Forest Biology Commons^™

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.

Integrating Belowground Recovery Into Tropical Forest Restoration Design And Monitoring, Lauren Toro, Leland K. Werden, Shalom D. Addo-Danso, Kelly M. Andersen, Sarah Batterman, Matilde M. Bragadini, Pooja Choksi, Rebecca J. Cole, Liza S. Comita, Daniela Cusack, Daisy H. Dent, Lee H. Dietterich, Joshua B. Fisher, Katrin Fleischer, Lucia Fuchslueger, Nohemi Huanca-Nunez, Janey R. Lienau, Lindsay A. Mcculloch, Ember M. Morrissey, Jennifer S. Powers, Mareli Sánchez-Juliá, Oscar Valverde-Barrantes, Anita Weissflog, Michelle Y. Wong

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

There is growing recognition that tropical forest restoration is key for sequestering carbon and enhancing ecosystem resilience. Soils, roots, and soil biota are central to ecosystem function and services, but belowground recovery is largely overlooked in restoration monitoring frameworks. Here, we outline current understanding of the links between above- and belowground recovery in tropical forests by examining how belowground properties before and after intervention influence recovery; by evaluating whether aboveground recovery can serve as a proxy for belowground dynamics; and by proposing a blueprint for monitoring dynamic soil physical (bulk density, aggregate stability), chemical (organic matter or carbon, pH), and …

Monitoring Mangrove Dynamics And Evaluating Future Afforestation Potential In The Egyptian Red Sea, Rasha M. Abou Samra, Mansour Almazroui, Wenzhao Li, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Mangrove forests are vital for ecosystem services and coastal management but face stressors from anthropogenic activities and climate change. This study estimates the extent and afforestation potential of mangroves along the Egyptian Red Sea coast from 1984 to 2022 using NDVI derived from Landsat-5 and Sentinel-2 data in Google Earth Engine. Aboveground biomass (AGB), belowground biomass (BGB), carbon (C) stock, and CO₂ sequestration potential were evaluated using Sentinel-2 and elevation data. Future afforestation suitability (2020–2050) under SSP2-4.5 and SSP5-8.5 scenarios was assessed with the MaxEnt model. Mangrove area increased from 0.95 km² in 1984 to 1.46 km^{2 …}

Dam It All: A Multi-Scalar Investigation Into The Ecological Role And Function Of Beaver Dams, Kenneth Larsen

Dissertations, Master's Theses and Master's Reports

The central theme of this dissertation is ecological scaling, which examines how small, localized features, such as beaver ponds, contribute to large-scale watershed processes and how different modeling approaches at various scales reveal distinct insights. Through a combination of probabilistic modeling and high-resolution empirical research, this work demonstrates that small ponded systems, particularly those created by beavers (Castor canadensis), serve as critical biogeochemical control points, whose contributions to sediment and nutrient dynamics have been historically underestimated.

In Chapter 1, I contextualize this research within the broader fields of freshwater ecology, watershed modeling, and ecological restoration. I introduce the …

Scaling Individual Tree Transpiration With Thermal Cameras Reveals Interspecies Differences To Drought Vulnerability, Mostafa Javadian, Donald M. Aubrecht, Joshua B. Fisher, Russell L. Scott, Sean P. Burns, Jen L. Diehl, J. William Munger, Andrew D. Richardson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding tree transpiration variability is vital for assessing ecosystem water-use efficiency and forest health amid climate change, yet most landscape-level measurements do not differentiate individual trees. Using canopy temperature data from thermal cameras, we estimated the transpiration rates of individual trees at Harvard Forest and Niwot Ridge. PT-JPL model was used to derive latent heat flux from thermal images at the canopy-level, showing strong agreement with tower measurements (R2 = 0.70–0.96 at Niwot, 0.59–0.78 at Harvard at half-hourly to monthly scales) and daily RMSE of 33.5 W/m2 (Niwot) and 52.8 W/m2 (Harvard). Tree-level analysis revealed species-specific responses to …

Chinese Tallow Long-Term Impact On Stand Dynamics In A Bottomland Hardwood Forest Following Vegetation Management, Nicklaus R. Langlois

Electronic Theses and Dissertations

Chinese tallow (Triadica sebifera (L.) Small) is an invasive tree known to have negative impacts on bottomland hardwood forests. Chinese tallow is proficient in reproducing and surviving in bottomland hardwood forests because it is more flood and shade tolerant than most native trees. The long-term effectiveness of Chinese tallow control is an important topic to research as only a few long-term studies of Chinese tallow control have been conducted. A 10-year re-measurement of 22 paired plots installed in 2012 on the Pineywoods Mitigation Bank near Diboll, Texas following herbicide treatments examined Chinese tallow and native tree stand structure. Each …

A Seasonal Decomposition Comparison Between Forest And Turf Habitats: Implications For Climate Change, Amanda Shirmer

DePaul Discoveries

Decomposition is an essential ecosystem service in which microorganisms breakdown organic matter. This process improves soil health and acts as a vital step in global carbon cycles. In this study, we examined decomposition rates and associated soil properties in turf and forest habitats across summer and fall seasons in order to determine how land management practices and climate change may be altering local decomposition regimes. Our study determined that there was a statistically significant difference between decomposition rates in turf and forest ecosystems (P=0.003) and a significant difference in decomposition rate across season (P

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

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

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Forests are expected to mitigate some of the negative effects of climate change by sequestering anthropogenic carbon (C) from the atmosphere, but the degree to which they drawn down C will depend on the availability of key nutrients, such as nitrogen (N). There is a fair amount of uncertainty in the future of the forest C sink, mostly owing to the fate of soil organic matter (SOM) and soil heterotrophic respiration to future conditions. In N limited systems, plants allocate a significant amount of their photosynthate belowground for the acquisition of nutrients, but under conditions of chronic N deposition, plants …

Marketing Agroforestry Products: Lessons From Producers

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

This publication shares producer experiences with marketing agroforestry products, including how producers entered — or created — the markets for their products. These individual stories highlight a diversity of experiences, from family-run farms to intermediaries assisting with market access. United States Department of Agriculture (USDA) and other federal, state, and local programs can provide capital or technical assistance to farmers at different phases of market development. The case studies in this publication highlight programs and resources available through USDA.

While marketing tree crops and non-timber forest products can be a challenge for producers, there is room for growth and opportunities …

The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann

Electronic Theses and Dissertations

Owing to the geographic isolation and unique climatic conditions which occur in tropical montane forests (TMFs), these systems are highly sensitive to changes in both climate and disturbance. Therefore, as ongoing climate change alters disturbance regimes – potentially facilitating multiple disturbance interactions much greater than that of isolated disturbances – TMFs may be shifted to alternate stable states. However, study of TMF resilience is essentially unknown given the lack of long-term studies in these systems. We address the resiliency of the tropical montane pine forests of the Cordillera Central, Dominican Republic using long-term climate records, remeasured vegetation data, and reconstructed …

A Floristic Survey Of Andalusia: A Historic Preservation Site In Baldwin County, Georgia, William Pharr

Biology Theses

A survey of the vascular plants of Andalusia, a historic preservation site located along Highway 441 north of Milledgeville in Baldwin County, Georgia, was conducted between August 2018 and February 2020. The site was the late home of esteemed author, Flannery O’Connor, and resides along the Georgia fall line, making it a historically significant area that could yield a unique plant community convergence, as well as rare endemic species. This floristic inventory provides baseline data on the species and plant communities of Andalusia for use in future studies regarding the flora of this area. A total of 191 vascular species …

Remote Sensing Monitoring Of Vegetation Dynamic Changes After Fire In The Greater Hinggan Mountain Area: The Algorithm And Application For Eliminating Phenological Impacts, Zhibin Huang, Chunxiang Cao, Wei Chen, Min Xu, Yongfeng Dang, Ramesh P. Singh, Barjeece Bashir, Bo Xie, Xiaojuan Lin

Mathematics, Physics, and Computer Science Faculty Articles and Research

Fires are frequent in boreal forests affecting forest areas. The detection of forest disturbances and the monitoring of forest restoration are critical for forest management. Vegetation phenology information in remote sensing images may interfere with the monitoring of vegetation restoration, but little research has been done on this issue. Remote sensing and the geographic information system (GIS) have emerged as important tools in providing valuable information about vegetation phenology. Based on the MODIS and Landsat time-series images acquired from 2000 to 2018, this study uses the spatio-temporal data fusion method to construct reflectance images of vegetation with a relatively consistent …

Leaf Angle And Leaf Stomata Responses To Experimental Drought In Quercus Velutina And Acer Saccharum, Brittany Nichole Casey

Graduate Theses, Dissertations, and Problem Reports (ETD)

The possibility of increased severity and frequency of drought conditions, as a result of global climate variability, greatly complicates our ability to forecast future forest functions such as productivity and carbon sequestration. Assessing how tree species vary in their response to drought can aid in predicting the impact on forest ecosystems as a whole. Throughfall exclusion (TfE) experiments are potentially useful tools to simulate realistic drought conditions within intact forest ecosystems. We employed a TfE experiment during the 2018 growing season within the WV Land Trust’s Elizabeth’s Woods Nature Preserve, near Morgantown, WV, to assess the leaf angle and leaf …

Enhancing Rural Economies Through Agroforestry, Gary Bentrup, Dean Current, Christopher Hartley, Marlen Eve, Tricia Kovacs, Kate Mcfarland, Eric Norland, David Smith, Susan Stein, Richard Straight

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

Executive Summary

Accelerating the adoption of agroforestry will require a better understanding of the economic opportunities and financial benefits to society, says a recent assessment of United States agroforestry.1 Providing this understanding is critical for agroforestry to reach its full potential, whereby it enhances rural economies and provides ecological services that people need, such as clean drinking water. To assess emerging opportunities, the United States Department of Agriculture (USDA) convened more than 60 people in March 2018 to learn, network, and, above all, generate ideas for raising the economic profile and viability of agroforestry in the United States.

The effort …

Using Multi-Indices Approach To Quantify Mangrove Changes Over The Western Arabian Gulf Along Saudi Arabia Coast, Wenzhao Li, Hesham El-Askary, Mohamed A. Qurban, Jingjing Li, K. P. Manikandan, Thomas Piechota

Mathematics, Physics, and Computer Science Faculty Articles and Research

Mangroves habitat present an important resource for large coastal communities benefiting from activities such as fisheries, forest products and clean water as well as protection against coastal erosion and climate related extreme events. Yet they are increasingly threatened by natural pressure and anthropogenic activities. We observed an inaccurate distribution of mangroves over the Western Arabian Gulf (WAG) which is a vital habitat and resource for the local ecosystem, according to the United Stated Geological Survey (USGS) mangrove database through spectral analysis. Change detection analysis is conducted on mangrove forests along the Saudi Arabian coast of the WAG for the years …

Agroforestry Strategic Framework, Fiscal Years 2019-2024, Susan Stein

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

America’s farmers, ranchers, and forest landowners are integrating trees with agriculture to address a variety of conservation and production goals. A unique land management approach, agroforestry provides opportunities to integrate productivity and profitability with environmental stewardship to support healthy, sustainable agriculture systems, economies, and communities.

Assessment Of The Ponderosa Woodlands In Nebraska's Wildcat Hills: Implications For Juniperus Encroachment And Management, Allie Victoria Schiltmeyer

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

Ponderosa pine (Pinus ponderosa) is a dominant tree species across western North America. Its eastern distribution includes three populations in western Nebraska. This study assesses the distribution, structure and age of ponderosa pine woodlands in one of those regions, the Wildcat Hills. The Wildcat Hills have escaped severe wildfires seen in recent decades in other ponderosa pine regions. Nevertheless, the Wildcat Hills woodlands face multiple threats including climate change, wildfire, drought, pine beetles, and invasive species. Key to these threats is the stand structure of pine woodlands, which have increased in density across much of ponderosa pine’s range. …

Guide To Usda Agroforestry Research Funding Opportunities

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

This guide is intended for researchers and academics pursuing funding opportunities for research in agroforestry - the intentonal integration of trees and agriculture. The guide provides an overview of external agroforestry research funding opportunities offered by the United States Department of Agriculture (USDA) agencies.

This publication was created for serveral reasons. Agroforestry is not always clearly identified in announcements about research funding opportunities. In addition, research on agroforestry can require a longer time horizon than research on annual systems, so awareness of multiple funding sources or multi-year funding opportunities can be useful. Last, though USDA offers grants that can support …

Agroforestry Standards For Regenerative Agriculture [Review], Craig R. Elevitch, D. Niki Mazaroli, Diane Ragone

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

Agroforestry is increasingly being recognized as a holistic food production system that can have numerous significant environmental, economic, and social benefits. This growing recognition is paralleled in the USA by the budding interest in regenerative agriculture and motivation to certify regenerative practices. Current efforts to develop a regenerative agriculture certification offer an opportunity to consider agroforestry’s role in furthering regenerative goals. To understand this opportunity, we first examine how agroforestry practices can advance regenerative agriculture’s five core environmental concerns: soil fertility and health, water quality, biodiversity, ecosystem health, and carbon sequestration. Next, we review a subset of certification programs, standards, …

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 …

What Controls Variation In Carbon Use Efficiency Among Amazonian Tropical Forests?, Christopher E. Doughty, Gregory R. Goldsmith, Nicolas Raab, Cecile A. J. Girardin, Filio Farfan-Amezquita, Walter Huaraca-Huasco, Javier E. Silva-Espejo, Alejandro Araujo-Murakami, Antonio C. L. Da Costa, Wanderley Rocha, David Galbraith, Patrick Meir, Dan B. Metcalfe, Yadvinder Malhi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Why do some forests produce biomass more efficiently than others? Variations in Carbon Use Efficiency (CUE: total Net Primary Production (NPP)/ Gross Primary Production (GPP)) may be due to changes in wood residence time (Biomass/NPP_wood), temperature, or soil nutrient status. We tested these hypotheses in 14, one ha plots across Amazonian and Andean forests where we measured most key components of net primary production (NPP: wood, fine roots, and leaves) and autotrophic respiration (R_a; wood, rhizosphere, and leaf respiration). We found that lower fertility sites were less efficient at producing biomass and had higher rhizosphere respiration, …

High Resolution Land Cover Of Kansas (2015; Dataset), Darci A. Paull, Jakob W. Whitson, Abbey L. Marcotte, Greg C. Liknes, Dacia M. Meneguzzo, Todd A. Kellerman

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

This data publication contains 2015 high-resolution land cover data for each of the 105 counties within Kansas. These data are a digital representation of land cover derived from 1-meter aerial imagery from the National Agriculture Imagery Program (NAIP). There is a separate file for each county. Data are intended for use in rural areas and therefore do not include land cover in cities and towns. Land cover classes (tree cover, other land cover, water, or city/town) were mapped using an object-based image analysis approach and supervised classification.

Agroforestry: Enhancing Resiliency In U. S. Agricultural Landscapes Under Changing Conditions, Gary Bentrup, Michele M. Schoeneberger, Toral Patel-Weynand

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

Agroforestry, the intentional integration of trees and shrubs into crop and animal production systems, is being deployed to enhance productivity, profitability, and environmental stewardship of agricultural operations and lands across the United States. This assessment provides a science-based synthesis on the use of agroforestry for mitigation and adaptation services in the face of climatic variability and change. It provides technical input to land-use sector issues in the National Climate Assessment (NCA) and serves as a framework for including agroforestry systems in agricultural strategies to improve productivity and food security and to build resilience in these landscapes. It also provides follow-up …

Executive Summary, Agroforestry: Enhancing Resiliency In U. S. Agricultural Landscapes Under Changing Conditions, Toral Patel-Weynand, Gary Bentrup, Michele M. Schoeneberger

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

Agroforestry, the intentional integration of trees and shrubs into crop and animal production systems, is being deployed to enhance productivity, profitability, and environmental stewardship of agricultural operations and lands across the United States. The full assessment at https://doi.org/10.2737/WO-GTR-96 and summarized here provides a science-based synthesis on the use of agroforestry for mitigation and adaptation services in the face of climatic variability and change. It provides technical input to land-use sector issues in the National Climate Assessment (NCA) and serves as a framework for including agroforestry systems in agricultural strategies to improve productivity and food security and to build resilience in …

Agroforestry Horizons: Experiences And Reflections: Report-Out, Steve Rasmussen

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

The USDA National Agroforestry Center (NAC) is charting a course for the next five years. As part of this process, NAC and the USDA Interagency Agroforestry Team hosted a meeting of leaders in the fields of agroforestry, agriculture, and forestry, from government, universities, and the private sector, to share experiences and insights on agroforestry opportunities and challenges. The meeting occurred on April 27th and 28th, 2016, in Washington, DC, and entailed presentations and discussions on current and potential roles of agroforestry in supporting water quality, soil health, economic diversification, food security, and pollinator/wildlife habitat. This report-out provides a summary of …

Diseases Of Trees In The Great Plains, Aaron D. Bergdahl, Alison Hill, Gerard C. Adams, Rachel A. Allison, John A. Appel, John Ball, James T. Blodgett, Kelly S. Burns, Whitney Cranshaw, Kelsey L. Dunnell, Mark L. Gleason, Mark O. Harrell, Thomas C. Harrington, Marcus B. Jackson, William R. Jacobi, Jennifer Juzwik, Megan M. Kennwlly, Les Koch, Jared M. Leboldus, Phillip A. Mason, Douglas L. Mcnew, Judith O'Mara, Hayley M. Nelson, Nicole Opbroek, Michael E. Ostry, Scott C. Redlin, Glen R. Stanosz, Laurie J. Stepanek, Ned Tisserat, Timothy C. Todd, James A. Walla, James J. Worrall, Simeon Wright

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

Hosts, distribution, symptoms and signs, disease cycle, and management strategies are described for 84 hardwood and 32 conifer diseases in 56 chapters. Color illustrations are provided to aid in accurate diagnosis. A glossary of technical terms and indexes to hosts and pathogens also are included.

Scope

The purpose of this handbook is to assist users in diagnosing tree diseases and reducing their impact. Included are the most damaging diseases, along with some that are the subject of frequent inquiry although of minor importance. The diseases included were those encountered primarily on trees in conservation plantings such as windbreaks, farmstead plantings, …

Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman

STAR Program Research Presentations

Tropical forest soils have an important role in global carbon (C) stocks. Small changes in the cycling of C could drastically affect atmospheric carbon dioxide (CO2) concentrations and active cycling of carbon in a forest community. Currently, little is understood of how tropical forest soils will respond to the increasing global temperatures. To examine the effects of warming/ drought on losses of older versus younger soil C pools, we implemented radiocarbon (14C) isotopic characterization of various soil plot samples and depths from the Luquillo Experimental Forest, Puerto Rico. 14C was measured using Accelerated Mass Spectrometry (AMS) from catalytically condensed carbon …

A Win-Win On Agricultural Lands: Creating Wildlife Habitat Through Agroforestry, Gary Bentrup

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

With increasing demands from society for limited resources, agroforestry will likely be one source of solutions as people find it increasingly necessary to achieve multiple social, economic, and ecological objectives on the same plot of land. Indications are that this is a growing field, so wildlife biologists of the future may want to consider incorporating agroforestry into their career development.

Development And Evaluation Of High Resolution Simulation Tools To Improve Fire Weather Forecasts, Brian K. Lamb, Jason M. Forthofer, Peter R. Robichaud

Joint Fire Science Program Research Project Reports

Fire weather forecasts rely on numerical weather simulations where the grid size is 4 km x 4 km or larger. In areas of complex terrain, this model resolution will not capture the details of wind flows associated with complicated topography. Wind channeling in valleys, wind speed-up over mountains and ridges, and enhanced turbulence associated with rough terrain and tall forest canopies are poorly represented in current weather model applications. A number of numerical wind flow models have been developed for simulating winds at high resolution; however, there are limited observational data available at the spatial scales appropriate for evaluating these …