Life Sciences Commons^™

Practical Challenges In Delivering Dsrna For Woody Plant Protection, Zachary Bragg

Theses and Dissertations--Entomology

Unprecedented weather events associated with climate change, coupled with extensive anthropogenic stresses, have reduced the effectiveness of traditional forest pest management approaches, which can no longer keep pace with invasive species overwhelming naïve landscapes and native pests experiencing eruptive and expansive outbreaks. Double-stranded RNA-(dsRNA) mediated gene silencing, a type of RNA interference (RNAi), has been coopted for use as a biopesticide against a multitude of agricultural and horticultural pests and could serve as a powerful tool for woody plant protection. While effective initiation of gene silencing and subsequent mortality have been demonstrated in multiple tree pests, effective and efficient methods …

Interactive Effects Of Bark Beetles, Ophiostomatoid Fungi, And Subterranean Termites On Wood Decomposition And The Biogeochemical Cycling Of Pine Forests, Kimberlyn Pace

Theses and Dissertations

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the …

Effects Of Prescribed Fire On Drought Resistance And Recovery In Mixed Conifer Forests Of Lassen Volcanic National Park, California, Zachary J. Wenderott

Cal Poly Humboldt theses and projects

Forests throughout much of the western United States are experiencing increasing climatic variability, often resulting in decreased forest productivity and elevated likelihood of tree mortality. Severe drought, such California’s recent 2012-2015 drought, are projected to increase in intensity, frequency, and severity throughout much of this region in coming years. Forest management has long relied on prescribed fire and mechanical thinning to reduce fuel loads and ameliorate potential fire hazards. These treatments may also have the ability to reduce stand density, alleviate competitive pressures, and allow residual trees access to critical resources during periods of extreme stress. Utilizing a long-term National …

Comparison Of Unmanaged And Managed Trojan Fir-Scots Pine Forests For Structuralcomplexity, Ferhat Kara, John M. Lhotka

Turkish Journal of Agriculture and Forestry

Unmanaged forests may exhibit a higher degree of biodiversity compared to managed forests. We examined and compared the stand structure, density, and volume of deadwood components of managed and unmanaged mixed forests of Trojan fir (Abies nordmanniana subsp. equi-trojani [Asch. & Sint. ex Boiss] Coode & Cullen)-Scots pine (Pinus sylvestris L.) in northern Turkey. The single-tree selection method has been employed in the managed forests. Density of large live trees ha-1, density of standing deadwood (SDW) ha-1, and volume of lying deadwood (LDW) (m3 ha-1) were calculated for both treatments (i.e. managed or unmanaged). Results showed that unmanaged forests had …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

Habitat Use And Avoidance By Foraging Red-Cockaded Woodpeckers In East Texas, John N. Macey, Brent Burt, Daniel Saenz, Richard N. Conner

Faculty Publications

Picoides borealis (Red-cockaded Woodpecker) is an endangered bird endemic to the Pinus (pine) ecosystems of the southeastern US. Mature pine savannahs with a minimal midstory and lush herbaceous groundcover represent high-quality habitat. This study examines the foraging-habitat patterns of Red-cockaded Woodpeckers in East Texas. We present a logistic regression model that best differentiates between foraged and non-foraged habitat. Increases in hardwood-midstory basal area have the greatest negative impact on the probability of Red-cockaded Woodpeckers selecting a habitat patch for foraging. Five additional variables negatively impact foraging probability: shrub height, diameter at breast height (DBH) of pine midstory, canopy closure, density …

Ecosystem Services Of Woody Crop Production Systems, Ronald S. Zalesny Jr., John A. Stanturf, Emile S. Gardiner, James H. Perdue, Timothy M. Young, David R. Coyle, William L. Headlee, Gary S. Bañuelos, Amir Hass

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Short-rotation woody crops are an integral component of regional and national energy portfolios, as well as providing essential ecosystem services such as biomass supplies, carbon sinks, clean water, and healthy soils. We review recent USDA Forest Service Research and Development efforts from the USDA Biomass Research Centers on the provisioning of these ecosystem services from woody crop production systems. For biomass, we highlight productivity and yield potential, pest susceptibility, and bioenergy siting applications. We describe carbon storage in aboveground woody biomass and studies assessing the provision of clean and plentiful water. Soil protection and wildlife habitat are also mentioned, in …

Sirex Noctilio In North America: The Effect Of Stem-Injection Timing On The Attractiveness And Suitability Of Trap Trees, Kelley E. Zylstra, Kevin J. Dodds, Joseph A. Francese, Victor Mastro

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

1 Sirex noctilio Fabricius, an invasive woodwasp responsible for severe economic damage to pine industries in the southern hemisphere, is now established in the northeastern U.S.A. and portions of eastern Canada.

2 Parts of North America are considered to be high risk for S. noctilio invasion. Effective detection tools, including trap trees, are needed to monitor and survey S. noctilio populations.

3 The present study was conducted to determine the optimal time to chemically stress a tree when aiming to attract the most S. noctilio to the host substrate, as well as to determine which timing produced the most adult …

Evolution Of Genome Size And Complexity In Pinus., Alison M. Morse, Daniel G. Peterson, M. Nurul Islam-Faridi, Katherine E. Smith, Zenaida V. Magbanua, Saul A. Garcia, Thomas L. Kubisiak, Henry V. Amerson, John E. Carlson, C. Dana Nelson, John M. Davis

College of Agriculture & Life Sciences Publications and Scholarship

BACKGROUND: Genome evolution in the gymnosperm lineage of seed plants has given rise to many of the most complex and largest plant genomes, however the elements involved are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Gymny is a previously undescribed retrotransposon family in Pinus that is related to Athila elements in Arabidopsis. Gymny elements are dispersed throughout the modern Pinus genome and occupy a physical space at least the size of the Arabidopsis thaliana genome. In contrast to previously described retroelements in Pinus, the Gymny family was amplified or introduced after the divergence of pine and spruce (Picea). If retrotransposon expansions are responsible …

Severe Wind And Fire Regimes In Northern Forests: Historic Variability At The Regional Scale, Lisa A. Schulte-Moore, David J. Mladenoff

Lisa A. Schulte Moore

Within the northern Great Lakes region, mesoscale (10s to 100s of km2) forest patterning is driven by disturbance dynamics. Using original Public Land Survey (PLS) records in northern Wisconsin, USA, we study spatial patterns of wind and fire disturbances during the pre-Euroamerican settlement period (ca. 1850). Our goals were: (1) to determine how effectively wind and fire disturbance can be econstructed from the PLS, (2) to assess the roles of wind and fire in shaping vegetation patterns, (3) to evaluate landscape to regional controls of wind and fire regimes, and (4) to assess the potential for interactions between these disturbances. …

Conservation And Restoration Of Pine Forest Genetic Resources In México, C. Sáenz-Romero, Amy E. Snively, R. Lindig-Cisneros

Student Published Works

Deforestation rates in México are about 670,000 ha/year. This threatens the richness of forest genetic resources in México, causing the disappearance of locally adapted populations and rare and endangered pine species. México is one of the six megadiverse countries in the world, with half of the world’s Pinus species. Pinus is one of the most economically and ecologically important forest genera in México. We suggest that delineation of seed zones and the establishment of a network of Forest Genetic Resource Conservation Units (FGRCUs), linked with forest management and ecological restoration programs will protect this valuable resource. We estimate that FGRCUs …

Alley Farming : New Vision For Western Australian Farmland, Ted Lefroy, Phil Scott

Journal of the Department of Agriculture, Western Australia, Series 4

Alley farming is a system where crops and pastures are grown in the alleys between rows of trees and shrubs. The concept is new to Western Australia but one that is likely to become more familiar over the next few years. The objective is to use trees and shrubs to decrease the environmental side effects of agriculture, such as erosion and salinity while increasing farm profit through the direct and indirect value of the trees.

This article describes some examples of alley farming in Western Australia and discusses the challenge of getting the right tree species and layout to maximise …

The Testing Of Coniferous Tree Seeds At The School Of Forestry, Yale University, 1906-1926, James W. Toumey, Clark L. Stevens

Yale School of the Environment Bulletin Series

Quality in forest tree seed centers in (a) origin; (b) genuineness; (c) purity; and (d) viability. The purchaser should insist on knowing the origin of the seed and the locality where it was collected.

Without seed testing establishments for investigating forest tree seeds by standardized methods under an established technique, nurserymen and foresters will continue to sow seed beds and undertake direct seeding without an adequate knowledge of the origin, genuineness, purity, and viability of the seeds used.