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Full-Text Articles in Life Sciences

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel Jan 2020

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …


A Tale Of Two Cervids: Habitat Selection And Spatial Ecology Of Roosevelt And Tule Elk In California, Adam S. Mohr Jan 2020

A Tale Of Two Cervids: Habitat Selection And Spatial Ecology Of Roosevelt And Tule Elk In California, Adam S. Mohr

Cal Poly Humboldt theses and projects

California’s Roosevelt (Cervus canadensis rooseveltii) and tule elk (C. c. nannodes) populations have experienced a remarkable recovery after over-hunting and habitat loss nearly extirpated them from the state. Greater clarity of Roosevelt and tule elk habitat selection patterns would help managers continue to effectively support the recovery of these two iconic subspecies. As the manner in which elk populations balance their competing resource needs is unique to each population (Skovlin et al. 2002), I have examined Roosevelt and tule elk habitat selection patterns in separate analyses and present these results in independent chapters. In both cases, …


Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan Jan 2020

Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan

Cal Poly Humboldt theses and projects

The intraspecific genetic variation and diversity within the Humboldt’s flying squirrel (Glaucomys oregonensis) has not yet been characterized despite its elevation to full species in 2017. The San Bernardino flying squirrel (G. o. californicus) is thought to be the southernmost population of G. oregonensis and is restricted to the San Bernardino and San Jacinto Mountains in California, but recent surveys indicate they have been extirpated from the latter locality. In order to provide baseline genetic data across the geographic range of G. oregonensis, I had the following objectives: 1) investigate the intraspecific molecular variation in …


Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon Jan 2020

Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon

Cal Poly Humboldt theses and projects

Survival of juvenile ungulates is known to be highly variable, yet it is fundamental to understanding the dynamics and trends of wildlife populations. Factors influencing calf survival are poorly understood in northwestern California where Roosevelt elk (Cervus canadensis roosevelti) are known to exist. The objectives of this study were 1) to estimate summer and annual survival rates and determine recruitment rates for Roosevelt elk calves in the area, 2) to evaluate differences in calf survival by examining the effects of individual and population level covariates on summer and annual calf survival, 3) to identify factors influencing the timing …


Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong Jan 2020

Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong

Cal Poly Humboldt theses and projects

Distinct populations of steelhead in the wild are in decline. The propagation of steelhead in hatcheries has been used to boost population numbers for recreational fisheries and for use in conservation. However, hatchery breeding practices of steelhead can result in changes in genetic structure. I investigated the genetic structure of winter-run steelhead (Oncorhynchus mykiss) returning to the Mad River, California, where a hatchery has been used enhance production for recreational fisheries since 1971. Genetic variability in Mad River steelhead was evaluated using 96 single nucleotide polymorphisms (SNPs) among 4203 individuals, including the Mad River and nearby locations, and …


The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler Jan 2020

The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler

Cal Poly Humboldt theses and projects

Early successional wetland habitat is being lost in temperate regions worldwide as a result of changes in disturbance regimes that allow for the establishment and dominance of woody species. In particular, this phenomenon is pronounced in fens, which harbor high numbers of rare herbaceous species that require early successional habitat. I investigated the relationship between woody vegetation encroachment and herbaceous species diversity within a Northern California coastal fen that has been undergoing encroachment by woody vegetation for ca. 80 years by recording species richness and cover data from 338 permanent plots throughout the fen. I also investigated the effect of …