Thesis (Dr. rer. nat.)--Philipps-Universität Marburg, 2002. / Title from PDF t.p. (viewed on Apr. 24, 2007). Includes bibliographical references (p. 143-163).

Thesis (Ph. D.)--University of Adelaide, 2004. / Title from PDF t.p. (viewed on Sept. 25, 2005). Includes bibliographical references (p. 145-159).

Träd i tropiska våtmarker har uppmärksammats som en viktig källa till regionala och globala metan (CH4) utsläpp, då träd fungerar som utsläppskanaler för metan som bildas i sedimenten. Dock finns det en osäkerhet gällande säsongsvariation och rumslig variation samt mängden CH4 utsläpp från träd, eftersom kunskapen kring regionala flöden är begränsad. Därför strävar vi efter att optimera provtagningsinsatser för att öka möjligheten till representativa uppskattningar för olika typer av skogsekosystem och förbättra kunskapen om rumslig och temporär variabilitet för framtida mätningar i Amazonas. Vi undersökte variabiliteten i flöden av CH4 från träd belägna i tre periodvis översvämmade platser (Solimões, Negro and Tapajós) längs Amazonfloden, med olika karaktäristiska egenskaper. Studien genomfördes in situ med slutna kammare på 36 träd vid de tre provplatserna, under olika hydrologiska säsonger. Platserna visade en stor säsongsvariation i CH4-flöden, med de största bidragen under högvattensäsong. En signifikant skillnad mellan två av platserna upptäcktes endast under högvatten och detta kan vara ett resultat av vattnets varierande fysikaliska och kemiska egenskaper. Med hänsyn till variation inom studieplatserna har indelning av zoner betydelse för mätning av CH4-flöden i träd, då vattennivån är en påverkande faktor. En stor rumslig variation upptäcktes, med lägre flöden i zonen närmast land och med det högsta flödet i zonen där förhållanden varierar mest mellan blött och torrt. Detta mönster kan beaktas genom att utföra provtagningar längs zonerna med hänsyn till vattenavståndet. / Tropical wetland-adapted trees are recognized as an important source of regional and global methane (CH4) emissions, by transport of soil gas through wetland trees. However, spatiotemporal variability and controls on the magnitude of tree-mediated CH4 emissions remain unknown as fluxes are poorly constrained. Therefore, we aim to optimize sampling efforts to yield representative emission estimates for distinct types of forest ecosystems and improve knowledge on spatial and temporal variability. We examined the variability in tree stem mediated CH4 fluxes in situ, located in three different floodplains (Solimões, Negro and Tapajós) with various characteristics, during different hydrological seasons. The sampling was conducted by measuring fluxes from 36 trees at each location using closed chambers. All the three study sites, situated in the Amazon region, displayed seasonal variability in CH4 fluxes, with the largest contributions observed during the wet season. A significant difference between Solimões and Negro was detected during the wet season and this may be a result of the different chemical and physical characteristics between the sampling locations. As for within the study sites, zones played a significant role for CH4 flux from trees since the water level influences the fluxes. A strong spatial variability (lower fluxes in the land zone, and the highest flux obtained in the zone with greatest variability between dry and wet conditions) was found. This pattern can be addressed by sampling along flooded and non-flooded zones. / The Global Methane Budget

Light Detection and Ranging (LiDAR) is increasingly common in forestry applications, yet relatively little research has evaluated its use in quantifying carbon stocks in afforested bottomland hardwood forests. This study relates forest structural field measurements to metrics derived from low pulse density LiDAR data to assess the use of LiDAR in characterization of planted bottomland hardwood oak stands. Univariate and multivariate linear regressions were performed with field and LiDAR variables to determine relationships. The height-related field dependent variables average height, maximum height, and individual tree volume had the highest adjusted R-squared values of 0.5-0.6 (P<0.0001) for the univariate models and adjusted R-squared values of 0.70-0.79 for the multivariate models. These findings suggest that low-density LiDAR is capable of assessing forest structure and suggests that further research evaluating LiDAR quantification of bottomland hardwood carbon stocks is warranted.

Die Verbreitung von gebietsfremden Arten in Gebiete außerhalb ihres natürlichen Verbreitungsgebietes kann zu einem Verlust der Biodiversität führen. Einst als produktionssteigerndes Mittel eingesetzt, wurden viele gebietsfremde Baumarten in Mitteleuropa und Deutschland eingeführt und verblieben dort in den Wäldern. Unter anderem wurde in den Hartholzauenwäldern der Mittelelbe in Sachsen-Anhalt die nordamerikanische Rot-Esche (Fraxinus pennsylvanica) eingebracht und sie nimmt heute rund 50 % der Fläche ein. Um die Fragen zum Einfluss der Etablierung von F. pennsylvanica auf die Vielfalt der Waldstrukturen und der Arten in der Krautschicht zu bearbeiten, wurden vergleichende Erhebungen in 20 Beständen durchgeführt, die sich hinsichtlich der Bestandsanteile von F. pennsylvanica im Oberstand unterscheiden. Die Bestände wurden hinsichtlich der Bestandsstruktur und Totholzaufkommen sowie auf kleineren Plots mit je einem Bezugsbaum (F. pennsylvanica oder Quercus robur als Referenz) das Bodenmikrobiom und Bodenvegetation sowie Naturverjüngung der Gehölze untersucht. Am deutlichsten scheint die Einflussnahme von F. pennsylvanica in Reinbeständen. Diese sind weniger stark strukturiert und weisen mehr Anfälligkeiten gegenüber Umwelteinflüssen auf. Für alle anderen Bestandsformen waren die Effekte eher gering und zum Teil konnte in Misch- oder Dominanzbeständen eine höhere Diversität als in Referenzbeständen festgestellt werden. Unabhängig von der gesetzlichen Lage zum Umgang mit Neophyten in Schutzgebieten wird F. pennsylvanica als in die Hartholzauenwälder der Mittelelbe eingegliederte Baumart eingeschätzt, die das Potenzial hat, ausfallende Arten, wie die heimische Gewöhnliche Esche (Fraxinus excelsior), zu ersetzen. / The spread of alien species in areas outside their natural range can lead to a loss of biodiversity. Once used as a tool of increasing production, many alien tree species were introduced into Central Europe and Germany and remained in the forests there. Among other, the north american Green Ash (Fraxinus pennsylvanica) was introduced into the hardwood floodplain forests of the Mittelelbe in the federal state of Saxony-Anhalt and today it occupies around 50% of the area. In order to address the questions about the influence of the establishment of F. pennsylvanica on the diversity of forest structures and species in the herbaceous layer, comparative surveys were carried out in 20 stands that differed in terms of the proportion of F. pennsylvanica in the upper stand. Investigations on stand structure and deadwood as well as, in smaller plots with a reference tree (F. pennsylvanica or Quercus robur as a reference), investigations on soil microbiome, ground vegetation and natural regeneration were examined. The influence of F. pennsylvanica appears to be clearest in pure stands. These are less structured and are more susceptible to environmental influences. For all other types of stands, the effects were rather small and, in some cases, a higher diversity was found in mixed or dominant stands than in reference stands. Regardless of the legal situation regarding the handling of neophytes in protected areas, F. pennsylvanica is considered to be a tree species integrated into the hardwood floodplain forests of the Mittelelbe, which has the potential to replace failing species such as the common ash (Fraxinus excelsior).

The molluscs are very suitable model of invertebrate group for ecological and palaeoecological studies for their specific traits. In the first part of the thesis, we showed based on available fossil mollusc successions that development of the floodplain mollusc fauna took place quite different way in various river floodplains, depending on their specifics and geographical location, because especially the ones situated in the chernozem area of the Czech Republic had very different history. Detailed processing of five fossil mollusc successions in the lower Ohře River floodplain confirmed the impoverishment of recent forest malacofauna does not relate to natural processes only (chapters 3 and 10), but it arises from historical development of this area which was under permanent stress of the human settlement and agricultural utilization (chapter 1) since the coming of the Neolithic people. We made similar conclusions in case of another 11 fossil mollusc successions in the neighbouring České Středohoří Mts. (chapter 2). In the second part of the thesis (chapter 3), we investigated the ecological patterns responsible for species richness and composition of the floodplain mollusc fauna are especially the elevation and humidity gradient, and then vegetation type and its biomass, light conditions of the...

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Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2017-05-12T19:13:31Z No. of bitstreams: 1 DISS_2015_Tonny Jader de Moraes.pdf: 1862734 bytes, checksum: a2ae7eacfbe28db2fbd49b7b10ef1d15 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2017-05-18T16:25:26Z (GMT) No. of bitstreams: 1 DISS_2015_Tonny Jader de Moraes.pdf: 1862734 bytes, checksum: a2ae7eacfbe28db2fbd49b7b10ef1d15 (MD5) / Made available in DSpace on 2017-05-18T16:25:26Z (GMT). No. of bitstreams: 1 DISS_2015_Tonny Jader de Moraes.pdf: 1862734 bytes, checksum: a2ae7eacfbe28db2fbd49b7b10ef1d15 (MD5) Previous issue date: 2015-05-22 / CAPES / O objetivo desta pesquisa, foi estudar as características estruturais das plantas em nível individual utilizando uma teoria quantitativa para a estrutura e dinâmica das florestas. A teoria usa relações de escala alométrica, baseado no metabolismo e biomecânica, sendo possível estudar propriedades geométricas e dinâmicas de plantas que se dimensionam de forma idêntica. A partir do conhecimento relacionado à Ciência da Complexidade, admite descrições dos fenômenos estudados, de uma forma mais próxima da dinâmica dos sistemas reais do comportamento global de um ecossistema a partir de medidas locais. A área de estudo é a mata da Baia das Pedras em floresta inundável na região do Pantanal. Para analisar as características estruturais como: a dimensão fractal, distribuição dos galhos em função do tamanho, a razão de escala entre os tamanhos das partes da planta, com foco em duas espécies Enterolobium contortisiliquum (Ximbuva) e Palicourea crocea (Erva d’água), para estas e outras plantas foram coletadas as seguintes medidas de plantas tomadas individualmente: diâmetro, comprimento e número de galhos, como também a massa dessas plantas. Os resultados indicam a capacidade do modelo de prever algumas características de auto similaridade referentes a arquitetura estrutural observada pela distribuição dos tamanhos, e razão entre os tamanhos dos galhos, assim como características estruturais idênticas nas plantas analisadas. / The purpose of this research was to study the structural characteristics of plants at the individual level using a quantitative theory for the structure and dynamics of forests. The theory using allometric scaling relations based on the metabolism and biomechanics, it is possible to study geometric and dynamic properties of plants that dimensioning identically. From related to complexity science knowledge, admits descriptions of the phenomena studied, more closely the dynamics of real systems the overall behavior of an ecosystem from local measures. The study area is the forest of Baia das Pedras in floodplain forest in the Pantanal region. To analyze the structural characteristics as the fractal dimension, distribution of branches depending on its size, the ratio of scale between the sizes of the parts of the plant, focusing on two species Enterolobium contortisiliquum (Ximbuva) and Crocea Palicourea (Erva d’água) for these and other plants were harvested plants the following measures taken individually: diameter, length and number of branches, as well as the mass of these plants. The results indicate the model's ability to predict certain characteristics of self similarity concerning structural architecture observed the distribution of sizes, and ratio between the sizes of the branches, as well as structural features identical in the analyzed plants.

Trees adjust wood anatomical structure to environmental conditions, predisposing time series of quantitative wood anatomical parameters to be valuable source of palaeoenvironmental information. In this doctoral project we analysed the response of vessel parameters of i) floodplain Quercus robur to groundwater level fluctuation, hydroclimate variability and extreme events (droughts and floods), and of ii) Betula pendula to mechanical damage caused by various disturbances. Although climatic signal as well as pointer years stored in tree-ring width chronologies of Quercus robur largely differ between sites, quantitative vessel parameters contain spatially- homogenous positive signal of previous year summer temperature and current year winter/early spring temperature. The only between-site difference in wood anatomical chronologies is negative effect of moisture on vessel size in floodplain, which does not occur in not-flooded lowland sites. We suggest that while tree productivity benefits from high water availability, the wood anatomical structure of Quercus robur is constrained by high soil water saturation in floodplain zone. In addition, the response of tree-ring widths to moisture availability is not uniform inside single stand, but subgroups of trees with completely opposite response coexist...

Das Ziel der vorliegenden Arbeit ist die ausführliche Analyse und Beschreibung langfristiger abiotischer Standortbedingungen von Fluss und Grundwasser für das in einem Hartholzauenwald gelegene Untersuchungsgebiet im Naturschutzgebiet Saalberghau an der Mittleren Elbe bei Dessau. Hierzu erfolgt zunächst die Entwicklung eines allgemeinen Konzeptes, dass die Modellierung des Fluss- und des Grundwasserregimes sowie die statistische Auswertung dieser miteinander verbundenen Regime umfasst. Es wird davon ausgegangen, dass nur eine Synthese dieser Einzelbausteine die Grundlage für eine zusammenhängende Analyse und Beschreibung der komplexen auentypischen Dynamik dieser beiden Regime anhand objektivierbarer statistischer Parameter bilden kann. Darüberhinaus stellt die Zielsetzung auf langfristige Aussagen eine unentbehrliche Voraussetzung dar, um das Zeitspektrum der hier zu betrachtenden Altbäume typischer Hartholzauenbaumarten adäquat berücksichtigen zu können. / The present dissertation aims at a detailed analysis and description of the long-term abiotic site conditions (river flow and groundwater) for the floodplain area under investigation, namely a hardwood forest in the nature reserve &amp;quot;Saalberghau&amp;quot; on the Middle Elbe close to the town Dessau. For this purpose, firstly a general concept which covers the modelling of the surface water and groundwater regime as well as a statistical interpretation of these two interconnected regimes is developed. It is assumed that only a synthesis of those separate modules can form a sufficient basis for a cohering analysis and description of the complex dynamics of these two regimes in floodplain forests by means of objective statistic parameters. Furthermore, only longterm statements can take into account the age spectrum of the hardwood stand.