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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Produção e consumo de frutos zoocóricos em dois fragmentos florestais do oeste do Rio Grande do Norte, Brasil. / Production and consumption of fruits zoochorous in two forest fragments in the west of Rio Grande do Norte, Brazil.

Torquato, Jânio Lopes 26 February 2015 (has links)
Made available in DSpace on 2016-08-31T13:19:25Z (GMT). No. of bitstreams: 1 JanioLT_DISSERT.pdf: 2434239 bytes, checksum: 49254b87885eb32f1754da2c513afabd (MD5) Previous issue date: 2015-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The availability of fleshy fruits in forest fragments is essential for the survival of many animal species. The disadvantage of small fragments to native wildlife is the decrease in fleshy fruits availability, especially in the period of food shortage. Together with the food shortage period there is an environmental factor, rainfall, which directly influences the production of fruits zoochorous, and consequently in the diet and survival of fauna. The goal of this study was to compare the production and consumption of fruits zoochorous in forest fragments in the western of Rio Grande do Norte state. The study took place in two forest fragments: Parque Nacional da Furna Feia PARNA Furna Feia (8.517ha) and Trilha dos Polinizadores TRIPOL (26ha), from June 2013 to July 2014. The data collection was done every 15 days in pre-established trails in forest fragments. The counting of ripe fruit zoochorous in forest fragments was done in two ways: estimation and absolute. The diet of the animals was analyzed by feces collected on the trails and screened in the ECOMOL/UFERSA lab. The frugivorous animals were recorded with the help of the trap camera and some Caatinga native fruit were placed in front camera. The data of rainfall were obtained from the National Institute of Meteorology INMET. In total, 270 individuals were recorded fruiting, 13 zoochorous specie and nine botanical families. Considering the 13 species recorded zoochorous, only 11 were fruitful, 10 in the rainy season. The accumulated abundance of ripe fruit registered at the TRIPOL (n = 36,494; 15.7 fruits/m²) was higher than in PARNA Furna Feia (n = 27 168; 3.7 fruits/m²). At TRIPOL, the species which produced more fruits were: Spondias tuberosa, Ziziphus joazeiro, Lantana camara, Tournefortia volubilis and Phoradendron affine. At PARNA Furna Feia, the species which produced more fruits were: Ziziphus joazeiro and Commiphora leptophloeos. The relationship between the abundance of zoochorous fruit and the precipitation was significant at TRIPOL (rs = 0.5438, p = 0.0041), but there was no significant relation at PARNA Furna Feia (rs = 0.1973, p = 0.3337). There was no significant relation between the abundance of zoochorous fruit and the number of seeds registered in the feces. In them, 666 seeds were registered at TRIPOL and 4.281 seeds at PARNA Furna Feia. Considering the total number of seed found in the feces, the species T. volubilis and Sideroxylon obtusifolium represented 55,2% and 72,2% of total seed, respectively in each fragment analyzes. The animals recorded by the trap cameras consuming the fruit-baits in forest fragments were Tupinambis merianae, Ameiva ameiva, Turdus rufiventris, Mimus saturninus, Coereba flaveola, Cyanocorax cyanopogon, Cerdocyon thous and Callithrix jacchus. Cerdocyon thous and Cyanocorax cyanopogon were the two species which most consumed the fruit-baits of Copernicia prunifera and Cereus jamacaru, respectively. The species C. thous and C. cyanopogon can be important seed dispersers in forest fragments of the Caatinga. The fruits of species T. volubilis and S. obtusifolium are important food source for fauna, especially S. obtusifolium which offers ripe fruit during fleshy fruit shortage period / A disponibilidade de frutos carnosos em fragmentos florestais é essencial para a sobrevivência de diversas espécies da fauna. A desvantagem dos pequenos fragmentos para a fauna nativa é a diminuição da abundância de frutos carnosos ao longo do tempo, principalmente no período de escassez de alimentos. Junto ao período de escassez de alimento há um fator ambiental, a precipitação pluviométrica, que influencia diretamente na produção de frutos de plantas zoocóricas e, consequentemente, na dieta e sobrevivência da fauna. O objetivo deste estudo foi comparar a produção e o consumo de frutos zoocóricos em fragmentos florestais no oeste potiguar nordestino. O estudo foi realizado em dois fragmentos florestais: Parque Nacional da Furna Feia PARNA Furna Feia (8.517ha) e a Trilha dos Polinizadores TRIPOL (26ha), durante junho de 2013 a julho de 2014. A coleta de dados foi realizada a cada 15 dias em trilhas pré-estabelecidas nos fragmentos florestais. A contagem dos frutos zoocóricos maduros nos fragmentos florestais foi realizada de duas formas: estimativa e absoluta. A dieta dos animais foi analisada por meio de fezes coletadas nas trilhas e triadas no laboratório ECOMOL/UFERSA. Os animais frugívoros foram registrados com o auxílio da câmera armadilha utilizando frutos de espécies nativas da Caatinga como isca. Os dados de precipitação pluviométrica foram obtidos no Instituto Nacional de Meteorologia INMET. No total foram registrados 270 indivíduos frutificando, sendo 13 espécies zoocóricas e nove famílias botânicas. Das 13 espécies zoocóricas foram registradas 11 que produziram frutos, sendo que 10 frutificaram no período chuvoso. A abundância absoluta acumulada de frutos maduros registrados na TRIPOL (n = 36.494; 15,7 frutos/m²) foi maior do que no PARNA Furna Feia (n = 27.168; 3,7 frutos/m²). Na TRIPOL, as espécies que produziram mais frutos foram: Spondias tuberosa, Ziziphus joazeiro, Lantana camara, Tournefortia volubilis e Phoradendron affine. No PARNA Furna Feia, as espécies que produziram mais frutos foram: Ziziphus joazeiro e Commiphora leptophloeos. A relação entre a abundância de frutos zoocóricos e a precipitação pluviométrica foi significativa na TRIPOL (rs = 0,5438; p = 0,0041), mas não houve relação significativa no PARNA Furna Feia (rs = 0,1973; p = 0,3337). Não houve relação significativa entre a abundância de frutos zoocóricos e o número de sementes registradas nas fezes. No total de amostras de fezes coletadas e analisadas foram registradas 666 sementes na TRIPOL e 4.281 sementes no PARNA Furna Feia. Do total de sementes encontradas nas fezes, as espécies T. volubilis e Sideroxylon obtusifolium representaram 55,2% e 72,2% do total de sementes, respectivamente. Os animais registrados pelas câmeras armadilha consumindo os frutos iscas nos fragmentos floretais foram: Tupinambis merianae, Ameiva ameiva, Turdus rufiventris, Mimus saturninus, Coereba flaveola, Cyanocorax cyanopogon, Cerdocyon thous e Callithrix jacchus. A C. thous e a C. cyanopogon foram as duas espécies que mais consumiram os frutos isca da Copernicia prunifera e do Cereus jamacaru, respectivamente. As espécies C. thous e o C. cyanopogon podem ser importantes dispersores de sementes em fragmentos florestais. Os frutos das espécies T. volubilis e S. obtusifolium são importantes fonte de alimento para a fauna em fragmentos florestais de Caatinga, com destaque para S. obtusifolium que disponibiliza frutos maduros durante o período de escassez de frutos carnosos
2

Adaptation and Constraint in the Plant Reproductive Phase

Bolmgren, Kjell January 2004 (has links)
<p>Conservatism is a central theme of organismic evolution. Related species share characteristics due to their common ancestry. Some concern have been raised among evolutionary biologists, whether such conservatism is an expression of natural selection or of a constrained ability to adapt.</p><p>This thesis explores adaptations and constraints within the plant reproductive phase, particularly in relation to the evolution of fleshy fruit types (berries, drupes, etc.) and the seasonal timing of flowering and fruiting. The different studies were arranged along a hierarchy of scale, with general data sets sampled among seed plants at the global scale, through more specific analyses of character evolution within the genus <i>Rhamnus </i>s.l. L. (Rhamnaceae), to descriptive and experimental field studies in a local population of <i>Frangula alnus</i> (Rhamnaceae). Apart from the field study, this thesis is mainly based on comparative methods explicitly incorporating phylogenetic relationships. The comparative study of <i>Rhamnus</i> s.l. species included the reconstruction of phylogenetic hypotheses based on DNA sequences.</p><p>Among geographically overlapping sister clades, biotic pollination was not correlated with higher species richness when compared to wind pollinated plants. Among woody plants, clades characterized by fleshy fruit types were more species rich than their dry-fruited sister clades, suggesting that the fleshy fruit is a key innovation in woody habitats. Moreover, evolution of fleshy fruits was correlated with a change to more closed (darker) habitats.</p><p>An independent contrast study within <i>Rhamnus</i> s.l. documented allometric relations between plant and fruit size. As a phylogenetic constraint, allometric effects must be considered weak or non-existent, though, as they did not prevail among different subclades within <i>Rhamnus</i> s.l. Fruit size was correlated with seed size and seed number in <i>F. alnus</i>. This thesis suggests that frugivore selection on fleshy fruit may be important by constraining the upper limits of fruit size, when a plant lineage is colonizing (darker) habitats where larger seed size is adaptive.</p><p>Phenological correlations with fruit set, dispersal, and seed size in <i>F. alnus</i>, suggested that the evolution of reproductive phenology is constrained by trade-offs and partial interdependences between flowering, fruiting, dispersal, and recruitment phases. Phylogenetic constraints on the evolution of phenology were indicated by a lack of correlation between flowering time and seasonal length within <i>Rhamnus cathartica</i> and <i>F. alnus</i>, respectively. On the other hand, flowering time was correlated with seasonal length among <i>Rhamnus</i> s.l. species. Phenological differences between biotically and wind pollinated angiosperms also suggested adaptive change in reproductive phenology.</p> / <p>Äpplet faller inte långt från trädet. Men varför? Den biologiska mångfalden präglas i stor utsträckning av fylogenetiskt bevarade karaktärsdrag; närbesläktade arter är lika. Det pågår en diskussion bland evolutionsbiologer om i vilken utsträckning denna konservatism är ett resultat av naturlig selektion eller av en begränsad anpassningsförmåga.</p><p>Denna avhandling diskuterar begreppet evolutionära begränsningar i relation till den reproduktiva fasen hos växter. I fokus ligger särskilt evolutionen av bärliknande (endozoochora) frukter respektive evolutionen av säsongsmässiga mönster (fenologi) för blomning och fruktsättning. Avhandlingen är hierarkiskt organiserad så att olika delstudier gjordes på olika skalnivåer: fenologi- och fruktevolution analyserades för fröväxter respektive gömfröiga växter; inom brakvedssläktena Rhamnus och Frangula (Rhamnaceae); samt för en lokal population av brakved (Frangula alnus). Populationsstudien baserades på såväl experimentella som deskriptiva data, medan övriga studier i huvudsak genomfördes med fylogenetisk komparativ metodik baserade på litteraturdata. Som en del av de komparativa studierna rekonstruerades fylogenetiska hypoteser för Rhamnus s.l. utifrån DNA-sekvenser (ITS, trnL-F), vilka gav stöd för att Frangula och Rhamnus är monofyletiska systersläkten.</p><p>I en biogeografiskt kontrollerad fylogenetisk kontrastanalys upptäcktes inga skillnader i artrikedom mellan djur- och vindpollinerade växter. Bärliknande frukter verkar dock vara en betydelsefull karaktär (key innovation) i skogsmiljöer. För det första var fylogenetiska klader med bärliknande frukter mer artrika än systerklader med torra frukter. Dessutom var uppkomster av bärliknande frukt korrelerad till habitat med mer sluten vegetation.</p><p>En fylogenetisk kontrastanalys av allometriska effekter visade på en positiv korrelation mellan växtindividens och fruktens storlek inom Rhamnus s.l. Upprepade analyser av dessa allometriska samband i olika monofyletiska subklader inom Rhamnus s.l. indikerar dock att allometri, såsom evolutionär begränsning, är svag. I populationsstudien av F. alnus var fruktstorlek positivt korrelerad till såväl fröantal som frövikt. En generell hypotes utifrån denna avhandling blir därför att frugivorer (de djur som äter bären och därmed sprider växtens frön) utövar ett starkt selektionstryck på växter som koloniserar ett habitat där fröstorlek är adaptivt, eftersom fruktstorlek påverkar frugivorernas (ssk. fåglars) sätt att hantera frukten.</p><p>Reproduktiv fenologi var korrelerad till fruktsättning, fröspridning och fröstorlek hos F. alnus. Detta stödjer tanken att evolutionen av blomnings- och fruktsättningstider begränsas av avvägningar (trade-offs) och partiella beroenden mellan blomning-, fruktsättnings-, spridnings och rekryteringsfaserna. Inomartsvariation i blomningstid för F. alnus respektive getapel (Rhamnus cathartica) över en nordeuropeisk latitudinell transekt var inte korrelerad till säsongslängd, vilket antyder att utvecklingen av blomningstider är evolutionärt begränsad. Å andra sidan påvisades en sådan korrelation mellan blomningstid och säsongslängd i en mellanartsstudie inom Rhamnus s.l. Den fylogenetiska kontrastanalysen mellan djur- och vindpollinerade växter visade också på adaptiva skillnader i fenologi. Blomningstiderna inom en klad med biotiskt pollinerade arter var mer åtskilda än inom den vindpollinerade systerkladen, och den välkända iakttagelsen att vindpollinerade träd blommor tidigare på säsongen fick även stöd i ett fylogenetiskt komparativt perspektiv.</p>
3

Adaptation and Constraint in the Plant Reproductive Phase

Bolmgren, Kjell January 2004 (has links)
Conservatism is a central theme of organismic evolution. Related species share characteristics due to their common ancestry. Some concern have been raised among evolutionary biologists, whether such conservatism is an expression of natural selection or of a constrained ability to adapt. This thesis explores adaptations and constraints within the plant reproductive phase, particularly in relation to the evolution of fleshy fruit types (berries, drupes, etc.) and the seasonal timing of flowering and fruiting. The different studies were arranged along a hierarchy of scale, with general data sets sampled among seed plants at the global scale, through more specific analyses of character evolution within the genus Rhamnus s.l. L. (Rhamnaceae), to descriptive and experimental field studies in a local population of Frangula alnus (Rhamnaceae). Apart from the field study, this thesis is mainly based on comparative methods explicitly incorporating phylogenetic relationships. The comparative study of Rhamnus s.l. species included the reconstruction of phylogenetic hypotheses based on DNA sequences. Among geographically overlapping sister clades, biotic pollination was not correlated with higher species richness when compared to wind pollinated plants. Among woody plants, clades characterized by fleshy fruit types were more species rich than their dry-fruited sister clades, suggesting that the fleshy fruit is a key innovation in woody habitats. Moreover, evolution of fleshy fruits was correlated with a change to more closed (darker) habitats. An independent contrast study within Rhamnus s.l. documented allometric relations between plant and fruit size. As a phylogenetic constraint, allometric effects must be considered weak or non-existent, though, as they did not prevail among different subclades within Rhamnus s.l. Fruit size was correlated with seed size and seed number in F. alnus. This thesis suggests that frugivore selection on fleshy fruit may be important by constraining the upper limits of fruit size, when a plant lineage is colonizing (darker) habitats where larger seed size is adaptive. Phenological correlations with fruit set, dispersal, and seed size in F. alnus, suggested that the evolution of reproductive phenology is constrained by trade-offs and partial interdependences between flowering, fruiting, dispersal, and recruitment phases. Phylogenetic constraints on the evolution of phenology were indicated by a lack of correlation between flowering time and seasonal length within Rhamnus cathartica and F. alnus, respectively. On the other hand, flowering time was correlated with seasonal length among Rhamnus s.l. species. Phenological differences between biotically and wind pollinated angiosperms also suggested adaptive change in reproductive phenology. / Äpplet faller inte långt från trädet. Men varför? Den biologiska mångfalden präglas i stor utsträckning av fylogenetiskt bevarade karaktärsdrag; närbesläktade arter är lika. Det pågår en diskussion bland evolutionsbiologer om i vilken utsträckning denna konservatism är ett resultat av naturlig selektion eller av en begränsad anpassningsförmåga. Denna avhandling diskuterar begreppet evolutionära begränsningar i relation till den reproduktiva fasen hos växter. I fokus ligger särskilt evolutionen av bärliknande (endozoochora) frukter respektive evolutionen av säsongsmässiga mönster (fenologi) för blomning och fruktsättning. Avhandlingen är hierarkiskt organiserad så att olika delstudier gjordes på olika skalnivåer: fenologi- och fruktevolution analyserades för fröväxter respektive gömfröiga växter; inom brakvedssläktena Rhamnus och Frangula (Rhamnaceae); samt för en lokal population av brakved (Frangula alnus). Populationsstudien baserades på såväl experimentella som deskriptiva data, medan övriga studier i huvudsak genomfördes med fylogenetisk komparativ metodik baserade på litteraturdata. Som en del av de komparativa studierna rekonstruerades fylogenetiska hypoteser för Rhamnus s.l. utifrån DNA-sekvenser (ITS, trnL-F), vilka gav stöd för att Frangula och Rhamnus är monofyletiska systersläkten. I en biogeografiskt kontrollerad fylogenetisk kontrastanalys upptäcktes inga skillnader i artrikedom mellan djur- och vindpollinerade växter. Bärliknande frukter verkar dock vara en betydelsefull karaktär (key innovation) i skogsmiljöer. För det första var fylogenetiska klader med bärliknande frukter mer artrika än systerklader med torra frukter. Dessutom var uppkomster av bärliknande frukt korrelerad till habitat med mer sluten vegetation. En fylogenetisk kontrastanalys av allometriska effekter visade på en positiv korrelation mellan växtindividens och fruktens storlek inom Rhamnus s.l. Upprepade analyser av dessa allometriska samband i olika monofyletiska subklader inom Rhamnus s.l. indikerar dock att allometri, såsom evolutionär begränsning, är svag. I populationsstudien av F. alnus var fruktstorlek positivt korrelerad till såväl fröantal som frövikt. En generell hypotes utifrån denna avhandling blir därför att frugivorer (de djur som äter bären och därmed sprider växtens frön) utövar ett starkt selektionstryck på växter som koloniserar ett habitat där fröstorlek är adaptivt, eftersom fruktstorlek påverkar frugivorernas (ssk. fåglars) sätt att hantera frukten. Reproduktiv fenologi var korrelerad till fruktsättning, fröspridning och fröstorlek hos F. alnus. Detta stödjer tanken att evolutionen av blomnings- och fruktsättningstider begränsas av avvägningar (trade-offs) och partiella beroenden mellan blomning-, fruktsättnings-, spridnings och rekryteringsfaserna. Inomartsvariation i blomningstid för F. alnus respektive getapel (Rhamnus cathartica) över en nordeuropeisk latitudinell transekt var inte korrelerad till säsongslängd, vilket antyder att utvecklingen av blomningstider är evolutionärt begränsad. Å andra sidan påvisades en sådan korrelation mellan blomningstid och säsongslängd i en mellanartsstudie inom Rhamnus s.l. Den fylogenetiska kontrastanalysen mellan djur- och vindpollinerade växter visade också på adaptiva skillnader i fenologi. Blomningstiderna inom en klad med biotiskt pollinerade arter var mer åtskilda än inom den vindpollinerade systerkladen, och den välkända iakttagelsen att vindpollinerade träd blommor tidigare på säsongen fick även stöd i ett fylogenetiskt komparativt perspektiv.
4

Small remnant habitats : Important structures in fragmented landscapes

Lindgren, Jessica January 2017 (has links)
The world-wide intensification of agriculture has led to a decline in species richness due to land use change, isolation, and fragmentation of natural and semi-natural habitats in agricultural and forestry landscapes. As a consequence, there is a current landscape management focus on the importance of green infrastructure to mitigate biodiversity decline and preserve ecosystem functions e.g. pollination services and pest control. Even though intensification in agriculture has been ongoing for several hundreds of years, remnant habitats from earlier management practices may still be remaining with a surprisingly high plant richness. Preserving these habitats could help conserving plant species richness in agricultural landscapes, as well as other organisms that are dependent on plants for food and shelter. In this thesis I focus on two small remnant habitats; midfield islets and borders between managed forest and crop field in southeastern Sweden. In the past, both habitats were included in the grazing system and therefore often still have remnant population of grassland specialist species left today. I have used these two remnant habitats as model habitats to investigate the effect of landscape factors and local factors on species richness of plants, flower morphologies and plants with fleshy fruits. Additively, I analysed the effect of surrounding landscape and local openness on the functions; pollination success, biological pest control of aphids and seed predation on midfield islets. One of my studies showed that spatial distribution and size of the habitat affected plant species richness. Larger habitat size and higher connectivity between habitats increased species richness of plants in the habitats. Openness of the habitats was shown to be an important factor to increase species richness and richness of flower morphologies, both on midfield islets and in forest borders. Even though midfield islets had the highest species and morphology richness, both habitat types are needed for habitat complementary as forest borders have more plants with fleshy fruits and a higher richness of plant species that flowers in spring/early summer. It was also shown that a more complex forest border, not just with gaps in the canopy, but also with high variation in tree stem sizes increases plant species richness in the field layer. The conclusion is that by managing small remnant habitats to remain or become more semi-open and complex in their structure, would increase species richness of plants, grassland specialist species, and flower morphologies. It would also increase some ecosystem functions as seed predation and biologic pest control of aphids are more effective close to trees. If both midfield islets and forest borders would be managed to be semi-open, the area and connectivity of semi-open habitat would increase in the agricultural landscape, which may also improve pollination success as the connectivity between populations has a possibility to increase. Grassland specialist species are clearly abundant in the small remnant habitats. As the decline of semi-natural grasslands is causing a decline in grassland specialists’ species, not only plants, I recommend that small remnant habitats are included in conservation and management plans and strategies to improve habitat availability and connectivity for grassland species in agricultural landscapes. / <p>Research funder Ekoklim. Project:4339602.</p><p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>

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