Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Environmental Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 8071 - 8100 of 22716

Full-Text Articles in Entire DC Network

Resource Extraction And Infrastructure Threaten Forest Cover And Community Rights, Anthony J. Bebbington, Denise Humphreys Bebbington, Laura Aileen Sauls, John Rogan, Sumali Agrawal, César Gamboa, Aviva Imhof, Kimberly Johnson, Herman Rosa, Antoinette Royo, Tessa Toumbourou, Ricardo Verdum Jan 2018

Resource Extraction And Infrastructure Threaten Forest Cover And Community Rights, Anthony J. Bebbington, Denise Humphreys Bebbington, Laura Aileen Sauls, John Rogan, Sumali Agrawal, César Gamboa, Aviva Imhof, Kimberly Johnson, Herman Rosa, Antoinette Royo, Tessa Toumbourou, Ricardo Verdum

Geography

Mineral and hydrocarbon extraction and infrastructure are increasingly significant drivers of forest loss, greenhouse gas emissions, and threats to the rights of forest communities in forested areas of Amazonia, Indonesia, and Mesoamerica. Projected investments in these sectors suggest that future threats to forests and rights are substantial, particularly because resource extraction and infrastructure reinforce each other and enable population movements and agricultural expansion further into the forest. In each region, governments have made framework policy commitments to national and cross-border infrastructure integration, increased energy production, and growth strategies based on further exploitation of natural resources. This reflects political settlements among …


Analysis Of Ambient Particulate Concentration Near A Coal Storage Pile, Jennifer Wittenburg Jan 2018

Analysis Of Ambient Particulate Concentration Near A Coal Storage Pile, Jennifer Wittenburg

Dissertations and Theses @ UNI

Fugitive dust sources such as aggregate storage piles contribute significantly to the total suspended particulate levels in the ambient air. Particulate levels are monitored and regulated by the Environmental Protection Agency to protect public health and welfare. This study monitored particulate concentrations in the ambient air near a coal storage pile. Air samplers and weather stations were placed at two locations, one to the north of the pile and one to the south of the pile, and were used to collect particulate and weather related data.

The data were analyzed to determine the origin of the particulate and to identify …


Blooms Of Dinoflagellate Mixotrophs In A Lower Chesapeake Bay Tributary: Carbon And Nitrogen Uptake Over Diurnal, Seasonal, And Interannual Timescales, Margaret R. Mulholland, Ryan Morse, Todd Egerton, Peter W. Bernhardt, K. C. Filippino Jan 2018

Blooms Of Dinoflagellate Mixotrophs In A Lower Chesapeake Bay Tributary: Carbon And Nitrogen Uptake Over Diurnal, Seasonal, And Interannual Timescales, Margaret R. Mulholland, Ryan Morse, Todd Egerton, Peter W. Bernhardt, K. C. Filippino

OES Faculty Publications

A multi-year study was conducted in the eutrophic Lafayette River, a sub-tributary of the lower Chesapeake Bay during which uptake of inorganic and organic nitrogen (N) and C compounds was measured during multiple seasons and years when different dinoflagellate species were dominant. Seasonal dinoflagellate blooms included a variety of mixotrophic dinoflagellates including Heterocapsa triquetra in the late winter, Prorocentrum minimum in the spring, Akashiwo sanguinea in the early summer, and Scrippsiella trochoidea and Cochlodinium polykrikoides in late summer and fall. Results showed that no single N source fueled algal growth, rather rates of N and C uptake varied on seasonal …


Composition Of Dissolved Organic Matter In Pore Waters Of Anoxic Marine Sediments Analyzed By 1h Nuclear Magnetic Resonance Spectroscopy, Christina A. Fox, Hussain A. Abdulla, David J. Burdige, James P. Lewicki, Tomoko Komada Jan 2018

Composition Of Dissolved Organic Matter In Pore Waters Of Anoxic Marine Sediments Analyzed By 1h Nuclear Magnetic Resonance Spectroscopy, Christina A. Fox, Hussain A. Abdulla, David J. Burdige, James P. Lewicki, Tomoko Komada

OES Faculty Publications

Marine sediments are globally significant sources of dissolved organic matter (DOM) to the oceans, but the biogeochemical role of pore-water DOM in the benthic and marine carbon cycles remains unclear due to a lack of understanding about the molecular composition of DOM. To help fill this knowledge gap, we used 1H nuclear magnetic resonance (NMR) spectroscopy to examine depth variability in the composition of pore-water DOM in anoxic sediments of Santa Barbara Basin, California Borderland. Proton detected spectra were acquired on whole samples without pre-concentration to avoid preclusion of any DOM components from the analytical window. Broad unresolved resonance (operationally …


Mchm (4-Methylcyclohexane Methanol) Influences The Predator-Prey Interaction Between Danio Rerio And Daphnia Magna, Anna C. Wagner Jan 2018

Mchm (4-Methylcyclohexane Methanol) Influences The Predator-Prey Interaction Between Danio Rerio And Daphnia Magna, Anna C. Wagner

College of Graduate Studies: Theses & Dissertations

Chemical contamination alters organism-level traits, such as activity and feeding, that can ultimately affect aquatic trophic interactions. Despite the importance of predator-prey relationships in aquatic communities, chemical toxicity is often tested on single species prior to use. For example, 4-methylcyclohexane methanol (MCHM) used in industrial coal-cleaning enters the environment regularly from low-level contamination during disposal and occasionally in high concentrations following accidental spills, but its effects on fish-zooplankton interactions remain unknown. It was hypothesized MCHM exposure affects zebrafish and D. magna swimming behavior differently when exposed individually or together, and ultimately affects their relationship. Zebrafish and D. magna were exposed …


Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee Jan 2018

Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee

Theses and Dissertations (Comprehensive)

Wildlife data is often limited by survey effort, small sample sizes, and spatial biases associated with collection and missing data. These factors can create unique challenges from a surveillance perspective when trying to extract spatial patterns of habitat suitability and disease distributions for conservation and management purposes. This thesis examined data quality from a wildlife health database in the context of spatial analysis of wildlife disease. Spatial analysis of the data to predict habitat suitability of bats and white nose syndrome afflicted bats was examined by using the MaxEnt modelling method. Methods to reduce spatial bias were examined and specific …


Ecological Resilience Indicators For Salt Marsh Ecosystems, Scott T. Allen, Camille L. Stagg, Jorge Brenner, Kathleen L. Goodin, Don Faber-Langendoen, Christopher A. Gabler, Katherine Wirt Ames Jan 2018

Ecological Resilience Indicators For Salt Marsh Ecosystems, Scott T. Allen, Camille L. Stagg, Jorge Brenner, Kathleen L. Goodin, Don Faber-Langendoen, Christopher A. Gabler, Katherine Wirt Ames

School of Earth, Environmental, & Marine Sciences Faculty Publications

Salt marshes are coastal ecosystems within the intertidal zone, characterized by hypoxic, saline, soil conditions and low biodiversity. Low diversity arises from frequent disturbance and stressful conditions (i.e., high salinity and hypoxia), where vegetative reproduction and low competition result in mostly monotypic stands, with some differences in plant community influenced by flooding regime (described below). While there are several types of salt marshes in the Northern Gulf of Mexico (NGoM), ranging from low to high salt marshes and salt flats (Tiner, 2013), Spartina alterniflora–dominated salt marshes in the Coastal and Marine Ecological Classification Standard (CMECS) Low and Intermediate Salt Marsh …


Development Of A Hierarchical Model For Predicting Microbiological Contamination Of Private Groundwater Supplies In A Geologically Heterogeneous Region, Jean O'Dwyer, Paul Hynds, Kenneth Byrne, Michael Ryan, Catherine Adley Jan 2018

Development Of A Hierarchical Model For Predicting Microbiological Contamination Of Private Groundwater Supplies In A Geologically Heterogeneous Region, Jean O'Dwyer, Paul Hynds, Kenneth Byrne, Michael Ryan, Catherine Adley

Articles

Private groundwater sources in the Republic of Ireland provide drinking water to an estimated 750,000 people or 16% of the national population. Consumers of untreated groundwater are at increased risk of infection from pathogenic microorganisms. However, given the volume of private wells in operation, remediation or even quantification of public risk is both costly and time consuming. In this study, a hierarchical logistic regression model was developed to ‘predict’ contamination with E. coli based on the results of groundwater quality analyses of private wells (n = 132) during the period of September 2011 to November 2012. Assessment of potential microbial …


A Marine Heatwave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks, A. Arias-Ortiz, Oscar Serrano, Pere Masque´, Paul S. Lavery, Ute Mueller, G. A. Kendrick, Mohammad Rozaimi, Alba Esteban, J. W. Fourqurean, N. Marba, Miguel-Angel Mateo, K. Murray, M. J. Rule, C. M. Duarte Jan 2018

A Marine Heatwave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks, A. Arias-Ortiz, Oscar Serrano, Pere Masque´, Paul S. Lavery, Ute Mueller, G. A. Kendrick, Mohammad Rozaimi, Alba Esteban, J. W. Fourqurean, N. Marba, Miguel-Angel Mateo, K. Murray, M. J. Rule, C. M. Duarte

Research outputs 2014 to 2021

Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass ecosystem, containing up to 1.3% of the total C stored within the top metre of seagrass sediments worldwide. On the basis of field studies and satellite imagery, we estimate that 36% of Shark Bay’s seagrass meadows were damaged following a marine heatwave in 2010/2011. Assuming that 10 to 50% of the seagrass sediment C stock was exposed to oxic conditions after disturbance, between 2 and 9 …


How Important Is Groundwater Availability And Stream Perenniality To Riparian And Floodplain Tree Growth?, Neil E. Pettit, Raymond H. Froend Jan 2018

How Important Is Groundwater Availability And Stream Perenniality To Riparian And Floodplain Tree Growth?, Neil E. Pettit, Raymond H. Froend

Research outputs 2014 to 2021

Riparian vegetation is important for stream functioning and as a major landscape feature. For many riparian plants, shallow groundwater is an important source of water, particularly in areas where rainfall is low, either annually or seasonally, and when extended dry conditions prevail for all or part of the year. The nature of tree water relationships is highly complex. Therefore, we used multiple lines of evidence to determine the water sources used by the dominant tree species Eucalyptus camaldulensis (river red gum), growing in riparian and floodplain areas with varying depth to groundwater and stream perenniality. Dendrometer bands were used to …


Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Vladimir Milosavljević, Patrick J. Cullen Jan 2018

Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Vladimir Milosavljević, Patrick J. Cullen

Articles

The use of plastics has spanned across almost all aspects of day to day life. Although their uses are invaluable, they contribute to the generation of a lot of waste products that end up in the environment and end up polluting natural habitats such as forests and the ocean. By treating low-density polyethylene (LDPE) samples with non-thermal plasma in ambient air and with an addition of ≈4% CO2, the biodegradation of the samples can be increased due to an increase in oxidative species causing better cell adhesion and acceptance on the polymer sample surface. It was, however, found that the …


First Record Of The Yellowfin Soldierfish, Myripristis Chryseresjordan & Evermann, 1903, In The Easter Island Ecoregion, Erin E. Easton, Javier Sellanes, Matthias Gorny Jan 2018

First Record Of The Yellowfin Soldierfish, Myripristis Chryseresjordan & Evermann, 1903, In The Easter Island Ecoregion, Erin E. Easton, Javier Sellanes, Matthias Gorny

School of Earth, Environmental, & Marine Sciences Faculty Publications

Myripristis chryseres Jordan & Evermann, 1903, is recorded for the first time in the Easter Island Ecoregion. Two specimens were observed swimming along a rock cliff and entering a cavern at ∼163 m depth near the peak of Pukao seamount, located ∼85 km (46 nm) west of Easter Island. This report expands the geographic range of M. chryseres eastward by ∼3,800 km and is the first report of the species for the eastern Pacific. It is unclear whether this new record is indicative of a relatively recent range expansion or a lack of visual surveys in the region, which …


Preliminary Multivariate Comparison Of Coral Assemblages On Carbonate Banks In The Western Gulf Of Mexico, Rebekah E. Rodriguez, Erin E. Easton, Thomas C. Shirley, John W. Tunnell, David Hicks Jan 2018

Preliminary Multivariate Comparison Of Coral Assemblages On Carbonate Banks In The Western Gulf Of Mexico, Rebekah E. Rodriguez, Erin E. Easton, Thomas C. Shirley, John W. Tunnell, David Hicks

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hermatypic corals flourished on reefs in the Gulf of Mexico (GOM) in the late Pleistocene and early Holocene. Today, many of these relict reefs are mesophotic banks that have unique coral assemblages and provide critical habitat; however, the South Texas Banks (STB) lack quantitative surveys. Therefore, we used a remotely operated vehicle to conduct quantitative surveys of 5 banks: Baker, Aransas, Dream, Blackfish Ridge, and Harte. Coral communities, based on estimated coral densities (colonies/m2), significantly differed among banks for terraces, slopes, and overall (combined terrace and slope) communities for most banks examined. Within banks, terrace and slope communities significantly differed …


The Value Of Animal Behaviour As A Bio-Indicator Of Restoration Quality, Floyd Holmes Jan 2018

The Value Of Animal Behaviour As A Bio-Indicator Of Restoration Quality, Floyd Holmes

Theses: Doctorates and Masters

Woodland restoration is a complex endeavour, and restoration ecology as a scientific discipline requires constant re-assessments and adjustments if it is to improve outcomes and better provide for biodiversity. The promise of effective restoration is often used to justify destructive processes that affect many of the world’s ecosystems. It is therefore imperative that those promises can be met, which comes down to restoration ecologists’ and land managers’ capacity to predict and facilitate desirable ecological changes in a timely and socio-economically responsible manner. As perspectives have changed, and knowledge has been gained over the past few decades there have been several …


Carbon Assimilation And Transfer Through Kelp Forests In The Ne Atlantic Is Diminished Under A Warmer Ocean Climate, Albert Pessarrodona, Philippa J. Moore, Martin Sayer, Dan Smale Jan 2018

Carbon Assimilation And Transfer Through Kelp Forests In The Ne Atlantic Is Diminished Under A Warmer Ocean Climate, Albert Pessarrodona, Philippa J. Moore, Martin Sayer, Dan Smale

Research outputs 2014 to 2021

Global climate change is affecting carbon cycling by driving changes in primary productivity and rates of carbon fixation, release and storage within Earth's vegetated systems. There is, however, limited understanding of how carbon flow between donor and recipient habitats will respond to climatic changes. Macroalgal‐dominated habitats, such as kelp forests, are gaining recognition as important carbon donors within coastal carbon cycles, yet rates of carbon assimilation and transfer through these habitats are poorly resolved. Here, we investigated the likely impacts of ocean warming on coastal carbon cycling by quantifying rates of carbon assimilation and transfer in Laminaria hyperborea kelp forests—one …


On Legitimacy In Impact Assessment: An Epistemologically-Based Conceptualisation, Alan Bond, Jenny Pope, Francois Retief, Angus Morrison-Saunders Jan 2018

On Legitimacy In Impact Assessment: An Epistemologically-Based Conceptualisation, Alan Bond, Jenny Pope, Francois Retief, Angus Morrison-Saunders

Research outputs 2014 to 2021

Impact assessment (IA) is carried out as an ex ante process to inform decision-making. It includes requirements for engagement with stakeholders (including the public) regarding actions proposed by a proponent. A key issue with the various stakeholders involved is the perceived legitimacy of the IA, which can have implications both for the reputation of the proponent, and the likelihood of conflict over the decision. But the understanding of legitimacy in the IA literature has changed over time in line with an ontological shift from positivism (that scientifically generated information leads to better informed decisions) to the post-positivist acknowledgement of the …


Post-Fire Regeneration And Fuel Succession Patterns In Hesperocyparis Bakeri Forests, Bret Anthony Mcnamara Jan 2018

Post-Fire Regeneration And Fuel Succession Patterns In Hesperocyparis Bakeri Forests, Bret Anthony Mcnamara

Cal Poly Humboldt theses and projects

Climate change is predicted to cause widespread redistribution of suitable tree habitats, as well as increase the size and frequency of wildfires in the western United States during the forthcoming century. Rare serotinous conifers may have heightened sensitivity to the impacts of both fire regime and climate shifts for multiple reasons. First, the rapid spatial rearrangement of suitable habitat will disproportionately affect trees with constrained seed dispersal capabilities, and limited dispersal is a trait associated with some genera of serotinous trees. Second, a number of serotinous conifers depend on fire disturbances for regeneration, though with the expected increase in annual …


The Effects Of Ocean Acidification And Reduced Oxygen On The Behavior And Physiology Of Juvenile Rockfish, Corianna H. Flannery Jan 2018

The Effects Of Ocean Acidification And Reduced Oxygen On The Behavior And Physiology Of Juvenile Rockfish, Corianna H. Flannery

Cal Poly Humboldt theses and projects

As climate change progresses, the frequency and duration of upwelling events that bring low pH, low dissolved oxygen (DO) water to nearshore habitats are expected to increase. In addition, long-term global changes in ocean pH and DO are expected to occur within the next few decades to centuries. Locally, there have been documented reductions in near-shore pH along with the expansion of oxygen minimum zones within the California Current System. However, very few studies have investigated the potential interactive effect of these stressors on temperate reef fish. For this thesis, two sets of laboratory experiments were conducted to determine the …


Effects Of Manual And Mechanical Ammophila Arenaria Removal Techniques On Coastal Dune Plant Communities And Dune Morphology, Monique R. Silva Crossman Jan 2018

Effects Of Manual And Mechanical Ammophila Arenaria Removal Techniques On Coastal Dune Plant Communities And Dune Morphology, Monique R. Silva Crossman

Cal Poly Humboldt theses and projects

The removal of invasive species as part of the restoration process can allow natives organisms to rebound. An ecosystem that incurs damages from invasive species is coastal sand dunes, which are dynamic systems. Some coastal sand dunes on the west coast of the United States have been invaded by Ammophila arenaria. The invasive grass, A. arenaria, is thought to alter and stabilize foredune morphology and reduce populations of native species. The objectives of my research are to examine the effects that manual and mechanical A. arenaria removal techniques have on coastal sand dune morphology and vegetative cover over time. …


Assessing Spatio-Temporal Patterns Of Forest Decline Across A Diverse Landscape In The Klamath Mountains Using A 28-Year Landsat Time-Series Analysis, Drew S. Bost Jan 2018

Assessing Spatio-Temporal Patterns Of Forest Decline Across A Diverse Landscape In The Klamath Mountains Using A 28-Year Landsat Time-Series Analysis, Drew S. Bost

Cal Poly Humboldt theses and projects

Rates of tree mortality in California and the Pacific Northwest have greatly increased in recent years, driven largely by pest and pathogen outbreaks as well as the effects of hotter, warmer droughts. While there have been a multitude of regional-scale assessments of mortality and forest decline, landscape-level studies are necessary to better identify forests that are most vulnerable to decline and to anticipate future changes. This need is particularly notable in the remote and little-studied mountains of northwest California, which are renowned for their diverse, heterogeneous vegetation types. A recent observation of elevated levels of Shasta red fir (Abies …


A Decision Tree Analysis Of Nonindigenous Species Risk From Ballast Water To The Lower Columbia River And Oregon Coast, Usa, Danielle Verna, Richard R. Rueb, Crysta Gantz, John Gala, Jeremiah Green, John A. Zalusky, Rian Vanden Hooff Jan 2018

A Decision Tree Analysis Of Nonindigenous Species Risk From Ballast Water To The Lower Columbia River And Oregon Coast, Usa, Danielle Verna, Richard R. Rueb, Crysta Gantz, John Gala, Jeremiah Green, John A. Zalusky, Rian Vanden Hooff

Environmental Science and Management Faculty Publications and Presentations

Hazard characterization and risk assessment are commonly used to prioritize vectors of nonindigenous species (NIS) for inspection or other prevention opportunities. Commercial shipping vessels are a target of such vector-based management since ballast water has been known to transport NIS between aquatic ecosystems globally. Here we used a risk-based screening protocol to prioritize vessels discharging ballast water to the lower Columbia River and Oregon coast. We began by adapting established methods of assessing risk factors that influence the initial stages of the invasion process (arrival and survival). We created relative risk scales for each factor using data collected from vessels …


Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu Jan 2018

Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu

Environmental Science and Management Faculty Publications and Presentations

Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after …


Wolbachia Modifies Thermal Reference In Drosophila Melanogaster, Amy Michelle Truitt, Martin Kapun, Rupinder Kaur, Wolfgang J. Miller Jan 2018

Wolbachia Modifies Thermal Reference In Drosophila Melanogaster, Amy Michelle Truitt, Martin Kapun, Rupinder Kaur, Wolfgang J. Miller

Environmental Science and Management Faculty Publications and Presentations

Environmental variation can have profound and direct effects on fitness, fecundity, and host symbiont interactions. Replication rates of microbes within arthropod hosts, for example, are correlated with incubation temperature but less is known about the influence of host-symbiont dynamics on environmental preference. Hence, we conducted thermal preference (Tp) assays and tested if infection status and genetic variation in endosymbiont bacterium Wolbachia affected temperature choice of Drosophila melanogaster. We demonstrate that isogenic flies infected with Wolbachia preferred lower temperatures compared to uninfected Drosophila. Moreover, Tp varied with respect to three investigated Wolbachia variants (wMel, wMelCS and wMelPop). While uninfected individuals preferred …


Bioassessment Of A Drinking Water Reservoir Using Plankton: High Throughput Sequencing Vs. Traditional Morphological Method, Wanli Gao, Zhaojin Chen, Yuying Li, Yangdong Pan, Jingya Zhu, Shijun Guo, Lanqun Hu, Jin Huang Jan 2018

Bioassessment Of A Drinking Water Reservoir Using Plankton: High Throughput Sequencing Vs. Traditional Morphological Method, Wanli Gao, Zhaojin Chen, Yuying Li, Yangdong Pan, Jingya Zhu, Shijun Guo, Lanqun Hu, Jin Huang

Environmental Science and Management Faculty Publications and Presentations

Drinking water safety is increasingly perceived as one of the top global environmental issues. Plankton has been commonly used as a bioindicator for water quality in lakes and reservoirs. Recently, DNA sequencing technology has been applied to bioassessment. In this study, we compared the effectiveness of the 16S and 18S rRNA high throughput sequencing method (HTS) and the traditional optical microscopy method (TOM) in the bioassessment of drinking water quality. Five stations reflecting different habitats and hydrological conditions in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia, were sampled May 2016. Non-metric multi-dimensional scaling (NMDS) analysis showed …


Effects Of Variable Density Thinning On Spatial Patterns Of Overstory Trees In Mt. Hood National Forest, Emma Huston Jan 2018

Effects Of Variable Density Thinning On Spatial Patterns Of Overstory Trees In Mt. Hood National Forest, Emma Huston

Environmental Science and Management Professional Master's Project Reports

Variable density thinning (VDT) is a method of restoration thinning that attempts to increase ecosystem resilience and spatial heterogeneity in forest stands to more closely resemble mosaic-like patterns characteristic of late-successional forests, which consist of clusters of multiple trees, individual trees, and gaps. This study examines the spatial patterning of overstory trees resulting from VDT of conifer forests in Mt. Hood National Forest in the western Cascade Mountains and compares these patterns with reference conditions. Stem maps were created from field surveys of study plots within one mature stand and six thinned stands designated as Late-Successional Reserve (LSR) with varying …


Existing Ecological Conditions And Management Recommendations For A Portion Of The Chehalem Ridge Nature Park, Oregon, Amanda Pole Jan 2018

Existing Ecological Conditions And Management Recommendations For A Portion Of The Chehalem Ridge Nature Park, Oregon, Amanda Pole

Environmental Science and Management Professional Master's Project Reports

Effective land management and habitat restoration work rely on the collection of baseline information regarding the existing conditions of the planning area. Existing conditions assessments can include such information as hydrologic conditions, botanical species assessment, land use issues, wildlife surveys, habitat distribution/quality assessments, etc. This project provides Oregon Metro’s Parks and Nature department with updated information regarding the existing conditions of a portion of the Chehalem Ridge Nature Park (CRNP) as well as recommendations and supplemental maps to aid in future management planning.

Within the ~61-acre project area exist several habitat types: a developing seasonal wetland, riparian forest, Douglas-fir forest, …


Climate Change Challenges For Land Conservation: Rethinking Conservation Easements, Strategies, And Tools, W. William Weeks, Jessica Owley, Federico Cheever, Adena R. Rissman, M. Rebecca Shaw, Barton H. Thompson Jan 2018

Climate Change Challenges For Land Conservation: Rethinking Conservation Easements, Strategies, And Tools, W. William Weeks, Jessica Owley, Federico Cheever, Adena R. Rissman, M. Rebecca Shaw, Barton H. Thompson

Articles by Maurer Faculty

Climate change has significant consequences for land conservation. Government agencies and nonprofit land trusts heavily rely on perpetual conservation easements. However, climate change and other dynamic landscape changes raise questions about the effectiveness and adaptability of permanent conservation instruments like conservation easements. Building upon a study of 269 conservation easements and interviews with seventy conservation-easement professionals in six different states, we examine the adaptability of conservation easements to climate change. We outline four potential approaches to enhance conservation outcomes under climate change: (1) shift land-acquisition priorities to account for potential climate-change impacts; (2) consider conservation tools other than perpetual conservation …


Genotypic Responses Of Brachiaria Grass (Brachiaria Spp.) Accessions To Drought Stress, Duncan Cheruiyot, Charles Aura Odhiambo Midega, Johnnie Van Den Berg, John Anthony Pickett, Zeyaur Rahman Khan Jan 2018

Genotypic Responses Of Brachiaria Grass (Brachiaria Spp.) Accessions To Drought Stress, Duncan Cheruiyot, Charles Aura Odhiambo Midega, Johnnie Van Den Berg, John Anthony Pickett, Zeyaur Rahman Khan

All Peer-Reviewed Publications

Background and Objective: Brachiaria, a warm season C4 grass, is rapidly gaining popularity as fodder crop in Africa where it is also used as a component of a habitat management strategy for maize stem borers. However, increasing drought limits productivity of this grass species. The aim of this study was to evaluate and select high yielding brachiaria genotypes under simulated drought conditions. Materials and Methods: The morphological and physiological performance of 18 apomictic accessions of brachiaria in simulated drought conditions in a screen house were evaluated. Plants were exposed to different watering regimes. Well-watered (control) plants were watered every 48 …


Within-Fire Patchiness Associated With Prescribed Burning In The Northern Jarrah Forests Of Western Australia, Zigourney Nielsen Jan 2018

Within-Fire Patchiness Associated With Prescribed Burning In The Northern Jarrah Forests Of Western Australia, Zigourney Nielsen

Theses: Doctorates and Masters

There is growing understanding of the importance of landscape mosaics and heterogeneity for biodiversity outcomes in Western Australia. However, there is limited information on the patchiness (spatial configuration of unburnt and burnt patches which occur at a range of spatial scales) within the perimeter of a single prescribed burn. Of particular concern is the idea that prescribed burning operations, carried out under very restricted weather and environmental conditions, can lead to structural and floristic homogenization of the area within a burn perimeter. This may be evident as reduced post-fire vegetation patchiness. Western Australian Jarrah (Eucalyptus marginata) forests are managed to …


Exploring Technological Strategies For Valorization Of Solid Sisal Waste: A Research Review, Amelia Kivaisi, Anthony Mshandete Dec 2017

Exploring Technological Strategies For Valorization Of Solid Sisal Waste: A Research Review, Amelia Kivaisi, Anthony Mshandete

Tanzania Journal of Science

The sisal industry in Tanzania generates large amounts of waste which is an un-tapped bioresource. Research was undertaken to establish appropriate technologies  for its valorisation to mushrooms, biogas and biogas manure (BGM).Physical and biological pre-treatments achieved methane yield increments of 23-30% whereas co-digestion with fish waste achieved methane yield increments of 59-94%. Sisal fibre waste was demonstrated to be a novel biofilm-carrier for treating sisal pulp leachate. With a loading rate of 9.0 kgVS/m3/day, the packed-bed bioreactor was operated without process stress. Sisal decortication waste (SLDW) and sisal boles (SBW) were found to be suitable for oyster mushroom cultivation. With …