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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

Aprimoramentos, teste e uso do modelo 3-PG em plantios clonais de Eucalyptus no nordeste do estado de São Paulo / Improvements, test and use the 3-PG model in Eucalyptus clonal plantation in northeast of São Paulo state

Lemos, Cristiane Camargo Zani de 14 February 2012 (has links)
O 3-PG (Physiological Principles in Predicting Growth) é o modelo ecofisiológico mais difundido no setor florestal para a predição de crescimento de florestas. Este modelo estima o crescimento florestal com base na radiação fotossinteticamente ativa absorvida pelo dossel, convertida em carboidratos, e alocada nos compartimentos da floresta (folhas, tronco, galhos e raízes), fundamentados na dinâmica dos processos biológicos e suas interações com o clima e solo. No entanto, após quase 15 anos de existência do 3-PG unido a evolução em pesquisa florestal, é possível detectar alguns pontos no modelo com potencialidade para aprimoramento. O objetivo geral desta tese foi aprimorar o modelo 3-PG e aplicá-lo no zoneamento da produtividade em florestas de Eucalyptus plantadas no nordeste do estado de São Paulo. Os objetivos específicos foram: i) aprimorar o modelo para retenção máxima de água no solo; ii) para queda de folhedo; iii) calibrar e validar o modelo 3-PG usando os pares de parcelas gêmeas; iv) determinar o modificador de fertilidade (FR) do 3-PG usando análise química do solo; v) zonear a produtividade real estimada do Eucalyptus no nordeste do estado do São Paulo; vi) determinar os fatores de restrição da produtividade nestas áreas. Para tanto, utilizou-se de dois projetos de pesquisas instalados na empresa International Paper do Brasil: projeto BEPP (Brasil Eucalyptus Produtividade Potencial) e projeto Parcelas Gêmeas de Inventário. O projeto BEPP foi utilizado para o aprimoramento do modelo em relação à retenção de água e queda de folhedo. Para tanto, utilizou-se de dois tratamentos: o tratamento fertilizado irrigado e o tratamento controle (fertilização tradicional sem irrigação). A quantidade máxima de água no solo adotada pelo modelo, antes considerada como um valor constante, passou a variar segundo a dinâmica de crescimento e exploração do sistema radicular. Esta modificação melhorou a estimativa de biomassa do tronco. No aprimoramento do modelo para a queda de folhedo, ajustou-se quatro modelos: linear; logístico; não lineares e modelo combinado. Todos proporcionaram melhores estimativas da taxa de queda de folhedo do que a função atualmente adotado pelo 3-PG com destaque para o modelo combinado, o qual representou duas fases da queda de folhedo: antes e após o fechamento do dossel. Usando os 113 pares de parcelas gêmeas, verificou-se que 63% responderam à fertilização após 48 meses de instalação do experimento, com ganho médio de 12% em produtividade. Com estas parcelas gêmeas foi possível calibrar e validar o modelo 3-PG para a produtividade atingível e real, com adequada precisão. O FR foi correlacionado à somas de bases do solo (Ca, Mg e K), as quais explicaram as maiores respostas à fertilização, sendo possível determinar uma equação para este modificador. Após a calibração e validação e adequações do modelo foi possível zonear a produtividade real do nordeste do estado de São Paulo. O déficit de pressão de vapor e água no solo foram os fatores que mais limitaram o crescimento do Eucalyptus nesta área. / The 3-PG (Physiological Principles in Predicting Growth,) is the most widespread ecophysiological model in the forest sector to predict the forest growth. It is driven by intercepted radiation with the maximum canopy quantum efficiency, which is limited by the temperature, vapour pressure deficit, available soil water, stand age and site fertility, assimilating the carbon into the forest; supported by physical and ecophysiological processes. However, after almost 15 years of development and use, associated by new scientific knowledge in forest research, some improvement in this model can be done, such as: soil water content and litterfall rate. The objectives of this thesis were improve the 3-PG model and zone the real productivity of Eucalyptus plantation in northeast of São Paulo State. The specifics objectives were: i) improve the 3-PG model regarding water soil content; ii) regarding litterfall; iii) calibrate and validate the 3-PG model using the twin-plot experimental design; iv) determine the fertilization modifier (FR) using soil chemical analysis; v) zoning the real productivity for Eucalyptus plantation in northeast of São Paulo State; and vi) determine the main growth constraints. Aiming these objectives, two main research projects were used: BEPP project (Brasil Eucalyptus Produtividade Potencial) and the Twin-plot of inventory. The BEPP was used to improve the 3-PG model for water soil content and litterfall. Two treatments were used: fertilized plus rainfed and extra fertilized plus irrigation. The water soil content had a constant value and was replaced by a dynamic value, changing with root growth and exploratiion depth with the age. This modification improved the stem biomass production estimatives by the model. For the litterfall improvement, 4 functions were fitted (linear, logistic, non linear and mixed). All of those had better performance in estimating the litter fall than the original 3-PG equation, highlighting the mixed model that could represent before and after canopy closure. Using 113 pairs of twin-plots, 63% of those responded the extra fertilization after 48 months, the production gain was 12%. The twin-plots were used to calibrate and validate the 3-PG model for attainable and real productivity resulted in adequated accuracy for stem biomass estimation. The FR could be associated with chemical analysis, and sum of bases (Ca, Mg and K) were used to fit an FR equation. After calibration and valitadation of the 3-PG model, were possible to zone the real productivity in northeast of São Paulo; the two main constraints of productivity for those area were vapour pressure deficit and soil water.
2

名古屋市近郊の二次林の生態 - リター量とそれによる養分の還元について –

平泉, 智子, HIRAIZUMI, Satoko, 河口, 順子, KAWAGUCHI, Junko, 只木, 良也, TADAKI, Yoshiya 12 1900 (has links) (PDF)
農林水産研究情報センターで作成したPDFファイルを使用している。
3

Aprimoramentos, teste e uso do modelo 3-PG em plantios clonais de Eucalyptus no nordeste do estado de São Paulo / Improvements, test and use the 3-PG model in Eucalyptus clonal plantation in northeast of São Paulo state

Cristiane Camargo Zani de Lemos 14 February 2012 (has links)
O 3-PG (Physiological Principles in Predicting Growth) é o modelo ecofisiológico mais difundido no setor florestal para a predição de crescimento de florestas. Este modelo estima o crescimento florestal com base na radiação fotossinteticamente ativa absorvida pelo dossel, convertida em carboidratos, e alocada nos compartimentos da floresta (folhas, tronco, galhos e raízes), fundamentados na dinâmica dos processos biológicos e suas interações com o clima e solo. No entanto, após quase 15 anos de existência do 3-PG unido a evolução em pesquisa florestal, é possível detectar alguns pontos no modelo com potencialidade para aprimoramento. O objetivo geral desta tese foi aprimorar o modelo 3-PG e aplicá-lo no zoneamento da produtividade em florestas de Eucalyptus plantadas no nordeste do estado de São Paulo. Os objetivos específicos foram: i) aprimorar o modelo para retenção máxima de água no solo; ii) para queda de folhedo; iii) calibrar e validar o modelo 3-PG usando os pares de parcelas gêmeas; iv) determinar o modificador de fertilidade (FR) do 3-PG usando análise química do solo; v) zonear a produtividade real estimada do Eucalyptus no nordeste do estado do São Paulo; vi) determinar os fatores de restrição da produtividade nestas áreas. Para tanto, utilizou-se de dois projetos de pesquisas instalados na empresa International Paper do Brasil: projeto BEPP (Brasil Eucalyptus Produtividade Potencial) e projeto Parcelas Gêmeas de Inventário. O projeto BEPP foi utilizado para o aprimoramento do modelo em relação à retenção de água e queda de folhedo. Para tanto, utilizou-se de dois tratamentos: o tratamento fertilizado irrigado e o tratamento controle (fertilização tradicional sem irrigação). A quantidade máxima de água no solo adotada pelo modelo, antes considerada como um valor constante, passou a variar segundo a dinâmica de crescimento e exploração do sistema radicular. Esta modificação melhorou a estimativa de biomassa do tronco. No aprimoramento do modelo para a queda de folhedo, ajustou-se quatro modelos: linear; logístico; não lineares e modelo combinado. Todos proporcionaram melhores estimativas da taxa de queda de folhedo do que a função atualmente adotado pelo 3-PG com destaque para o modelo combinado, o qual representou duas fases da queda de folhedo: antes e após o fechamento do dossel. Usando os 113 pares de parcelas gêmeas, verificou-se que 63% responderam à fertilização após 48 meses de instalação do experimento, com ganho médio de 12% em produtividade. Com estas parcelas gêmeas foi possível calibrar e validar o modelo 3-PG para a produtividade atingível e real, com adequada precisão. O FR foi correlacionado à somas de bases do solo (Ca, Mg e K), as quais explicaram as maiores respostas à fertilização, sendo possível determinar uma equação para este modificador. Após a calibração e validação e adequações do modelo foi possível zonear a produtividade real do nordeste do estado de São Paulo. O déficit de pressão de vapor e água no solo foram os fatores que mais limitaram o crescimento do Eucalyptus nesta área. / The 3-PG (Physiological Principles in Predicting Growth,) is the most widespread ecophysiological model in the forest sector to predict the forest growth. It is driven by intercepted radiation with the maximum canopy quantum efficiency, which is limited by the temperature, vapour pressure deficit, available soil water, stand age and site fertility, assimilating the carbon into the forest; supported by physical and ecophysiological processes. However, after almost 15 years of development and use, associated by new scientific knowledge in forest research, some improvement in this model can be done, such as: soil water content and litterfall rate. The objectives of this thesis were improve the 3-PG model and zone the real productivity of Eucalyptus plantation in northeast of São Paulo State. The specifics objectives were: i) improve the 3-PG model regarding water soil content; ii) regarding litterfall; iii) calibrate and validate the 3-PG model using the twin-plot experimental design; iv) determine the fertilization modifier (FR) using soil chemical analysis; v) zoning the real productivity for Eucalyptus plantation in northeast of São Paulo State; and vi) determine the main growth constraints. Aiming these objectives, two main research projects were used: BEPP project (Brasil Eucalyptus Produtividade Potencial) and the Twin-plot of inventory. The BEPP was used to improve the 3-PG model for water soil content and litterfall. Two treatments were used: fertilized plus rainfed and extra fertilized plus irrigation. The water soil content had a constant value and was replaced by a dynamic value, changing with root growth and exploratiion depth with the age. This modification improved the stem biomass production estimatives by the model. For the litterfall improvement, 4 functions were fitted (linear, logistic, non linear and mixed). All of those had better performance in estimating the litter fall than the original 3-PG equation, highlighting the mixed model that could represent before and after canopy closure. Using 113 pairs of twin-plots, 63% of those responded the extra fertilization after 48 months, the production gain was 12%. The twin-plots were used to calibrate and validate the 3-PG model for attainable and real productivity resulted in adequated accuracy for stem biomass estimation. The FR could be associated with chemical analysis, and sum of bases (Ca, Mg and K) were used to fit an FR equation. After calibration and valitadation of the 3-PG model, were possible to zone the real productivity in northeast of São Paulo; the two main constraints of productivity for those area were vapour pressure deficit and soil water.
4

Untersuchungen zur einzelbaumverursachten kleinräumigen Variabilität und regenhöhenbasierten Dynamik des Bestandesniederschlages am Beispiel zweier Buchen-Fichten-Mischbestände / Study on the single-tree related small-scale variability and quantity-dependent dynamics of net forest precipitation using the example of two mixed beech-spruce stands

Frischbier, Nico 03 September 2012 (has links) (PDF)
Trifft herabfallender Regen auf Waldflächen, so wird dieser Niederschlag umverteilt zu Interzeption, Stammabfluss, durchfallenden und abtropfenden Niederschlag. Besonders hohe Stammablaufmengen im Kronenzentrum und markante Abtropfstellen am Kronenrand einzelner Baumarten lassen sich zudem nur erklären, wenn am jeweiligen Messplatz unter Baumkronen eine weitere Niederschlagskomponente zugelassen wird, mit der laterale Wasserbewegungen innerhalb der expliziten Einzelbaumkrone beschrieben und bilanziert werden (lateraler [Zu- oder Ab-]Fluss). Ziel dieser Arbeit war es deshalb, der niederschlagsabhängigen und kleinräumigen Dynamik dieser Umverteilung im Wald am Beispiel der Baumarten Buche (Fagus sylvatica L.) und Fichte (Picea abies (L.) Karst.) durch Aufnahmen und Auswertungen in zwei Mischbeständen beider Baumarten nachzugehen. Wiederholende Niederschlagsaufzeichnungen einzelner Regenereignisse wurden hierzu in Relation zur jeweiligen Freilandniederschlagsmenge, zur Art der Messplatzüberschirmung im Kronendach und zur Distanz des Messplatzes zum ihn dominierenden Baum varianz- und regressionsanalytisch untersucht und um Ergebnisse aus Stammablaufanalysen und Streumodellen ergänzt. Auf dieser Basis konnten Kausalmodelle zur Schätzung des Unterkronenniederschlages mit hoher Güte hergeleitet werden, die im Detail ein baumartspezifisches räumliches Verhalten der einzelnen Niederschlagskomponenten beim Passieren der Baumkrone belegen. Neben den Besonderheiten, die sich bei Messungen in Bestandeslücken einstellen, ergeben sich so z.B. in der Vegetationsperiode je nach Messplatzposition und Freilandniederschlagsmenge Unterschiede im Niederschlag unter beiden Baumartenkronen von bis zu 35 % des Freilandniederschlages je Einzelereignis und zwar stets zugunsten der Buchenüberschirmung. Am Stammfuss von Buchen kann darüber hinaus zusätzliches Wasser durch den Stammabfluss eingetragen werden. Hierfür notwenige Wassermengen können plausibel aus dem nachgewiesenen lateralen Wasserabfluss im inneren Kronendrittel von Buchen gedeckt werden. Über ein räumlich konkretes Interzeptionsmodell, kombiniert mit Blattflächenschätzungen für Einzelbäume konkreter Dimension, konnte ein räumliches LAI-Modell für Buchen abgeleitet werden, dass höchste LAI-Werte im Kronenzentrum annimmt. Da der Bestandesniederschlag hinsichtlich Niederschlagsmenge, Bestockung, Belaubungszustand und zum räumlich konkreten Messplatz unter der einzelnen Baumkrone veränderlich ist, wird die gewissenhaftere Berücksichtigung dieser Einflussvariablen angeregt und der bisher häufig praktizierten pauschalen Aufteilung des Niederschlages in einzelne Niederschlagskomponenten auf Basis von Flächen- und Messphasendurchschnittswerten widersprochen. / Forests redistribute the precipitation falling on their canopy into interception, stemflow, drip or direct throughfall. Extremely high amounts of stemflow in the centre of the crown and distinct drip points along the crown edge of certain tree species can only be explained by admitting an additional precipitation component at these measurement locations that describes and captures the lateral movement of water within the individual tree crown (lateral in- or outflow). The aim of this study was therefore to analyse these precipitation-dependent, small-scale dynamics of precipitation redistribution in forests using field-measurements from two mixed stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.). Periodic measurements of individual precipitation events were examined in relation to the respective gross precipitation, the type of canopy above a plot and the distance of a plot to its dominant sheltering canopy tree using variance and regression analysis, and complemented with stemflow analyses and litterfall models. Using this dataset, causal models for the high-precision estimation of throughfall were derived, showing tree species-specific pathways of the individual precipitation components through the tree crown. Apart from the particularities of measurements in canopy gaps, differences in throughfall between spruce and beech during the vegetation period amount to up to 35 % of gross precipitation per event, in favour of the beech canopy and depending on plot location. At the stem base of beech trees additional water can reach the forest floor via stemflow. The amount of water required to generate this stemflow can plausibly be explained by means of the verified lateral water flow in the inner third of beech crowns. Using a spatially explicit interception model combined with LAI estimates for specific individual trees, a spatial LAI model was developed for beech, showing maximal LAI values in the crown centre. As the net forest precipitation is sensitive with respect to precipitation amount, stand type, foliage status and the spatially explicit plot location below an individual tree crown, this study recommends the consideration of these influential factors and contradicts the commonly practiced blanket partitioning of precipitation into individual components based on spatial and temporal averages.
5

Untersuchungen zur einzelbaumverursachten kleinräumigen Variabilität und regenhöhenbasierten Dynamik des Bestandesniederschlages am Beispiel zweier Buchen-Fichten-Mischbestände

Frischbier, Nico 19 March 2012 (has links)
Trifft herabfallender Regen auf Waldflächen, so wird dieser Niederschlag umverteilt zu Interzeption, Stammabfluss, durchfallenden und abtropfenden Niederschlag. Besonders hohe Stammablaufmengen im Kronenzentrum und markante Abtropfstellen am Kronenrand einzelner Baumarten lassen sich zudem nur erklären, wenn am jeweiligen Messplatz unter Baumkronen eine weitere Niederschlagskomponente zugelassen wird, mit der laterale Wasserbewegungen innerhalb der expliziten Einzelbaumkrone beschrieben und bilanziert werden (lateraler [Zu- oder Ab-]Fluss). Ziel dieser Arbeit war es deshalb, der niederschlagsabhängigen und kleinräumigen Dynamik dieser Umverteilung im Wald am Beispiel der Baumarten Buche (Fagus sylvatica L.) und Fichte (Picea abies (L.) Karst.) durch Aufnahmen und Auswertungen in zwei Mischbeständen beider Baumarten nachzugehen. Wiederholende Niederschlagsaufzeichnungen einzelner Regenereignisse wurden hierzu in Relation zur jeweiligen Freilandniederschlagsmenge, zur Art der Messplatzüberschirmung im Kronendach und zur Distanz des Messplatzes zum ihn dominierenden Baum varianz- und regressionsanalytisch untersucht und um Ergebnisse aus Stammablaufanalysen und Streumodellen ergänzt. Auf dieser Basis konnten Kausalmodelle zur Schätzung des Unterkronenniederschlages mit hoher Güte hergeleitet werden, die im Detail ein baumartspezifisches räumliches Verhalten der einzelnen Niederschlagskomponenten beim Passieren der Baumkrone belegen. Neben den Besonderheiten, die sich bei Messungen in Bestandeslücken einstellen, ergeben sich so z.B. in der Vegetationsperiode je nach Messplatzposition und Freilandniederschlagsmenge Unterschiede im Niederschlag unter beiden Baumartenkronen von bis zu 35 % des Freilandniederschlages je Einzelereignis und zwar stets zugunsten der Buchenüberschirmung. Am Stammfuss von Buchen kann darüber hinaus zusätzliches Wasser durch den Stammabfluss eingetragen werden. Hierfür notwenige Wassermengen können plausibel aus dem nachgewiesenen lateralen Wasserabfluss im inneren Kronendrittel von Buchen gedeckt werden. Über ein räumlich konkretes Interzeptionsmodell, kombiniert mit Blattflächenschätzungen für Einzelbäume konkreter Dimension, konnte ein räumliches LAI-Modell für Buchen abgeleitet werden, dass höchste LAI-Werte im Kronenzentrum annimmt. Da der Bestandesniederschlag hinsichtlich Niederschlagsmenge, Bestockung, Belaubungszustand und zum räumlich konkreten Messplatz unter der einzelnen Baumkrone veränderlich ist, wird die gewissenhaftere Berücksichtigung dieser Einflussvariablen angeregt und der bisher häufig praktizierten pauschalen Aufteilung des Niederschlages in einzelne Niederschlagskomponenten auf Basis von Flächen- und Messphasendurchschnittswerten widersprochen. / Forests redistribute the precipitation falling on their canopy into interception, stemflow, drip or direct throughfall. Extremely high amounts of stemflow in the centre of the crown and distinct drip points along the crown edge of certain tree species can only be explained by admitting an additional precipitation component at these measurement locations that describes and captures the lateral movement of water within the individual tree crown (lateral in- or outflow). The aim of this study was therefore to analyse these precipitation-dependent, small-scale dynamics of precipitation redistribution in forests using field-measurements from two mixed stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.). Periodic measurements of individual precipitation events were examined in relation to the respective gross precipitation, the type of canopy above a plot and the distance of a plot to its dominant sheltering canopy tree using variance and regression analysis, and complemented with stemflow analyses and litterfall models. Using this dataset, causal models for the high-precision estimation of throughfall were derived, showing tree species-specific pathways of the individual precipitation components through the tree crown. Apart from the particularities of measurements in canopy gaps, differences in throughfall between spruce and beech during the vegetation period amount to up to 35 % of gross precipitation per event, in favour of the beech canopy and depending on plot location. At the stem base of beech trees additional water can reach the forest floor via stemflow. The amount of water required to generate this stemflow can plausibly be explained by means of the verified lateral water flow in the inner third of beech crowns. Using a spatially explicit interception model combined with LAI estimates for specific individual trees, a spatial LAI model was developed for beech, showing maximal LAI values in the crown centre. As the net forest precipitation is sensitive with respect to precipitation amount, stand type, foliage status and the spatially explicit plot location below an individual tree crown, this study recommends the consideration of these influential factors and contradicts the commonly practiced blanket partitioning of precipitation into individual components based on spatial and temporal averages.

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