Global warming will affect every level of biological organization from the metabolism of individuals to the functioning of ecosystems. I explored the effects of warming on three rock-pool meioinvertebrate communities along a latitudinal gradient (temperate, tropical, and sub-Arctic regions) to determine effects on community and food-web structure and functioning. Warming affected regions differently, having a positive effect on sub-Arctic communities, a negative effect on temperate communities, and intermediate responses in tropical communities in terms of abundance, stability and extinction frequency. Differences in structural properties of the food webs supported the insurance hypothesis: that greater redundancy in webs results in greater stability, and helped to explain why the tropical community was more stable than the temperate community in warmed treatments. My study highlights the importance of considering differential response of species and communities from different latitudes and the importance of food web structure in predicting species response to global climate change.

Made available in DSpace on 2014-06-11T19:35:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-25Bitstream added on 2014-06-13T18:47:10Z : No. of bitstreams: 1 nardy_o_dr_rcla.pdf: 3226439 bytes, checksum: 5a6b6af0a77e36a028fdd67051607c4c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foram realizadas meta análises com o Gradiente Latitudinal de Riqueza de espécies, a Regra de Rapoport e sua interação para vertebrados ao longo de todo o Globo. Com os resultados é possível concluir que ambos os padrões são generalizáveis e consistentes para todos os grupos de vertebrados, no entanto nenhuma variável moderadora associada à característica ecológicas, biológicas ou biogeográficas pode ser confirmada como principal condicionante destes padrões, não apresentando padrões constantes entre hemisférios, continentes, classes, número de províncias biogeográficas, tamanho corpóreo ou outra variável analisada. Foram utilizados como effect sizes a inclinação da reta de regressão ou o coeficiente angular da regressão linear (b) e o Coeficiente de Correlação de Spearman corrigido por Z-Fisher (r), entre estes dois, o segundo apresentou melhores resultados referentes as suas adequações e restrições associadas a meta análise, tais como normalidade dos dados e pressupostos de viés de publicações. As variáveis moderadoras associadas a características metodológicas como poder do teste, significância e tamanho amostral apresentaram maior poder explicativo do padrão do que as demais variáveis, sugerindo uma necessidade de se adotar um padrão mais rigoroso no delineamento de estudos que abordem este tema. Para a Regra de Rapoport o método utilizado na confecção do teste foi a variável moderadora mais evidente para a detecção de uma estrutura nos dados. / In the present work where made meta analysis with Latitudinal Gradient of Species richness, Rapoport Rule and their interaction for vertebrates along a global scale. With the results is possible to conclude that both patterns are general for vertebrates, nevertheless none of the ecological, biological or biogeographical moderators variables could be confirmed as the primary cause of the patterns, don’t showing any constant pattern between hemispheres, continents, classes, number of biogeographical provinces or other analyzed variable. It will be used as effect size the angular coefficient or the linear regression (b) and the Spearman Correlation Coefficient transformed by Z-Fisher (r), among these two effect size, the second presents best results associated with restrictions and fits inherent to meta analysis, such as normality and publication bias. The moderator’s variables associates with methodological issues, like statistical power, significance and sample size show higher explanation strength than the others variables, suggesting a necessity of more strength methods in the studies that claim these global patterns. For Rapoport Rule the method used to do the test was the moderator variable more evident to detect some data structure.

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Mountain pine beetle (Dendroctonus ponderosae, Hopkins) is a major disturbance agent in pine ecosystems of western North America. Adaptation to local climates has resulted in primarily univoltine (one generation per year) generation timing across a thermally diverse latitudinal gradient. We hypothesized that this pattern in total development time is shaped by selection for slower developmental rates, altered developmental thresholds, or oviposition rates in southern populations inhabiting warmer climates. To investigate traits responsible for latitudinal differences we measured lifestage-specific development of southern mountain pine beetle eggs, larvae and pupae across a range of temperatures. We also describe and model oviposition of southern US MPB. Using a novel technique that included frequent X-ray imaging, oviposition rate and fecundity were estimated separately and shown to both be significant and independent sources of variation. When compared with previously collected data for a northern MPB population, total oviposition time predicted for southern MPB at a constant 20°C was slightly longer than that of northern MPB, but the delay was too small to account for significant differences between the populations in total development time. Developmental rate curves for eggs, larvae, and pupae were fit using maximum posterior likelihood estimation with a Bayesian prior to improve fit stability. When compared to previously published data for a northern population (Régnière et al. 2012), observed developmental rates of the southern and northern populations were similar across all studied lifestages at 20 and 25°C, although southern individuals were generally faster at temperature extremes (10 and 27°C). These findings were inconsistent with our hypothesis that southern individuals would have consistently slower rates. Optimal development of southern individuals occurred at higher temperatures, with higher development thresholds, as compared with northern individuals. Our results suggest that evolved traits in the remaining unstudied lifestage, teneral (i.e., pre-emergent) adult, likely influence latitudinal differences in mountain pine beetle generation time.

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Orientador: Elza Guimarães / Resumo: A variação em atributos de proteção, principalmente os foliares, pode ter importante papel no desempenho das espécies ao longo de um gradiente de condições ambientais ou em hábitats heterogêneos. O domínio Cerrado está inserido em um gradiente climático e suas formações savânicas estão submetidas a queimadas recorrentes. Neste trabalho nós caracterizamos atributos de proteção às gemas em três espécies lenhosas, coocorrentes em fitofisionomias savânicas ao longo do gradiente latitudinal N-S do Cerrado e investigamos a ocorrência de fogo em uma escala espácio-temporal. Caracterizamos a posição das gemas nas plantas, morfologia e anatomia e indicadores de flamabilidade das mesmas. De modo geral, as plantas de diferentes localidades apresentaram diferenças quanto a altura das gemas na planta em relação ao nível do solo, sendo que plantas mais altas foram observadas nas latitudes menores e as mais baixas nas latitudes maiores, provavelmente devido a maior produtividade associada à proximidade da linha do Equador. Primórdios com maior área ocupada por idioblastos fenólicos foram observados nas duas localidades mais próximas à linha do Equador, possivelmente devido a alta intensidade de radiação. Além disso, registramos distintos regimes de queimada nas cinco localidades nos últimos 15 anos. Considerando a ampla distribuição geográfica das três espécies deste estudo, podemos concluir que suas gemas axilares toleram certa variação nos fatores climáticos como a amplitude de temperatur... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The variation in protection traits, especially the foliar ones, can play an important role in species performance along a gradient of environmental conditions or in heterogeneous habitats. The Cerrado domain is inserted in a climatic gradient and its savannah formations are under recurrent burning. In this study, we characterized bud protection traits of three woody species that co-ocurr in savannah phytophysiognomys along the Cerrado latitudinal gradient and we investigated fire occurrence in a spatio-temporal scale. We characterized bud position in each plant species, its morphology, anatomy and flammability indicators. In general, plants of different locations showed differences in bud height in relation to soil level. Taller plants were observed at lower latitudes and the smallest ones at higher latitudes, probably due to the higher productivity associated to the proximity to Equator line. Primordia with a larger area occupied by phenolic idioblasts were observed in the two locations nearest to the Equator line, possibly due to high radiation intensity. Besides that, we registered different fire regimes at the five locations in the last 15 years. Considering the wide distribution of the three species of this study, we can conclude that their axillary buds tolerate some variation in climatic factors like temperature, solar radiation and pluviosity amplitude. Besides that, this species are capable of persisting in environments under different fire frequency. Additionally, b... (Complete abstract click electronic access below) / Mestre

Orientador: Harold Gordon Fowler / Banca: Adler Guilherme Viadana / Banca: Wesley Augusto Conde Godoy / Banca: Marcelo Nogueira Rossi / Banca: Sofia Campiolo / Apresenta anexos em CD-ROM / Resumo: Foram realizadas meta análises com o Gradiente Latitudinal de Riqueza de espécies, a Regra de Rapoport e sua interação para vertebrados ao longo de todo o Globo. Com os resultados é possível concluir que ambos os padrões são generalizáveis e consistentes para todos os grupos de vertebrados, no entanto nenhuma variável moderadora associada à característica ecológicas, biológicas ou biogeográficas pode ser confirmada como principal condicionante destes padrões, não apresentando padrões constantes entre hemisférios, continentes, classes, número de províncias biogeográficas, tamanho corpóreo ou outra variável analisada. Foram utilizados como effect sizes a inclinação da reta de regressão ou o coeficiente angular da regressão linear (b) e o Coeficiente de Correlação de Spearman corrigido por Z-Fisher (r), entre estes dois, o segundo apresentou melhores resultados referentes as suas adequações e restrições associadas a meta análise, tais como normalidade dos dados e pressupostos de viés de publicações. As variáveis moderadoras associadas a características metodológicas como poder do teste, significância e tamanho amostral apresentaram maior poder explicativo do padrão do que as demais variáveis, sugerindo uma necessidade de se adotar um padrão mais rigoroso no delineamento de estudos que abordem este tema. Para a Regra de Rapoport o método utilizado na confecção do teste foi a variável moderadora mais evidente para a detecção de uma estrutura nos dados. / Abstract: In the present work where made meta analysis with Latitudinal Gradient of Species richness, Rapoport Rule and their interaction for vertebrates along a global scale. With the results is possible to conclude that both patterns are general for vertebrates, nevertheless none of the ecological, biological or biogeographical moderators variables could be confirmed as the primary cause of the patterns, don't showing any constant pattern between hemispheres, continents, classes, number of biogeographical provinces or other analyzed variable. It will be used as effect size the angular coefficient or the linear regression (b) and the Spearman Correlation Coefficient transformed by Z-Fisher (r), among these two effect size, the second presents best results associated with restrictions and fits inherent to meta analysis, such as normality and publication bias. The moderator's variables associates with methodological issues, like statistical power, significance and sample size show higher explanation strength than the others variables, suggesting a necessity of more strength methods in the studies that claim these global patterns. For Rapoport Rule the method used to do the test was the moderator variable more evident to detect some data structure. / Doutor

Main goal of this thesis was to compare geographical variability of sizes of colonies in the relationship with the type of roost of 6 models of originally cave bats species: Greater mouse-eared bat (Myotis myotis), Geoffroy's bat (Myotis emarginatus), Common bent-wing bat (Miniopterus schreibersii), Greater horseshoe bat (Rhinolophus ferrumequinum), Lesser horseshoe bat (Rhinolophus hipposideros) a Mediterranean horseshoe bat (Rhinolophus euryale). The selected data set was also analyzed the possible influence of the composition of land cover in roosts around the variability of the size of the colonies. Based on compilation of literature and active communication with regional bat-monitoring coordinators, entries about size of colonies from 2 603 locations in 24 countries of Europe were collected. 1 952 entries were from roosts in buildings and 651 from caves. Based on statistical analysis, conclusive influence of type of roost on size of colonies by M. schreibersii, M. myotis a R. hipposideros was discovered. While in M. schreibersii and M. myotis are human colonies in smaller buildings, in R. hipposideros by contrast, they are larger. Simultaneously, north-west gradient in geographical distribution of maternal bat- colonies in dependence on type of roost (caves vs. buildings): in southern areas...

For evolution to occur over time, it is necessary for animals and plants to show phenotypic variation. If the individuals within populations of a species do not show observable differences among themselves, there will be a lack of driving force for natural selection to act on and decide which characteristic gets inherited from one generation to the next. It is hence important to study phenotypic variation, especially against environmental gradients such as latitude and altitude, which gives us an insight into the pattern of change according to essential factors such as temperature and length of seasons. The latter would impose time constraints on growing populations, leading to periods of unfavourable conditions limiting their growth and development. In many cases, such organisms would tend to compensate for the period of slow growth and catch up to the others that did not have to endure the same situation and grow to the same size as them. This study aims to find differences in three key larval life-history traits of the moor frog (Rana arvalis), namely metamorphic mass, larval period, and growth rate, and find what kind of pattern is observed in case of these phenotypic variations. It also aims to find differences in the strength of compensatory response between populations from lower and higher latitudes. A common garden experiment was conducted with populations originating from both sides of the Baltic Sea, ranging from southern Sweden and Latvia to central Finland and northern Sweden. It was expected that the northern populations would grow faster and show a countergradient variation pattern since they are faced with more strict time constraints at higher latitudes, but in most cases, we observed a co-gradient pattern, wherein the environmental effect amplifies the individual’s genetic predisposition instead of opposing it. We also observed a stronger compensatory response in the northern populations as compared to their southern counterparts. Effects of climate change and subsequent rise in temperatures making the environment unpredictable over time could be used to speculate about the reason behind the results obtained. Epigenetics could also be used as an approach to study long lasting changes in an organism’s gene expression to make it adapt better to changing conditions and hence show different patterns of variation from studies in the past. Studying such changes, expected or not, is important to keep up with the needs of the species that require conservation, and will help conservation biologists to formulate strategies that would be effective even in the face of constant change in the world.

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.