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Dendrocronologia de árvores de Tectona grandis L. e Pinus caribaea var. hondurensis Barr. et Golf de plantação da Mata da Pedreira, Campus da ESALQ-USP, Piracicaba, SP / Dendrochronology of Tectona grandis L. and Pinus caribaea var. hondurensis Barr. et Golf. trees from plantation of Mata da Pedreira, Campus ESALQ-USP,Piracicaba,SP.Alejandro Danilo Venegas González 31 October 2013 (has links)
As árvores de Tectona grandis (Verbenaceae) e de Pinus caribaea var. hondurensis (Pinaceae) são utilizadas em estudos dendroecológicos e dendroclimatológicos pela formação de anéis de crescimento anuais duas espécies plantadas na Mata da Pedreira do Campus da ESALQ/USP para estudos ecológicos e climáticos. Foram selecionadas 8 árvores de Tectona grandis (4 com e 4 sem lianas ocupando a copa das árvores) e 10 árvores de Pinus caribaea var. hondurensis (8 vivas - 4 com e 4 sem lianas ocupando a copa das árvores - e 2 mortas). Com a utilização de sondas de Pressler foram extraídas 2-6 amostras do lenho/árvore das 2 espécies para analisar seus anéis de crecimiento. Foi realizada (i) a caracterização anatômica macro e microscópica dos anéis de crescimento; (ii) estudos de dendrocronologia, pela datação e avaliação do crescimento radial do tronco das árvores; (iii) avaliação da densidade do lenho por densitometria de raios X para a determinação da densidade dos anéis de crescimento, incremento de biomassa e de carbono; (iv) avaliação da influência do clima local e em grande escala no crescimento do tronco das árvores; (v) análise dos vasos das árvores de T. grandis e dos anéis de crescimento falsos nas árvores de P. caribaea. Os resultados principais mostraram que as características anatômicas dos anéis de crescimento das árvores as 2 espécies coincidem com os descritos na literatura; a série de anéis de crescimento mostrou correlação significativa em relação à sincronização dos anéis de crescimento das árvores das 2 espécies. O efeito prejudicial das lianas na copa das árvores de T. grandis e de P. caribaea foi comprovado pela redução da largura dos anéis de crescimento no período de 2000-11 e de 1971-2011, respectivamente. A densidade aparente média dos anéis de crescimento (T. grandis: 0,64 g/cm3 e de P. caribaea: 0,60 g/cm3) permitiu calcular o incremento de massa de carbono, resultando que as árvores sem lianas apresentam maior estoque de carbono do que as com lianas. A análise dendroclimatológica mostrou que as árvores de P. caribaea apresentaram correlações positivas com a disponibilidade de água no solo no período de seca; as árvores de T. grandis mostram correlação positiva com o período de maior chuva, temperatura de primavera e a oscilação antártica (AAO) de outono no ano corrente de crescimento, e correlação negativa com o evento de El Niño (TNI) em outono anterior. A ocupação das lianas na copa das árvores de T. grandis provocou o aumento da área dos vasos; os vasos do lenho inicial (e sua frequência) mostraram correlação significativa com a largura dos anéis de crescimento, possibilitando a construção de cronologias desses parâmetros e a avaliação da influência climática nas árvores. A ocupação das lianas na copa das árvores de P. caribaea induziu diminuição da frequência dos anéis de crescimento falsos, formados, principalmente, pelo aumento das pricipatações de Julio anterior y verão (DJF) e corrente. Os resultados deste estudo permitiram concluir que a análise dos anéis de crescimento das árvores das 2 espécies tem grande potencial para estudos ecológicos e ambientais no Brasil. / The trees of Tectona grandis (Verbenaceae) and Pinus caribaea var. hondurensis (Pinaceae) are used in dendroecological and dendroclimatologal studies by formation the annual growth rings. For these reasons, the study aimed to examine the tree-rings of the two species planted in Mata da Pedreira in Campus ESALQ/USP to climatic and ecological studies. We selected eight T. grandis trees (4 with and 4 without lianas occupying the trees canopy) and 10 P. caribaea trees (8 live - 4 with and 4 without lianas- and 2 dead). With the use Pressler increment borer was extracted 2-6 wood samples/tree of two species to analyze their trees-rings growth. Were applied: i) anatomical characterization macro and microscopic of trees-rings; ii) dendrochronology studies, by dating and evaluation of the trees radial growth; iii) evaluating the density of the wood by X-ray densitometry for determination of tree-rings density, biomass and carbon increment; iv) evaluating of influence of local climate and large-scale on tree-rings; v) Analysis of the vessel in T. grandis trees and false rings in P.caribaea trees. The main results showed that the anatomical characteristics of trees-rings of the both species coincide with those described in the literature; the series of trees-rings showed significant correlation with respect to the synchronization of trees-rings in the two species. The unfavorable effect of lianas in the canopy of trees T. grandis and P. caribaea was confirmed by the reduction of the tree-rings width in period 2000-2011 and 1976-2011, respectively. . The apparent density average of tree-rings (T. grandis: 0,64 g/cm3 e de P. caribaea: 0,60 g/cm3) allowed us to calculate the increase of carbon mass, resulting that trees without lianas had higher carbon stocks than those with lianas. The climatological analysis showed that P. caribaea showed positive correlations with water availability in the soil in the dry season; T. grandis trees showed positive correlations with period of highest rainfall, temperature of spring and AAO of fall in the current growing season, and negative correlation with El Niño event (TNI) in the fall. The ocupation of lianas on T. grandis trees caused the increase of the vessels area; the earlywood vessels (and frequency) had a significant correlation with the tree-rings, allowing build of chronologies of these parameters and evaluate the influences climate in the trees. The ocupation of lianas on P. caribaea trees induced a decrease in false rings, which are formed primarily by the increase of the previous July and current summer (DJF). The results of this study showed that the tree-rings analysis of the two species has great potential to ecological and climatical studies in Brazil.
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Matéria orgânica de um argissolo vermelho distrófico úmbrico após a introdução de fitofisionomias antrópicas / Organic matter in argissolo vermelho distrófico úmbrico after introduction of anthropogenic fitofisionomys FITOFISIONOMYS.Soares, Julio Cesar Wincher 04 May 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In the state of Rio Grande do Sul the expansion of forestry has been one of the major
agents of landscape change, occupying land previously intended for livestock farming
and agriculture with low technical level, in areas under the influence of the Pampa
biome and the transition of this biome for the Atlantic Forest. There is a widespread
belief about the negative impacts caused by forest plantations on natural resources.
Thus, it is necessary to evaluate the impacts caused by the introduction of forest
plantations on the landscape components, especially on the soil and organic matter. This
study was performed to characterize the components of the landscape topography,
vegetation cover and their relations with soil, as well as temporal variation in soillandscape
Forestry Experiment Station, located in the central region of Rio Grande do
Sul were also found, changes in inventory levels and nitrogen (N and SN) and organic
carbon (CO and SCO) in profiles Typic Umbrian and the labile and stable organic
matter in surface horizon of the soil under native forest at the intermediate stage
regeneration and field man-made with over 35 years, mixed forest of Eucalyptus and
Eucalyptus robusta 35, forest of Eucalyptus grandis with 4 and 21 years, forest of
Acacia mearnsii at age 7, forest of Eucalyptus saligna and 6 years mixed forest with
Pinus 10 years. The results indicated that there is a transitory components of the
landscape between the edge of the Southern Rio Grande Plateau and the Central
Depression of Rio Grande do Sul, as well, there is a characterization of the natural
vegetation types and conflicts of land use. It was also found that the relief and the
genesis of the soils were vegetational conditions for development and that in 22 years
there have been expanding cultivation of Eucalyptus and Pinus and the native forest on
the anthropic field, especially in lands with Argissolos Bruno-Acinzentados and
Argissolos Vermelhos. The organic matter of Argissolo Vermelho distrófico úmbrico,
the results suggest that the levels and stocks of nitrogen and organic carbon of their
surface horizon, altered by the introduction of man-made forest and field areas of
deciduous forest, with a decrease especially in land occupied by forest of Acacia
mearnsii and field of human activity. In relation to the stocks of organic carbon and
nitrogen in the soil profile had a greater influence of other factors and processes of soil
formation than the occupation of land in the last four decades. We also observed
changes in the distribution of particulate organic carbon (POC g.kg-1) in the surface
horizon of the soil, and this organic matter fraction of a sensitive indicator of changes in
land use and soil. / No estado do Rio Grande do Sul a expansão da silvicultura tem atuado como um dos
principais agentes de alteração da paisagem, ocupando terras anteriormente destinadas à
pecuária extensiva e à agricultura com baixa tecnificação, em áreas sob a influência do
bioma Pampa e na transição desse bioma para o de Mata Atlântica. Existe uma crença
generalizada acerca dos impactos negativos ocasionados pelas plantações florestais
sobre os recursos naturais. Assim, faz-se necessária a avaliação dos impactos causados
pela introdução dos plantios florestais sobre os componentes da paisagem,
principalmente sobre o solo e sua matéria orgânica. Neste estudo foi realizada a
caracterização dos componentes da paisagem relevo, cobertura vegetal e suas relações
com os solos, além da variação temporal da relação solo-paisagem numa Estação
Experimental de Silvicultura, localizada na região central do Rio Grande do Sul. Foram
verificadas também, as alterações nos teores e estoques de nitrogênio (N e SN) e de
carbono orgânico (CO e SCO) em perfis de Argissolo Vermelho distrófico úmbrico e as
frações lábeis e estáveis da matéria orgânica do horizonte superficial desse solo sob a
Floresta nativa em estágio médio de regeneração e campo antrópico com mais de 35
anos, floresta mista do gênero Eucalyptus e de Eucalyptus robusta com 35 anos, floresta
de Eucalyptus grandis com 4 e 21 anos , floresta de Acacia Mearnsii com 7 anos,
floresta de Eucalyptus saligna com 6 anos e floresta mista do gênero Pinus com 10
anos. Os resultados indicaram que há um caráter transitório nos componentes da
paisagem, entre o Rebordo do Planalto Sul-Riograndense e a Depressão Central do Rio
Grande do Sul, como também, existe uma descaracterização das fitofisionomias naturais
e a existência de conflitos de uso do solo. Constatou-se também, que o relevo e a gênese
dos solos foram condicionantes para o desenvolvimento fitofisionômico e que em 22
anos houve expansão dos cultivos de Eucalyptus e Pinus, e da floresta nativa sobre o
campo antrópico, principalmente nas terras com Argissolos Bruno-Acinzentados e
Argissolos Vermelhos. Quanto à matéria orgânica do Argissolo Vermelho distrófico
úmbrico, os resultados sugerem que os teores e estoques de nitrogênio e carbono
orgânico do seu horizonte superficial, apresentam alterações frente à introdução de
florestamentos e do campo antrópico sobre áreas de Floresta Estacional Decidual,
havendo decréscimo principalmente em terras ocupadas pela floresta de Acacia
Mearnsii e campo antrópico. Já em relação aos estoques de nitrogênio e carbono
orgânico no perfil do solo, houve maior influência dos demais fatores e processos de
formação do solo do que a ocupação das terras nas últimas quatro décadas. Foram
constatadas também alterações na distribuição do carbono orgânico particulado (POC
g.kg-1) no horizonte superficial do solo, sendo esta fração da matéria orgânica um
indicador sensível às alterações no uso e ocupação do solo.
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Análise bioeconômica do seqüestro florestal de carbono e da dívida ecológica: uma aplicação ao caso do Rio Grande do Sul / .Giacomelli Sobrinho, Valny 03 December 2007 (has links)
Though heavily criticized, the Kyoto Protocol has stood out as the key political tool in addressing climate change. However the only of its instruments (IET, JI, CDM) that allows industrialized and developing countries to cooperate towards mitigation of GHGs is CDM. The underlying assumption of forestry CDM is that forest plantations (afforestation/ reforestation) might help to remove carbon dioxide (the most representative GHG) emissions. This assumption takes for granted that forest plantations might compensate for the loss of natural forests. Therefore this alleged trade-off constitutes the very focus of this study. Due to high monetary price instability in brand new markets, like the carbon offset one, the analysis abstracts out money variables. Additionally, this engine helps overcome the trap set up by monetary prices as scarcity indicators. Thus, to go along with the bioeconomic analysis, a Gordon-Schaefer fishery-like model is applied to carbon forest sequestration in Rio Grande do Sul. This state is thought of bringing an interesting picture to the analysis of the claimed trade-off between natural and planted forests. This owes both to Rio Grande do Sul s unworthy deforestation rates and to its high natural-to-planted forest ratio. This land use assortment is thought of as if there were two countries or regions: a forest-rich one, where natural forests still remain, and a forest-poor one, where afforestation and/or reforestation takes place. Only physical units (MtC) are used to calculate exchange and interest rates as well as non-monetary prices. Next, a function that assigns the land use to natural and planted forests is arrived at. As such, it works as the emission removal demand. On the other hand, the emission supply function depends on the economic growth rates. The results show that, eventually, the sustainability of economic growth hinges on a region s or country s ecological situation namely, equilibrium, credit or debt. The economic and environmental advantages of each mitigation strategy CDM and natural forest conservation are crosschecked. A nearly 40-year long overshoot rate is, after all, estimated for the forest sector in Rio Grande do Sul. The estimates suggest that CDM might help relieve environmental stress only where ecological credit is reported. Where ecological debt is already on, CDM was found unable to compensate for conservation disregard. / Apesar das críticas que tem sofrido, o Protocolo de Kyoto tem-se constituído na principal ferramenta política para enfrentar a mudança climática. No entanto o único de seus instrumentos (comércio internacional de emissões, implementação conjunta e MDL) que prevê a cooperação entre países industrializados e em desenvolvimento para mitigar as emissões de GEE é o MDL. A modalidade florestal do MDL pressupõe que as plantações florestais (florestamento/reflorestamento) podem ajudar na remoção das emissões de dióxido de carbono (o GEE mais representativo). Esse pressuposto aceita que as plantações florestais podem compensar a perda de florestas naturais. Por isso esse proclamado trade-off constitui o foco principal deste estudo. Devido à grande instabilidade dos preços monetários em mercados incipientes como o do carbono, a análise abstém-se de utilizar variáveis monetárias. De resto, esse artifício ajuda a contornar certas dificuldades decorrentes da utilização dos preços monetários como indicadores de escassez. Assim, a análise bioeconômica prossegue com a aplicação, ao seqüestro florestal de carbono no Rio Grande do Sul, de um modelo similar ao de Gordon-Schaefer, tradicionalmente empregado na gestão da pesca. Por duas razões principais, o caso do Rio Grande do Sul contribui para a análise do suposto trade-off entre florestas naturais e plantadas. Em primeiro lugar, por não se registrarem taxas de desmatamento pronunciadas no estado. Em segundo lugar, pela elevada proporção de florestas naturais em relação às florestas plantadas em seu território. A repartição do uso do solo entre as florestas é utilizada para estudá-las como se representassem nações ou regiões diferentes: uma, rica em florestas, onde as formações florestais nativas permanecem em pé; outra, pobre em florestas, onde as plantações florestais se estabelecem através de florestamento e/ou reflorestamento. Apenas unidades físicas (MtC) são utilizadas para calcular taxas de câmbio, taxas de juro e preços não-monetários. A seguir, deduz-se uma função que reparte o uso da terra entre florestas naturais e plantadas. Essa função equivale à demanda por remoção de emissões. Sua contraparte é a função oferta de emissões, que depende das taxas de crescimento econômico. Os resultados mostram como, em última análise, a sustentação do crescimento econômico está condicionada à situação ecológica (dívida, crédito ou equilíbrio) de um país ou região. Em cada cenário, confrontam-se as vantagens econômicas e ambientais das estratégias do MDL e da conservação de florestas naturais. Além disso, estima-se uma taxa de overshoot para a atividade florestal no Rio Grande do Sul ao longo dos últimos 40 anos aproximadamente. As estimativas sugerem que o MDL pode aliviar pressões ambientais somente onde se registre crédito ecológico. Onde o endividamento ecológico já esteja em curso, o MDL não substitui a conservação.
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Geovisualization of boreal peatland architecture in a three dimensional hydrogeological framework using ground penetrating radar and LiDAR at Mariana Lakes, Alberta, CanadaShulba, William Paul 07 June 2021 (has links)
Communicating science in three-dimensional (3D) multimedia is an immersive and interactive way to explore scientific processes (Signals and Communication Technology, 2019). Geovisualization is an emerging 3D multimedia method for visual analysis, synthesis, and presentation of geospatial, geologic, and geophysical data (MacEachren & Kraak, 2001). There is an identified need to develop scientific communication tools to further understand boreal peatland evolution, hydrogeology, ecology, and geochemistry (Bubier et al., 2003) since the International Union of Conservation of Nature asserts that peatlands are among the most valuable ecosystems on Earth, critical for preserving global biodiversity, providing drinking water, minimising flood risk, preventing wildfire, and mitigating climate change (Hama et al., 2000).
The intention of this thesis is to communicate a novel approach to geovisualize boreal peatland architecture using Light Detection and Ranging (LiDAR) and Ground Penetrating Radar (GPR). GPR and LiDAR have been used to create 3D subsurface geovisualizations for archaeology (Kenady et al., 2018; Schultz & Martin, 2011) and resource geology (Corradini et al., 2020; Koyan & Tronicke, 2020) although application to peatland hydrogeology is uncommon.
Point-source hydrogeological and geochemical data were integrated with 3D geological models to estimate carbon and nitrogen storage in an archetypal boreal peatland near Mariana Lakes, Alberta. Peatland geometry resembled a shallow lake basin with depths greatest in fens (>10 m) and thinnest in bogs (<2 m). Hydraulic conductivity was only a few meters per year and vertical groundwater movement was limited. Sequestered carbon and nutrients increased with depth. The average concentration of dissolved ammonium was 3 grams per cubic metre of peat (g/m3), 5g/m3of Total Kjeldahl Nitrogen, 60g/m3 of dissolved organic carbon and 200g/m3 of dissolved inorganic carbon. Tritium detection from atmospheric atomic weapons radionuclide fallout revealed that in deeper anaerobic peat (catotelm), tritium was absent, signifying groundwater was older than 50 years and not mixed with meteoric waters. Fen catotelm channels are likely acting as gravity-driven hydraulic traps (Tóth, 1999). / Graduate
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Quantifying Global Exchanges of Methane and Carbon Monoxide Between Terrestrial Ecosystems and The Atmosphere Using Process-based Biogeochemistry ModelsLicheng Liu (8771531) 02 May 2020 (has links)
<p>Methane (CH<sub>4</sub>) is the
second most powerful greenhouse gas (GHG) behind carbon dioxide (CO<sub>2</sub>),
and is able to trap a large amount of long-wave radiation, leading to surface
warming. Carbon monoxide (CO) plays an important role in controlling the
oxidizing capacity of the atmosphere by reacting with OH radicals that affect
atmospheric CH<sub>4</sub> dynamics. Terrestrial ecosystems play an important
role in determining the amount of these gases into the atmosphere. However,
global quantifications of CH<sub>4</sub> emissions from wetlands and its sinks
from uplands, and CO exchanges between land and the atmosphere are still
fraught with large uncertainties, presenting a big challenge to interpret
complex atmospheric CH<sub>4</sub> dynamics in recent decades. In this
dissertation, I apply modeling approaches to estimate the global CH<sub>4</sub>
and CO exchanges between land ecosystems and the atmosphere and analyze how
they respond to contemporary and future climate change.</p>
<p>Firstly, I develop
a process-based biogeochemistry model embedded in Terrestrial Ecosystem Model
(TEM) to quantify the CO exchange between soils and the atmosphere at the
global scale (Chapter 2). Parameterizations were conducted by using the CO <i>in
situ</i> data for eleven representative ecosystem types. The model is then
extrapolated to global terrestrial ecosystems. Globally soils act as a sink of
atmospheric CO. Areas near the equator, Eastern US, Europe and eastern Asia
will be the largest sink regions due to their optimum soil moisture and high
temperature. The annual global soil net flux of atmospheric CO is primarily
controlled by air temperature, soil temperature, SOC and atmospheric CO
concentrations, while its monthly variation is mainly determined by air
temperature, precipitation, soil temperature and soil moisture. </p>
<p>Secondly, to
better quantify the global CH<sub>4</sub> emissions from wetlands and their
uncertainties, I revise, parameterize and verify a process-based biogeochemical
model for methane for various wetland ecosystems (Chapter 3). The model is then
extrapolated to the global scale to quantify the uncertainty induced from four
different types of uncertainty sources including parameterization, wetland type
distribution, wetland area distribution and meteorological input. Spatially,
the northeast US and Amazon are two hotspots of CH<sub>4</sub> emissions, while
consumption hotspots are in the eastern US and eastern China. The relationships
between both wetland emissions and upland consumption and El Niño and La Niña
events are analyzed. This study highlights the need for more in situ methane
flux data, more accurate wetland type and area distribution information to
better constrain the model uncertainty.</p>
<p>Thirdly, to
further constrain the global wetland CH<sub>4</sub> emissions, I develop a
predictive model of CH<sub>4</sub> emissions using an artificial neural network
(ANN) approach and available field observations of CH<sub>4</sub> fluxes
(Chapter 4). Eleven explanatory variables including three transient climate
variables (precipitation, air temperature and solar radiation) and eight static
soil property variables are considered in developing the ANN models. The models
are then extrapolated to the global scale to estimate monthly CH<sub>4</sub>
emissions from 1979 to 2099. Significant interannual and seasonal variations of
wetland CH<sub>4</sub> emissions exist in the past four decades, and the
emissions in this period are most sensitive to variations in solar radiation
and air temperature. This study reduced the uncertainty in global CH<sub>4</sub>
emissions from wetlands and called for better characterizing variations of
wetland areas and water table position and more long-term observations of CH<sub>4</sub>
fluxes in tropical regions.</p>
<p>Finally, in order
to study a new pathway of CH<sub>4</sub> emissions from palm tree stem, I
develop a two-dimensional diffusion model. The model is optimized using field
data of methane emissions from palm tree stems (Chapter 5). The model is then
extrapolated to Pastaza-Marañón foreland basin (PMFB) in Peru by using a
process-based biogeochemical model. To our knowledge, this is among the first efforts
to quantify regional CH<sub>4</sub> emissions through this pathway. The
estimates can be improved by considering the effects of changes in temperature,
precipitation and radiation and using long-period continuous flux observations.
Regional and global estimates of CH<sub>4</sub> emissions through this pathway
can be further constrained using more accurate palm swamp classification and
spatial distribution data of palm trees at the global scale.</p>
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QUANTIFYING CARBON FLUXES AND ISOTOPIC SIGNATURE CHANGES ACROSS GLOBAL TERRESTRIAL ECOSYSTEMSYoumi Oh (9179345) 29 July 2020 (has links)
<p>This thesis is a collection of three research
articles to quantify carbon fluxes and isotopic signature changes across global
terrestrial ecosystems. Chapter 2, the first article of this thesis, focuses on
the importance of an under-estimated methane soil sink for contemporary and
future methane budgets in the pan-Arctic region. Methane emissions from
organic-rich soils in the Arctic have been extensively studied due to their
potential to increase the atmospheric methane burden as permafrost thaws.
However, this methane source might have been overestimated without considering
high affinity methanotrophs (HAM, methane oxidizing bacteria) recently identified
in Arctic mineral soils. From this study, we find that HAM dynamics double the
upland methane sink (~5.5 TgCH<sub>4</sub>yr<sup>-1</sup>) north of 50°N in
simulations from 2000 to 2016 by integrating the dynamics of HAM and
methanogens into a biogeochemistry model that includes permafrost soil organic
carbon (SOC) dynamics. The increase is equivalent to at least half of the
difference in net methane emissions estimated between process-based models and
observation-based inversions, and the revised estimates better match site-level
and regional observations. The new model projects double wetland methane
emissions between 2017-2100 due to more accessible permafrost carbon. However,
most of the increase in wetland emissions is offset by a concordant increase in
the upland sink, leading to only an 18% increase in net methane emission (from
29 to 35 TgCH<sub>4</sub>yr<sup>-1</sup>). The projected net methane emissions
may decrease further due to different physiological responses between HAM and
methanogens in response to increasing temperature. This article was published
in <i>Nature Climate Change</i> in March
2020.</p>
<p>In Chapter 3, the second article of this
thesis, I develop and validate the first biogeochemistry model to simulate
carbon isotopic signatures (δ<sup>13</sup>C)
of methane emitted from global wetlands, and examined the importance of the wetland
carbon isotope map for studying the global methane cycle. I incorporated a carbon isotope-enabled module into an
extant biogeochemistry model to mechanistically simulate the spatial and
temporal variability of global wetland δ<sup>13</sup>C-CH<sub>4</sub>. The new
model explicitly considers isotopic fractionation during methane production,
oxidation, and transport processes. I estimate a mean global wetland δ<sup>13</sup>C-CH<sub>4</sub> of
-60.78‰ with its seasonal and inter-annual variability. I find that the new
model matches field chamber observations 35% better in terms of root mean
square estimates compared to an empirical static wetland δ<sup>13</sup>C-CH<sub>4</sub> map.
The model also reasonably reproduces the regional heterogeneity of wetland δ<sup>13</sup>C-CH<sub>4</sub> in
Alaska, consistent with vertical profiles of δ<sup>13</sup>C-CH<sub>4</sub>
from NOAA aircraft measurements. Furthermore, I show that the latitudinal
gradient of atmospheric δ<sup>13</sup>C-CH<sub>4</sub> simulated by a chemical
transport model using the new wetland δ<sup>13</sup>C-CH<sub>4</sub> map
reproduces the observed latitudinal gradient based on NOAA/INSTAAR global
flask-air measurements. I believe this study is the first process-based
biogeochemistry model to map the global distribution of wetland δ<sup>13</sup>C-CH<sub>4</sub>,
which will significantly help atmospheric chemistry transport models partition
global methane emissions. This article is in preparation for submission
to <i>Nature Geoscience</i>.</p>
<p>Chapter 4 of this thesis, the third
article, investigates the importance of leaf carbon allocation for seasonal
leaf carbon isotopic signature changes and water use efficiency in temperate
forests. Temperate deciduous trees remobilize stored carbon early in the
growing season to produce new leaves and xylem vessels. The use of remobilized
carbon for building leaf tissue dampens the link between environmental stomatal
response and inferred intrinsic water use efficiency (iWUE) using leaf carbon
isotopic signatures (δ<sup>13</sup>C). So far, few studies consider carbon
allocation processes in interpreting leaf δ<sup>13</sup>C signals. To
understand effects of carbon allocation on δ<sup>13</sup>C and iWUE estimates,
we analyzed and modeled the seasonal leaf δ<sup>13</sup>C of four temperate
deciduous species (<i>Acer saccharum, Liriodendron tulipifera, Sassafras
albidum, </i>and <i>Quercus alba</i>)
and compared the iWUE estimates from different methods, species, and drought
conditions. At the start of the growing season, leaf δ<sup>13</sup>C values
were more enriched, due to remobilized carbon during leaf-out. The bias towards
enriched leaf δ<sup>13</sup>C values explains the higher iWUE from leaf
isotopic methods compared with iWUE from leaf gas exchange measurements. I
further showed that the discrepancy of iWUE estimates between methods may be
species-specific and drought sensitive. The use of δ<sup>13</sup>C of plant
tissues as a proxy for stomatal response to
environmental processes, through iWUE, is complicated due to carbon
allocation and care must be taken when interpreting estimates to avoid proxy
bias. This
article is in review for publication in <i>New
Phytologist</i>.</p>
<p> </p>
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Geochemical impact of super-critical C02 injection into the St. Peter Sandstone Formation within the Illinois Basin : implication for storage capability in a carbon dioxide sequestrian systemThomas, Richard Michael January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Deep injection of waste CO2 and fluids from regional energy plants into the St. Peter Formation of the Illinois Basin, could effectively provide long term deep geologic storage. This research aims to explore the viability of this proposed injection. There are some basic criteria that must be met to effectively store waste in a geologic reservoir.
First, the reservoir must have sufficient porosity and permeability for both injectivity and for migration of the injected fluid through the reservoir. Second, the reservoir must be overlain by some form of impermeable seal or cap layer(s). Third, the reservoir should be sufficiently isolated from interaction with surface and near surface water. Finally, the formation must contain enough storage volume to handle significant amounts of injected material.
Massive sandstone formations that host large saline aquifers have the potential to serve as high capacity storage sites. Much of the research targeting the potential suitability and storage capacity attributes of these formations has been promising, but reproducibility of the results has been less than ideal. Some of this variability has been attributed to petrological differences in the sandstone reservoirs that are not readily evident when studying the target formation over a geographically significant area.
Based on the criteria, a promising candidate for injection and storage is the St. Peter Sandstone of the Illinois Basin. This study investigates the viability of liquefied CO2 storage within the St. Peter Sandstone on a micro scale.
Initial porosity and permeability of the formation plug samples ranged from 16% to 19% and 26 to 981 millidarcies (mD), respectively. The wide difference in permeability is attributed to variations in strength of the cement, in this case quartz overgrowth in the sandstone. This preliminary evidence indicates that the storage capacity of the formation will remain constant or increase depending on injection location, suggesting that the St. Peter Formation will lend itself well to future storage.
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Laser-Induced Breakdown Spectroscopy: Simultaneous Multi-Elemental Analysis and Geological ApplicationsSanghapi, Herve Keng-ne 06 May 2017 (has links)
Under high irradiation, a fourth state of matter named plasma can be obtained. Plasmas emit electromagnetic radiation that can be recorded in the form of spectra for spectroscopic elemental analysis. With the advent of lasers in the 1960s, spectroscopists realized that lasers could be used simultaneously as a source of energy and excitation to create plasmas. The use of a laser to ignite a plasma subsequently led to laser-induced breakdown spectroscopy (LIBS), an optical emission spectroscopy capable of analyzing samples in various states (solids, liquids, gases) with minimal sample preparation, rapid feedback, and endowed with in situ capability. In this dissertation, studies of LIBS for multi-elemental analysis and geological applications are reported. LIBS was applied to cosmetic powders for elemental analysis, screening and classification based on the raw material used. Principal component analysis (PCA) and internal standardization were used. The intensity ratios of Mg/Si and Fe/Si observed in talcum powder show that these two ratios could be used as indicators of the potential presence of asbestos. The feasibility of LIBS for the analysis of gasification slags was investigated and results compared with those of inductively-coupled plasma−optical emission spectrometry (ICP-OES). The limits of detection for Al, Ca, Fe, Si and V were determined. The matrix effect was studied using an internal standard and PLS-R. Apart from V, prediction results were closed to those of ICP-OES with accuracy within 10%. Elemental characterization of outcrop geological samples from the Marcellus Shale Formation was also carried out. The matrix effect was substantially reduced. The limits of detection obtained for Si, Al, Ti, Mg, Ca and C were determined. The relative errors of LIBS measurements are in the range of 1.7 to 12.6%. Gate delay and laser pulse energy, have been investigated in view of quantitative analysis of variation of trace elements in a high-pressure environment. Optimization of these parameters permits obtaining underwater plasma emission of calcium with quantitative results on the order of 30 ppm within a certain limit of increased pressure. Monitoring the variation of the trace elements can predict changes in the chemical composition in carbon sequestration reservoir.
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Quantification of carbon emissions and removals from land, plants, and products : A case study of cotton used in IKEA'sproductsXie, Ting January 2021 (has links)
The method framework for quantifying the carbon emissions and removals from land, plants and products for cotton is developed in this study, which is feasible for most cotton supply chains. Collected defaults and suggested sources for required data inputs are provided. Current data gaps are defined, including the knowledge gap found in the storage time of cotton in the product pool, which requires further investigation in the future. Based on the quantification results of IKEA's case in 2019, there is a net 2.9 kg carbon stock increase per kg purchased cotton on average, equivalently offsetting 10.2% of global warming potential caused by cotton lint production emissions. Analysis results indicate that land-based carbon removals can be a cost-effective approach to achieve climate mitigation for cotton corporations. The amount of removed carbon can be greatly improved by avoiding emissions from land use change, adopting a higher level of conservation tillage to improve mineral soil carbon sequestration, and increasing carbon storage time in products to enlarge the climate benefit of cotton products carbon removals. Based on case study results, the carbon removals potential of global cotton production is estimated to be 5.4 Mt CO2-eq in 2019 and projected to reach 6.2 Mt CO2-eq in2029, which can mitigate over 0.01% of the GWP caused by the total worldwide anthropogenic emissions. Though this climate mitigation is relatively small, it breaks out the general cognition of agriculture carbon removals and provides us preliminary insight into cotton carbon sequestration capability and its potential.
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Functioning of Mediterranean ecosystems in response to forest fires and post-fire management activitiesMoghli, Aymen 15 July 2022 (has links)
In Valencia region (SE Spain), many post-fire communities are dominated by non-resprouting (seeder) species, because of the long history of land exploitation and subsequent abandonment during the last half of 20th century. These communities accumulate fine dry biomass and, therefore, can burn again easily. In fact, Mediterranean forests are suffering from an increase in wildfire frequency since the early 1970s. Wildfires shape the composition and functioning of Mediterranean ecosystems, but we do not know how these ecosystems respond to both the higher fire recurrence and shorter recovery times expected for future climatic scenarios. In this sense, Aleppo pine forest (Pinus halepensis) is one of the most fire affected vegetation of this type in the Mediterranean Basin and to know how it respond to fire is fundamental to design management plans. After fire, regeneration of this forest can be highly variable, and it can go from extremely dense tree stands (overstocked pine) to treeless shrublands dominated by seeder species. All these regenerated stands are fire prone with limited ability to deliver multiple ecosystem services. Although several management techniques are applied to redirect these post-fire ecosystems towards less vulnerable and more functional communities, we do not know yet which amongst them could serve to foster more diverse and multifunctional landscapes. Therefore, the general objective of this thesis is to investigate the functioning of these Mediterranean ecosystems as consequence of shifts in fire regime and forest management application, using different techniques, in different post-fire regenerated ecosystems (overstocked pine forests and dense shrublands). To do so, we calculate, within Mediterranean Pinus halepensis forests affected by wildfires, the supply of multiple ecosystem services (biodiversity conservation, carbon sequestration, disturbance regulation, food production, supporting services, and multifunctionality), through up to 25 aboveground and belowground attributes. Our main findings are (1) High fire recurrence and time since last fire interacted to determine ecosystem services but did not affect their synergies and trade-offs between them. Their combined effects reduced carbon sequestration and multifunctionality. Disturbance regulation diminished drastically with the first fire, with no effect of further fires. However, their effects dampened, and even became positive, for biodiversity conservation and food production services if provided enough time to recover. (2) Thinning in overstocked pine stands enhances ecosystem attributes associated with biodiversity conservation without compromising the provision of carbon sequestration. After 10 years, two levels of thinning, (600 and 1200 trees·ha-1), similarly affected ecosystem attributes, which suggest that 1200 trees·ha-1 suffice to enhance individual ecosystem attributes. (3) Clearing within dense shrubland dominated by seeder species enhances ecosystem attributes associated with biodiversity conservation without compromising the capacity of ecosystem to sequester carbon. (4) Plantation of resprouting species combined with thinning and clearing, in overstocked pine forests and dense shrublands respectively, can enhance the provision of ecosystem services of disturbance regulation, food production and ecosystem multifunctionality. (5) Prescribed burning reduces the amount of dead fuel, increases biodiversity conservation, and improves food production. However, these effects become negative, in addition to the decline in disturbance regulation and multifunctionality, if prescribed burning is applied frequently. (6) Combining different management activities can enhance the supply of multiple ecosystem services simultaneously by reducing the trade-offs in between them and therefore, establish multifunctional Mediterranean landscapes.
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