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Tesis sobre el tema "Forest and tea soils"

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Publicado: 18 de mayo de 2024

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1

Ombina, Christian Ahmed. "Soil characterisation for teak (Tectona grandis) plantations in the Nzara district of Southern Sudan". Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2260.

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Thesis (MScFor (Forest and Wood Science))--Stellenbosch University, 2008.
The characterization of soils in Nzara District of Southern Sudan in comparison to other tropical teak growing countries (Tectona grandis) – in respect of extensions to existing and/or the establishment of new teak plantations – were done by firstly considering the soils of three existing plantations: Yoboa, Mabarizinga and Nagondi, and secondly by considering soils outside and inside the existing teak plantations in respect of land uses. From these soil characterizations, it emerged that considerable positive returns can be expected from teak plantings in the area as an investment, provided that appropriate site management is implemented. Climatic data of the Nzara area compared favorably with the climatic range of areas where teak grows naturally and the world’s dominant producers: mean annual rainfall 1350-1600 mm with a distribution over 6-8 months compares well with that of Myanmar (1250-3750 mm) and Indonesia (1511-2108 mm) both with at least 3 months of dry season. The mean annual temperature of 28-350C compares well with 15-410C and 30-320C of Myanmar and Indonesia respectively. The Yoboa and Mabarizinga sites should be prioritized as they appear slightly more suitable than the Nagondi site. All three sites have a dominant soil texture of Sandy Clay Loam similar to Sandy Loam of most areas of other tropical countries where teak is growing well (such as India, Indonesia and Nigeria). Yoboa and Mabarizinga however distinguish themselves by having the highest soil pHwater values range from 6.4±0.56 and 6.04±0.7 in top soils; 5.91±0.5 and 5.46±0.61 in subsoils at Yoboa and Mabarizinga respectively; the highest soil organic matter content 1.8±0.34% and 1.92±0.43% in topsoil 0.89±0.16% and 1.13±0.19% in subsoils; as well as the highest P content in both available (0.09±0.04% and 0.03±0.04% for topsoils) and total forms (1.19±0.26% and 0.9±0.3% also on topsoils). These values though very low in absolute terms, are not much different from those of other tropical teak-growing countries. Management strategies intended to preserve and improve the present status, particularly the protection of top soil horizons against mainly water erosion, would be able to boost the site productivity.
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2

Amponsah, Isaac G. "Forest soil characteristics and variability under teak, Tectona grandis Linn. F, plantations and natural forests in Ashanti Region, Ghana". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0023/MQ52036.pdf.

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3

Offord, Jilene L. "Nitrogen mineralization patterns of boreal forest soils". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ40091.pdf.

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4

Rudebeck, Anna. "Factors affecting nitrification in European forest soils /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5879-X.pdf.

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5

Michopoulos, P. "Studies on manganese cycling in forest soils". Thesis, University of Aberdeen, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593112.

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An assessment of manganese distribution in podzols, brown earth, gley, and peat soils in NE Scotland showed that most of the manganese was in a form unavailable to plants (residual manganese). Among the available forms, exchangeable manganese in litter had by far the largest concentration. The percentage of total manganese in the exchangeable form in forest soils was found to have a very good correlation with organic matter concentration. Manganese oxides made a negligible contribution to the available manganese pool. It is believed that their supply is limited due to dissolution. Heather litter was found to contain larger concentrations of total manganese than forest litter. However, exchangeable manganese is lost easier from heather litter than forest litter, probably through leaching. A slow equilibration technique was applied to obtain Langmuir adsorption isotherms for manganese in simulated throughfall and Sitka spruce litter. It showed that the maximum adsorption capacity of litter reached a value of many thousands mg kg-1. Competition between hydrogen and manganese ions in simulated throughfall for adsorption sites on Sitka spruce litter was examined. It was found that the more acid treatments can leach significantly more manganese; however, exchangeable manganese is influenced by manganese concentration in throughfall and can increase in concentration proportionally to the manganese content in throughfall. It is believed that this is a defensive mechanism against excess manganese leaching from litter. A simulated acid rain experiment involving reconstituted soil profiles and young Sitka spruce trees was set up to investigate manganese fluxes and manganese cycling in the microcosms thus created.
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6

Voinot, Alexandre. "Contribution des isotopes du bore à l'étude des mécanismes et bilans de l'altération des minéraux des sols". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00873615.

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L'objectif de cette thèse est d'estimer la capacité du bore et de ses isotopes à évaluer les mécanismes et bilans de l'altération des minéraux dans les sols. Pour ce faire, trois axes ont été développés : 1) une approche expérimentale, durant laquelle un minéral-test (la biotite) est soumis à l'action de différents agents altérants représentatifs de ceux trouvés dans les sols. 2) une approche in-situ dans un sol forestier acide, menée sur des minéraux séparés (biotite, muscovite,feldspath potassique et albite), au cours de leur altération à différentes profondeurs (site de Breuil-Chenue, France). L'objectif de cette étude est de déterminer la sensibilité du bore aux processus de la formation des sols. 3) une seconde approche in-situ sur le même site expérimental, menée cette fois-ci sur les horizons superficiels (horizon A et horizon d'accumulation des oxy-hydroxydes d'aluminium), dont le but est de déterminer la sensibilité du bore et de ses isotopes aux processus liés à la proximité de la végétation (variations saisonnières, proximité des racines). Le bore permet, grâce à sa très grande réactivité durant les mécanismes d'altération par rapport aux éléments majeurs constitutifs du réseau cristallin (observable aussi bien en conditions expérimentales qu'en milieu naturel), de tracer avec une grande sensibilité les mécanismes de dissolution ou de transformation des différents minéraux primaires, et ouvre de nouvelles perspectives quant à la compréhension et la modélisation des sols.
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7

Ficklin, Robert L. "An empirical approach for better estimating soil organic carbon and bulk density using a fixed-volume sampling method /". free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074401.

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8

Dmytriw, Russell Patrick. "The partitioning of mercury in the solid components of forest soils and flooded forest soils in a hydroelectric reservoir, Québec /". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68171.

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Upon inundation, the soils in a hydroelectric reservoir are subjected to several years of physical, biological, and chemical changes as the transition from a terrestrial to an aquatic ecosystem is achieved. Changes in Eh, pH, and microbial activity are believed to alter the metal binding capacity of solid substrates (e.g., organic matter, reactive Fe and Mn oxides, and clay minerals) within the soil profile, leading to the remobilization of mercury associated with these phases.
Four cores were collected along a transect from an unflooded forest soil to a pre-impoundment lake bottom sediment in the La Grande-2 (LG-2) Reservoir and watershed. The samples were sequentially extracted to determine the distribution of mercury between three operationally-defined solid compartments: organic carbon (1N NaOH-extractable), reactive Fe and Mn oxides/hydroxides (1N HCl-extractable), and the solid (clay and sulphide) residue.
Results indicate that up to 80% of the mercury in the O-horizon in forest soils and flooded forest soils, and up to 85% of the mercury in lake sediments, is bound to the NaOH-extractable organic carbon fraction.
In the B-horizon of a forest podzol where organic content is low, 40-60% of the total mercury was found to be associated with reactive Fe minerals. In contrast, the flooded soil contains very little reactive Fe at any depth and the associated mercury concentrations are low. I propose that, upon inundation, oxide minerals are reduced and Hg released to the pore waters where it is immediately bound to an available substrate. Analyses of the residues suggest that there is an enrichment of mercury in the residual fraction immediately above the B-horizon of a flooded soil while sulphide mineralization appears to play a role in sequestering mercury in lake sediments.
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9

Lundell, Ylva. "Aspects on nutrient availability in Swedish forest soils /". Umeå : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5869-2.pdf.

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10

Daniels, W. Lee. "Virgin hardwood forest soils of western North Carolina". Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/52288.

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Little is known about the original properties of soils in the East. Eight virgin soils and associated southern Appalachian hardwood vegetation were studied in western North Carolina. The study sites ranged in elevation from 720 to 1200 m on steep slopes. Overall these soils are quite deep and highly weathered due to high rainfall (>200 cm) and soluble feldspathic parent material. Organic matter contents of the surface·horizons were quite high (4.5 - 16 %), and they contained moderate to strong crumb structure. All but one soil contained cambic subsurface horizons and were either Typic Haplumbrepts or Umbric Dystrochrepts. The majority of soils in the watershed are formed in colluvium, but significant amounts of residual soils occur on sideslopes, and appear to be quite stable. The present day landforms appear to be the result of periglacial activity. North-facing soils were higher in whole soil clay, organic matter, and A horizon exchangeable cations than south-facing soils. Cation exchange capacity in these soils is almost totally dependent on organic matter content, and the mineral fraction is relatively inert. All soils were in the oxidic mineralogy class. Bibbsite was common throughout all soils and hydroxy-interlayered vermiculite (HIV) is the dominant clay-sized phyllosilicate in surface horizons. Kaolinite was low in all soils, but was more abundant on south-facing slopes. The silt fractions and sand fractions contained significant quantities of weathered 2:1-type minerals The vegetation varied from mixed-mesophytic cove hardwoods on north-facing slopes to mixed oak-hickory and oak-pine on south-facing slopes. Many trees in coves exceed 1.3 m in diameter and 50 m in height. Total litter production averaged 3494 kg/ha, and the litter layers were typified by thin leaf (L), and well developed fermentation (F) and humus (H) layers. Cations and P are concentrated in the litter layers and immediate surface soil, while N is mixed deep into the profile. Due to their oxidic mineralogy, low CEC, decreasing clay content with depth, and concentration of cations and P in litter and standing biomass these soils highly resemble tropical Oxisols.
Ph. D.
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11

Paz, Rivera Clea Lucrecia. "Forest-use history and the soils and vegetation of a lowland forest in Bolivia". [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001426.

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12

Jenkins, Anthony Blaine. "Organic carbon and fertility of forest soils on the Allegheny Plateau of West Virginia". Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2486.

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Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains x, 282 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
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13

Gibson, Richard W. "The characterisation of soluble organic matter from forest soils". Thesis, University of Aberdeen, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295565.

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The characteristics of water-soluble organic material in soil solutions has been studied extensively 'in situ'. Relatively little attention has focused on isolation of such material, particularly when comparison of a number of samples has been attempted. In this study the water-soluble organic acids leached from the soil horizons beneath eight different tree species were isolated by adsorption onto macroporous resins. Amberlite XAD-8 and XAD-4 resins were used in series therefore two samples, labelled as 'hydrophobic' and 'hydrophilic' acids were obtained. Practical amounts of free organic acids for characterisation purposes were isolated from each resin. Elemental analysis (carbon, nitrogen and sulphur) and acidity (measured by potentiometric titration) reflected the probable state of oxidation of the material. Lower molecular weight material was more abundant with depth. Copper binding ability correlated well with the acidity generally but a group of samples isolated from similar horizons and resin showed high acidity and poor metal binding ability. This was probably due to the inability of the acidic sites to be involved in chelation reactions. Metal binding was measured using gel filtration, dialysis and an ion-exchange method. Chromatography in gel filtration was monitored by direct feed of column effluent into an atomic absorption spectrophotometer, a technique attempted but not used successfully before. The method measured directly metal bound and required only 0.2 mg of sample per determination. For these reasons this method was used for routine analysis whereas dialysis and ion-exchange were only used for comparison purposes. As expected the samples isolated on each resin were very different. Comparison of samples from the horizons showed clearly the increased state of oxidation with depth. It was possible to establish differences in the organic material in the soil horizons on the basis of whether the stands were coniferous or deciduous trees but the similarities between the samples were perhaps equally striking.
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14

Bowell, Robert John. "The mobility of gold in tropical rain forest soils". Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359171.

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15

Kähkönen, Mika A. "Biodegradation activities in coniferous forest soils and freshwater sediments". Helsinki : University of Helsinki, 2003. http://ethesis.helsinki.fi/julkaisut/maa/skemi/vk/kahkonen/.

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16

Eshetu, Zewdu. "Forest soils of Ethiopian highlands : their characteristics in relation to site history : studies based on stable isotopes /". Umeå : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5881-1.pdf.

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17

Fölster, Jens. "Catchment hydrochemical processes controlling acidity and nitrogen in forest stream water /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-6074-3.pdf.

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18

Ring, Eva. "Nitrogen in soil water at five nitrogen-enriched forest sites in Sweden /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-5795-5.pdf.

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19

Taillon, Kate. "Modeling surface complexation relationships in forest and agricultural soil". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82435.

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The adsorption behaviour of trace metals in soil may provide us with a way to more accurately predict and assess the toxicity of metals in the environment. This thesis reports efforts to apply surface complexation modeling to agricultural and forest soil and to relate model parameters to common soil properties. This study considered Ca, Cd, Cu, Pb and Zn but the methods here could be applied to other metals. In Chapter 2, the surface charge and adsorption behaviour of a set of Ap horizons was characterised using back-titration and batch adsorption techniques. With the objective of simplifying the application of the NICCA model to surface charge and cation adsorption in whole soils the parameters of the NICCA model were related to soil properties (Chapter 3). Four of the six surface charge parameters could be predicted from soil properties and this enabled me to reasonably predict the surface charge of a second group of soils from soil properties. These results suggest that it is possible to make reasonable predictions about the surface charge and adsorption behaviour of a given type of soil using some easily measurable soil properties and a set of generic NICCA adsorption parameters for that soil type. In Chapter 4 this idea is applied to the determination of lime requirement for the agricultural soils.
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20

Poels, R. L. H. "Soils, water and nutrients in a forest ecosystem in Suriname". Wageningen : Agricultural University, 1987. http://catalog.hathitrust.org/api/volumes/oclc/23819734.html.

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21

Klaminder, Jonatan. "The fate of airborne lead pollution in boreal forest soils". Doctoral thesis, Umeå : Department of Ecology and Environmental Science, Umeå University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-631.

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22

Gregg, Ruth. "Methane fluxes from boreal forest soils along a successional chronosequence". Thesis, Lancaster University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543955.

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23

Zhou, Jizhong, Ye Deng, Lina Shen, Chongqing Wen, Qingyun Yan, Daliang Ning, Yujia Qin et al. "Temperature mediates continental-scale diversity of microbes in forest soils". NATURE PUBLISHING GROUP, 2016. http://hdl.handle.net/10150/618960.

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Climate warming is increasingly leading to marked changes in plant and animal biodiversity, but it remains unclear how temperatures affect microbial biodiversity, particularly in terrestrial soils. Here we show that, in accordance with metabolic theory of ecology, taxonomic and phylogenetic diversity of soil bacteria, fungi and nitrogen fixers are all better predicted by variation in environmental temperature than pH. However, the rates of diversity turnover across the global temperature gradients are substantially lower than those recorded for trees and animals, suggesting that the diversity of plant, animal and soil microbial communities show differential responses to climate change. To the best of our knowledge, this is the first study demonstrating that the diversity of different microbial groups has significantly lower rates of turnover across temperature gradients than other major taxa, which has important implications for assessing the effects of human-caused changes in climate, land use and other factors.
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24

Julich, Dorit y Karl-Heinz Feger. "Phosphorus in Preferential Flow Pathways of Forest Soils in Germany". Molecular Diversity Preservation International (MDPI), 2016. https://tud.qucosa.de/id/qucosa%3A30202.

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The transport of nutrients in forest soils predominantly occurs along preferential flow pathways (PFP). This study investigated the composition of phosphorus (P) forms in PFPs and soil matrix in several temperate beech forests with contrasting soil P contents in Germany. The PFPs were visualized using dye tracer experiments. Stained and unstained soil was sampled from three profile cuts per plot and analyzed for P fractions. The results show that labile P concentrations were highest in the O-layer and had the same range of values at all sites (240–320 mg·kg−1), although total P (TP) differed considerably (530–2330 mg·kg−1). The ratio of labile P to TP was significantly lower in the P-rich soil compared to the medium and P-poor soils. By contrast, the ratio of moderately labile P to TP was highest at the P-rich site. The shifts in P fractions with soil depth were generally gradual in the P-rich soil, but more abrupt at the others. The contents of labile and moderately labile P clearly differed in PFPs compared to soil matrix, but not statistically significant. The studied soils are characterized by high stone contents with low potential for P sorption. However, indications were found that labile organically bound P accumulates in PFPs such as biopores.
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25

Julich, Dorit y Karl-Heinz Feger. "Phosphorus in Preferential Flow Pathways of Forest Soils in Germany". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-220545.

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The transport of nutrients in forest soils predominantly occurs along preferential flow pathways (PFP). This study investigated the composition of phosphorus (P) forms in PFPs and soil matrix in several temperate beech forests with contrasting soil P contents in Germany. The PFPs were visualized using dye tracer experiments. Stained and unstained soil was sampled from three profile cuts per plot and analyzed for P fractions. The results show that labile P concentrations were highest in the O-layer and had the same range of values at all sites (240–320 mg·kg−1), although total P (TP) differed considerably (530–2330 mg·kg−1). The ratio of labile P to TP was significantly lower in the P-rich soil compared to the medium and P-poor soils. By contrast, the ratio of moderately labile P to TP was highest at the P-rich site. The shifts in P fractions with soil depth were generally gradual in the P-rich soil, but more abrupt at the others. The contents of labile and moderately labile P clearly differed in PFPs compared to soil matrix, but not statistically significant. The studied soils are characterized by high stone contents with low potential for P sorption. However, indications were found that labile organically bound P accumulates in PFPs such as biopores.
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26

Hendrayanto. "Analyses on Spatial Variability in Hydraulic Properties of Forest Soils". Kyoto University, 1999. http://hdl.handle.net/2433/181882.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第7873号
農博第1031号
新制||農||775(附属図書館)
学位論文||H11||N3236(農学部図書室)
UT51-99-G467
京都大学大学院農学研究科森林科学専攻
(主査)教授 水山 高久, 教授 三野 徹, 教授 吉田 博宣
学位規則第4条第1項該当
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27

King, Hen-Biau Carleton University Dissertation Geology. "Genesis and classification of three forest soils in central Taiwan". Ottawa, 1990.

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28

DeBano, Leonard F. y Malchus B. Jr Baker. "Runoff and Erosion from Hydrophobic Forest Soils During Simulated Rainfall". Arizona-Nevada Academy of Science, 1998. http://hdl.handle.net/10150/296500.

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29

FERRE', CHIARA. "Monitoring of greenhouse gas emissions from agricultural and forest soils". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7483.

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Global climate change is becoming a central issue in contemporary science as well as politics. There is a long-lasting debate about the cause of the climate change: anthropogenic activity versus the natural cycle. However, a scientific consensus is coming a conclusion that the contemporary climate change is mainly caused by anthropogenic emissions of the greenhouse gases (GHG), including carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4). The main objective of the thesis is the monitoring of such GHG emissions from two ecosystem types: a forest and a rice paddy ecosystem. The forest site is a EMEP experimental station, taking part of the activity of GHG-AGOLU of FP7-JRC project, while the agricultural ecosystem was included in the CarboEurope project and represents also a Level 3 site in the frame of NitroEurope project. The gas monitoring was carried out in 2008. The thesis is composed by 4 chapters, corresponding to specific objectives. The first chapter is relative to the study of the spatial variability of the main soil chemical and physical properties on the basis of which the gas monitoring points were selected. The second and the third chapters are relative to a cropland site. In particular, the second chapter includes monitoring data of CH4, N2O and CO2 fluxes from the paddy field, both during the crop growth season and the fallow period, and the validation results of the DeNitrification DeComposition (DNDC) model, a process-oriented biogeochemical model used for simulating soil gas emissions from the paddy field, are reported. The third chapter contains the study of characterization of microbial community composition using phospholipid fatty acid analysis (PLFA), at eight sampling dates representative of different soil conditions and crop stages and consequently characterized by distinct soil greenhouse emission rates. The fourth and last chapter includes the monitoring study of soil respiration in a forest site and its partitioning into autotrophic and heterotrophic components, applying the indirect linear regression method.
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30

Sjödin, Sophia. "The Forest Fire in Västmanland, South Central Sweden, and its Effects on Soils and Forest Recovery". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303526.

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Forest fires can have a great impact on the relationship between soil organic matter (SOM) and soilbulk density (SBD). SOM will reduce with increased fire intensity, which ultimately leads to more compaction of the soil. The compaction rate might increase to the limit of where root growth will be absent thus leading to actions to restore the soil. This study investigates changes in the relationship between SOM and SBD in spodosol and histosol in Seglingsberg, located in South-central Sweden, where a forest fire occurred summer 2014.  In addition, changes of pH values in the two types of soilwere examined in order to receive information about the chemical states of the different soil types.A total of 29 samples at depths of 0-17 cm were received from one day of fieldwork and these were later analysed concerning the pH, the SBD and the SOM content. The results showed an increase of pH-values in the fire-exposed area compared to pH values measured at the reference site (pH ~5). More importantly, the results from the SBD and SOM analyses indicated that there was in fact an inversely proportional relationship between the two soil parameters. In addition, high pH values were measured at the same subareas of which the highest SBD- and the lowest SOM values were obtained.Statistical analyses were applied on the results in order to conclude if the soil property changes caused by the fire were significantly different from normal conditions or not. The results from the statistical analyses revealed that 25% of the fire-exposed sites had changed significantly. However, more samples should have been taken while in field, since lack of data is thought to have had a great impact on the final results.Although there were no strong statistical evidence for the hypothesis, it is clear that the forest firein Västmanland year 2014 affected both the SOM, SBD and pH values in the soils.
Under sommaren år 2014 utbröt en omfattande skogsbrand i Västmanlands län, vilket medföljdedramatiska konsekvenser för framförallt ett flertal skogsbolag, men även för boende i området. Med skogsbränder följer negativa såväl som positiva konsekvenser, där de positiva framförallt gäller med avseende på arter som har evolverat i samband med bränder. Förutom ovannämnda konsekvenser så finns det risk för att markförhållandena ändras till följd av en skogsbrand. I denna studie undersöktes hur  markegenskaper  i  torv-  samt  podsoljordar  hade  förändrats  med  avseende  på  pH,  halten  avorganiskt material samt packningsgrad. Fältstudien genomfördes i ett drabbat brandområde strax norrom Seglingsberg, Surahammars kommun. Totalt togs 29 stycken jordprover inom fem stycken transekter i området. Av dessa kunde 25 stycken användas till alla tre analyserna. Resultaten från jordprovsanalyserna användes därefter till att genomföra statistiska undersökningar. Detta för att se hur stor spridningen var mellan och inom de fem transekterna samt för att kunna avgöra om jordproverna visade sig vara signifikant förändrade från ursprungsförhållanden.Resultaten från jordprovsanalyserna visade att det fanns mest organiskt material kvar i de östra delarna av området, medan det var kraftigt reducerat ju längre nordväst jordproverna hade hämtats. I samband med att markens organiska material hade reducerats kunde man även bevittna att jordtäcket hade blivit mer kompakterat. Resultaten från pH-analysen pekar också på att förändringarna varit som störst i de nordvästliga delarna. pH-analysen bevisade att markkemin ser annorlunda ut än innanbranden, då värdena ibland låg 2 enheter för högt än vad man vanligen brukar observera i podsol- ochtorvjordar. Då pH-skalan är logaritmisk innebär detta en minskad försurning med 100 gånger. Resultaten från alla jordprovsanalyser tyder att branden varit som mest intensiv i den nordvästra delen av undersökningsområdet, i området bestående av ungskog.Även om resultaten från jordprovsanalyserna pekade på att branden orsakat tydliga mark- förändringar, visade majoriteten av de statistiska undersökningarna inte på signifikanta förändringar. Det är därför inte möjligt att generalisera resultaten och således applicera dessa på hela brandområdet i Västmanland.Eftersom att naturligt förekommande skogsbränder är relativt få till antalet i Sverige, finns därmed få studier tillgängliga inom ämnesområdet. Det finns en upplaga av studier inom kontrollerade och anlagda brandfält, men i och med att dessa förhållanden är fixerade, så påverkas markegenskaperna sällan avsevärt. Forskningsrapporter indikerar på ett mer extremt klimat i framtiden, som förmodas leda till en ökad omfattning samt ett ökat antal naturligt förekommande skogsbränder. Om denna prognos stämmer är det viktigt att undersöka markförhållandena, då en skogsbrand kan ha direktavgörande effekt på återväxten.
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31

Au, William R. "Relationships between microbial physiological status and nitrogen availability in forest soils". Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21506.

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Although the physiological nitrogen demand of the soil microbial biomass is a major determinant of N mineralization in forest soils, the exact nature of the relationship is unclear. This study investigated the relationships between a respiration-based indicator of microbial physiological N demand (NIR) and N availability in forest soils. NIR was found to correlate significantly with net mineralized N in the field and annual foliar litterfall N fluxes. In a laboratory incubation, NIR was shown to be sensitive to changes in soil available C and N pools. These results demonstrated that microbial physiological N demand is determined by relative availabilities of labile C and N, and that it is significantly related to N cycling in forest soils. Results from a seasonal study of a forested watershed suggest that nutrient availability determined tree production and soil C availability, which in turn determined microbial physiological N demand and nitrogen dynamics in the forest.
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32

Pelletier, Bernard 1964. "A multivariate analysis of tree species influence on forest floor fertility /". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68239.

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The objective of this study was to assess tree species influence on forest floor fertility in a mixed forest stand using Redundancy Analysis (RDA). Eighty microsites were located in a beech-hemlock-red maple forest. Forest floor was analyzed for thirteen variables; total N, P, K, Ca and Mg, extractable Ca, Mg and K, mineralizable N (NH$ sb{4+}$), basal microbial respiration (CO$ sb2$), pH, thickness and bulk density. The influence of seven tree species was calculated as a function of tree diameter and distance from each microsite. Spatial patterns were detected by using correlograms and incorporated in a variation-partitioning model with trend surface analysis. Tree species, microtopography, and spatial structure explained 53% of the total variation in forest floor data. The fraction explained by tree species alone (16%) was studied with a RDA ordination biplot. The main source of variation in the soil data was related mainly to the opposite effects of American beech and eastern hemlock on calcium while most of the other species had a beneficial effect on soil fertility. This study showed the potential of RDA as a tool for studying the role of tree species in mixed forests.
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33

Ilstedt, Ulrik. "Soil degradation and rehabilitation in humid tropical forests (Sabah, Malaysia) /". Umeå : Swedish University of Agricultural Sciences, 2002. http://diss-epsilon.slu.se/archive/00000233/.

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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2002.
Abstract inserted. Appendix reprints four papers and manuscripts co-authored with others. Includes bibliographical references. Also partially issued electronically via World Wide Web in PDF format; online version lacks appendix.
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34

Chandler, Douglas Scott. "An area approach to forest slope stability /". Thesis, Connect to this title online; UW restricted, 1992. http://hdl.handle.net/1773/10181.

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35

Au, William R. "Relationships between microbial physiological status and nitrogen availability in forest soils". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50713.pdf.

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36

Jaeger, Alexa. "Methane and carbon dioxide cycling in soils of the Harvard Forest". Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/117912.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 18).
Soil is Earth's largest terrestrial carbon pool (Oertel et al., 2016) and can act as a net source of greenhouse gases (GHG). However, if organic material accumulates in soils faster than it is converted to CO2 by cellular respiration, soil becomes a smaller GHG source and even has the potential to become a GHG sink. Not much is known about factors that drive soil to be a source or a sink of GHG. Soil temperature and moisture have both been shown to correlate with CH4 emissions and temperature has been shown to correlate with CO 2 emissions (Jacinthe et al., 2015). Currently these relationships are not well constrained, particularly in upland soils, which are soils found at elevations between 100 and 500 m (Carating et al., 2014). Soil from the Harvard Forest was collected and used in two in-lab flux experiments to constrain the effect that soil moisture has on i.) the rate of CH4 and CO2 production/consumption and ii.) the fraction of injected CH4 that is oxidized to CO2 by soil microbes. The first experiment involved injecting vials containing soil samples with CH4 , taking an initial measurement with a residual gas analyzer (RGA), incubating for three days, and taking final measurements using the RGA. The results of this experiment indicated that cellular respiration is an important carbon source in these soils, with more CO2 coming from cellular respiration than from the oxidation of CH4. The second experiment involved injecting vials containing soil samples with CH4 and 14CH4 as a tracer, incubating for six days, and analyzing CO2 from each sample using a scintillation counter. This experiment showed a weak trend indicating that increased soil moisture may result in decreased CH4 oxidation. Results showed that decays per minute from the samples were lower than in a control. These results indicated that not all CO 2 from each sample was successfully captured and analyzed using the methods here. So while the trend may hold true, it should be supported by reconducting the experiment using a more reliable means of CO2 capture. The unexpected results from both experiments indicated that there is still much to be learned about the reactions that occur in these soils and how to perfect laboratory methods to study them.
by Alexa Jaeger.
S.B.
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37

Nottingham, Andrew Thomas. "The carbon balance of tropical forest soils : partitioning sources of respiration". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608423.

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38

Kraus, Tamara Esther Caroline. "Tannins and nutrient dynamics in forest soils : plant-litter-soil interactions /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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39

Cushon, Geoffrey H. "Gaseous nitrogen transformations in a mature forest ecosystem". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24623.

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In mature forests, gains and losses of nitrogen may be dominated by the gaseous transformations, asymbiotic nitrogen fixation and biological denitrification. Both are reduction reactions and are affected by moisture conditions, temperature, pH, supply of organic carbon and the availability of mineral nitrogen. Gaseous nitrogen inputs, due to asymbiotic nitrogen fixation, and outputs, due to biological denitrification were quantified for a mature coniferous forest in southwestern British Columbia. Forest floor material, mineral soil, decaying wood, foliage and bark were incubated in an atmosphere of 0.1 atm acetylene to allow the simultaneous measurement of N₂0 production by denitrifying bacteria and acetylene reduction by free-living bacteria and blue-green algae. Forest floor material accounted for 80% of a total annual input of 0.8 kg N ha⁻1 a⁻1. Relatively small amounts of nitrogen were fixed in mineral soil, decaying wood and foliage and no indication of nitrogen fixation activity in bark was detected. Traces of denitrification were found, but gaseous output of nitrogen was effectively 0.0 kg N ha⁻1 a⁻1. It is hypothesized that this forest may prevent nitrogen Joss by outcompeting other sinks for mineral nitrogen, thereby allowing a slow accretion of nitrogen by asymbiotic nitrogen fixation and bulk precipitation input.
Forestry, Faculty of
Graduate
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40

Groeschl, David A. "Forest soil and vegetation characteristics in two forest types following wildfire in the Shenandoah National Park, Virginia". Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-11242009-020129/.

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41

Nelson, Leslie B. "The Role of Forest Soils in a Northern New England Effluent Management System". Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/NelsonLB2002.pdf.

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42

Feldman, Steven B. "Taxonomy, genesis, and parent material distribution of high- elevation forest soils in the southern Appalachians". Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/53211.

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High-elevation spruce-fir forests in the southern Appalachians may potentially be in a state of decline as a result of either natural or anthropogenic causes. Soils were investigated in areas representative of 117 permanent intensive field plots established to evaluate changes in forest composition that may be influenced by the deposition of atmospheric pollutants. A total of 35 pedons were described, sampled, and characterized. Over 75% of the soils studied were classified in the field as either Typic or Pachic Haplumbrepts, but weakly developed spodic horizons were identified in 13 of the soils by chemical determinations in the laboratory. A high degree of morphological similarity exists between soils in these areas despite widespread differences in parent material and local geology. This similarity is the result of physical mixing of these soils by climatically-driven slope processes. A considerable amount of chemical variability exists in these soils which is not expressed in morphological characteristics. Multiple discriminant analysis established that physical and morphological properties used to separate and classify these soils in the field were not significantly different between study areas. Parent material differences, however, expressed in both soil chemical and mineralogical properties, were sufficiently different between study areas to result in the clear separation of soils into distinct groups. The importance of nutrient cycling in these spruce-fir forests is underscored by high levels of exchangeable bases in surface horizons relative to lower in the profile. This suggests that disturbances to the forest floor resulting from fire, overgrazing, logging, or erosion could have a major impact on ecosystem resilience during stress.
Master of Science
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43

Martin, Wayne Lloyd. "Post-clearcutting forest floor nitrogen dynamics and regeneration response in the Coastal Western Hemlock wet subzone". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25937.

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The objective of this study was to describe the dynamics of post-clearcutting forest floor N on mesic sites in the wet subzone of the Coastal Western Hemlock biogeoclimatic zone. Post-clearcutting release of N was examined by measuring the following parameters for a chronosequence of five sites ranging in age from an old-growth forest to a 26-yr-old stand: forest floor N capital; rate of in situ mineralization of forest floor; rate of decomposition of cellulose; concentrations of inorganic-N and total-N in soil solution; and adsorption of inorganic-N by ion exchange resin bags. Effects of the post-clearcutting release of N on tree growth were assessed by measuring foliar N levels and height growth of Abies amabilis (Dougl.) Forbes advanced regeneration. The following sinks for the mineralized forest floor N were investigated: accumulation in plant biomass; solution transfer of inorganic-N and total-N from the forest floor to storage in the upper mineral soil. Based on the difference between the old-growth and the 6- year-old forest floor N capitals, post-clearcutting mobilization of forest floor N was estimated to be 950 kg.N.ha⁻¹ . Although not significant (P=.05), rates of cellulose decomposition were about 3 times higher in the young clearcuts than in the old-growth stand. Indicators of N availability, including in situ rates of mineralization, soil water concentrations and ion exchange resin bags, revealed higher levels of nitrate in the forest floor and/or mineral soil in the 3- and 6-year-old clearcuts than in the other sites. Nitrate concentrations declined to pre-clearcut levels by 8-10 years after clearcutting. %N and N content of current needles, and 1983 height increment of amabilis fir regeneration reflected the pattern of N availability. Of the observed change in forest floor N (kg.N.ha⁻¹ ) over the 10 year post-clearcutting period, plant biomass accumulation accounted for 105 and solution transfer from the forest floor for 187. Together, this amounts to 1/3 of the observed decline of 950 kg.N.ha⁻¹ Potential rates of denitrification in the 5- and 12-year-old clearcut forest floors were 2-5 times greater than in the old-growth stand. The potential rates were sufficiently high to provide a plausible explanation for the post-clearcutting decline in forest floor N.
Forestry, Faculty of
Graduate
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44

Kabzems, Richard Darwin. "Quantitative classification of soil nutrient regimes of some mesothermal Douglas-fir ecosystems". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24691.

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Previous attempts to classify nutrient regimes of forest soil have been qualitative evaluations utilizing vegetation and/or physiographic site characteristics, morphological soil properties, and parent material. The major objective of this study was to describe and classify the soil nutrient regimes (SNR) of some Pseudotsuga menziesii ecosystems on southern Vancouver Island, British Columbia. The order of increasing variability for forest floor properties was pH(H₂0) Forestry, Faculty of
Graduate
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45

Fung, Ka Fai. "Effects of agronomic practices on aluminium and fluoride concentrations in soil and tea plants". HKBU Institutional Repository, 1999. http://repository.hkbu.edu.hk/etd_ra/244.

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46

Lazzaro, Anna. "Estimation of critical limits for cadmium and lead in Swiss forest soils /". Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16834.

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47

Bryson, Autumn Leah. "Sulfate sorption of acidified forest soils in the Otter Creek Wilderness area". Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4900.

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Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains vi, 36 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 31-36).
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48

Gärdenäs, Annemieke. "Soil organic matter in forest soils : effects of climate and water balance /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1998. http://epsilon.slu.se/avh/1998/91-576-5530-8.gif.

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49

Fröberg, Mats. "Processes controlling production and transport of dissolved organic carbon in forest soils /". Uppsala : Dept. of Soil Sciences, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a475.pdf.

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50

Dennis, Wilson Dennis. "Estimation of Carbon Dioxide emissions from forest soils based on CO2 concentrations". Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-33240.

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Forest soil is an important source of atmospheric CO2. Emission of CO2 from soil is the result of respiration of plant roots and soil organisms (Autotrophic and Heterotrophic respiration). This soil CO2 emission has a variation throughout the year with maximum emissions being in the summer. However, the seasonal variation affected by the external factors is not fully known. The aim of this thesis is to analyze a relationship between concentration of CO2 in the soil-atmosphere and CO2 emissions to the aboveground atmosphere. When knowing the relationship between CO2 concentration in the soil-atmosphere and the emission of CO2 from the soil atmosphere, a function (equation) can be established. Usually, the best fit is considered to establish the relationship. With the equations obtained, it is possible to calculate CO2 emissions using data different projects, where only soil-atmosphere CO2 concentrations were determined. Using the relationships, emissions rates in different soil types and in forest transect have been analyzed for a large number of samples. The effect of nitrogen deposition on CO2 emissions and seasonal variation of CO2 emission has also been studied. The sampled sites chosen for this study were located in different parts of Southern Scandinavia and Germany. A closed chamber was used to measure CO2 emission from soil. Soil CO2 concentrations were measured at every station and the equations were established. Finally, these relationships were used for analyses and comparison of the sites. An equation (best fit) obtained was used to calculate the emission values of CO2. The soil texture had a great influence on the CO2 from the soil besides the atmospheric pressure and temperature variations during the seasons. It is concluded that, therefore the soil texture and had a great influence on the CO2 emission from the soil besides the atmospheric pressure and temperature variations during the season. When knowing the equation between CO2 concentration and emission for a special type of soil, it is possible to estimate emissions based on CO2 concentrations. Therefore large scale sampling of CO2 concentrations could be done and this will facilitate the inventories carried out in e.g. global change studies.
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