Botany Commons^™

Oregon State Rank Assessment For Schweinitz's Cyperus (Cyperus Schweinitzii), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Schweinitz's cyperus (Cyperus schweinitzii) using NatureServe methodology, 2026.

Nasa’S Ecostress Satellite Reveals Widespread Midday Depression In Ecosystem Evapotranspiration, Jingyi Bu, Jingfeng Xiao, Joshua B. Fisher, Yiqi Luo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Plants often exhibit a midday depression in water use (i.e., transpiration), reflecting a constraint on their ability to sustain maximum water transport, which may occur at the cost of reduced photosynthesis. Eddy covariance observations and geostationary satellites cannot quantify this widespread phenomenon globally while resolving fine-scale spatial variability. Using evapotranspiration measurements from the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) and machine learning, we quantify the global distribution of midday depression in evapotranspiration. Midday depression primarily occurs during peak-growing seasons in temperate zones and dry periods in the tropics, with a morning shift of the peak evapotranspiration time …

Oregon State Rank Assessment For Koehler's Rockcress (Boechera Koehleri), Lindsey K. Wise, Gabriel Campbell

Institute for Natural Resources Publications

Oregon state conservation status assessment for Koehler's rockcress (Boechera koehleri) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Deer-Cabbage (Nephrophyllidium Crista-Galli), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Deer-cabbage (Nephrophyllidium crista-galli) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Alpine Smelowskia (Smelowskia Ovalis), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Alpine smelowskia (Smelowskia ovalis) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Ithuriel's Spear (Triteleia Laxa), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Ithuriel's spear (Triteleia laxa)
 using NatureServe methodology, 2026.

Oregon State Rank Assessment For Thompson Mistmaiden (Romanzoffia Thompsonii), Nora Dunkirk, Gabriel Campbell, Sue Vrilakas

Institute for Natural Resources Publications

Oregon state conservation status assessment for Thompson mistmaiden (Romanzoffia thompsonii) using NatureServe methodology, 2026.

Oregon State Rank Assessment For California Pinefoot (Pityopus Californicus), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for California Pinefoot (Pityopus californicus) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Steens Mountain Cushion Buckwheat (Eriogonum Ovalifolium Var. Rubidum), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Steens Mountain Cushion Buckwheat (Eriogonum ovalifolium var. rubidum) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Oregon Daisy (Erigeron Oreganus), Nora Dunkirk, Sue Vrilakas

Institute for Natural Resources Publications

Oregon state conservation status assessment for Oregon Daisy (Erigeron oreganus) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Bensonia (Bensoniella Oregana), Nora Dunkirk, Sue Vrilakas, Gabriel Campbell

Institute for Natural Resources Publications

Oregon state conservation status assessment for Bensonia (Bensoniella oregana) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Deschutes Milkvetch (Astragalus Tegetarioides), Nora Dunkirk, Gabriel Campbell, Sue Vrilakas

Institute for Natural Resources Publications

Oregon state conservation status assessment for Deschutes Milkvetch (Astragalus tegetarioides) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Mt. Hood Bugbane (Actaea Laciniata), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Mt. Hood Bugbane (Actaea laciniata) using NatureServe methodology, 2026.

Exploring The Relationship Between Tree Dbh And Lichen Cover On Coast Redwood, Grace M. Personeus, Sierra Gittleman, Alisa A. Zarattini

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

We investigated the relationship between Diameter at Breast Height (DBH) and lichen cover on coast redwood (Sequoia sempervirens) to see if larger trees had higher percentages of cover. We measured cover using 10 cover classes on the southeastern and southwestern sides of trees in a secondary growth forest. We found a significant relationship between DBH and cover, yet no significant difference between the two sides measured. We suggest that further research with a larger sample size and more varied age classes will provide further insight into the relationship.

Oregon State Rank Assessment For Willamette Navarretia (Navarretia Willamettensis), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Willamette Navarretia (Navarretia willamettensis) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Straggling Gilia (Allophyllum Gilioides), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Straggling gilia (Allophyllum gilioides) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Wiens' Dwarf Mistletoe (Arceuthobium Abietinum Ssp. Wiensii), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Wiens' dwarf mistletoe (Arceuthobium abietinum ssp. wiensii) using NatureServe methodology, 2026.

Oregon State Rank Assessment For Bedstraw Broomrape (Aphyllon Epigalium Ssp. Epigalium), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Bedstraw broomrape (Aphyllon epigalium ssp. epigalium) using NatureServe methodology, 2026.

Investigating The Taxonomic Uncertainties Of Potentilla Rupincola, Natalie Elizabeth Hieber

Master's Theses

Landscape stewardship is an integral role for land managers that becomes more important when rare or endangered species occur within managed areas. Conservation across the landscape is a primary concern for land managers, but resources allocated for conservation can be limited due to many competing goals. Taxonomic uncertainty surrounding rare and endangered taxa, particularly plant taxa, that have historically been classified solely using morphological features further complicates conservation planning. One such taxon is Potentilla rupincola, a rare plant endemic to the eastern Rocky Mountains in Colorado. For over a century, botanists have debated whether P. rupincola is a distinct species …

Dendroclimatic Response Of The Wet Miombo Woodland Species: A Case Study Of Mufulira District, Copperbelt Province, Zambia, Collins Chibuye Malubeni

All-Inclusive List of Electronic Theses and Dissertations

Zambia is a tropical, landlocked country that lies in the South-Central part of Africa. The climate in Zambia includes distinct dry and rainy seasons, mainly influenced by the north-south movement of the Intertropical Convergence Zone (ITCZ), which shifts seasonally. This research is focused on understanding the relationship between tree growth and climate using dendrochronology. Forty-nine tropical species, including Julbernardia paniculata, Brachystegia longifolia, and Pericopsis angolensis, were analysed for dendroclimatic potential, and 70% showed clear ring formation, indicating that trees in this locality produce distinct annual ring boundaries. For the single species chronology, thirteen cores from eight trees that were initially …

Testing The Intermediate Disturbance Hypothesis On Anthropogenic Pressure In Central Alabama, Gavin Terrell

Theses

Biodiversity is fundamental to maintaining ecosystem structure and function globally. Prior to the late 20th century, ecological theory generally predicted that biodiversity would be highest in systems experiencing minimal disturbance. However, Joseph H. Connell challenged this view with the Intermediate Disturbance Hypothesis (IDH), which posits that species diversity peaks at intermediate levels of disturbance and declines under conditions of both low and high disturbance. Although widely cited, the applicability of the IDH to natural systems remains debated, particularly in the context of anthropogenic disturbances and when diversity is measured beyond species richness alone.

This study evaluated the predictions of the …

Depth And Soil Physical Context Govern Soil Organic Carbon, While Woody Cover Moderates Native Vegetation Relationships In California Rangelands, Dabid Zuniga Garcia

Cal Poly Humboldt theses and projects

Soil organic carbon (SOC) is central to soil function and an important component of climate mitigation in rangeland ecosystems, but the controls on SOC across California’s working rangelands remain understudied. Using data from Point Blue Conservation Science’s Rangeland Monitoring Network, this study evaluated how soil properties, vegetation structure, and recent climate relate to SOC concentration at depths of 0–10 cm and 10–40 cm across 145 ranches spanning four California regions. Linear mixed-effects models showed that SOC was consistently higher in topsoil than subsoil and highest in coastal sites relative to interior valleys. Bulk density was the strongest negative predictor of …

Clerodendrum Kelli (Lamiaceae), A New Species From Carranglan, Nueva Ecija, Philippines, And Lectotypification Of Clerodendrum Mindorense, David Justin R. Ples, Jacek Patykowski, John Charles A. Altomonte, Adriene B. Tobias, Rene Alfred Anton Bustamante

Biology Faculty Publications

Clerodendrum kelli (Lamiaceae), a new species from the montane forests of Carranglan, Nueva Ecija, Philippines, is described and illustrated. The species shares morphological features with Clerodendrum quadriloculare and C. mindorense, but differs in inflorescence structure, corolla tube length, and calyx shape and color. A lectotype for C. mindorense is also designated. Preliminary conservation assessment places C. kelli in the Critically Endangered category (CR B1ab(iii)+2ab(iii)). This study contributes to Philippine plant biodiversity knowledge and informs conservation strategies.

Oregon State Rank Assessment For Plumed Clover (Trifolium Plumosum Var. Plumosum), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Plumed Clover (Trifolium plumosum var. plumosum) using NatureServe methodology, 2025.

Exploring The Potential Of Martian Agriculture: Assessing Viability And Nutritional Composition Of Plants Cultivated In Martian Regolith, Abigail Ross

Honors Theses

In addition to sunlight and water, plants can utilize a small number of nutrients from the soil to biosynthesize all the materials that are needed for growth and development. However, plants require an environment where they are able to obtain those nutrients, such as iron, magnesium, potassium, sulfur, and nitrogen. Environmental factors determine the types and accessibility of nutrients available to plants. Plants then take up these nutrients from the soil to aid in biological mechanisms and the synthesis of important molecules needed for growth and development. Ascorbic acid, commonly known as Vitamin C, is a vital molecule that is …

Nepenthes Megastoma (Nepenthaceae), A Micro-Endemic Pitcher Plant From Puerto Princesa Subterranean River National Park, Palawan, Philippines, John Charles A. Altomonte, John Paul R. Collantes, Vernaluz Mangussad, Rene Alfred Anton Bustamante, Alastair S. Robinson

Environmental Science Faculty Publications

Nepenthes megastoma is described and illustrated as a new species from the Puerto Princesa Subterranean River National Park, a UNESCO World Heritage Site in Palawan Philippines. This carnivorous tropical pitcher plant is currently known from just three locations in the Mount Saint Paul karst formation, where it grows on vertical limestone walls. Morphologically, N. megastoma is characterised by its highly branched stems, campanulate pitchers, peltate tendril exsertion, dimorphic upper pitchers, and unidirectionally upturned female flowers. It is assessed as Critically Endangered under the IUCN Red List criteria, based on its restriction to three subpopulations comprising few total individuals. Pitcher morphology …

Modeling The Probability Of N Clonal Rosettes In A Bromeliaceae Genetic Individual, Erin N. Bodine, Layla K. Lammers

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Limited Soil Water Recharge In Summer Affects Seasonal Isotopic Signatures Of Tree Xylem Water, Marius G. Floriancic, Gregory R. Goldsmith, Harsh Beria, Scott T. Allen, James W. Kirchner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent studies have reported that xylem waters in forest trees during the summer growing season are often isotopically similar to winter, rather than summer, precipitation. Several hypotheses have been proposed to explain this observation, which can be viewed as a form of ecohydrological separation, but empirical tests spanning space and time remain limited. We hypothesise that variations in the seasonal origin of precipitation found in tree xylem waters can be explained by seasonal differences in soil water recharge. We test this hypothesis by evaluating to what extent climatic aridity can explain seasonal signals in extensive surveys of the isotope ratios …

Soil Health In Nebraska: Exploring Practitioners' Needs And Insights From A Long-Term Organic Farm, Ingrids Isabel Mata Vigil

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Soil health is foundational to sustainable agriculture, environmental resilience, and long-term food security. Yet, the adoption of soil health assessments remains limited, often perceived as too technical, costly, or difficult to implement in real-world contexts. To better understand these challenges, the first chapter presents findings from a statewide survey of 41 soil health practitioners in Nebraska, including farmers, extension educators, NRCS staff, and conservation professionals. Respondents highlighted the need for simpler, more accessible, and context-specific tools for soil health assessment that help practitioners make informed decisions aligned with their management goals. Complementing these insights, the second chapter includes an independent, …

Catching A Fever: A Comparison Of Vachellia Xanthophloea Populations In The Limpopo And Luvuvhu River Floodplains Of The Makuleke Contractual Park, Kianie B. David

School of Natural Resources: Dissertations, Theses, and Student Research

This study investigates patterns of stand structure regeneration, growth characteristics, and coarse woody debris (CWD) patterns in Vachellia xanthophloea (fever tree) stands within the Makuleke Contractual Park (MCP), a semi-arid savanna system in northern Kruger National Park (KNP), South Africa. Fieldwork was conducted across two stand types: a monospecific fever tree stand in Rietbok Vlei and a mixed-species stand in the Western Nhlangaluwe Floodplain where fever tree is established with Faidherbia albida (ana tree). Data were collected from 20 total 1/4-acre (1,011 m²) circular plots between both stands in 2024 and 2025, including seedling root collar diameter (RCD), …