Natural Resources and Conservation Commons^™

Common Raven Resource Selection, Diet, And Behavior Around A Threatened Shorebird, Janelle Chojnacki

Cal Poly Humboldt theses and projects

Human food subsidies have allowed populations of the common raven (Corvus corax) to expand and increase in density, especially in the western United States, which has amplified predation risk for other native species. Common ravens are well-documented nest predators of the federally threatened Western snowy plover (Anarhynchus nivosus nivosus) in Humboldt County, California; however, little is known about raven movement and foraging behavior in and around snowy plover habitat. Using GPS tracking and behavioral surveys, I examined movement and foraging behavior of beach-going ravens across snowy plover nesting habitat and I explored raven diet through stable isotope …

Barn Owls Exert Top-Down Effects On The Abundance And Behavior Of Rodent Pests, Katherine C. Larson

Cal Poly Humboldt theses and projects

Predators can exert top-down effects on their prey by direct consumption, by imposing risk of predation, or a combination of both. However, empirical evidence for these effects is mixed and inconsistent. Barn owls in agriculture present a system with attributes that should, according to theory, lead to strong top-down effects, but research is limited and the distinction between effects on prey abundance and behavior remains unresolved. Understanding the top-down effect of predators on pests is a cornerstone of integrated pest management and important where barn owls may contribute to the control of rodents on farms. Vegetation can mediate the top-down …

Fire Severity Mediates Marten And Fisher Occurrence: Impacts Of The Dixie Fire On A Carnivore Community, Christopher James Collier

Cal Poly Humboldt theses and projects

The consumption of an astounding one million acres resulted from California’s largest single fire to date, the 2021 Dixie Fire. The social and economic losses associated with the fire were immediately apparent, but the effects on wildlife remained unknown. While previous research has suggested mixed or low severity fire may be beneficial to certain wildlife species, the responses to megafires are poorly understood for many carnivores. To better understand these responses to severe fire, I used a random sampling design stratified by burn severity to survey in and around the Dixie Fire footprint using baited camera stations. This allowed me …

Post Wildfire Vegetation Response To The Wildland-Urban Interface: A Case Study Of The Station Fire, Angelo C. De Guzman, Raju Bista, Parveen K. Chhetri

CSU Journal of Sustainability and Climate Change

In the past, wildfires served as a method for mother nature to promote biodiversity and to help maintain a functioning ecosystem. However, climate change alters the fire regime, significantly impacting vegetation recovery. Human disturbances and increased land use and land cover heighten vegetation disruption and abundance after a fire. Wildland-urban interface (WUI) – the region where the vegetation intermingles with the roads, houses, and human-made structures – threatens vegetation and the human population. Overall vegetation recovery after the Station Fire of 2009 spread through the San Gabriel Mountains, Los Angeles County was observed using Digital Elevation Model (DEM), Normalized Difference …

Evaluating Benthic Macroinvertebrate Populations In Response To Scouring Events In The Trinity River, Ca, Liam Hay, Michael W. O'Neil, Chloe Pieper-Wasem

Environmental Science & Management Senior Capstones

River systems across California have been impacted by appurtenant structures such as dams and diversions. These structures have had an adverse impact on Benthic invertebrate (BMI) communities by regulating river systems and changing the natural hydraulic pulses that follow seasonal precipitation. Benthic invertebrates are a critical food resource for salmonids and serve as an indicator of ecosystem health. Our study was interested in seeing the effects of scouring events on BMI in the Trinity River of Trinity County, C.A. Following a large precipitation event that occurred in the region in December 2022, an influx of water entered the river through …

Modeling Current And Future Saltmarsh Distribution In Arcata Marsh, Madeline Kay Mcnerthney

Cal Poly Humboldt theses and projects

Saltmarsh habitat is vulnerable to Sea Level Rise (SLR) and requires long-term management plans for communities to continue to benefit from their ecosystem services. This study analyzed the variation of above-ground vegetation biomass throughout I Street Marsh, using multiple variables, including classified vegetative community types, elevation and remote sensing indexes comprised of both visual (Red, Green, Blue) and non-visual (Red Edge, Near Infrared) bands. Plant community types were classified using a cluster analysis, and distinguished three communities, based on dominant species: Salicornia, Spartina, and a mixed type (diverse floristic makeup, with no dominant species). Above-ground biomass was significantly higher in …

Treatment Plan And Educational Guide For Removing Invasive Barnyard Grass, Canada Thistle, And Cocklebur Within The Baduwa't (Mad River) Estuary, Ashley S. Turner, Alex D. Lallman

Undergraduate Scholarship

Our project is located at the Baduwa’t Estuary. We partnered with CalTrout to assist them with meeting one of the objectives for their Mad River (Baduwa’t) Estuary Floodplain Habitat and Public Access Enhancement Project. CalTrout partnered with the landowner, McKinleyville Community Services District, to restore 4.25 acres of the estuary. Our project focused on reducing the abundance of invasive plant species within the estuary area. The target plant species were barnyard grass, Canada thistle, and cocklebur. First, we conducted a literature review to learn the best management practices for eradicating the three target species. Then we conducted a field survey …

Comparing Fish Species Assemblage Between Impacted And Restored Estuarine Salt Marshes Within The Eel River Estuary, Humboldt Co. Ca, Adam Aguilar, Isaac Basham-Clair, Tristan F. Parkinson, Larkin C. Wells

Undergraduate Scholarship

This report details a study assessing the fish assemblages of a recently restored estuarine salt marsh site, and a similar unrestored and impacted site along the Eel River estuary. These two sites are located within the Eel River (Wiya’t) estuary, roughly 10 miles west of the city of Fortuna, CA. This study was conducted during the months of September through October 2023. Data collection was done through seine net dragging at randomly selected sample points across both sites. Seine net hauls were recorded by species and species count, which were later computed using a diversity index to provide values representative …

Prevalence Of Hesperevax Sparsiflora Var. Brevifolia (Short-Leaved Evax) At Ocean Ranch, Humboldt County, California: Exploring The Effects Of Disturbance, Shelby Diquirco, Matthew Estrada, Alana T. Fraley, Alexander D. Smith

Environmental Science & Management Senior Capstones

The prevalence of special-status plants within a landscape can be an indicator of the ecological health of that site, and therefore inform restoration efforts and post-restoration monitoring. Hesperevax sparsiflora var. brevifolia (short-leaved evax) is a special status species found within the Ocean Ranch unit of Humboldt, California. A primary threat to native plant communities are invasive plant species. Coastal dune ecosystems are largely dominated by invasive species, including Ammophila arenaria (European beachgrass). To work towards the eradication of A. arenaria, the California Department of Fish and Wildlife utilized treatment combinations of herbicide and prescribed fire at Ocean Ranch in …

Carnivore And Ungulate Occurrence In A Fire-Prone Region, Sara J. Moriarty-Graves

Cal Poly Humboldt theses and projects

Increasing fire size and severity in the western United States causes changes to ecosystems, species’ habitat use, and interspecific interactions. Wide-ranging carnivore and ungulate mammalian species and their interactions may be influenced by an increase in fire activity in northern California. Depending on the fire characteristics, ungulates may benefit from burned habitat due to an increase in forage availability, while carnivore species may be differentially impacted, but ultimately driven by bottom-up processes from a shift in prey availability. I used a three-step approach to estimate the single-species occupancy of four large mammal species: mountain lion (Puma concolor), coyote …

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Monitoring Bull Kelp (Nereocystis Leutkeana) Remotely At High Resolutions, Hannah E. Joss

Cal Poly Humboldt theses and projects

Bull kelp (Nereocystis leutkeana) is a foundational seaweed in nearshore, marine systems, traditionally supporting economically important fisheries, extracting nutrients in its vicinity, and sequestering carbon and transporting it great distances to subsidize shallow and deep-sea environments. Bull kelp is also a culturally important species for some indigenous peoples along the northeastern Pacific coastline and provides a harvestable product with growing demand. Global trends in kelp distribution show patterns of decline, and the immense loss of northern California bull kelp forests in response to climatic changes have highlighted the need for alternative sources of kelp, both for the product …

Macrolichen Inventory Of The Horse Mountain Botanical Area, Six Rivers National Forest, California, Usa, Sarah Norvell Conway

Cal Poly Humboldt theses and projects

Macrolichen diversity and community composition was determined for an area of high botanical interest in the Coast Ranges of Northern California – the Horse Mountain Botanical Area (HMBA) in Six Rivers National Forest. The Coast Ranges have been suggested to have high epiphytic macrolichen diversity, yet detailed site-specific macrolichen surveys are lacking for the area. Here we present comprehensive data on macrolichens of the HMBA integrated with environmental metadata at the landscape level. Twenty 0.4 ha sampling plots were positioned across the varying habitats of the HMBA and macrolichens were intensively sampled from all substrata. Out of 888 total collections, …

The Effects Of Post-Harvest Residue On Plantation Forest Soils And Early Growth Of Redwood And Douglas-Fir Seedlings In Humboldt County California, Robert W. Raibley

Cal Poly Humboldt theses and projects

Forest harvest residue (slash) usefulness has been up for debate among private timberland owners, public land managers, and the timber industry for decades. The disposal of slash, viewed as having low ecological value, has received considerable attention as wildfire risk has made burning it harder. In recent years, forest scientists and ecologists have recognized the importance of decaying wood and its relationship to forest growth and regeneration. At this site in Northern California, we looked at whether forest harvest residue enriches soil near slash windrows through soils coring and lab analyses, looking for primary limited nutrients nitrate (NO₃-N) …

Habitat Selection And Habitat Use Of Gray Foxes (Urocyon Cinereoargenteus) On Trespass Cannabis Grows., Haley-Marie R. Jones

Cal Poly Humboldt theses and projects

Trespass cannabis grow sites, otherwise known as illegal cultivation sites on public lands, are extremely hazardous to the environment and can severely impact wildlife movement and behavior. Trespass grow sites are dangerous to wildlife as they negatively impact the quality of habitat and wildlife behavior through habitat modification, pesticide use, discarding of trash, and poaching on national forests. I researched gray fox habitat selection and habitat use at six different grow sites in the Klamath National Forest and Shasta-Trinity National Forest in northwestern California. I deployed GPS collars on three gray foxes at two of those grow sites and three …

Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty

Cal Poly Humboldt theses and projects

The Scott River supports the most robust population of threatened Coho Salmon Oncorhynchus kisutch remaining in the Klamath River basin. Even in the Scott River, low quality and restricted extent of juvenile rearing habitat limits the Coho Salmon population to a small fraction of historic abundance. To support persistence and recovery of Scott River Coho Salmon, the Scott River Watershed Council (SRWC) has constructed a portfolio of restoration projects to improve juvenile rearing habitat, including beaver dam analogs (BDAs). The Scott River BDAs were the first implemented anywhere in California. This study compares juvenile Coho Salmon responses associated with production …

Highlighting The Disconnect Between Legislation And Sustainable Cannabis, Johnathon A. Macias

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

Current legislation takes little regard for two major issues challenging the cannabis industry. The carbon footprint and legislation of cannabis are looked at where it is realized that neither is currently sustainable long-term. Solutions that require social responsibility from the legislation to preserve the culture and industry are delved into.

Evaluating Science Communication Efforts And Citizen Scientists' Knowledge Of, Attitude Toward, And Behavioral Intentions Related To The North American River Otter, Karlee D. Jewell

Cal Poly Humboldt theses and projects

Citizen Science (CS) and scientific visual, spatial, and graphic art projects have the potential to engage community members, provide opportunities for advances in scientific literacy, increase interest in science and local environmental knowledge, and elevate pro-environmental attitudes. CS depends upon public participation, and motivation for participation is varied, including participants’ desire to learn something new or contribute to science or scientific knowledge. An effective CS project will be rooted in an understanding of individuals’ motivations for participation, striving to meet those motivations, and effectively evaluating not only the scientific outputs of the project but also whether participants’ motivations are being …

Estimating The Ecosystem Service Of Aleutian Cackling Goose Droppings On Pastures, Brian G. Fagundes

Cal Poly Humboldt theses and projects

The Aleutian cackling goose (Branta hutchinsii leucopareia) experienced a population low of 790 geese in 1974 and has recovered to the current estimate of 186,100 geese in 2021. Private livestock producers view geese as pasture competitors and use hazing and hunting to scare geese from private lands to adjacent public lands. I investigated if geese provide an ecosystem service via dropping fertilizing effects to improve pastures in northern California.

A greenhouse experiment was conducted from February-August 2019 at Cal Poly Humboldt, divided into two experiments: freshly sown ryegrass pasture and established plant and soil communities removed intact from …

Carnivore And Ungulate Responses To Cattle In A Grazed Forest Ecosystem, Rebecca Carniello

Cal Poly Humboldt theses and projects

Habitat disturbance, a leading threat to biological diversity, comes in many forms and can alter the behavior of wildlife and reduce the amount of suitable habitat. Livestock grazing, a form of habitat disturbance, is the most widespread influence on native ecosystems of western North America. Research on the impacts of introduced domestic herbivores on wild carnivores and ungulates varies, and the degree to which wildlife species are affected is often species-specific. I used remote trail cameras to compare the activity patterns of black bears (Ursus americanus), coyotes (Canis latrans), bobcats (Lynx rufus), mountain lions …

Factors Affecting The Production Of Berries Of The Red Huckleberry Plant In The Redwood Experimental Forest, Kagat G. Mcquillen

Cal Poly Humboldt theses and projects

Vaccinium parvifolium (red huckleberry) is a culturally and commercially valued food for different coastal tribes of northwestern California.

Today some tribes are regaining access to ancestral lands, and Indigenous researchers are working to document information about culturally significant plant species and their management to reclaim traditional ecological knowledge and restore food sovereignty.

The present study, focused on red huckleberry, Vaccinium parvifolium, took place in the ancestral territory of the Yurok Tribe, currently managed by the US Forest Service as the Redwood Experimental Forest (REF) in Klamath, CA. Geographic Information Systems-based mapping, forest ecological field data collection, and a literature …

Sediment Production From Forest Roads In Areas Affected By The August Complex Fire In Northern California, Zachary J. Gigone

Cal Poly Humboldt theses and projects

Wildfire activity is increasing in California and is an important factor affecting erosion rates. Landscapes recently affected by wildfire, areas that have been salvage logged after a fire, and unpaved forest roads are all major sources of sediment which can impair water quality and negatively impact many aquatic species. Therefore, this study was conducted to quantify erosion rates from native and gravel surfaced forest road segments after the August Complex fire, evaluate the impact of salvage logging activities on sediment production from roads, and understand the effect of soil burn severity on sediment production from these road segments. Finally, this …

Comparison Of Environmental Dna And Underwater Visual Count Surveys For Detecting Juvenile Coho Salmon (Oncorhynchus Kisutch) In Rivers, Jason T. Shaffer

Cal Poly Humboldt theses and projects

Environmental DNA (eDNA) has developed into a useful tool for determining the distribution of rare aquatic species, but relatively few studies have directly compared the detection probabilities of this method with other conventional survey techniques. These comparisons can inform which method may be better suited to address study objectives. In this study, the overall goal was to compare the ability of eDNA and underwater visual count (UVC) surveys to detect juvenile coho salmon (Oncorhynchus kisutch), a species of conservation concern at the southern extent of its geographic range. Specifically, I address two objectives: (1) compare the ability of …

Comparing Molecular Methods To Estimate Fish Stomach Contents And Gastric Evacuation Rates: Implications For Measuring The Impacts Of Predation On Central Valley Chinook Salmon, Cory M. Dick

Cal Poly Humboldt theses and projects

Juvenile Chinook Salmon (Oncorhynchus tshawytscha) migrating through the Sacramento – San Joaquin Delta (the Delta) in central California have higher mortality rates than salmonids migrating through other west coast estuaries. Some hypotheses for high mortality rates include entrainment into water export facilities, physical alterations of the river system, and predation. Of these factors, predation is considered the least understood but may have the largest impact. Predation from large populations of non-native piscivorous fishes in the Delta is believed to effect abundances of Central Valley Chinook salmon, however sufficient data supporting this hypothesis is scarce. In this study, I …

Combined Use Of Data From Avian Surveys Along The Pacific Crest Trail With Biodiversity Repositories To Model Habitat Suitability Throughout Northern California, Holli N. Pruhsmeier, Michael C. Mcgrann, Jim Graham

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

Models that describe species distributions are valuable in guiding management decisions. We compared and combined two avian datasets during the 2010 breeding season in northern California, USA. These datasets were a large-scale avian diversity survey from McGrann and Furnas (2016; 2018) and combined data from Biological Information Serving Our Nation (BISON) and Global Biodiversity Information Facility (GBIF). Our objective was to compare the utility of these two datasets, that employ separate field protocols, to model habitat use for the Black-headed Grosbeak, Hairy Woodpecker, and Yellow-rumped Warbler, three common forest birds in our study area that occupy distinctive habitat types. We …

On The Acceptance Of Urban Beavers In Martinez, California, Zane A. Eddy

Cal Poly Humboldt theses and projects

As ecosystem engineers, beavers construct complex riparian and wetland habitats that benefit many other species, including endangered salmonids. Through their landscape alterations, beavers also promote increased groundwater recharge and provide refugia during wildfires and high flow events by impounding water and allowing it to spread across the landscape. Prior to the North American colonial fur trapping campaigns, there were between 60 and 400 million beavers in North America. By the beginning of the 20th century, beavers were extirpated from many parts of the continent, however through human efforts, their population has since rebounded to between 10 and 15 million. The …

Satellite-Based Phenology Analysis In Evaluating The Response Of Puerto Rico And The United States Virgin Islands' Tropical Forests To The 2017 Hurricanes, Melissa Collin

Cal Poly Humboldt theses and projects

The functionality of tropical forest ecosystems and their productivity is highly related to the timing of phenological events. Understanding forest responses to major climate events is crucial for predicting the potential impacts of climate change. This research utilized Landsat satellite data and ground-based Forest Inventory and Analysis (FIA) plot data to investigate the dynamics of Puerto Rico and the U.S. Virgin Islands’ (PRVI) tropical forests after two major hurricanes in 2017. Analyzing these two datasets allowed for validation of the remote sensing methodology with field data and for the investigation of whether this is an appropriate approach for estimating forest …

Comparison Of Low-Cost Commercial Unpiloted Digital Aerial Photogrammetry To Airborne Laser Scanning Across Multiple Forest Types In California, James Edward Lamping

Cal Poly Humboldt theses and projects

Science-based forest management requires quantitative information about forest attributes traditionally collected via sampled field plots in a forest inventory program. Remote sensing tools, such as active three-dimensional (3D) Light Detection and Ranging (lidar), are increasingly utilized to supplement and even replace field-based forest inventories. However, lidar remains cost prohibitive for smaller areas and repeat measurement, often limiting its use to single acquisitions of large contiguous areas. Recent advancements in unpiloted aerial systems (UAS), digital aerial photogrammetry (DAP) and high precision global positioning systems (HPGPS) have the potential to provide low-cost time and place flexible 3D data to support forest inventory …

Using Uav And Traditional Remote Sensing Data To Detect Vegetation Vigor And Monitor Stream Morphology In A Desert Riparian Ecosystem, Jordan Bradley Adair

Cal Poly Humboldt theses and projects

Mono Lake is a terminal lake in the Eastern Sierra Nevada Mountains. The streams that feed Mono Lake support a unique desert riparian ecosystem. Rush Creek was the stream of interest for this study. The objective of this research is to determine if remotely sensed imagery can be used to determine vegetation vigor and measure stream morphologic features in a desert riparian area. The goals were to evaluate different sources of remotely sensed imagery to make these determinations. The Normalized Difference Vegetation Index (NDVI) was used to monitor vegetation vigor along Rush Creek. Google Earth imagery and UAV derived imagery …

A Look At Land Cover Classification Methods In Northern California With The Use Of High Spatial Resolution Geospatial Data, Lucila Corro

Cal Poly Humboldt theses and projects

Land use and land cover (LULC) mapping plays a vital role in understanding the state of the world, showing us a visual representation of the natural and anthropogenic features covering our planet. Northern California in the United States is home to many critical habitats that provide for a variety of endemic and some threatened and engendered species, making it an area of particular concern to better understand and monitor. There is a greater need to identify specific methods for vegetation modeling in Northern California due to its unique species; to do this we examined two case studies with the following …