Life Sciences Commons^™

Interactions Between Fire Severity And Forest Biota In The Central Sierra Nevada: Formation And Impact Of Small-Scale Fire Refugia And The Effect Of Fire On Forest Structure Predictive Of Fisher (Pekania Pennanti) Den Habitat, Erika M. Blomdahl

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fire is a natural and essential component of forests in western North America. Fire maintains biodiversity through the creation of different habitat types, and regular fire rotations reduce the accumulation of woody fuels and thick understory plant densities that give rise to catastrophic fire. The practice of fire exclusion has altered western forests and increased the risk of widespread change under rising temperatures projected for the 21^st century. To manage for the reintroduction of fire it is critical that we understand the interactions between fire and forest biota in recently fire-suppressed forests.

In Chapter 2, I studied the formation …

Modeling The Response Of Black Walnut -Dominant Mixed Hardwoods To Seasonal Climate Effects With Uav-Based Hyperspectral Sensor And Aerial Photogrammetry, Tyler G. Bradford

MSU Graduate Theses

The development of compact sensors in recent years has inspired the use of UAS-based hyperspectral and aerial imaging techniques for small-scale remote sensing applications. With increasing concerns about climate change, spectrally-derived vegetation indices (VIs) have proven useful for quantifying stress-induced vegetation response. The goal of this study was to develop predictive models and assess methodology for modeling the biological response of a black walnut -dominant mixed hardwood stand to seasonal climate events using UAV-based hyperspectral remote-sensing. The derived VIs were evaluated against the means of four seasonal measures of climate calculated for a two-week period prior to the flight date. …

Assessing The Cooling Effects Of Urban Vegetation On Urban Heat Mitigation In Selected U.S. Cities, Qiuyan Yu

USF Tampa Graduate Theses and Dissertations

Urban Heat Island (UHI) is a growing problem worldwide. Mitigation of UHI is necessary for cities to adapt to climate change and enhance sustainable development at a city scale. Cooling cities with urban vegetation management is a sustainable solution for urban heat mitigation. Urban vegetation influences urban microclimate through the shading effect, surface roughness, and evapotranspiration. The differences in horizontal and vertical structures of urban vegetation determine the shading effect, surface roughness, and evapotranspiration. Enhancing the cooling effect of urban vegetation requires a comprehensive understanding of how vegetation structure affects UHI. The effects of horizontal structure on land surface temperature …

Forest Disturbance Detection And Aboveground Biomass Modeling Using Moderate-Resolution, Time-Series Satellite Imagery, John B. Kilbride

Electronic Theses and Dissertations

Human-induced and natural disturbances are an important feature of forest ecosystems. Disturbances influence forest structure and composition and can impact crucial ecosystem services. However, deriving spatially explicit estimates of past forest disturbance across a large region can prove challenging. Researchers have recognized that remote sensing is an important tool for monitoring forest ecosystems and mapping land use and land cover change. One of the most important sources of remotely sensed imagery is the United States Geologic Survey’s Landsat program which has continuously acquired earth observations since 1972. This repository of imagery has the spatial, spectral, and temporal resolution necessary to …

Spatio-Temporal Variations Of Soil Active Layer Thickness In Chinese Boreal Forests From 2000 To 2015, Xiongxiong Bai, Jian Yang, Bo Tao, Wei Ren

Forestry and Natural Resources Faculty Publications

The soil active layer in boreal forests is sensitive to climate warming. Climate-induced changes in the active layer may greatly affect the global carbon budget and planetary climatic system by releasing large quantities of greenhouse gases that currently are stored in permafrost. Ground surface temperature is an immediate driver of active layer thickness (ALT) dynamics. In this study, we mapped ALT distribution in Chinese boreal larch forests from 2000 to 2015 by integrating remote sensing data with the Stefan equation. We then examined the changes of the ALT in response to changes in ground surface temperature and identified drivers of …

Developing A Coastal Gis Model Of Sri Lanka To Pinpoint Areas At Risk Of Tsunamis, John E. Dellysse, Buddhika D. Madurapperuma

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

No abstract provided.

Predicting Potential Fire Severity Using Vegetation, Topography And Surface Moisture Availability In A Eurasian Boreal Forest Landscape, Lei Fang, Jian Yang, Megan White, Zhihua Liu

Forestry and Natural Resources Faculty Publications

Severity of wildfires is a critical component of the fire regime and plays an important role in determining forest ecosystem response to fire disturbance. Predicting spatial distribution of potential fire severity can be valuable in guiding fire and fuel management planning. Spatial controls on fire severity patterns have attracted growing interest, but few studies have attempted to predict potential fire severity in fire-prone Eurasian boreal forests. Furthermore, the influences of fire weather variation on spatial heterogeneity of fire severity remain poorly understood at fine scales. We assessed the relative importance and influence of pre-fire vegetation, topography, and surface moisture availability …

Patterns And Drivers Of Recent Disturbances Across The Temperate Forest Biome, Andreas Sommerfeld, Cornelius Senf, Brian Buma, Anthony W. D’Amato, Tiphaine Després, Ignacio Díaz-Hormazábal, Shawn Fraver, Lee E. Frelich, Álvaro G. Gutiérrez, Sarah J. Hart, Brian J. Harvey, Hong S. He, Tomáš Hlásny, Andrés Holz, Thomas Kitzberger, Dominik Kulakowski, David Lindenmayer, Akira S. Mori, Jörg Müller, Juan Paritsis, George L.W. Perry, Scott L. Stephens, Miroslav Svoboda, Monica G. Turner, Thomas T. Veblen, Rupert Seidl

Geography

Increasing evidence indicates that forest disturbances are changing in response to global change, yet local variability in disturbance remains high. We quantified this considerable variability and analyzed whether recent disturbance episodes around the globe were consistently driven by climate, and if human influence modulates patterns of forest disturbance. We combined remote sensing data on recent (2001–2014) disturbances with in-depth local information for 50 protected landscapes and their surroundings across the temperate biome. Disturbance patterns are highly variable, and shaped by variation in disturbance agents and traits of prevailing tree species. However, high disturbance activity is consistently linked to warmer and …

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 …

Remote Sensing Methods And Applications For Detecting Change In Forest Ecosystems, David James Gudex-Cross

Graduate College Dissertations and Theses

Forest ecosystems are being altered by climate change, invasive species, and additional stressors. Our ability to detect these changes and quantify their impacts relies on detailed data across spatial and temporal scales. This dissertation expands the ecological utility of long-term satellite imagery by developing high quality forest mapping products and examining spatiotemporal changes in tree species abundance and phenology across the northeastern United States (US; the ‘Northeast’).

Species/genus-level forest composition maps were developed by integrating field data and Landsat images to model abundance at a sub-pixel scale. These abundance maps were then used to 1) produce a more detailed, accurate …

Automated Tree-Level Forest Quantification Using Airborne Lidar, Hamid Hamraz

Theses and Dissertations--Computer Science

Traditional forest management relies on a small field sample and interpretation of aerial photography that not only are costly to execute but also yield inaccurate estimates of the entire forest in question. Airborne light detection and ranging (LiDAR) is a remote sensing technology that records point clouds representing the 3D structure of a forest canopy and the terrain underneath. We present a method for segmenting individual trees from the LiDAR point clouds without making prior assumptions about tree crown shapes and sizes. We then present a method that vertically stratifies the point cloud to an overstory and multiple understory tree …