem papel chave na regulação natural de populações de muitas espécies de Mycetophilidae e Sciaridae (Diptera) e o conhecimento sobre a diversidade desta subfamília no bioma Mata Atlântica é relativamente pequeno. O material utilizado neste estudo provém de coletas realizadas em 18 localidades regularmente espaçadas, da Paraíba à Santa Catarina, entre os anos de 2000 e 2002, no âmbito do projeto Riqueza e diversidade de Hymenoptera e Isoptera ao longo de um gradiente latitudinal na Mata Atlântica - a floresta pluvial do leste do Brasil (Biota/SP Fapesp). Através de um número padronizado de armadilhas Malaise e de Moericke, e varredura da vegetação foram obtidos 1241 exemplares separados em 115 morfoespécies e oito gêneros. Destes, Scorpioteleia é registrado pela primeira vez na região neotropical e sete (Aclista, Belyta, Cinetus, Odontopsilus, Scorpioteleia, Lyteba e Camptopsilus) são registrados pela primeira vez no Brasil. Foram feitos mapeamentos e diagnoses para todas as morfoespécies e gêneros; as morfoespécies foram todas ilustradas com pelo menos duas fotos. A maior parte das morfoespécies (86) está presente em apenas uma ou duas localidades. Nota-se uma tendência das localidades nas maiores latitudes de apresentarem riquezas de morfoespécies e gêneros significativamente maiores que as das localidades em latitudes menores, mesmo que estas apresentem quantidades de indivíduos significativamente maiores que as daquelas. Os resultados da análise da distribuição dos Belytinae indicam uma quantidade de morfoespécies exclusivas do sul do bioma (6 ou 8) ligeiramente maior que as exclusivas do norte (2), apesar das diferenças serem pouco significativas. A análise de similaridade indicou que a proximidade geográfica parece ser importante condicionante para o padrão de distribuição da fauna na maioria das localidades; os três agrupamentos principais formados nos dendogramas de índices de Sørensen e Jaccard sugerem a presença de dois sub-biomas (Sul + Sudeste e Nordeste). Indícios obtidos a partir das análises e dos dados do presente estudo combinados com informações da literatura ou de pesquisadores sobre a biologia, ecologia e distribuição da riqueza dos Belytinae, seus hospedeiros e fungos do solo, tornam plausível a ideia de que os Belytinae tenham a riqueza de espécies aumentada com o aumento da latitude, contrariamente ao padrão mais comum para a maioria dos grupos animais. / The main objectives of this work were to describe the distribution of Hymenoptera parasitoids Diapriidae Belytinae richness along a latitudinal gradient of Atlantic Forest and to explain the reasons for the pattern of richness found, by comparison with patterns described for other groups. The Belytinae play a key role in the natural regulation of populations of many species of Mycetophilidae and Sciaridae (Diptera) and the knowledge about the diversity of this subfamily in the Atlantic Forest biome is relatively poor. The material used in this study comes from collections in 18 regularly spaced locations, from Paraiba to Santa Catarina, between the years of 2000 and 2002, under the project \"Richness and Diversity of Hymenoptera and Isoptera along a latitudinal gradient in the Atlantic forest - the Eastern Brazilian Rain Forest\" (Biota/SP - FAPESP). Using a standardized number of Malaise and Moericke traps, and sweeping the vegetation a total of 1241 specimens separated in 115 morphospecies and eight genera were obtained. Of these, Scorpioteleia is recorded for the first time in the neotropical region and seven genera (Aclista, Belyta, Cinetus, Odontopsilus, Scorpioteleia, Lyteba and Camptopsilus) are recorded for the first time in Brazil. Mappings and diagnoses were made for all morphospecies and genera; all morphospecies were illustrated with at least two pictures. There is a tendency of localities in the highest latitudes to present similar or significantly greater richness of morphospecies and genera than those of localities in lowest latitudes, even if these present quantities of individuals significantly higher than the latter. The results of the analysis of the distribution of Belytinae indicate a quantity of exclusive morphospecies of the southern biome (6 or 8) slightly higher than the exclusive northern (2), although these differences are not highly significant. Most morphospecies (86) are present in only one or two locations. The similarity analysis indicated that the geographical proximity appears to be important to define the pattern of distribution of fauna in most localities; the three main groups formed in dendograms with indices of Sorensen and Jaccard suggest the presence of two sub-biomes (South + East and Northeast). Evidences obtained with the data and analyzes of the present study combined with information deducted from or obtained through literature or researchers about the biology, ecology and distribution of the richness of Belytinae, their hosts and soil fungi, make plausible the idea that the Belytinae have the species richness increased with the increase of latitude, unlike the most common pattern displayed by most animal groups.

Dictyostelids (Amoebozoa) are a group of social amoebae consisting of approximately 150 species, which are found in terrestrial habitats worldwide. They are divided into eight major clades based on molecular phylogeny, and within these clades are many species complexes. Some species are seemingly cosmopolitan in distribution, while others are geographically restricted. In this thesis dictyostelids were recovered from high latitude habitats (soils in Sweden and Iceland) as well as from the soles of shoes. Morphological characters and DNA sequence analyses were used to identify isolates that were recovered and delimit new species, as well as to investigate the monophyly of Dictyostelium aureostipes. Nine species were reported from Northern Sweden and four from Iceland. Among the isolates recorded in Sweden were two new species, described as D. barbibulus and Polysphondylium fuscans. P. fuscans was among the four species recovered from footwear, contributing evidence for anthropogenic transport of dictyostelids. Ecological patterns were assessed using linear regression and generalized linear models. The ecological analyses of dictyostelids recovered from Iceland indicate that these organisms are most frequently found in soils of near-neutral pH, but also exhibit a species richness peak in moderately acidic soils. These analyses indicate that in Iceland dictyostelid species richness decreases with altitude, and in the northern hemisphere the species richness increases with decreasing latitude. A three-region analysis of the D. aureostipes species complex indicated that this species is in fact made up of at least five phylogenetically distinct clades, and in light of this the group is in need of taxonomic revision. These results indicate that the dictyostelid species richness is higher than previously known, especially in high-latitude regions, and that even seemingly well-defined species may harbour cryptic diversity. Presently, species ranges may be expanding via anthropogenic dispersal but despite this, the dictyostelids are found to exhibit biogeographic trends well known from macroorganisms, such as a latitudinal gradient of species richness.

Plant populations near the northern limits of their geographic distribution may experience different biotic pressures than southern populations. For instance, if herbivores are scarce in northern populations, performance of their host plants may benefit. In this study, I looked at populations of burdock (Arctium minus) along an 815 km latitudinal gradient from the northern range limit to more southern populations. I found that plant height, stem diameter, and number of seeds all increased on approaching the northern limit. In addition, I also found significant decreases in herbivory by generalist and specialist leaf and seed predators, even though northern plants invested less in physical and possibly chemical defenses. In an experiment in which seeds were planted in different soils, marginal soil initially produced smaller plants, but subsequently larger plants than soil from southern populations. These results indicate northern populations experience relaxed pressure from natural enemies and may benefit as a result.

Plant populations near the northern limits of their geographic distribution may experience different biotic pressures than southern populations. For instance, if herbivores are scarce in northern populations, performance of their host plants may benefit. In this study, I looked at populations of burdock (Arctium minus) along an 815 km latitudinal gradient from the northern range limit to more southern populations. I found that plant height, stem diameter, and number of seeds all increased on approaching the northern limit. In addition, I also found significant decreases in herbivory by generalist and specialist leaf and seed predators, even though northern plants invested less in physical and possibly chemical defenses. In an experiment in which seeds were planted in different soils, marginal soil initially produced smaller plants, but subsequently larger plants than soil from southern populations. These results indicate northern populations experience relaxed pressure from natural enemies and may benefit as a result.

The purpose of this research was to investigate the physical weathering of rock along the Victoria Land Coast, Antarctica. It was designed to contribute to the Latitudinal Gradient Project, a joint initiative between the New Zealand, Italian and United States Antarctic Programmes. The Latitudinal Gradient Project aims to improve our understanding of the ecosystems of the Dry Valleys and ice-free areas of the Ross Sea Region and, by using latitude as a proxy measure, identify how they might be affected by future climate change. The approach taken for this research was to use information on rock (from one rock group) temperature and moisture conditions gathered from three field locations to inform laboratory simulations. The laboratory simulations would then be used to investigate the weathering of small rock blocks and aggregates. Two temperature cycles approximating those experienced during summer and spring/autumn were identified and simulations undertaken in a specially adapted freezer. Three levels of moisture were applied: no moisture, half saturation and full saturation. Results of the laboratory simulations indicated that although rocks responded in different ways to different processes, granular disintegration took place even in the absence of additional moisture and did not require crossings of the 0 OC isotherm, nor were high levels of moisture required for across zero temperature cycling to produce weathering effects. A model that related weathering to latitude was developed and changes in climate explored. It was found that the weathering effect of summer and spring/autumn cycles was different and depended on rock characteristics rather than latitude. Increasing the ratio of summer to spring/autumn temperature cycles by 10% indicated that weathering could decrease or remain the same depending on the particular rock. Changes in temperature were found to be more important than changes in moisture. A weathering index that related local climate and rock properties to weathering was also developed and this highlighted the difficulties of using laboratory results to predict field rates of weathering. There were some surprising results from the field, including the presence of much more moisture on the surface of the rock, primarily from blowing snow, than had been predicted for this dry environment. This occurred even in the presence of negative rock surface temperatures. In addition, winter rock surface temperatures can fluctuate up to 25 OC, getting as warm as -10 OC. Macro-climate and changes in air temperature in response to foehn and katabatic winds were the drivers for these fluctuations.

Os principais objetivos deste trabalho foram conhecer a distribuição da riqueza dos Hymenoptera parasitoides Diapriidae Belytinae ao longo de um gradiente latitudinal da Mata Atlântica e explicar as causas do padrão de riqueza encontrado por comparação com os padrões descritos para outros grupos. Os Belytinae exercem papel chave na regulação natural de populações de muitas espécies de Mycetophilidae e Sciaridae (Diptera) e o conhecimento sobre a diversidade desta subfamília no bioma Mata Atlântica é relativamente pequeno. O material utilizado neste estudo provém de coletas realizadas em 18 localidades regularmente espaçadas, da Paraíba à Santa Catarina, entre os anos de 2000 e 2002, no âmbito do projeto Riqueza e diversidade de Hymenoptera e Isoptera ao longo de um gradiente latitudinal na Mata Atlântica - a floresta pluvial do leste do Brasil (Biota/SP Fapesp). Através de um número padronizado de armadilhas Malaise e de Moericke, e varredura da vegetação foram obtidos 1241 exemplares separados em 115 morfoespécies e oito gêneros. Destes, Scorpioteleia é registrado pela primeira vez na região neotropical e sete (Aclista, Belyta, Cinetus, Odontopsilus, Scorpioteleia, Lyteba e Camptopsilus) são registrados pela primeira vez no Brasil. Foram feitos mapeamentos e diagnoses para todas as morfoespécies e gêneros; as morfoespécies foram todas ilustradas com pelo menos duas fotos. A maior parte das morfoespécies (86) está presente em apenas uma ou duas localidades. Nota-se uma tendência das localidades nas maiores latitudes de apresentarem riquezas de morfoespécies e gêneros significativamente maiores que as das localidades em latitudes menores, mesmo que estas apresentem quantidades de indivíduos significativamente maiores que as daquelas. Os resultados da análise da distribuição dos Belytinae indicam uma quantidade de morfoespécies exclusivas do sul do bioma (6 ou 8) ligeiramente maior que as exclusivas do norte (2), apesar das diferenças serem pouco significativas. A análise de similaridade indicou que a proximidade geográfica parece ser importante condicionante para o padrão de distribuição da fauna na maioria das localidades; os três agrupamentos principais formados nos dendogramas de índices de Sørensen e Jaccard sugerem a presença de dois sub-biomas (Sul + Sudeste e Nordeste). Indícios obtidos a partir das análises e dos dados do presente estudo combinados com informações da literatura ou de pesquisadores sobre a biologia, ecologia e distribuição da riqueza dos Belytinae, seus hospedeiros e fungos do solo, tornam plausível a ideia de que os Belytinae tenham a riqueza de espécies aumentada com o aumento da latitude, contrariamente ao padrão mais comum para a maioria dos grupos animais. / The main objectives of this work were to describe the distribution of Hymenoptera parasitoids Diapriidae Belytinae richness along a latitudinal gradient of Atlantic Forest and to explain the reasons for the pattern of richness found, by comparison with patterns described for other groups. The Belytinae play a key role in the natural regulation of populations of many species of Mycetophilidae and Sciaridae (Diptera) and the knowledge about the diversity of this subfamily in the Atlantic Forest biome is relatively poor. The material used in this study comes from collections in 18 regularly spaced locations, from Paraiba to Santa Catarina, between the years of 2000 and 2002, under the project \"Richness and Diversity of Hymenoptera and Isoptera along a latitudinal gradient in the Atlantic forest - the Eastern Brazilian Rain Forest\" (Biota/SP - FAPESP). Using a standardized number of Malaise and Moericke traps, and sweeping the vegetation a total of 1241 specimens separated in 115 morphospecies and eight genera were obtained. Of these, Scorpioteleia is recorded for the first time in the neotropical region and seven genera (Aclista, Belyta, Cinetus, Odontopsilus, Scorpioteleia, Lyteba and Camptopsilus) are recorded for the first time in Brazil. Mappings and diagnoses were made for all morphospecies and genera; all morphospecies were illustrated with at least two pictures. There is a tendency of localities in the highest latitudes to present similar or significantly greater richness of morphospecies and genera than those of localities in lowest latitudes, even if these present quantities of individuals significantly higher than the latter. The results of the analysis of the distribution of Belytinae indicate a quantity of exclusive morphospecies of the southern biome (6 or 8) slightly higher than the exclusive northern (2), although these differences are not highly significant. Most morphospecies (86) are present in only one or two locations. The similarity analysis indicated that the geographical proximity appears to be important to define the pattern of distribution of fauna in most localities; the three main groups formed in dendograms with indices of Sorensen and Jaccard suggest the presence of two sub-biomes (South + East and Northeast). Evidences obtained with the data and analyzes of the present study combined with information deducted from or obtained through literature or researchers about the biology, ecology and distribution of the richness of Belytinae, their hosts and soil fungi, make plausible the idea that the Belytinae have the species richness increased with the increase of latitude, unlike the most common pattern displayed by most animal groups.

No description available.

Non-native species richness has been observed to peak at mid-temperate latitudes, shaping a pattern of richness and abundance that is distinct from native species patterns that peak in the tropics. Stronger species interactions, and therefore biotic resistance, may lower invasion success in the tropics and help explain the discrepancy between native and non-native richness and abundance. To test the hypothesis that strong predation and competition in the tropics could limit invasion success, we conducted a distributed experiment on sessile marine invertebrate communities in four regions spanning 47-degrees latitude of the eastern Pacific Ocean. We manipulated predator access and resource availability at 12 sites and sampled experimental communities in early and late stages of assembly. Overall, our results suggest that biogeographic location, assembly timescale, and predation interactively shape invasion success across latitude. Strong predation reduced richness of non-native species in the tropics at both assembly timescales but increased non-native species richness in the subtropics during early assembly. Predation also increased non-native abundance in the tropics by late-stage assembly and shaped non-native composition at both assembly stages. Effects of predation at higher latitudes were weak or undetectable, and increasing resource availability never had a positive impact on non-native richness or abundance at any latitude. Further, non-native richness was greater at early relative to late assembly stages at mid to low latitudes and was consistently low in our high latitude region at both timescales. In a complementary experiment, short-term predator exposure reduced non-native abundance in Panama, further confirming the influence of predation in this tropical region. Our results highlight important biogeographic differences in invasion dynamics and disentangle local mechanisms that can shape regional patterns. / Biology

Master of Science / Department of Biology / Anthony Joern / Temperature and food quality vary across broad latitudinal gradients, greatly affecting performance by insect herbivores. The contribution of each varies latitudinally so that geographically distinct populations are challenged by differences in nutritional needs and energetic demands. While there has been extensive work studying diet selectivity and nutritional ecology of insect herbivores, few studies have focused on how insect herbivores adapt across such vast environmental gradients. The generalist-feeding grasshopper, Melanoplus femurrubrum (DeGreer), has a broad geographic range that extends across much of North America, making this species ideal for comparative investigations of intrinsic performance responses to extensive but predictable patterns of environmental variation. I compared responses by six populations collected from populations located from Texas to North Dakota (USA) using a common garden experimental design to investigate clinal responses in grasshopper performance. I examined responses in: (1) body size, (2) thermoregulation and adaptive coloration, (3) developmental and growth rates, (4) metabolic rates, (5) total consumption and rates, (6) diet ratio selection, and (7) digestive processing efficiencies across the latitudinal gradient. Grasshopper body size followed the Converse Bergmann’s Rule with decreasing body size as latitude increased. Temperature influenced all other responses, but responses to diet were not always significant or directional. Latitudinal trends for development and growth rates were observed but mass-specific metabolic rates were similar for all populations. Total consumption was body size dependent but independent of diet type. Mass-specific consumption varied but no single directional trend was detected. There was a shift in carbohydrate-biased diet preference at low latitude toward protein-biased diet ratios at higher latitudes, suggesting adaptations to different energetic demands by these populations. However, post-ingestive (digestive) efficiencies demonstrated variable responses with northern populations observing highest efficiencies for some indices but not all. Overall, this research documents phenotypic plasticity to environmental variability to some degree for digestive efficiencies, but ecotypic responses in body size and diet preference among M. femurrubrum populations were observed.

This study investigated the impact of three edaphic factors on the distribution of forest plants in Sweden. Based on 2657 plots with 22 common species, Canonical Correspondence Analysis (CCA) and Generalized-linear-model (GLM) were performed with pH measurements in the top layer of the soil, latitude and deciduous tree proportion as explanatory variables. Variation of the species occurrence could to a substantial degree be explained by pH, latitude and proportion of timber volume of deciduous tree species. Furthermore, the majority of species were affected by the studied environmental variables. Therefore, these factors have an important role in the ecological interactions in the forest. All species also showed broad pH-niches with many occurrences spread out within the species entire pH-range. Finally, the study relates to educational science through designing a meaningful excursion for secondary school when teaching ecology.