Polycyclic aromatic hydrocarbons(PAHs) are one of major classes of organic pollutants that transport through air-sea exchange in the environment. The objectives of this study were to quantify the PAHs concentrations in air and seawater and calcu-late the exchange fluxes by using Whitman¡¦s two-film mode. Spatial and temporal distributions were also determined through the sampling strategy of this study. In ad-dition, particulate concentrations in the ambient air were used to estimate the dry de-position fluxes of PAHs. Seasonal fluxes of PAHs in Gao-Ping coastal areas ranged from -2020 to +320 ng/m2day. The net gas exchange fluxes were negative (net absorption) in August, No-vember and March but positive (net volatilization) in May at Kaohsiung Harbor (KH), Off Shore (OFS) and Gao-ping River Estuary (GRE). Howerer negative exchange fluxes were found in each sampling month at Liu-Chiu Isle (LCI). In contrast, Lanyu Isle (LI) showed a different tend in exchange fluxes. It¡¦s exchange fluxes were all positive in each sampling month and ranged from the +121 to +1020 ng/m2day. Mostly the net fluxes of low molecular weight PAHs were volatile; while high molecular weight PAHs were absorptive. The compound with highest flux was mostly phenanthrene, therefore, it dominates the gas exchange fluxes in Gao-Ping coastal areas. The highest average net gas exchange fluxes among stations were observed at LCI (-1650 ng/m2day) and decreased in the following order: GRE (-932 ng/m2day), KH (-824 ng/m2day), OFS (-523 ng/m2day), LI (+358 ng/m2day). Dry particle deposi-tion fluxes were higher in November and March. The high molecular weight PAHs were found predominant in these particles. Even adding up with the wet deposition, the magnitude of total deposition fluxes(dry+wet) were still lower than those of gas exchange. Therefor, gas exchange is the main transport pathway for PAHs in Gao-Ping coastal areas. By identifying composition patterns of PAHs in each sample, source of PAHs in dissolved phase were mainly from traffic emission. However, KH is indicative of in-dustrial and petrogenic souces; while grass and wood combustion and petrogenic might be the dominant source of PAHs at LI. In gas phase, sources of PAHs were mostly from combustion, including traffic emission and diesel combustion. Finally, the transport pathway of the airflow was analyzed through back trajectory analysis. The results show that the PAH concentrations in gas phase might be affected by re-gional pollution in August and May, and long-rang atmospheric transport in March at Gao-Ping coastal areas and LI. Local origin was suggested for PAHs from Gao-Ping coastal areas in November and March.

This study is aiming to investigate the distribution of epibenthic shrimp communities in relation to the environmental factors of their habitats in the coastal sandy bottom of southwestern Taiwan. Shrimp samples were collected from April 2002 to July 2003, with a beam trawl operated at seven stations along the coasts. Simultaneously, water temperature, salinity, dissolved oxygen were measured and sediments were collected. Particle size and organic matter of the sediments were then analyzed in the laboratory. The results of PCA analyses on these environmental factors revealed that the observations could be segregated into two groups along the PC1, representing rainy season with high temperature, low salinity and dry season with low temperature, high salinity, respectively. The observations with coarse particle (>0.125 mm), representing samples from north sites, were found to distribute in the upper part of the PC2; while those with fine particle (<0.125 mm), representing samples from south sites, distributed in the lower part. In total, 15,591 individuals of shrimp were collected, including 20 genus, 39 species. Metapenaeopsis palmensis (88.2%), Trachysalambria curvirostris (3.6%), M. barbata (3.5%) and Parapenaeopsis cornuta (1.4%) were the four dominant species. Significant differences in the spatial distribution were due to the different composition of the dominant species. Although M. palmensis was the most abundant species in most stations, its percentage abundance was the lowest at Fangliao and Jiading, where the dominant species were T. curvirostris for the former and M. barbata and P. cornuta for the latter. Species preferences for various combinations of environmental variables are responsible for shifts in the structure and overall abundance of assemblages and dictated some patterns. Higher abundances of T. curvirostris, Trachypenaeus granulosus, and Solenocera koelbeli were associated with the appearance of high temperature, low salinity and very fine sand, representing the environmental features of Fangliao and Linbian during the rainy season. Stenopus hispidus, Metapenaeus moyebi, Metapenaeus ensis and M. palmensis were abundant coinciding with low temperature, high salinity and high silt and clay that reflecting the dry season of Linyuan and Linbian waters. Metapenaeopsis dalei and M. barbata appeared in large numbers at habitats with high temperature, low salinity and coarse sand, which mainly occurred in Zouying to Jhongjhou during the rainy season. Moreover, Scyllarus rugosus and Parapenaeopsis cornuta seemed to prefer coarse sandy bottom mainly distributed from Jiading to Linyuan. Temporal fluctuations were associated with the population dynamic of the dominant species. The abundance was reduced while the M. palmensis migrated to open sea in late summer and early autumn. As the juveniles of M. palmensis and M. barbata back to the inshore waters, the abundance were increased and reached the peak in spring. Because of the limited distribution, T. curvirostris and P. cornuta were not influence the overall temporal fluctuations but the local fluctuations. Overall, temporal fluctuations act more at a specific level even structural one, and may be linked to some particular stages of the benthic shrimp life cycle, but do not significantly influence the spatial organization.

This study aimed at providing a thorough understanding of temporal and spatial variations of VOCs and underlying factors in different microenvironments in two different urban atmospheres, with different degrees of regulatory enforcement. The VOC data were collected in field campaigns conducted in Ankara, Turkey, and Ottawa, Canada over the years 2000-2004. Insight into the sources of VOCs in different urban atmospheres was sought by using three commonly used receptor models namely / Positive Matrix Factorization (PMF), Chemical Mass Balance (CMB) Model and Conventional Factor Analysis (CFA). Motor vehicle related source profiles were developed to use in receptor modeling. Motor vehicles are the most abundant VOC sources with about 60% and 95% contributions to ambient levels in Ankara and Ottawa, respectively. Residential heating (31%) during winter season, biogenic (9%) and architectural coating (12%) emissions during summer season and solvent use (about 12%) emissions are the next abundant VOC sources in Ankara. In addition, a new method to estimate the contribution of sources from wind sectors in urban atmosphere was developed and implemented in this study. The comparison of the results of these two cities demonstrated the influence of control measures on ambient levels and sources of VOCs observed in different urban atmospheres. VOC levels in Ankara exceed EU levels and they are about factor of two higher than that are measured in Ottawa owing to lack of implementation of emission control regulations for VOCs in Ankara compared to well adopted regulations in Ottawa.

Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic air pollutants formed during incomplete combustion and are ubiquitously distributed in the environment. To determine particle-bound PAHs in archived PM2.5 samples taken with low flow rate in Atlanta, a sensitive and robust method was developed for measuring 28 PAHs and methyl PAHs in PM samples using isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS). The method was then used to analyze PM2.5 samples collected at three sites (rural, urban, suburban-highway) from the Assessment of Spatial Aerosol Composition in Atlanta (ASACA) network. Distinct seasonal and spatial variations were observed in PAH concentration. Particle-bound PAH levels were significantly higher in winter than in summer. The suburban-highway site had higher PM2.5-bound PAH concentration than did the urban site, and the rural site had the lowest PAH levels. Retene, a proposed biomass burning tracer, captured both the high leaves-grasses-bushes-branches burning season and the high wood burning months, suggesting that it might be a better marker for all biomass burning, while potassium ion might be a more specific tracer for wood burning. Human exposure to PAHs can be assessed by characterizing their hydroxy PAH (OH-PAH) metabolites in urine samples. A method was developed to measure 24 urinary OH-PAHs, metabolites of 8 parent PAHs, using enzymatic de-conjugation, automatic liquid-liquid extraction, and GC/HRMS. A study was then carried out to evaluating the variability of the urinary biomarker levels in a non-occupationally exposed non-smoking reference group. Levels of urinary PAH metabolites varied widely both within-subject and between-subjects and the within-day variance far exceeded the between-day variance. There were also considerable temporal correlations for these biomarkers. Sample size calculations were conducted and taking 24-hour voids would require the least number of subjects, which should be considered during epidemiological study design. Finally, a study was conducted to evaluate exposure to ambient PAHs in an urban setting among 8 non-occupationally exposed non-smoking volunteers employing both personal air sampling and urine biomonitoring. PAH levels varied largely in air samples taken at home, at work, and while driving or jogging. Monitoring urinary OH-PAH levels can capture both inhalation and dietary exposures. Total inhaled PAH was correlated with total excreted OH-PAHs, suggesting that by combining personal air sampling and biomonitoring, exposure to environmental PAHs can be well characterized even for low-level exposure.

Denna avhandling behandlar den småskaliga rumsliga variationen av löst organiskt kol (DOC, engelsk term: dissolved organic carbon), dess koncentration, masstransport och karaktär, i bäckar inom två barrskogsbeklädda avrinningsområden (delavrinningsområden 0,01-78 km²). Provtagningen gjordes uppströms och nedströms varje bäckförgrening under sommarbasflöde. Koncentrationen av DOC varierade inom en tiopotens (4-66 mg/l), liksom flera andra kemiska parametrar. Vid riksinventeringen av vattendrag för 2000 i norra Sverige noterades en snarlik spännvidd. Enligt Naturvårdverkets bedömningsgrunder för sjöar och vattendrag återfanns alla tillståndsklasser för DOC och pH, samt mänsklig påverkansgrad till försurningen inom de två studerade områdena. Den specifika avrinningen (flöde per areaenhet) varierade kraftigt i källflödena och inverkade på deras bidrag till kemin nedströms. Vattenkemin och specifika avrinningen var stabila i delavrinningsområden större än 15 km². Det kan vara nödvändigt att provta så stora områden om generella värden för landskapet önskas, men källflödenas kemi kommer då inte att kunna karakteriseras, ehuru källflödena utgör den största delen av bäcksträckan och det akvatiska ekosystemet. Nedströms är DOC-koncentrationen, och många andra kemiska parametrar, lika med summan av bidragen från källflödena och nedströms utspädning av inflödande vatten. Tillkommer gör processer inom bäcken och vattnets utbyte med botten/grundvatten (den hyporheiska zonen), men även DOC-förluster/transformationer vid vissa bäckförgreningar och sjöar. Ovanstående resonemang förklarade bäckvattenkemins minskande variation och vanligen lägre DOC-koncentrationer nedströms i ett landskapsperspektiv. Längs bäcksträckorna observerades ingen generell minskning av DOC-koncentration eller ändring av dess karaktär. Skillnaden i DOC-koncentration och relaterade parametrar mellan källflöden och nedströms styrdes i hög grad av vilka landskapselement (myrar, sjöar och skogsmark) som vattnet hade passerat innan det hamnade i bäckarna, samt samspelseffekter med den specifik avrinningen och platserna med DOC-förlust. Prognoser med multivariata modeller baserade på kartinformation testades men kunde inte förutsäga det rumsliga mönstret eller DOC-koncentrationen med erforderlig precision. Lämpliga rutiner inom miljöövervakningen för att övervaka den rumsliga variationen av kemin i ytvatten saknas alltjämt. Vid planering av terrestra och akvatiska skötselåtgärder bör man beakta bäckvattnets naturliga kemiska variation. / This thesis quantifies the small-scale spatial variation of dissolved organic carbon (DOC) concentrations, fluxes and character in two boreal catchments (subcatchments 0.01-78 km²) using ”snapshots” of summer base flow where samples were taken upstream and downstream from every node in the stream network. An order of magnitude variation was found in DOC-concentrations, and many other chemical parameters. The range was similar to that found in all of northern Sweden by the national stream survey in 2000. According to the official assessment tools used in Sweden, the entire range of environmental status for DOC, pH and human acidification influence existed within these two study catchments. A large variability in specific discharge had a major impact on the contribution of headwaters to downstream chemistry. The water chemistry parameters were relatively stable at catchment areas greater than 15 km². Sampling at that scale may be adequate if generalised values for the landscape are desired. However the chemistry of headwaters, where much of the stream length and aquatic ecosystem is found would not be characterized. Downstream DOC-concentrations, as well as many other chemical parameters, are the sum of headwater inputs, in combination with progressive downstream dilution by inflowing water with its own DOC-concentration and character. Superimposed upon this are in-stream and hyporheic processes, as well as discrete loci of DOC loss/transformation at lakes and stream junctions. At the landscape scale, this results in a decreased downstream variation in stream water chemistry and often, but not necessarily, lower average DOC-concentrations. Along stream reaches there was not a loss of DOC-concentration or a consistent change in character. While the importance of in-stream/hyporheic processes that consistently alter DOC-concentrations along the channel network cannot be ruled out, the differences between headwater and downstream DOC-concentrations and related parameters depend largely on the mosaic of landscape elements (mires, lakes and forest soil) contributing water to the channel network, combined with patterns of specific discharge and discrete loci of DOC loss. Assessment would be facilitated by map information that could predict spatial patterns. Multivariate models using maps, however, did not give satisfactory predictions. Appropriate procedures for dealing with spatial variation in the environmental assessment of surface waters are not yet established. An awareness of stream water chemistry’s natural spatial variability should be considered when planning aquatic and terrestrial management.

Drought and poor soil fertility are often cited as major constraints to rainfed lowland rice production in Laos, particularly in the central and southern parts of the country, where uncertainty in the growing season is common, due mainly to a combination of unreliable rainfall and coarse textured soils with a low water holding capacity and high rates of deep percolation. The soil conditions, together with fluctuations in rainfall distribution, are regarded as the most serious constraints to achieving high and stable grain yields in the rainfed lowland rice ecosystem in this region. Improvements in rainfed lowland rice productivity depend, in part, on improved predictions of water availability, as well as better understanding of soil nutrient and water stress limitations to grain yield. The use of a soil water balance model, in conjunction with the quantification of soil nutrient availability, can help in estimating free water levels in the rice fields, thereby helping determine the duration of the growing period, as well as, helping with predictions of potential yield reduction due to water stress and soil nutrient limitations. Linking the simulated results with Geographic Information System (GIS) can help quantify the spatial pattern of these attributes at a provincial or regional scale. This study was aimed at quantifying the spatial distribution of water availability, including the frequency and severity of water stress development during the growing period, and to estimate the effects of soil fertility and water stress on rice productivity in Savannakhet province in southern Lao PDR. The current status in relation to the variability in field water availability, soil fertility, farm crop management practices and grain yield throughout Savannakhet province were quantified, first by collecting farm data from 53 and 48 farmers’ fields in the 2007 and 2008 cropping seasons, respectively, These farms were selected to be representative of a wide range of soil and climate conditions within the province. The results show that rainfall distribution pattern, soil type and toposequence position of paddy fields, are crucial factors contributing to the temporal variation in field water availability. The overall yield loss due to water stress associated with late season drought was estimated to be rather small (10%, 5% and 3% for the top, middle and bottom toposequence positions of rice fields, respectively) in the 2008 wet season. On the other hand, application of chemical fertilizer has a large effect on final grain yield, with 50 kg N ha-1 and 30 kg P2O5 ha-1 increasing yield by 600 to 800 kg and 800 to 1000kg ha-1 respectively, in the 2007 and 2008 cropping seasons. A new soil water balance (SWB) model that incorporates the effect of low soil clay content on deep percolation, was developed to quantify field water availability and the length of growing period (LGP) for various rainfall lowland rice cropping environments. The model estimates the amount of water stored in a soil profile, the profile being divided into two layers: Layer 1 (0-200 mm) consists of standing water and the topsoil layer, while Layer 2 (200-1000 mm) is the subsoil layer. The SWB model was validated with field experimental data obtained in the 2002 and 2008 cropping seasons. The simulated free water levels were close to those recorded for the observed field data, with a small mean average error, lower root mean square error, and significant correlation coefficient and index of agreement over all sites across the three toposequence positions of paddy fields. Maps of the length, start and end of growing period (LGP, SGP and EGP, respectively) for rainfed lowland rice in Savannakhet province, were developed using the SWB model, with inputs of median weekly climatic data and soil water characteristics. The province was delineated into three main LGP zones with a short LGP zone (less than 21 weeks) in the east, northwest and some rice fields in the south-western corner of the province; an intermediate LGP zone (21 to 24 weeks) was defined in the central and western part of the province; and a long LGP zone (greater than 24 weeks) for the south and for some rice fields in the western part of the province. The variation in the SGP from year-to-year was due largely to the variation in rainfall early in the wet-season (e.g. April), while EGP was strongly dependent upon the clay content of the soils being cropped. The SWB model was combined with other models that estimate yield potential, soil nutrient supply and yield reduction by low soil water level, to characterize and map the suitability zones for rainfed lowland rice in Savannakhet province. The overall results of the model performance on yield estimates were satisfactorily, with a significant correlation coefficient (0.54**) and high index of agreement (0.68) over the 2007 and 2008 seasons. The model classified three main rice agro-ecological zones according to the suitability of climate and soil conditions. The majority of the lowland rice growing areas are classified as moderately suitable to marginally suitable, while the potential area classified as being high suitable is very small. A large potential response of rice yields to fertilizer inputs is predicted for most of rice growing areas in the province. The best sowing time for achieving a high yield, as evaluated by the model, is the first half of June. Appropriate crop phenology and increasing fertilizer use efficiency that matches with water availability and soil conditions in each rice agro-ecological zone, are important in achieving improvements in rice productivity, as substantial improvements in rice fields cannot be achieved by improving water availability alone, where paddy fields are dominated by soils with low level of indigenous fertility. Although the model is capable of quantifying field water availability and crop yield due to the limitations associated with low levels of soil nutrients and water stress, the model has the potential for further improvements in two areas. First, the estimates of water loss need to be modified by incorporating variable factors such as slope of paddy field, which can affects lateral water movement and hence free water level. Second, the model should incorporate some key agronomic variables, such as internal efficiencies and recovery efficiencies of applied fertilizer, which depend on variety, crop management and climatic conditions, and these factors can be modelled.

The spatial data community relies on the quality of its data. This research investigates new ways of storing and retrieving spatial data quality information in databases. Given the importance of features and sub-feature variation, three different data quality models of spatial variation in quality have been identified and defined: per-feature, feature-independent and feature-hybrid. Quality information is stored against each feature in the per-feature model. In the feature-independent model, quality information is independent of the feature. The feature-hybrid is derived from a combination of the other two models. In general, each model of spatial variation is different in its representational and querying capabilities. However, no model is entirely superior in storing and retrieving spatially varying quality. Hence, an integrated data model called as RDBMS for Spatial Variation in Quality (RSVQ) was developed by integrating per-feature, feature-independent and feature-hybrid data quality models. The RSVQ data model provides flexible representation of SDQ, which can be stored alongside individual features or parts of features in the database, or as an independent spatial data layer. / The thesis reports on how Oracle 10g spatial RDBMS was used to implement this model. An investigation into the different querying mechanisms resulted in the development of a new WITHQUALITY keyword as an extension to SQL. The WITHQUALITY keyword has been designed in such a way that it can perform automatic query optimization, which leads to faster retrieval of quality when compared to existing query mechanism. A user interface was built using Oracle Forms 10g which enables the user to perform single and multiple queries in addition to conversion between models (example, per-feature to feature-independent). The evaluation, which includes an industry case study, shows how these techniques can improve the spatial data community’s ability to represent and record data quality information.

Drought and poor soil fertility are often cited as major constraints to rainfed lowland rice production in Laos, particularly in the central and southern parts of the country, where uncertainty in the growing season is common, due mainly to a combination of unreliable rainfall and coarse textured soils with a low water holding capacity and high rates of deep percolation. The soil conditions, together with fluctuations in rainfall distribution, are regarded as the most serious constraints to achieving high and stable grain yields in the rainfed lowland rice ecosystem in this region. Improvements in rainfed lowland rice productivity depend, in part, on improved predictions of water availability, as well as better understanding of soil nutrient and water stress limitations to grain yield. The use of a soil water balance model, in conjunction with the quantification of soil nutrient availability, can help in estimating free water levels in the rice fields, thereby helping determine the duration of the growing period, as well as, helping with predictions of potential yield reduction due to water stress and soil nutrient limitations. Linking the simulated results with Geographic Information System (GIS) can help quantify the spatial pattern of these attributes at a provincial or regional scale. This study was aimed at quantifying the spatial distribution of water availability, including the frequency and severity of water stress development during the growing period, and to estimate the effects of soil fertility and water stress on rice productivity in Savannakhet province in southern Lao PDR. The current status in relation to the variability in field water availability, soil fertility, farm crop management practices and grain yield throughout Savannakhet province were quantified, first by collecting farm data from 53 and 48 farmers’ fields in the 2007 and 2008 cropping seasons, respectively, These farms were selected to be representative of a wide range of soil and climate conditions within the province. The results show that rainfall distribution pattern, soil type and toposequence position of paddy fields, are crucial factors contributing to the temporal variation in field water availability. The overall yield loss due to water stress associated with late season drought was estimated to be rather small (10%, 5% and 3% for the top, middle and bottom toposequence positions of rice fields, respectively) in the 2008 wet season. On the other hand, application of chemical fertilizer has a large effect on final grain yield, with 50 kg N ha-1 and 30 kg P2O5 ha-1 increasing yield by 600 to 800 kg and 800 to 1000kg ha-1 respectively, in the 2007 and 2008 cropping seasons. A new soil water balance (SWB) model that incorporates the effect of low soil clay content on deep percolation, was developed to quantify field water availability and the length of growing period (LGP) for various rainfall lowland rice cropping environments. The model estimates the amount of water stored in a soil profile, the profile being divided into two layers: Layer 1 (0-200 mm) consists of standing water and the topsoil layer, while Layer 2 (200-1000 mm) is the subsoil layer. The SWB model was validated with field experimental data obtained in the 2002 and 2008 cropping seasons. The simulated free water levels were close to those recorded for the observed field data, with a small mean average error, lower root mean square error, and significant correlation coefficient and index of agreement over all sites across the three toposequence positions of paddy fields. Maps of the length, start and end of growing period (LGP, SGP and EGP, respectively) for rainfed lowland rice in Savannakhet province, were developed using the SWB model, with inputs of median weekly climatic data and soil water characteristics. The province was delineated into three main LGP zones with a short LGP zone (less than 21 weeks) in the east, northwest and some rice fields in the south-western corner of the province; an intermediate LGP zone (21 to 24 weeks) was defined in the central and western part of the province; and a long LGP zone (greater than 24 weeks) for the south and for some rice fields in the western part of the province. The variation in the SGP from year-to-year was due largely to the variation in rainfall early in the wet-season (e.g. April), while EGP was strongly dependent upon the clay content of the soils being cropped. The SWB model was combined with other models that estimate yield potential, soil nutrient supply and yield reduction by low soil water level, to characterize and map the suitability zones for rainfed lowland rice in Savannakhet province. The overall results of the model performance on yield estimates were satisfactorily, with a significant correlation coefficient (0.54**) and high index of agreement (0.68) over the 2007 and 2008 seasons. The model classified three main rice agro-ecological zones according to the suitability of climate and soil conditions. The majority of the lowland rice growing areas are classified as moderately suitable to marginally suitable, while the potential area classified as being high suitable is very small. A large potential response of rice yields to fertilizer inputs is predicted for most of rice growing areas in the province. The best sowing time for achieving a high yield, as evaluated by the model, is the first half of June. Appropriate crop phenology and increasing fertilizer use efficiency that matches with water availability and soil conditions in each rice agro-ecological zone, are important in achieving improvements in rice productivity, as substantial improvements in rice fields cannot be achieved by improving water availability alone, where paddy fields are dominated by soils with low level of indigenous fertility. Although the model is capable of quantifying field water availability and crop yield due to the limitations associated with low levels of soil nutrients and water stress, the model has the potential for further improvements in two areas. First, the estimates of water loss need to be modified by incorporating variable factors such as slope of paddy field, which can affects lateral water movement and hence free water level. Second, the model should incorporate some key agronomic variables, such as internal efficiencies and recovery efficiencies of applied fertilizer, which depend on variety, crop management and climatic conditions, and these factors can be modelled.

Distintos padrões de composição e diversidade de espécies podem ser observados ao longo de comunidades que variam em relação ao ambiente e à posição geográfica, sendo possível a identificação de potenciais espécies indicadoras destas mudanças. Diversos estudos sobre a variação na diversidade de espécies têm demonstrado a influência de condições ambientais (teoria de nicho) e/ou da limitação na dispersão (teoria neutra), com diferentes proporções de explicação. Esta dissertação aborda a especificidade de espécies arbóreas no sudeste da Mata Atlântica e alguns padrões de variação da diversidade beta em Florestas com Araucária, na região nordeste do Rio Grande do Sul. Na abordagem de especificidade de espécies, analisamos um gradiente ambiental e espacial a partir de 21 trabalhos abrangendo diferentes tipologias florestais: Floresta de Restinga (3), Floresta Ombrófila Densa (7), Floresta Ombrófila Mista (8) e Floresta Nebular (3). Foram observados diferentes níveis de riqueza e de espécies indicadoras para cada tipo florestal. Além disso, a altitude foi a principal variável ambiental associada aos padrões florísticos observados neste estudo, que formam um continuum de substituição de espécies ao longo do gradiente. Para a abordagem da diversidade beta, foram realizados levantamentos quantitativos do estrato inferior e superior em três áreas de conservação de Floresta com Araucária, onde foram explorados a partição aditiva da diversidade em diferentes escalas espaciais e o papel do ambiente e do espaço na substituição de espécies. Ao todo foram registradas 86 espécies, contemplando 22% do pool de espécies da região sul para esta formação. A partição aditiva da diversidade revelou que a diversidade beta é significativa apenas na maior escala para ambos os estratos. Pela Análise de Redundância parcial, o espaço foi responsável pela maior fração de explicação (21%) para o estrato inferior, enquanto para o superior, o ambiente estruturado pelo espaço obteve a maior fração de explicação (36%). Sugere-se que para o estrato inferior algumas espécies da encosta apresentam limitação de dispersão em relação à distância das áreas da encosta ou mesmo pelo padrão de deposição de diásporos pelos dispersores. Para o estrato superior, a relação do ambiente com o espaço está na distância entre as áreas e como ela atua na variação do ambiente, sendo a distância destas em relação ao mar provavelmente a variável mais correlacionada, pois esta influencia a temperatura e o regime de chuvas. / Distinct patterns of species composition and diversity can be observed throughout communities that change in relation to environment and geographic position, making possible to identify potential indicator species of these changes. Several studies on species diversity variation have demonstrated the influence of environmental conditions (niche theory) and / or dispersal limitation (neutral theory), with different proportions of explanation. This thesis emphasizes tree specificity in southern Atlantic forest and some patterns of beta diversity variation in Araucaria forests in northeastern Rio Grande do Sul. In the approach of species specificity, we analyzed environmental and spacial gradients from 21 studies covering different forest types: Restinga forest (3), Tropical Rainforest (7), Araucaria forest (8) and Cloud forest (3). We observed different richness levels and different indicator species for each forest type. Furthermore, altitude was the main environmental variable associated to the floristic patterns observed in this study, which form a continuum of species turnover along the gradient. For the approach of beta diversity, quantitative surveys of the inferior and superior strata were taken out in three conservation units of Araucaria forest, where additive diversity partitioning were exploited in different spatial scales, as well as the role of environment variables and the space in species turnover. Altogether, 86 species were recorded, comprising 22% of the southern region species pool for this forest type. The additive partitioning revealed that beta diversity is significant only in larger scale for both strata. Through partial Redundancy Analyses, the space was responsible for the largest fraction of explanation (20.70%) for the inferior stratum, while the environment structured by space had the most fraction of explanation (36.43%) for the superior one. It is suggested that some colonizing species from the inferior stratum show dispersal limitation in relation to distance from the slope or even due to seeds deposition patterns. For the superior stratum, the presented relationship between environment and space seems to indicate that the distance between areas acts on the environmental variation, where the sea distance is probably the most correlated variable, since it affects temperature and rainfall.

Distintos padrões de composição e diversidade de espécies podem ser observados ao longo de comunidades que variam em relação ao ambiente e à posição geográfica, sendo possível a identificação de potenciais espécies indicadoras destas mudanças. Diversos estudos sobre a variação na diversidade de espécies têm demonstrado a influência de condições ambientais (teoria de nicho) e/ou da limitação na dispersão (teoria neutra), com diferentes proporções de explicação. Esta dissertação aborda a especificidade de espécies arbóreas no sudeste da Mata Atlântica e alguns padrões de variação da diversidade beta em Florestas com Araucária, na região nordeste do Rio Grande do Sul. Na abordagem de especificidade de espécies, analisamos um gradiente ambiental e espacial a partir de 21 trabalhos abrangendo diferentes tipologias florestais: Floresta de Restinga (3), Floresta Ombrófila Densa (7), Floresta Ombrófila Mista (8) e Floresta Nebular (3). Foram observados diferentes níveis de riqueza e de espécies indicadoras para cada tipo florestal. Além disso, a altitude foi a principal variável ambiental associada aos padrões florísticos observados neste estudo, que formam um continuum de substituição de espécies ao longo do gradiente. Para a abordagem da diversidade beta, foram realizados levantamentos quantitativos do estrato inferior e superior em três áreas de conservação de Floresta com Araucária, onde foram explorados a partição aditiva da diversidade em diferentes escalas espaciais e o papel do ambiente e do espaço na substituição de espécies. Ao todo foram registradas 86 espécies, contemplando 22% do pool de espécies da região sul para esta formação. A partição aditiva da diversidade revelou que a diversidade beta é significativa apenas na maior escala para ambos os estratos. Pela Análise de Redundância parcial, o espaço foi responsável pela maior fração de explicação (21%) para o estrato inferior, enquanto para o superior, o ambiente estruturado pelo espaço obteve a maior fração de explicação (36%). Sugere-se que para o estrato inferior algumas espécies da encosta apresentam limitação de dispersão em relação à distância das áreas da encosta ou mesmo pelo padrão de deposição de diásporos pelos dispersores. Para o estrato superior, a relação do ambiente com o espaço está na distância entre as áreas e como ela atua na variação do ambiente, sendo a distância destas em relação ao mar provavelmente a variável mais correlacionada, pois esta influencia a temperatura e o regime de chuvas. / Distinct patterns of species composition and diversity can be observed throughout communities that change in relation to environment and geographic position, making possible to identify potential indicator species of these changes. Several studies on species diversity variation have demonstrated the influence of environmental conditions (niche theory) and / or dispersal limitation (neutral theory), with different proportions of explanation. This thesis emphasizes tree specificity in southern Atlantic forest and some patterns of beta diversity variation in Araucaria forests in northeastern Rio Grande do Sul. In the approach of species specificity, we analyzed environmental and spacial gradients from 21 studies covering different forest types: Restinga forest (3), Tropical Rainforest (7), Araucaria forest (8) and Cloud forest (3). We observed different richness levels and different indicator species for each forest type. Furthermore, altitude was the main environmental variable associated to the floristic patterns observed in this study, which form a continuum of species turnover along the gradient. For the approach of beta diversity, quantitative surveys of the inferior and superior strata were taken out in three conservation units of Araucaria forest, where additive diversity partitioning were exploited in different spatial scales, as well as the role of environment variables and the space in species turnover. Altogether, 86 species were recorded, comprising 22% of the southern region species pool for this forest type. The additive partitioning revealed that beta diversity is significant only in larger scale for both strata. Through partial Redundancy Analyses, the space was responsible for the largest fraction of explanation (20.70%) for the inferior stratum, while the environment structured by space had the most fraction of explanation (36.43%) for the superior one. It is suggested that some colonizing species from the inferior stratum show dispersal limitation in relation to distance from the slope or even due to seeds deposition patterns. For the superior stratum, the presented relationship between environment and space seems to indicate that the distance between areas acts on the environmental variation, where the sea distance is probably the most correlated variable, since it affects temperature and rainfall.