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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.
21

Comportamento ecofisiológico de espécies arbóreas nativas do Cerrado e exóticas / Behavior Ecophysiology of native tree species of the Cerrado and exotic tree species

SOUZA, Cynthia Domingues de 17 January 2008 (has links)
Made available in DSpace on 2014-07-29T14:52:03Z (GMT). No. of bitstreams: 1 TESE COMPORTAMENTO ECOFISIOLOGICO.pdf: 1820060 bytes, checksum: cc63b18f41fa04014c546ac63af492df (MD5) Previous issue date: 2008-01-17 / It was used the "transpirometer of balance" for planting of five tree species to evaluate the physiological behaviour regarding: total transpiration, stomatal conductance and transpiration leaf, growth, partition of phytomass, study the fluorescence of chlorophyll a e anatomical study of leaves of the species : Tabebuia serratifolia Nichols (Ipê yellow), Hymenaea stigonocarpa Mart. Ex Hayne (Jatobá), Myroxilum balsamum (Linn) Harms (Balsamo), Eucalyptus camaldulensis Dehn and Eucalyptus citriodora Hook (eucalyptus). The equipment consisted of a hydraulic system, composed of three elements: a reservoir of water (R1), another with a buoy (R2) to control the level of water in vessels (V) where the tree species were planted. The soil was analyzed by LASF / UFG-AGRO. It recommended, for pot, dolomitic lime (50g) and 88g of NPK (4-14-8). This study is subdivided parcels of split plot in time (split-plot in time), at a significance level of 5%, analyzed by SAS / STAT. E. camaldulensis and E. citriodora showed similar transpiration. Ipê, jatobá and balsamo showed no significant difference between them. The porometric measures suggested that the species obey strict control stomatic, with the closing of the stomates in the light of high evaporative demand of the air, changing the rates transpiration and stomatal conductance along the hours of the day. Evaluations biophysical showed that the growth in height, diameter and leaf area of E. camaldulensis was superior to other species. To partition of biomass, this species showed significant difference in dry stems, leaves and roots. The photochemical efficiency of photosystem II (Fv / Fm) was statistically similar to the species E. citriodora, E. camaldulensis, ipê and balsamo, with a significant difference between the ratio (Fv / Fm), E. camaldulensis and jatobá, suggesting that the jatobá showed greater susceptibility of photosystem II in this experiment because of the high brightness. The study of the anatomy leaf showed that E. camaldulensis and E. citriodora have leaves amphistomatic with stomatestype anomocytic, ipê and balsamo have leaves hypostomatics with stomates anomocytic. Jatobá leaves hypostomatics with paracytic stomates. Given the results, it is suggested that the leaf anatomy influenced the rate transpiration resulting in differences in growth and biomass of partition. Ipê, jatobá and balsamo had more layers of lacunary parenchyma than eucalyptus, adaptive characteristics that allow those species colonize places of lesser brightness. All species showed secretory cavities. The stomatic density estimated average of each species indicated proximity of the values found in sclerophylly plants (100-500/mm ²). This work showed the importance of the physiological responses of the tree species, on the consumption of water, helping in the definition of strategies for management of natural environments, guided information for reflorestations with native and exotic species in the savanna in Goias states. / Utilizou-se o Transpirômetro de equilíbrio para plantio de cinco espécies arbóreas para avaliar o comportamento fisiológico quanto à: transpiração total, transpiração e condutância estomática foliar, crescimento, partição de fitomassa, estudo da fluorescência da clorofila a e estudo anatômico de folhas das espécies: Tabebuia serratifolia (Vahl) Nichols (Ipê amarelo), Hymenaea stigonocarpa Mart. Ex Hayne (Jatobá), Myroxilum balsamum (Linn) Harms (Balsamo), Eucalyptus camaldulensis Dehn e Eucalyptus citriodora Hook (eucaliptos). O equipamento consistiu de um sistema hidráulico, composto de três elementos: um reservatório de água (R1), outro com uma bóia (R2) para controlar o nível de água nos vasos (V) onde foram plantadas as espécies arbóreas. O solo foi analisado por LASF/UFG-AGRO. Recomendou-se, por vaso, calcário dolomítico (50g) e 88g de NPK (4-14-8). Configurou-se experimento de parcelas subdivididas no tempo (split-plot in time), a um nível de significância de 5%, analisados por SAS/STAT. E. camaldulensis e E. citriodora apresentaram transpiração semelhantes. Ipê, jatobá e bálsamo não apresentaram diferença significativa entre si. As medidas porométricas sugeriram que as espécies obedecem a rigoroso controle estomático, com o fechamento dos estômatos em função da alta demanda evaporativa do ar, alterando as taxas transpiratórias e de condutância estomática ao longo das horas do dia. As avaliações biofísicas evidenciaram que o crescimento em altura, diâmetro e área foliar de E. camaldulensis foi superior às outras espécies. Para partição de fitomassa, essa espécie apresentou significativa diferença em matéria seca de caule, folhas e raiz. A eficiência fotoquímica do fotossistema II (Fv/Fm) foi estatisticamente semelhante para as espécies E. citriodora, E. camaldulensis, ipê e bálsamo, havendo diferença significativa entre a razão (Fv/Fm) de E. camaldulensis e do jatobá, sugerindo que o jatobá apresentou maior susceptibilidade do fotossistema II nesse experimento em razão da alta luminosidade. O estudo da anatomia foliar revela que E. camaldulensis e E. citriodora têm folhas anfiestomáticas com estômatos tipo anomocítico, T. serratifolia e M. balsamum têm folhas hipostomáticas com estômatos anomocíticos, Hymenaea stigonocarpa folhas hipostomáticas com estômatos paracíticos. Diante dos resultados, sugere-se que a anatomia foliar influenciou a taxa transpiratória resultando em diferenças no crescimento e partição de fitomassa. Ipê, jatobá e bálsamo apresentaram mais camadas de parênquima lacunoso do que os eucaliptos, características adaptativas que permitem essas espécies colonizar locais de menor luminosidade. Todas as espécies estudadas apresentaram cavidades secretoras. A densidade estomática média estimada de cada espécie indicou proximidade dos valores encontrados em plantas esclerófilas (100-500/mm²). Este trabalho evidencia a importância das respostas fisiológicas das espécies arbóreas, quanto ao consumo de água, contribuindo na definição de estratégias de manejo de ambientes naturais, norteando informações para reflorestamentos com espécies exóticas e nativas no Cerrado goiano.
22

Post-fire effects of invasive exotic plants on seed banks, regeneration, soil chemistry and selected soil microbial populations in the Silvermine Nature Reserve, Cape Peninsula, South Africa

Cilliers, Charl Daniel 04 1900 (has links)
Thesis (MSc) -- University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The fires, which occurred during January 2000 on the Southern Cape Peninsula, Cape Province, South Africa, focused attention on the importance of sound, informed management of exotic plant invaders in fynbos, especially at the urban interface. The fires also highlighted the relative lack of knowledge about the combined impacts of fire, exotic plants and the exotic-clearing programme on soil seed banks and regeneration. This study examines soil borne seed banks, regeneration, soil chemistry and micro biota in different postfire environments, focusing on three components of exotic plant management: The post-fire effects of standing invasive exotic plants; stacks of slashed exotic plant material which were deliberately burnt and stacks reduced to heat scars by a wildfire. The primary hypothesis addressed is that post-fire vegetation regeneration patterns, seed bank diversity and seed bank abundance are linked to pre-fire vegetation characteristics and, in particular, to the treatment of exotic plant species. It is also hypothesised that soil microbe population sizes are linked to pre-fire vegetation and soil chemical composition. Differences in soil seed banks, soil micro biota and vegetation regeneration patterns occur in different post-fire environments. High volumes of (live or dead) woody exotic biomass negatively impact upon postfire indigenous species diversity and abundance, both above and below-ground. Soil seed banks and above-ground regeneration decline with increasing fire intensity, wildfire burnt stack treatments showing the largest declines followed by wildfire burnt standing exotics, control burnt stacks, wildfire burnt cleared areas and wildfire burnt Mountain Fynbos treatments. Persistent indigenous seed banks are found under some exotic dominated stands. Heat damage, associated with high woody exotic biomass, affects seeds of all species into deep soil layers. Depth of burial is a more important determinant of seed survival during fires than seed size. Soil microbial populations are variably affected by exotic plants, their management and increases in fire intensity. The most drastic microbial population changes are in post-fire treatments of high exotic plant biomass. Soil chemistry affects microbial population sizes as does seasonal climatic changes. In this thesis vegetation, seed bank and microbial responses to various exotic plant management practices are shown and management recommendations are made. Keywords: exotic plants, fire, Fynbos Siome, microbes, post-fire succession, soil seed banks. / AFRIKAANSE OPSOMMING: Die Januarie 2000 vure op die Suid Kaapse Skiereiland het fokus gerig op die belangrikheid van goeie, ingeligte bestuur van uitheemse indringerplante in fynbos, veral naby stedelike gebiede. Die vure het ook 'n relatiewe .gebrek aan kennis aangaande die gekombineerde impakte van vuur, uitheemse plantegroei en indringer plant beheer programme op grond saadbanke en die hergroei van plante na 'n vuur aan die lig gebring. Hierdie projek bestudeer die invloed van vuur op grond saadbanke, hergroei van plante, grond chemie en mikro-organismes. Die klem lê op drie komponente van uitheemse plant bestuur: waar staande uitheemse plante voorkom; waar skoongekapte uitheemse plante in hope gestapel is en gekontraleerd gebrand is en waar soortgelyke hope in 'n onbeplande weghol vuur gebrand is. Die primêre hipotese is dat plant herstelpatrone, saadbank diversiteit en grootte gekoppel is aan veldtoestande voordat daar gebrand is, en veral aan die bestuur van uitheemse plantspesies. Nog 'n sentrale hipotese is dat die grootte van grond mikrobiale populasies gekoppel is aan veld toestande voor die brand en aan grond chemiese samestelling. Hierdie studie dui verskille aan in grond saadbanke, mikro-organismes en plant hergroeipatrone onder verskeie toestande na vuur. Die brand van hoë volumes (lewende of dooie) houtagtige uitheemse plant biomassa benadeel inheemse plant spesie diversiteit en getalle (bo en onder die grond oppervlak). Grond saadbanke neem af met vehogings in vuur intensiteit. Die grootste afnames is in wegholvuur gebrande gestapelde uitheemse plantmateriaal gevolg deur wegholvuur gebrande staande uitheemse plante, opsetlik gebrande hope uitheemse plante, gebrande skoongekapte areas en wegholvuur gebrande Berg Fynbos. Ou inheemse saadbanke is gevind onder sommige areas wat voor die vuur oorheers was deur uitheemse plantegroei. Hitteskade, geassosieer met hoë volumes houtagtige uitheemse biomassa, affekteer sade van alle spesies tot diep in die grond. Saad oorlewing tydens brande is meer geaffekteer deur diepte van begrawing in die grond as deur saad grootte. Grond mikro-organisme populasies is geaffekteer deur uitheemse indringer plante, die bestuur van uitheemse plante en vuur intensiteit. Die grootste veranderinge is waar die biomassa van uitheemse plantegroei baie hoog is. Grond chemiese samestelling en seisoenale veranderinge in weerspatrone affekteer die grootte van mikrobiale bevolkings. In hierdie tesis word verskille in plantegroei, saad store en grond mikrobes, soos geaffekteer deur uitheemse plant beheer programme uitgewys en voorstelle vir toekomstige bestuur gemaak. Sleutelwoorde: Fynbos Bioom, grond saad stoor, mikrobes, plant hergroei, uitheemse plante, vuur.
23

Flora alòctona de les Illes Balears. Ecología de dos especies invasoras: Carpobrotus edules y Carpobrotus aff. acinaciformis

Moragues Botey, Eva 24 March 2006 (has links)
La llegada de plantas exóticas fuera de su rango de distribución original y su posterior asentamiento en ecosistemas naturales no es una excepción en las Islas Baleares. En la actualidad tenemos 308 especies no nativas naturalizadas y subespontáneas que representan el 16% del total de la flora Balear. En esta tesis se ha evaluado el estado de la cuestión a nivel global y local. Se ha confeccionado el primer catálogo de flora introducida y se ha analizado cuales de ellas son más abundantes y peligrosas; así como también qué ecosistemas son más vulnerables a la introducción de éstas. También se ha profundizado en el conocimiento de dos de las especies exóticas más peligrosas en el litoral Balear: Carpobrotus edulis y C. affine acinaciformis. Se ha evaluado su influencia sobre la polinización, su tasa de crecimiento bajo diferentes escenarios ambientales, se ha confeccionado un modelo de crecimiento y se ha evaluado su impacto sobre la composición y estructura de las comunidades nativas. / L'arribada de plantes exòtiques fora del seu rang de distribució original i el seu posterior assentament a ecosistemes naturals no és una excepció a les Illes Balears. A l'actualitat tenim 308 espècies no natives naturalitzades i subespontànies que representen el 16% del total de la flora Balear. En aquesta tesi s'ha avaluat l'estat de la qüestió a nivell global i local. S'ha confeccionat el primer catàleg de flora introduïda i s'han analitzat quines d'elles són més abundants i perilloses; així com també quins ecosistemes són més vulnerables a la introducció d'aquestes. També s'ha profunditzat en el coneixement de dues de les espècies exòtiques més perilloses del litoral Balear: Carpobrotus edulis y C. affine acinaciformis. S'ha avaluat la seva influència damunt els vectors de pol·linització, la taxa de creixement a diferents escenaris ambiental, s'ha confeccionat un model de creixement, i s'ha avaluat el seu impacte damunt la composició i estructura de les comunitats natives. / The constant arrival of exotic plants into areas outside their original distribution range and further settlement in natural ecosystems is not an exception in the Spanish Balearic archipelago. At the moment we have 308 non native species (naturalized and casual), the 16% from the total Balearic flora. This thesis has evaluated the exotic plant problematic at global and local level. We have elaborated the first exotic plants list, its distribution and abundance, as well as its degree of impact on the more vulnerable environments. We went deeply into the knowledge of two very invasive plants along the coast of the Balearic islands: Carpobrotus edulis y C. affine acinaciformis. We have evaluated its influence over pollen transmission, its growth rate at different environmental conditions, we have too elaborated a non liner growth model and its impact on composition and structure in natural communities

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