Integrative Biology Commons^™

Diversity And Evolution Of Fruits In Cuscuta (Dodders; Convolvulaceae), Anna Ho

Theses and Dissertations (Comprehensive)

Cuscuta (dodder) is a genus of roughly 200 species of obligate stem parasites with sub-cosmopolitan distribution. The fruit, generally regarded as a capsule, has a thin pericarp containing one to four seeds and opening at the base (circumscissile dehiscence; DE), or remaining closed (indehiscent; IN). IN has evolved multiple times in Cuscuta from DE, and is most common in the North American clades of subgenus Grammica. In addition, some species produce fruits that open irregularly. Characteristics pertaining to the fruits of Cuscuta are important as their seeds contribute most to their distribution and prevalence across the globe, and their reduced …

An Assessment Of How Plant And Mycorrhizal Communities Have Been Affected Along A Mine-Impacted Watershed In The Northwest Territories, Kevin Maccoll

Theses and Dissertations (Comprehensive)

Giant Mine is an inactive gold mine located nine kilometers north of Yellowknife, Northwest Territories. Giant Mine has been the source of arsenic trioxide for the Baker Creek watershed since it opened over 60 years ago. Although arsenic levels in the creek are above the limits considered to be biologically relevant, there is no concrete evidence that plants and mycorrhizae have actually been affected. This study provides an initial assessment of the impacts mining activity at Giant Mine has had on plants and mycorrhizae in the Baker Creek watershed. Nine sites were sampled around Giant Mine: five sites downstream from …

Influence Of Topography And Moisture And Nutrient Availability On Green Alder Function On The Low Arctic Tundra, Nt, Katherine Louise Black Ms., Jennifer Lynn Baltzer Dr.

Theses and Dissertations (Comprehensive)

The Arctic has warmed by at least 3^°C over the past 50 years and this rapid warming is expected to continue. Climate warming is driving the proliferation of shrubs across the tundra biome with implications for energy balance, climate, hydrology, nutrient cycling, and biodiversity. Changes in tundra plant water use attributable to shrub expansion are predicted to increase evapotranspirative water loss which may amplify local warming and reduce run-off. However, little is known about the extent to which shrubs will enhance evapotranspirative water loss in these systems. Direct measures of shrub water use are needed to accurately predict …

Quantifying Relationships Between Phosphorus Availability And Mycorrhizal Associations In Wetland Plants, Daniel Marshall

Theses and Dissertations (Comprehensive)

Increasing evidence indicates that plant community structure and therefore ecosystem function are mediated by below-ground fungal communities that form intracellular associations with plant roots called mycorrhizal associations. Arbuscular mycorrhizal fungi (AMF) are a type of mycorrhiza that colonize the plant host intracellularly but maintain hyphae outside the root cell for resource acquisition. The importance and function of AMF associations are well-documented in terrestrial ecosystems, but are less understood in aquatic or semi-aquatic systems. Phosphorus availability is the primary factor influencing mycorrhizal colonization and growth in terrestrial soils, with phosphorus-abundant soils leading to a decrease in mycorrhizal growth. However, the relationship …

The Complexity Of Electron Transport: A Study Of Variegation Through Chemical Inhibition Of Plastoquinol Terminal Oxidase (Ptox) In Tobacco (Nicotiana Tabacaum), Hillary Peon

Theses and Dissertations (Comprehensive)

The photosynthetic electron transport (PET) chain relies on the chlorophyll and carotenoid biosynthetic pathways for pigments that harness light, and protect the photosynthetic apparatus from damage by light. The pigment pathways also connect to the PET chain through electron transfer where the plastoquinol (PQ) pool accepts electrons from phytoene desaturase (PDS) of the carotenoid pathway and the aerobic cyclase (ACS) of the chlorophyll biosynthetic pathway. Genetic studies have shown a plastoquinol terminal oxidase (PTOX) protein functions to regulate the redox state of the PQ pool. Without PTOX to maintain balance between the two redox states of the PQ pool it …

Habitat Use And Movement Patterns Of Two Redwood Forest Salamanders, Aneides Vagrans And Ensatina Eschscholtzii, With An Examination Of The Efficacy Of Pit Tags For Marking Small Plethodontids, Christian Brown

Cal Poly Humboldt theses and projects

The habitat use and movements of small, secretive salamanders are generally poorly understood, in part due to the difficulty associated with marking and recapturing such animals. This study was designed to test the efficacy, both in the laboratory and in the field, of using passive integrated transponder (PIT) tags to mark and track two small-bodied plethodontid salamander species native to coastal northwestern California, Aneides vagrans, the Wandering Salamander, and Ensatina eschscholtzii, the Ensatina Salamander.

Aneides vagrans inhabits tree crowns. Using cover objects and visual encounter surveys, I searched for A. vagrans in the angiosperm understory canopy at least twice …