Micrometazoans are animals smaller than 2 mm. Their biogeography is poorly understood, and tardigrades provide a tractable phylum for exploring distribution patterns at a variety of scales. Polylepis forest habitat offers considerable advantages for making tardigrade comparisons across a wide range of scales in the Andes. This thesis aims to improve identifications of tardigrades with a character matrix approach, to assess the relative importance of habitat and bryophyte host on tardigrades, to describe the fine-scale spatial structure of tardigrade assemblages, and to estimate the sampling effort required for a reliable estimate of tardigrade diversity within Polylepis forest. Samples of bryophytes and lichens were collected from Polylepis forest and neighbouring habitats, and the tardigrades extracted and identified, mostly to operational taxonomic units. Some new species were discovered during the course of this work; one is described here. Abundance, diversity and composition of tardigrade samples were compared quantitatively. The thesis presents the first example of a character matrix for a tardigrade genus, bringing together information for the genus Isohypsibius from many different sources and describing suites of characters for each species. It will facilitate identification within the genus in future. Tardigrade assemblage data were highly variable within the samples, with empty samples dominating one study. Analysis of one forest site indicated that at least 50 samples would be needed to characterise the tardigrade diversity there. Although both were important, habitat-scale effects were more influential on tardigrade abundance, diversity and composition than host-scale effects. In both cases, microenvironmental and resource filters are the likely mechanisms driving these differences. Based on the results, recommendations are made for expanding such research into broader geographical scales: standardising sample volume, replicate sampling across hosts on the forest floor, recognising the importance of habitat-scale effects when selecting study sites, and the development of character matrices for tardigrade genera.

The coastal plain of the southeastern United States is historically wet pine savannahs, prairie, and hardwoods. However, many exotic species have invaded this area and become a serious threat to native forest ecosystems. Among those exotic species, Chinese tallow (Triadica sebifera) has become one of the most pervasive tree species in the southern coastal states, including Alabama, Mississippi, Louisiana, and Texas. Therefore, to understand the distribution and spread mechanisms has become important in the management and control of Chinese tallow in the southeastern United States. In this research, distribution and spread mechanisms of Chinese tallow were studied at multiple spatial scales, including regional, landscape, and stand. Effects of predisposing (community and landscape features) and inciting (natural disturbance and human activities) factors on Chinese tallow invasion had been evaluated by using a comprehensive data set (field data and Forest Inventory and Analysis data) and spatial statistical models. Results indicated that propagule pressure of Chinese tallow is the main force driving tallow dispersal at different spatial scales. Predisposing and inciting factors such as natural disturbances, anthropogenic disturbances, forest types, forestland ownerships, and landscape features are significantly related to the spread of Chinese tallow at different spatial scales. Regionally, Chinese tallow initially started to spread from southern Texas and Louisiana to the northeastern portion of the Gulf Coastal area. At landscape and stand scales, Chinese tallow has commonly invaded from edges of forests and habitats such as roads and firebreaks. Inciting factors, including hurricanes/storms and prescribed fires, could accelerate the spread of Chinese tallow at different spatial scales, especially in habitats that have previously been invaded. Compared to pine forests, it is easier for Chinese tallow to invade bottomland hardwood forests at the regional scale. The efficient dispersal distance of tallow seeds is 250-300 m, and its distribution is affected by the microtopography in forest stands. Management of Chinese tallow invasion should be focused at selected scales, such as landscape and stand levels, because of variations of site conditions.

A major challenge in agroecosystems is how to manage the systems so that it reduces crop pests and enhances natural pest control. This thesis investigates patterns of crop pests and top-down effects of birds and arthropod predators in relation to land-use composition across spatial scales. In paper (I) I examined the crop distribution and land-use types in relation to the crop raiding patterns in 15 transectsin sites close to and far from forests along with a questionnaire survey at household level. I found severe crop raiding close to forests, but it had no impact on crop composition growing between the two sites. In paper (II) I examined the effect of forest and tree cover, at local and landscape scales, on the abundance of arthropod predators by collecting specimens from 40 home gardens. My result showed higher abundance of arthropod predators when either the home garden or the surroundings had a high tree-cover, compared to when tree-cover at both scales was similarly either high or low. In paper (III) I investigated the effect of excluding birds and arthropod predators on leaf damage on rape seed in 26 home gardens. I found stronger top-down impacts from arthropod predators on crop pests in tree-poor gardens than in tree-rich gardens. There was no effect of birds. In paper (IV) I explored the effect of landscape complexity on bird and arthropod predation using plasticine caterpillars in 36 home gardens across landscapes. The rate of arthropod predation on caterpillars was higher in simple than in complex landscapes. The rate of bird predation did not vary between complex and simple landscapes. In simple landscapes, arthropod predation was higher than that of birds. The overall results suggest that simplified gardens/landscapes still have enough habitat heterogeneity to support arthropod predators for the significant top-down controlling effect on crop pests. However, I did not find clear effect of complexityon the top-down effect of birds. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Manuscript; Paper 3: Manuscript; Paper 4: Manuscript</p>

This thesis includes two different studies in an attempt to investigate and better understand the key characteristics of landscape evolution. In the first study, the rate of surface particle creep was investigated through the use of Terrestrial lidar at an archaeological site in Grand Canyon National Park. The second study developed ways to quantify metrics of the Colorado River drainage and reports the role of bedrock strength in the irregular profile of the trunk Colorado River drainage. Archaeological sites along the Colorado River corridor in Grand Canyon National Park are eroding due to a variety of surficial processes. The nature of surface particle creep is difficult to quantify and managers of this sensitive landscape wish to know the rates of erosion in order to make timely decisions regarding preservation. In the first study, two scans of a single convex hillslope were collected over the span of 12 months through the use of a ground-based lidar instrument. The scans were used to track the movement of rock clasts. This study, with a relatively small data set, did not show the expected positive relations of creep rate to slope or clast size, but did not preclude the existence of these relations either. The remarkably irregular long profile of the Colorado River has inspired several questions about the role of knickpoint recession, tectonics, and bedrock in the landscape evolution of Grand Canyon and the region. Bedrock resistance to erosion has a fundamental role in controlling topography and surface processes. In this second study, a data set of bedrock strength data was compiled and presented, providing relations of bedrock strength to hydraulicdriving forces of the trunk Colorado River drainage. Results indicate that rock strength and topographic metrics are strongly correlated in the middle to lower reaches of the plateau drainage. In the upper reaches of the drainage, intact-rock strength values are ~25% higher without a matching increase in stream power. As more tensile strength samples are analyzed and appropriately scaled with respect to fracturing and shale content, we believe we will see a clearer and more consistent pattern in the upper reaches.

Oaks (Quercus robur) are an important substrate for many epiphytic lichens, and with increasing age the bark of oaks becomes suitable for red-listed species. These species may respond to environmental and landscape factors differently, and at different spatial scales. We tested the effect of tree, environmental and land use factors on the occurrence and richness patterns of lichens species at various spatial scales (circles with radius ranging from 28 to 1225 m), in a heterogeneous landscape in South Eastern Sweden. The occurrence patterns of Cliostomum corrugatum and Chaenotheca phaeocephala were best explained by the density of oaks within radii of 400 and 302 m, respectively. In contrast, Ramalina baltica was best explained at smaller scale (263 m) as was species richness (302 m). This study shows that the most important factor for the occurrence and richness patterns of lichens was oak density at almost all the considered scales. Tree circumference also positively affected all four response variables.

Nest success of dabbling ducks in the Prairie Pothole region of North America has been declining for the past 40 years in parallel with declines in duck populations. Low nest success seems to result from the combination of an extremely fragmented breeding ground in a human-dominated landscape with an abundant and expanding ii community of generalist nest predators. Studies that examined variables associated with nest vulnerability to predation have produced contradictory results, likely because of simplistic approaches, lack of spatio-temporal replication, use of artificial nests , and the effect of confounding variables. I attempted to clarify the equivocal findings of previous studies by using multiple regression to simultaneously examine the effect of several variables purportedly related to nest predation risk. I collected data on >1,800 dabbling duck nests and associated variables for 16 habitat patches (14 managed for duck production) during two nesting seasons in North Dakota. At the habitat patch level, early and late in each breeding season, I studied the relationship of nest success and upland area, nest density, predator abundance and richness, abundance of alternative prey for predators, and visual and physical obstruction provided by the vegetation . At the spatial scale of the nest and its neighborhood, I examined the likelihood of nest predation in association to nest initiation date, year, distance from nest to a wetland and to an edge, vegetation type at the nest, visual obstruction and heterogeneity of the vegetation around the nest, duck nest species , predator abundance, and presence/absence of 5 carnivorous predators at the nest habitat patch. Nest success was generally low and highly variable in time, and among and within habitat patches. I found no relationship between nest success and any of the variables measured at the patch scale. At the nest level, only initiation date, distance to water, visual obstruction, predator abundance, and duck species had an effect. High variability in the data and the lack of patterns in the relationship of nest predation and the predictor variables precluded me from building a predictive model that explains nest success. Nest success could not be predicted, predation was incidental and risk was high, and there were no safe nest sites for hens to choose in a landscape swamped by nest predators . Nests were located randomly; therefore, there were no clues predators could use to enhance their success in finding nests.

Coastal foredunes are natural aeolian bedforms located landward of the backshore and which interact continuously with the beach. Traditionally, coastal dunes have been associated with onshore winds, however they can be found under more complex wind regimes where offshore winds are common such as the UK East coast, Northern Ireland and New Zealand. This research investigates the ways in which foredune-beach interactions occur under a complex wind regime at a range of overlapping temporal and spatial scales and is innovative in that it explicitly links small-scale processes and morphodynamic behaviour to large scale and long-term dynamics. The study area is the north Lincolnshire coast, East England. Detailed observations of airflow at three locations under varying wind regimes revealed considerable spatial variations in wind velocity and direction, however it was possible to determine a general model of how foredune topography deflected and modified airflow and the resultant geomorphological implications (i.e. erosion and deposition). During direct offshore and onshore winds, airflow remained attached and undeflected; and distinct zones of flow deceleration and acceleration could be identified. During oblique winds airflow was deflected to become more parallel to the dune crest. The field sites used are characterized by a seasonal erosion/accretion cycle and a series of increasingly complex models was developed and tested to determine whether it was possible to predict sand volume changes in the foredune-beach system based on a limited number of variables. The model predictions were tested against detailed digital terrain models at a seasonal timescale. The model prediction that best matched the observed (surveyed) sand volume changes included wind speed, direction, grain size, fetch effect controlled by beach inundation and angle of wind approach was accurate to within ±10% for 18 out of 48 tests at the seasonal scale and 6 out of 12 tests over periods of >5 years. A key variable influencing foredune-beach sand volume is the magnitude and frequency of storm surge events and this was not factored in to the model, but may explain the model-observation mismatch over the medium-term on two occasions. Over the past 120 years historical maps and aerial photographs indicate long-term foredune accretion of approximately 2 m year-1 at the three study sites (1891-2010). At this timescale, rates of coastal foredune accretion reflect the low occurrence of severe storm surges and suggest rapid post-storm recovery. The morphological response of the foredune-beach morphology is considered to be a combination of controlling and forcing factors. Process-responses within the system, associated with nearshore interactions and sediment transfer from the littoral drift, are compiled into a multi-scale morphodynamic model. Important to match appropriate dataset to scale of research question or management plan being explored. In the case of management, long-term records of past activity are necessary to predict the future but also to understand natural responses of system to short-term impact such as storm surge.

Nas últimas décadas, em decorrência da globalização e do comércio internacional, o deslocamento de espécies para longe de suas regiões de origem tem crescido em frequência e extensão, aumentando o risco de invasões biológicas, que podem impactar significativamente a economia, o funcionamento dos ecossistemas e causar perdas de biodiversidade. A erradicação de espécies invasoras tem poucas chances de sucesso, de modo que prevenir a invasão constitui a melhor alternativa de manejo. Técnicas de modelagem preditiva de distribuição têm sido globalmente aplicadas para prever a distribuição potencial de espécies invasoras. No Brasil, são poucos e recentes os estudos sobre invasões biológicas. Visando ampliar o conhecimento sobre plantas consideradas invasoras e sua distribuição no estado de São Paulo, neste estudo aplicamos técnicas de modelagem preditiva a 10 espécies. Para cada uma delas buscamos caracterizar o padrão de invasão e identificar os fatores ambientais atuantes que limitam ou potencializam sua distribuição, por meio de modelos multi-hierárquicos de nicho ecológico. Para tanto, coletamos informações de ocorrência dessas espécies em todo o mundo e registramos coordenadas geográficas, características das populações e dos ambientes invadidos por essas espécies em todos os tipos de vegetação e em todas as regiões do estado de São Paulo. Com base nesses dados, caracterizamos o padrão de invasão de cada espécie e a invasibilidade de cada tipo vegetacional estudado. Aplicamos a metodologia de modelagem multi-hierárquica de nicho ecológico por meio do algoritmo MaxEnt em macro escala para todo o globo e em meso escala para o estado de São Paulo. Apesar das peculiaridades das espécies e dos tipos de vegetação, nossos resultados evidenciam a influência do estado de conservação do ecossistema e da posição na paisagem sobre a severidade da invasão e, também, sobre a invasibilidade dos tipos de vegetação em escala local. Mesmo os tipos de vegetação mais resistentes, como a restinga e a floresta ombrófila densa, podem se tornar suscetíveis à invasão em função de distúrbios e da pressão de propágulos. Em fragmentos conservados, porém, são raras as espécies exóticas capazes de se estabelecer e se tornar uma ameaça real à conservação. As fitofisionomias mais abertas do Cerrado mostraram-se como os tipos de vegetação suscetíveis à invasão pelo maior número de espécies, entre as estudadas. Em macro escala, os modelos de nicho ecológico identificaram as áreas potenciais de invasão e revelaram os limites fisiológicos de temperatura e precipitação para cada espécie, enquanto em meso escala, os modelos de nicho refinaram estas previsões e revelaram novos padrões associados com a distribuição das espécies na escala do estado de São Paulo. Este estudo gera contribuições importantes em termos de informação sobre as características e áreas potenciais de invasão para gestores e tomadores de decisão no processo de prevenção e controle de invasões, bem como identifica limites e fatores ambientais que contribuem para a melhor compreensão de invasões biológicas no Brasil. De forma geral, a abordagem multi-hierárquica se mostrou uma ferramenta poderosa para explorar padrões de distribuição em escalas apropriadas com os objetivos de conservação, prevenção e controle de espécies exóticas. / In recent decades, as a result of globalization and international trade, the movement of species away from their native regions has grown in frequency and extent, increasing the risk of biological invasions, which can significantly impact the economy, the functioning of ecosystems and cause biodiversity loss. The eradication of invasive species it is not an easy task, usually with little chance of success, so that prevent the invasion is still the best management alternative. Predictive species distribution modeling techniques have generally been applied to predict the potential distribution of invasive species. In Brazil, studies on biological invasions are recent and insufficient to understand the current invasive status. To enhance understanding about invasive plants and its distribution in the state of São Paulo, in this study we apply predictive modeling techniques to 10 species considered invasive. For each of the selected species we seek to characterize the invasion pattern and identify the active environmental factors that limit or leverage its distribution through multihierarchical ecological niche models. For this purpose, we collect information for these species occurring worldwide and recorded geographical coordinates characteristics of populations and environments invaded by these species in all vegetation types and in all regions of the state of São Paulo. Based on these data, we characterize the invasion pattern of each species and the invasiveness of each vegetation type studied. We applied the multihierarchical ecological niche modeling methodology through MaxEnt algorithm in macro scale for the entire globe and meso scale for the state of São Paulo. Despite the peculiarities of species and vegetation types, our results highlight the influence of ecosystem conservation status and position in the landscape on the severity of the invasion and on the invasiveness of vegetation types on a local scale. Even the most resistant types of vegetation, such as the restinga and the tropical rain forest, can become susceptible to invasion because of disturbances and seedlings pressure. In conserved fragments, however, exotic species were rarely able to settle down and become a real threat to conservation. The more open forms of the Cerrado vegetation types appeared as the most susceptible to invasion by most of the studied species. In macro scale, the ecological niche models identified the potential areas of invasion and revealed the physiological limits of temperature and precipitation for each species, while in meso scale, niche models refined these projections and revealed new patterns associated with the distribution of species on the scale of São Paulo. This study provides important contributions in terms of information about the characteristics and potential areas of invasion for managers and decision makers in prevention and control of invasions and identifies limitations and environmental factors that contribute to a better understanding of biological invasions in Brazil. In general, the multihierarchical approach proved to be a powerful tool to explore patterns of distribution at scales compatible with conservation objectives, prevention and control of alien species.

Submitted by Ronildo Prado (ronisp@ufscar.br) on 2017-08-21T18:35:10Z No. of bitstreams: 1 TeseRAL.pdf: 3616408 bytes, checksum: 1f059af1e83546f934fb09bda5b63e7f (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-21T18:35:17Z (GMT) No. of bitstreams: 1 TeseRAL.pdf: 3616408 bytes, checksum: 1f059af1e83546f934fb09bda5b63e7f (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-21T18:35:23Z (GMT) No. of bitstreams: 1 TeseRAL.pdf: 3616408 bytes, checksum: 1f059af1e83546f934fb09bda5b63e7f (MD5) / Made available in DSpace on 2017-08-21T18:35:30Z (GMT). No. of bitstreams: 1 TeseRAL.pdf: 3616408 bytes, checksum: 1f059af1e83546f934fb09bda5b63e7f (MD5) Previous issue date: 2017-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The conversion of natural areas to human activities in watersheds is the main cause of riparian forest degradation, which, consequently, decreases the integrity of aquatic ecosystems. Therefore, restoration of riparian forests has been recommended as the best strategy for the recovery of streams in watersheds deforested by land use and cover. In Brazil, projects of riparian forest restoration are still recent and little is known about their effects on adjacent streams ecosystems. This study evaluated the effects of riparian forest restoration on stream water quality and aquatic macroinvertebrate communities using the multiple spatial scales approach. Sampling was carried out using the field protocol developed by the Environmental Protection Agency of the United States of America (US-EPA). We compared streams with natural riparian forests, streams with riparian forests in restoration and streams with riparian zones covered by pasture or grasses. A 150m reach was defined in each stream, and measurements of the physical structure of habitats and water quality were made, as well as samples of aquatic macroinvertebrates. Land-use and cover of each stream sub-basin was carried out through an environmental characterization of the landscape. Riparian forest restoration did not affect stream water quality and biological diversity after 10 and 13 years of project implementation, suggesting that the recovery of tropical streams in response to riparian forest restoration may be slow in sub-basin heavily altered by human activities. The present study fills a knowledge gap on the effects of riparian restoration and suggests the need for further studies and long term evaluations integrating new riparian forest restoration projects in watersheds with different intensities of human degradation to better understand the effects of the implementation of these projects on the quality of stream water and aquatic communities. / A conversão de áreas naturais para as atividades humanas nas bacias hidrográficas é a principal causa da degradação de florestas ripárias, o que, consequentemente, diminui a integridade dos ecossistemas aquáticos. Assim a restauração de florestas ripárias tem sido recomendada como a melhor estratégia visando à recuperação de riachos em bacias desmatadas pelo uso e ocupação do solo. No Brasil, projetos de restauração de florestas ripárias ainda são recentes e pouco se conhece sobre os seus efeitos nos ecossistemas de riachos adjacentes. Este estudo avaliou os efeitos de florestas ripárias em restauração na qualidade da água e nas comunidades de macroinvertebrados aquáticos de riachos, utilizando a abordagem de múltiplas escalas espaciais de investigação. Para a amostragem, foi utilizado o protocolo desenvolvido pela Agência de Proteção Ambiental Norte-Americana (US-EPA). Foram comparados riachos com floresta ripária natural, floresta ripária em restauração e com zonas ripárias alteradas por pastagem ou gramíneas. Um trecho de 150 m foi definido em cada riacho e em cada trecho foram realizadas medidas da estrutura física dos habitats e da qualidade da água e amostragens de macroinvertebrados aquáticos. Na microbacia de cada riacho foi realizada a caracterização ambiental da paisagem para analisar o uso e ocupação do solo. A floresta ripária em restauração após 10 e 13 anos de implantação não afetou a qualidade da água e a diversidade biológica, sugerindo que a recuperação de riachos tropicais em resposta à restauração de florestas ripárias pode ser lenta em bacias hidrográficas fortemente alteradas pelas atividades humanas. O presente estudo preenche uma lacuna de conhecimento sobre os efeitos de florestas ripárias em restauração em riachos de paisagens rurais e sugere a necessidade de mais estudos e avaliações em longo prazo, integrando novos projetos de restauração de floresta ripária em bacias hidrográficas com diferentes intensidades vii de degradação humana, para melhor se compreender os efeitos da implantação destes projetos na qualidade da água e comunidades aquáticas. / FAPESP: 2013/19950-9

La chasse – comme la prédation naturelle - induit des réponses comportementales par les individus chassés qui cherchent ainsi à éviter ou à reduire le risque. Il est en particulier fréquent d'observer un changement dans leur utilisation de l'espace, mais l'articulation et les déterminants des réponses aux différentes échelles spatiales restent mal compris. De même, s'il a été suggéré que ces modifications comportementales pouvaient affecter en cascade la végétation, cela reste à tester. Pour combler ces lacunes, j'ai, (1) étudié, dans un paysage agricole du sud de la France, une population chassée de chevreuils et leur utilisation des milieux ouverts risqués et des couverts boisés, au cours de périodes de risque contrasté ; (2) testé, sur une population canadienne de cerfs à queue noire dépourvue de prédateurs et exempte de chasse, l'influence d'une chasse expérimentale sur le comportement des animaux et sur la végétation. J'ai montré que les chevreuils répondaient à une augmentation du risque à plusieurs échelles spatiales. Ils réduisaient leur utilisation des habitats risqués, et dans certains cas se rapprochaient des couverts, de jour ces deux réponses étant couplées au niveau individuel. Le gradient paysager d'ouverture du milieu contraignait cependant les niveaux de réponses observées et les stratégies individuelles. Au Canada, j'ai observé un évitement de la zone chassée par les cerfs les plus sensibles à la présence humaine, corrélé à une diminution de l'abroutissement pour deux des quatre espèces de plantes étudiées. J'ai intégré ces résultats dans une discussion sur l'utilisation de la chasse pour gérer les populations d'herbivores et leurs impacts sur la végétation. / Hunting – similarly to natural predation – induces behavioural responses of hunted individuals which aims at avoiding or reducing risk. Particularly, changes in space use are frequently observed, but the articulation and determinants of these changes at multiple spatial scales are still poorly understood. Also, although it has been suggested that these changes might cascade on the vegetation, this remains to be tested. To fill these gaps, I (1) studied a hunted roe deer population living in an agricultural landscape in southern France where roe deer can find open risky habitats and woody covers; and (2) tested black-tailed deer behavioural response to an experimental hunt in a predator- and hunting-free population in the Haïda-Gwaii archipelago (BC, Canada). I also investigated the possible cascading effects on the vegetation. I showed that roe deer responded to increased hunting pressure at multiple scales, reducing their use of the risky habitats and, in specific situations, their distance to the nearest cover. At day-time those two responses were coupled at the individual level. Generally, landscape openness constrained individual responses and strategies. In the hunting-for-fear experiment conducted on Haida Gwaii, I found that only the deer less-tolerant to human disturbance avoided the hunting area. A simultaneous reduction in browsing pressure on two out of the four plant species monitored was found however. I integrated these results in a general discussion on the possible role of hunting as a tool to manage abundant deer populations and their impacts on the vegetation.