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Full-Text Articles in Life Sciences

Methane Fluxes And Porewater Dissolved Organic Carbon Dynamics From Different Peatlands Types In The Pastaza-Marañon Basin Of The Peruvian Amazon., Jhon Del Aguila-Pasquel Jan 2017

Methane Fluxes And Porewater Dissolved Organic Carbon Dynamics From Different Peatlands Types In The Pastaza-Marañon Basin Of The Peruvian Amazon., Jhon Del Aguila-Pasquel

Dissertations, Master's Theses and Master's Reports

Relevant components of the carbon budget such as methane fluxes and porewater dissolved organic carbon (DOC) are poorly characterized in the Peruvian Pastaza Marañon basin (PMB). PMB is associated with a tropospheric hotspot for methane and therefore it may represent a significant methane source. We aimed to quantify the magnitude of CH4 fluxes and porewater DOC; and to determine their predictors across different peatland types in the PMB (open peatland, palm swamp, and pole forest). The study was conducted in two peatland sites covering the three main vegetation types in PMB. We collected gas and water samples using chamber-based …


The Influence Of Native Woody Species, Combretum Glutinosum And Piliostigma Reticulatum, On Soil Fertility In Dialacoto, Senegal, Gwen Jacobson Jan 2017

The Influence Of Native Woody Species, Combretum Glutinosum And Piliostigma Reticulatum, On Soil Fertility In Dialacoto, Senegal, Gwen Jacobson

Dissertations, Master's Theses and Master's Reports

In the low-fertility soils of Senegal, West Africa, management of woody species in agricultural fields has the potential to improve soil fertility and crop production. However, optimal species for this purpose have not been clearly defined. Thus, the objective of this study was to evaluate the potential for two native woody species, Combretum glutinosum and Piliostigma reticulatum, to improve soil fertility. Soil samples were collected from beneath tree crowns of P. reticulatum and C. glutinosum and compared with fertilizer-amended and non-amended soil from adjacent open fields in a bioassay experiment. Two common crops, millet (Pennisetum glaucum) and maize (Zea mays), …


Effects Of In-Situ Leaf-Level Canopy Warming In A Northern Hardwood Forest, Kelsey Carter Jan 2017

Effects Of In-Situ Leaf-Level Canopy Warming In A Northern Hardwood Forest, Kelsey Carter

Dissertations, Master's Theses and Master's Reports

Rising mean annual temperatures due to climate change have intensified the need to understand the effects of warming on plant physiological processes. Forest photosynthesis is the most important pathways of terrestrial carbon sequestration, yet continued warming could reduce this important carbon sink. Photosynthesis is highly sensitive to temperature and begins to decline after an optimum temperature (Topt) is reached, leading to reduced carbon uptake. To date, logistical difficulties have limited our ability to test photosynthetic responses to sustained warming in mature forest canopies. In order to understand how elevated temperatures will affect forest ecosystems, we need to be …


Dynamics Of Wild Red Raspberry (Rubus Idaeus L.) And The Influence On Tree Regeneration Within Silvicultural Openings In A Northern Hardwood Stand, Matthew J. Widen Jan 2017

Dynamics Of Wild Red Raspberry (Rubus Idaeus L.) And The Influence On Tree Regeneration Within Silvicultural Openings In A Northern Hardwood Stand, Matthew J. Widen

Dissertations, Master's Theses and Master's Reports

Previous studies have investigated how the abundance of raspberries (Rubus idaeus L.) impacts tree regeneration, but few have linked these impacts to location within canopy openings with a legacy tree. To fill this knowledge gap, we investigated the presence, abundance, and location of raspberries within openings containing legacy trees and the resulting impacts on tree regeneration. During the winter of 2003, 49 openings were created of three sizes: small, medium, large and 20 reference single-tree selection sites in a northern hardwood stand in Ford Forest near Alberta, Michigan. Tree regeneration and vegetative species cover were recorded in 2005 and …


Assessing Growth, Yield, And Carbon Dynamics In Upper Great Lakes Jack Pine And Hybrid Poplar Managed For Biomass Production, Ashlee Baker Lehner Jan 2017

Assessing Growth, Yield, And Carbon Dynamics In Upper Great Lakes Jack Pine And Hybrid Poplar Managed For Biomass Production, Ashlee Baker Lehner

Dissertations, Master's Theses and Master's Reports

Woody biomass for use as coal-replacing bioenergy has garnered increasing interest as federal and local governments require larger portions of energy production to come from renewable sources. Woody biomass can be produced from dedicated plantations grown and harvested solely for biomass production, or non-dedicated sources such as harvest residues from traditional timber operations. The creation of site index curves for hybrid poplar were established from the Michigan Technological University Hybrid Poplar Network in the upper Great Lakes Region. These site index models are to be used for landowners to assess the predicted yield at established plantations, or possibly within spatial …


Characterization Of Genic Microsatellite Markers (Est-Ssrs) In The Endangered Oak Species Quercus Georgiana M.A.Curtis, Priyanka Dipak Kadav Jan 2017

Characterization Of Genic Microsatellite Markers (Est-Ssrs) In The Endangered Oak Species Quercus Georgiana M.A.Curtis, Priyanka Dipak Kadav

Dissertations, Master's Theses and Master's Reports

Quercus is important ecologically and economically because it provides food and habitat for wildlife, wood and paper products for humans. Oaks are endangered due to various factors like shifting climates, habitat loss, drought, pathogens and genetic swamping. Quercus georgiana (M.A. Curtis) is an endangered and restricted oak species which is remaining only in the southeastern part of the US. Efforts are required to conserve this endangered species from extinction. Conservation of this species can be done through these methods: ex-situ conservation (arboretum and botanical garden) and in-situ conservation strategies which protect the species in its natural habitat. For this conservation …


Effects Of Post-Fire Salvage Logging On Compaction, Infiltration, Water Repellency, And Sediment Yield And The Effectiveness Of Subsoiling On Skid Trails, Iskender Demirtas Jan 2017

Effects Of Post-Fire Salvage Logging On Compaction, Infiltration, Water Repellency, And Sediment Yield And The Effectiveness Of Subsoiling On Skid Trails, Iskender Demirtas

Dissertations, Master's Theses and Master's Reports

Post-fire salvage logging operations can induce environmental problems. This study assessed the effects of different disturbances from post-fire salvage logging on soil bulk density, water repellency, field saturated hydraulic conductivity (Kfs), ground cover, and sediment yields after the 2013 Rim Fire in California. Hillslope plots were installed in three locations (Sawmill, lower Femmons, and upper Femmons). The plot-scale disturbances were burned and untrafficked (low and high slope controls and logged only with no traffic), or burned and trafficked (few and many pass skid trails). Additional measurements were made in nearby areas that included the plot-scale disturbances as well as feller …


Effects Of Group Selection With Yellow Birch (Betula Alleghaniensis) Retention On The Understory And Sapling Layer In Northern Hardwood Forests, Megan A. Petras O'Neil Jan 2017

Effects Of Group Selection With Yellow Birch (Betula Alleghaniensis) Retention On The Understory And Sapling Layer In Northern Hardwood Forests, Megan A. Petras O'Neil

Dissertations, Master's Theses and Master's Reports

Gap partitioning theory predicts that changes in microenvironment conditions found within a forest opening promote diversity in forest ecosystems. Under this theory we would expect to see variations in tree and understory diversity throughout and surrounding a forest opening. In order to test this theory, we examined manmade openings with legacy-tree retention in a northern hardwood forest located in the Upper Peninsula of Michigan. This work is part of an ongoing study that was started in 2003 with the creation of 49 openings centered on a reserve dominant or co-dominant yellow birch (Betula alleghaniensis Britt.). The primary objective of …


Models Of Forest Inventory For Istanbul Forest Using Airborne Lidar And Spaceborne Imagery, Mustafa Kagan Ozkal Jan 2017

Models Of Forest Inventory For Istanbul Forest Using Airborne Lidar And Spaceborne Imagery, Mustafa Kagan Ozkal

Dissertations, Master's Theses and Master's Reports

Active remote sensing technology (LiDAR) and passive remote sensing technology (Pleiades and Göktürk-2 satellites) were used to find a meaningful relationship between ground data and remote sensing instruments for Istanbul Forest, Turkey. Two dominant species in the field, oak (deciduous trees) and maritime pine (coniferous trees), were researched. There were 86 plots total, 41 for maritime pine and 45 for oak. Three diameter at breast height (DBH) thresholds were studied. Trees of any DBH (DBH≥0.1 cm), trees ≥8 cm DBH thresholds and, trees ≥10 cm DBH thresholds. Both satellite image metrics were derived from Grey Level Co-occurrence Measures (GLCM). All …


Development Of Gene-Based Microsatellite Markers In Acer Saccharum Marsh., Monica Harmon Jan 2017

Development Of Gene-Based Microsatellite Markers In Acer Saccharum Marsh., Monica Harmon

Dissertations, Master's Theses and Master's Reports

Sugar maple (Acer saccharum Marsh) is an important ecological and economic resource. Despite its significance, there are few molecular genetic resources available to date. This study used previously developed EST libraries generated for sugar maple and other hardwood species to develop and characterize EST-SSRs in sugar maple and test their transferability to other Acer species. Out of 58 markers tested, 22 showed amplification in the expected size range. From these, 16 polymorphic markers were selected to test transferability and 13 of these showed amplification in at least one other Acer species.


The Effects Of Early Pruning On The Near-Ground Branch Density Of Four Live Fencing Species, Aric Devens Jan 2017

The Effects Of Early Pruning On The Near-Ground Branch Density Of Four Live Fencing Species, Aric Devens

Dissertations, Master's Theses and Master's Reports

Crop losses in home gardens greatly impact the wellbeing of rural West African families. Herbivory by migratory or local livestock represents a significant source of crop loss. Live-fencing gardens with thorny hedges is a low-cost and sustainable strategy for reducing losses due to herbivory. However, guidance on the establishment of thorny hedges is inconsistent, poorly publicized, and often anecdotal. Therefore, this study evaluated the effects of three early pruning treatments on near-ground branch density of four thorny species: Vachellia nilotica, Senegalia laeta, Senegalia mellifera, and Prosopis juliflora. Physical measurements and photographic data indicated that after one growing season, V. …