<p>Rich fens are an important, but threatened, habitat type in the boreal landscape. In this thesis I have examined responses of rich fen vascular plants and bryophytes after drainage and restoration. </p><p>The effects of drainage on the rich fen flora were observed in a long time study and the responses were rapid and drastic. During an initial stage a rapid loss of brown mosses was observed, followed by increases of sedges and early successional bryophytes, and later by an expansion of dominants. Initial effects of hydrological restoration showed that rewetting can promote re-establishment of an ecologically functional rich fen flora, but has to be combined with other treatments, such as mowing or surface disturbance. </p><p>After restoration, re-establishment of locally extinct species may be hampered by dispersal limitations. To test if reintroductions could help to overcome dispersal limitations I performed transplantation studies with four common rich fens bryophytes to a rewetted site. The results showed that the species were able to establish, and that survival and growth were promoted by desiccation protection and liming. </p><p>I further examined competition among three of the most common bryophytes in natural boreal rich fens that usually occur mixed in a mosaic pattern but show small but important microtopographical niche separation. The results indicate similar competitive abilities among the species, and no case of competitative exclusion occurred. The results help to explain the coexistence of these species under natural conditions with microtopographic variation and repeated small scale natural disturbances. </p><p>Restoring a functional flora in drained rich fens is a complex task, which requires understanding of underlying causes of substrate degradation in combination with suitable restoration measures. The thesis suggests how the results can be used in practical restoration work, and also stresses the need for monitoring of restoration experiments over longer time. </p>

Rich fens are an important, but threatened, habitat type in the boreal landscape. In this thesis I have examined responses of rich fen vascular plants and bryophytes after drainage and restoration. The effects of drainage on the rich fen flora were observed in a long time study and the responses were rapid and drastic. During an initial stage a rapid loss of brown mosses was observed, followed by increases of sedges and early successional bryophytes, and later by an expansion of dominants. Initial effects of hydrological restoration showed that rewetting can promote re-establishment of an ecologically functional rich fen flora, but has to be combined with other treatments, such as mowing or surface disturbance. After restoration, re-establishment of locally extinct species may be hampered by dispersal limitations. To test if reintroductions could help to overcome dispersal limitations I performed transplantation studies with four common rich fens bryophytes to a rewetted site. The results showed that the species were able to establish, and that survival and growth were promoted by desiccation protection and liming. I further examined competition among three of the most common bryophytes in natural boreal rich fens that usually occur mixed in a mosaic pattern but show small but important microtopographical niche separation. The results indicate similar competitive abilities among the species, and no case of competitative exclusion occurred. The results help to explain the coexistence of these species under natural conditions with microtopographic variation and repeated small scale natural disturbances. Restoring a functional flora in drained rich fens is a complex task, which requires understanding of underlying causes of substrate degradation in combination with suitable restoration measures. The thesis suggests how the results can be used in practical restoration work, and also stresses the need for monitoring of restoration experiments over longer time.

<p>In Sweden today, deciduous woodlands are often restricted to small isolated remnants of what it once was. Managing practices have changed concerning both cattle grazing and logging. Thus, dispersal, habitat requirements and their importance for forest species distributions become a relevant issue. Most of the species found in the deciduous flora are perennial herbs. I have examined population dynamics in the forest perennial <i>Sanicula europaea</i>, and its relation to environmental factors such as grazing, competition and spatial and temporal variation in such factors. Moreover I examined species distributions in relation to dispersal and habitat suitability in <i>S. europaea</i> and<i> Dentaria bulbifera</i>. To understand mechanisms behind the observed patterns I performed a number of experiments.</p><p>The results clearly demonstrated that the distribution and abundance of <i>S. europaea</i> was not dispersal limited, whereas the opposite held true for <i>D. bulbifera. Moreover</i>, mollusc exclusion increased recruitment thus influencing population dynamics in <i>D. bulbifera</i>. Leaf losses had negative effects on <i>S. europaea</i> individuals. These negative effects depended both on the extent, frequency and timing of the leaf losses and early losses were more severe than late. Population level effects of grazing were not negative as negative direct effects were counterblanced by positive indirect effects. The positive effects of grazing were mainly in terms of an increased recruitment. </p><p>In<i> S. europaea</i>, high variation in a life cycle transition was always coupled to low elasticity, and traits that varied much due to the examined environmental factors had little importance to population growth rate. A population level perspective is required to assess total effects of environmental factors. In perennial organisms such evaluations need to calculate integrated measures of the effects over the entire life cycle. Field studies spanning several years and demographic models are important to achieve these objectives.</p>

In Sweden today, deciduous woodlands are often restricted to small isolated remnants of what it once was. Managing practices have changed concerning both cattle grazing and logging. Thus, dispersal, habitat requirements and their importance for forest species distributions become a relevant issue. Most of the species found in the deciduous flora are perennial herbs. I have examined population dynamics in the forest perennial Sanicula europaea, and its relation to environmental factors such as grazing, competition and spatial and temporal variation in such factors. Moreover I examined species distributions in relation to dispersal and habitat suitability in S. europaea and Dentaria bulbifera. To understand mechanisms behind the observed patterns I performed a number of experiments. The results clearly demonstrated that the distribution and abundance of S. europaea was not dispersal limited, whereas the opposite held true for D. bulbifera. Moreover, mollusc exclusion increased recruitment thus influencing population dynamics in D. bulbifera. Leaf losses had negative effects on S. europaea individuals. These negative effects depended both on the extent, frequency and timing of the leaf losses and early losses were more severe than late. Population level effects of grazing were not negative as negative direct effects were counterblanced by positive indirect effects. The positive effects of grazing were mainly in terms of an increased recruitment. In S. europaea, high variation in a life cycle transition was always coupled to low elasticity, and traits that varied much due to the examined environmental factors had little importance to population growth rate. A population level perspective is required to assess total effects of environmental factors. In perennial organisms such evaluations need to calculate integrated measures of the effects over the entire life cycle. Field studies spanning several years and demographic models are important to achieve these objectives.

Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T17:18:37Z No. of bitstreams: 1 SILVA_Vanessa Mariano_2015.pdf: 1028554 bytes, checksum: b983689081dffe8a634db905adc7c152 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T17:19:59Z (GMT) No. of bitstreams: 1 SILVA_Vanessa Mariano_2015.pdf: 1028554 bytes, checksum: b983689081dffe8a634db905adc7c152 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T17:20:07Z (GMT) No. of bitstreams: 1 SILVA_Vanessa Mariano_2015.pdf: 1028554 bytes, checksum: b983689081dffe8a634db905adc7c152 (MD5) / Made available in DSpace on 2017-01-12T17:20:15Z (GMT). No. of bitstreams: 1 SILVA_Vanessa Mariano_2015.pdf: 1028554 bytes, checksum: b983689081dffe8a634db905adc7c152 (MD5) Previous issue date: 2015-12-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Plant recruitment can be constrained by seed and establishment limitation and these processes can affect community species composition and diversity. In Neotropical savannas the relative importance of these processes for plant regeneration are unclear because of the scarcity of studies. The aim of this study was to evaluate the importance of seed and establishment limitation to plant recruitment on cerrado savanna in Itirapina, southeast Brazil (22°12´S, 47°52´W). We spread 49 seed traps in a 0.64-ha plot and monitored seed rain monthly for a year, and also conducted seed addition experiments. Seed production presented a peak in rainy season, with zoochoric and anemochoric species producing seeds mainly in rainy and dry season respectively. Our study indicates a strong influence of seed limitation on recruitment, with most seed rain species presenting seed limitation values higher than 65%. Only 23% of woody species in the plot had at least one seed trapped. Seed and source limitation was negative related to adult abundance, indicating that the increase of seed sources enhances the number of suitable sites reached by seeds. There was no relation between seed, source and dispersal limitation and plant life form, dispersal syndrome and seed mass. Seed addition was unable to increase seedling regeneration in the four species tested, which presented high values of establishment limitation. Our study shows that Neotropical savanna plants recruitment is restricted by seed and establishment limitation and highlights the role of seed production and dispersal to colonization of new sites. / O recrutamento de plantas pode ser restringido pelas limitações de sementes e no estabelecimento, os quais afetam a composição e diversidade de uma comunidade. Em savanas neotropicais a importância relativa desses processos ainda não é clara em decorrência da falta de estudos. O objetivo desse estudo foi avaliar a importância das limitações de sementes e no estabelecimento para o recrutamento de uma comunidade de cerrado no sudeste do Brasil. Foram posicionados 49 coletores de sementes em uma parcela de 0,64 ha e a chuva de sementes foi monitorada mensalmente durante um ano. Além disso, foram realizados experimentos de adição de sementes. A produção de sementes apresentou um pico durante a estação chuvosa, sendo que as espécies zoocóricas produziram principalmente durante a estação chuvosa e as anomocóricas, durante a estação seca. Houve uma influência significativa da limitação de sementes no recrutamento, sendo que a maioria das espécies presentes na chuva de sementes apresentou valores dessa limitação maiores que 65%. Apenas 23% das espécies arbustivo-arbóreas presentes na parcela tiveram, pelo menos, uma semente coletada. As limitações de sementes e na fonte apresentaram uma relação negativa com o número de adultos, indicando que o aumento de fontes de sementes eleva o número de locais atingidos por sementes. Não houve relação entre limitações de sementes, na fonte e na dispersão com forma de vida, síndrome de dispersão e peso da semente. A adição de sementes não aumentou a regeneração de plântulas das quatro espécies testadas, as quais apresentaram valores elevados de limitação no estabelecimento. O presente estudo indica que o recrutamento de plantas de savanas neotropicais é restringido pelas limitações de sementes e no estabelecimento e ressalta a importância da produção e dispersão de sementes para a colonização de novos locais.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-09-23T10:56:00Z No. of bitstreams: 2 Dissertação - Barbbara da Silva Rocha - 2016.pdf: 2351043 bytes, checksum: d95e10f7a1753a91ecc8fa4dfc41a698 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-26T12:08:34Z (GMT) No. of bitstreams: 2 Dissertação - Barbbara da Silva Rocha - 2016.pdf: 2351043 bytes, checksum: d95e10f7a1753a91ecc8fa4dfc41a698 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-26T12:08:34Z (GMT). No. of bitstreams: 2 Dissertação - Barbbara da Silva Rocha - 2016.pdf: 2351043 bytes, checksum: d95e10f7a1753a91ecc8fa4dfc41a698 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / One of the main focuses of ecology and biogeography has been better understanding as historical factors, environmental factors and dispersal ability influence the pattern of species distribution. Besides the environmental conditions and space being considered important components to control the variation in communities, another factor that can influence the beta diversity, but has been little studied, is the land use type. We aimed determine the relative influence of local, spatial components (directional and non-directional) and land use in the taxonomic and functional composition of phytoplankton and zooplankton communities in tropical reservoirs. Data was collected in 25 sampling points in reservoirs in the Rio Preto Basin, which is located in the Federal District-DF, Brazil. We performed a partial redundancy analysis to determine the influence of each component. The space was the only component with significant influence over the two groups (phytoplankton and zooplankton) and both approaches. Local variables had no significant influence on the variation of the communities, as well as the land use. Given the importance of space in the analyzed communities, we applied a protocol based on an spatial autocorrelation analysis, which indicated that the spatial pattern of the communities could be purely associated with dispersal by neutral factors. Our results demonstrated that the spatial component can be significant even in small scale studies to organisms with passive dispersal. Furthermore, it is important consider the connectivity among the environments in investigations with these microorganisms. as well as the use of the functional approach for studies of planktonic distribution, because of it show patterns similar to those found in the taxonomic approach. / Um dos principais focos da ecologia e biogeografia tem sido conhecer melhor como fatores históricos, ambientais e a capacidade de dispersão das espécies influenciam no padrão da distribuição das mesmas. Além das condições ambientais e do espaço serem considerados importantes componentes ao controlar a variação nas comunidades, outro fator que também pode influenciar a diversidade beta em ambientes aquáticos é o tipo de uso de solo. O objetivo do presente trabalho é determinar a influência relativa dos componentes locais, espaciais (direcional e não-direcional) e de uso de solo na composição taxonômica e funcional das comunidades fitoplanctônicas e zooplanctônicas em reservatórios tropicais. Os dados foram coletados em 25 pontos amostrais em reservatórios na Bacia do Rio Preto, que está localizada no Distrito Federal- DF, Brasil. Para determinar a influência relativa dos componentes realizamos uma análise de redundância parcial. O espaço foi o único componente com influência significativa sobre os dois grupos (fitoplanctônico e zooplanctônico) em ambas abordagens. As variáveis locais não apresentaram influência significativa sobre a variação das comunidades, assim como o tipo de uso de solo. Devido ao importante papel apresentado pelo espaço nas comunidades analisadas, foi aplicado um protocolo baseado em uma análise de autocorrelação espacial, na qual demonstrou que o padrão espacial das comunidades poderia ser associado puramente a fatores neutros de dispersão. Nossos resultados demonstraram que o componente espacial pode ser significativo mesmo em estudos de pequenas escalas para organismos com dispersão passiva. Além disso, é importante considerar a conectividade dentre os ambientes em investigações com esses microrganismos, bem como a utilização da abordagem funcional para estudos sobre a distribuição planctônica, pelo fato da mesma demonstrar padrões semelhantes aos encontrados na abordagem taxonômica.

Species assembly into local communities from the surrounding region can be caused either by species failure to reach the site (i.e. seed limitation) or to establish (i.e. establishment limitation). The aim of this thesis was to investigate plant species assembly and to determine the relative importance of different factors in that process. In a cultivated landscape in southeast Sweden, plant community assembly was studied in grazed ex-arable fields. Community assembly from the surrounding region into the local community was explored using trait-based null models and seed sowing and transplanting experiments. The influence of local environmental factors and landscape history and structure on community assembly was also studied. In addition, differences in species assembly between ex-arable fields and semi-natural grasslands were explored. Seed limitation was the strongest filter on local community assembly. Only a fraction (36%) of species in a region dispersed to a local site and adding seeds/transplants increased species establishment. Species abundance at the regional scale, species dispersal method and seed mass strongly influenced which species arrived at the local sites. Establishment limitation also affected the assembly. Of species arriving at a site 78% did establish, seedling survival was low and which species established was influenced by species interactions, local environmental conditions and stochastic events. In addition, landscape structure that determined the species richness in the regional species pool influenced the local assembly. The comparison between assembly in ex-arable fields and semi-natural grasslands indicated that the main cause of difference in species assembly between them was difference in their age. The main conclusion of this thesis is that regional processes are more important than local factors in determining plant community assembly. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Submitted. Paper 5: Manuscript.</p>

To assess the status of a rare plant species, we must first understand the factors that affect the size of populations and their numbers. In this thesis, I study processes affecting plant species prosperity on local scale (paper 1), factors influencing species distribution in landscape and ability of species to colonize new habitats (paper 2) and species traits responsible for gene flow between established populations (paper 3). Since I work with rare plants, I also aim to turn theoretical knowledge into practical recommendations for nature conservation (paper 4) to help effectively preserve rare and endangered species. In the first 3 papers, I work with two rare fern species restricted to serpentine rocks, Asplenium adulterinum and A. cuneifolium, in a study system covering 10 × 10 km. I found that both species are long living (several decades) and in the study region, populations are in a good state and slowly growing. Even very small populations (10 individuals) have quite high chance to survive. In both fern species, I found dispersal limitation, which might be surprising regarding huge production of small spores in ferns (paper 2). The species differ in ploidy and thus, also mating system. A. adulterinum is tetraploid and its main breeding system is intragametophytic selfing. A. cuneifolium is...

There are generally two contrasting alternatives to what limits recruitment in plants, namely the availability of seeds (seed limitation) or the quality or quantity of suitable sites (microsite limitation). Dust seeds, the smallest existing seeds, lack or have minimal nutrient reserves. During germination and initial development they consequently parasitize on mycorrhizal fungi. This is called mycoheterotrophy, and can vary in degree of fungal dependency in adult plants from full, partial or initial mycoheterotrophy. The aim of this thesis was to investigate the recruitment ecology of mycoheterotrophic Ericaceae (tribe Pyroleae) species with dust seeds, and to determine what limits their recruitment. The investigated species were: Chimaphila umbellata, Moneses uniflora, Orthilia secunda, Pyrola chlorantha, P. minor and P. rotundifolia. This aim was achieved by combining field experiments (seed sowing) with isotope analysis and fungal host pyrosequencing. Results provide evidence that the species in Pyroleae are heterogeneous, not only with regard to their degree of mycoheterotrophy, but also concerning germination and early seedling development. A combination of microsite and seed limitation is thus likely to be of importance for all studied species, but the relative importance of these limitations varies among species. Despite having adaptations for wind dispersal the majority of the seeds were deposited in close vicinity of the seed source. But with high seed production at least some seeds should be able to disperse long-distance. Seedlings of all studied species were found to associate with a wide range of ectomycorrhizal fungi, at least during their initial developmental stages. There seems to be a tendency for host narrowing in some Pyroleae species, but not as strict as the host specialization seen in fully mycoheterotrophic Monotropa hypopitys, supporting the hypothesis of geographical and developmental host shifts. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.</p>

Submitted by Lara Gomes Melchior null (lahtuti@hotmail.com) on 2016-04-14T21:11:04Z No. of bitstreams: 1 Mestrado Lara Versão Final.pdf: 949503 bytes, checksum: 2675776db95f4fd4b4d6542497c65b45 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-15T13:12:06Z (GMT) No. of bitstreams: 1 melchior_lg_me_sjrp.pdf: 949503 bytes, checksum: 2675776db95f4fd4b4d6542497c65b45 (MD5) / Made available in DSpace on 2016-04-15T13:12:06Z (GMT). No. of bitstreams: 1 melchior_lg_me_sjrp.pdf: 949503 bytes, checksum: 2675776db95f4fd4b4d6542497c65b45 (MD5) Previous issue date: 2016-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A escolha da unidade amostral e extensão da área de estudo é crucial para a compreensão dos processos e mecanismos influenciando os padrões de distribuição da biodiversidade. Dependendo da escala espacial escolhida, os padrões de distribuição serão influenciados por processos ecológicos e biogeográficos diferentes. Neste trabalho, nós alternamos as unidades amostrais e extensões da área estudada (corpos d’água em um município, corpos d’água em uma ecoregião, municípios em uma ecoregião e municípios na área total de estudo) para avaliar a importância relativa das variáveis ecológicas e biogeográficas na diversidade beta de anuros na Floresta Atlântica Brasileira. Para isso, nós parcionamos a diversidade beta total nos componentes substituição espacial de espécies e aninhamento. Nós observamos que, mantendo a mesma unidade amostral e aumentando a extensão da área de estudo, os valores da substituição espécies aumentam. Por outro lado, mantendo a mesma extensão e aumentando a unidade amostral, os valores da substituição de espécies diminuem. Além disso, nossos resultados concordam que a importância relativa dos fatores ecológicos e biogeográficos na diversidade beta de anuros é dependente da escala espacial. Considerando as menores unidade amostral e extensão, as variáveis ambientais e distância geográfica se alternam na importância relativa associada aos valores de diversidade beta, enquanto que, em escalas espaciais maiores, as ecoregiões passam a ter uma importância relativa maior. / The selection of the sampling unit and extension of the study area is crucial for understanding the processes and mechanisms influencing biodiversity distribution patterns. Depending on the chosen scale, patterns of distribution will be influenced by different ecological and biogegraphical processes. Here, we alternate the sample units and extensions of the study area (water bodies in a municipality, water bodies in an ecoregion, municipalities in an ecoregion, and municipalities in total area of study) to assess the relative importance of ecological and biogeographical factors in the beta diversity of frogs in the Brazilian Atlantic Forest. We partitioned total beta diversity into two additive components, spatial species turnover and nestedness. We found that considering the same sample unit and increasing the extent of the study area the turnover values increased. On the other hand, considering the same extension and increasing the sampling unit, the turnover values decreased. Furthermore, our results agree that relative importance of the ecological and biogeographical processes in frog beta diversity is dependent on spatial scales. Considering the smallest sampling unit and extension, environmental variables and geographic distance alternated in their relative importance associated with beta diversity, while at largest spatial scales, ecoregions showed higher values of relative importance.