Forest Biology Commons^™

Climate Constrains The Enhancement Of Co2 Fertilization On Forest Gross Primary Productivity, Xinyuan Wei, Daniel J. Hayes, Christopher R. Schwalm, Joshua B. Fisher, Deborah N. Huntzinger, Lei Ma, Rodrigo Vargas, Nathaniel A. Brunsell

Mathematics, Physics, and Computer Science Faculty Articles and Research

Forest gross primary production (GPP) is influenced by the interplay between climate conditions and atmospheric CO₂ levels, which interact in complex ways, generating both compensating and amplifying effects. In this study, eddy covariance flux measurements from 50 forest ecosystems were integrated with simulations from 14 terrestrial biosphere models to investigate how climate conditions and atmospheric CO₂ concentrations regulate forest GPP. This approach bridges site-level observations with biome-scale model estimates to develop a global understanding. Our findings suggest that in boreal and cold temperate regions, temperature primarily constrains the enhancement of the CO₂ fertilization on forest GPP; however, …

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 …}

Impact Of Invasive Pine Trees And Their Ectomycorrhizal Fungi Symbionts Upon The Properties And Functions Of Soils In Southern Hemisphere Eucalyptus Forests, Jack T. Baker

Honors Theses

P. radiata trees are invading Southern Hemisphere Eucalyptus forests within New Zealand and southeastern Australia, resulting in a novel codominant forest system. This codominant invasion is unique relative to other pine invasions throughout the Southern Hemisphere. Ectomycorrhizal fungi (EMF) play an important role in all pine invasions and are found within each instance of invasion. The impact of ectomycorrhizal fungi and Pinus trees upon the properties of the soil within Eucalyptus forests is not very well studied nor understood. Our study sought to provide insight into the implications of this invasion upon the soil, and consequently the ecosystem as …

Patterns Of Fire History And Vegetation Changes In The Last 5000 Years: A Paleoecological Study Of Iquitos, Annabel Zwarts

Theses and Dissertations

The vegetation of the Amazonian rainforest is hypothesized to have been shaped by pre-Columbian activities, such as burning and palm management to various extents. Management of palms is hypothesized to have caused some of the most useful species to become hyperdominant in Amazonia. This study investigated the extent to which human activities over the past 5000 years affected palm abundances in mature lowland rainforests near Iquitos, Peru. I used phytoliths and charcoal from soil cores to determine the history of local floras, and modern palm surveys to compare modern phytolith occurrence with modern vegetation. Because pre-Columbian activity clustered along the …

The Forest Through The Trees: Modeling The Ecological Niche And Potential Assemblage Distribution Of Oak-Hickory Forests Across The Eastern U.S., Elijah Worley

Electronic Theses and Dissertations

Understanding how tree species’ ranges and populations may shift by the end of the 21^st Century is critical for effective conservation and forest management. Ecological niche models are widely used to predict species distributions by modeling the relationships between environmental variables and species presence. While numerous models have been developed for individual tree species across the USA, there is limited research on how tree species assemblages, such as oak-hickory forests, will respond to changes in climate over time. Maxent modeling software was used to predict potential shifts in suitable habitat for the oak-hickory forest type, based on environmental variables …

Life After Death: Investigating The Resistance And Recovery Of Fungal Communities To Foundation Tree Mortality, Jessie F. Marlenee

Biology ETDs

Tree mortality can have cascading effects on the composition and resilience of interacting fungal communities. Yet, little is known about the impact tree mortality, distinct from abiotic drivers (i.e., drought), has on these communities. This dissertation focuses on the resilience of fungal communities to experimental tree mortality in a piñon-juniper woodland. In chapter one, I found that piñon mortality reduced piñon fine root biomass and piñon mycorrhizal fungal diversity, whereas juniper mycorrhizal fungi were unaffected by juniper mortality. In chapter two, I revealed that piñon mortality altered the composition and spatial structure of mycorrhizal and saprotrophic fungi in the soil, …

Color Aberrations In Seven Bird Species In Costa Rica, Lucia Isabel Lopez, Jose Manuel Mora, Adrian Alvarado Rivera

Biology Faculty Publications and Presentations

Although there are 935 species of birds in Costa Rica, scientific reports of pigmentation abnormalities in this group are limited. Nevertheless, several cases have been recently documented, including Leucism, Ino mutation, Progressive Graying, Dilution, and two unusual color aberrations in a toucan and a motmot. Here we describe seven cases of color aberrations observed over a period of five years in native birds of Costa Rica. An Eastern Wood-Pewee Contopus virens and a White-collared Manakin manacus candei were Brown. A Scintillant Hummingbird Selasphorus scintilla and a Talamanca Hummingbird, Eugenes spectabilis, also showed a Brown mutation, however, these two cases may …

Occurrence Of Spotted Wing Drosophila (Drosophila Suzukii) In Wild Berries In Forested Areas Of Marquette And Keweenaw Counties, Upper Peninsula Of Michigan, Alexis M. Shatrau, Erika I. Hersch-Green

The Great Lakes Entomologist

Spotted-wing Drosophila (SWD, Drosophila suzukii Matsumura, Diptera: Drosophilidae) is an invasive fly that targets unripe soft-fruits causing premature ripening, dehiscence, and rotting. While the presence of SWD in agricultural systems is well-documented, much less is known about the host range of SWD in wild areas, especially in more northern latitudes where colder temperatures and short summers are thought to restrict their life-cycles and limit population growth. In 2019 and 2020, we collected wild berries from two counties in the Upper Peninsula of Michigan, with long, cold winters, to determine the prevalence, host range, and seasonal/temporal variation of SWD. We found …

Woody Plant Reinvasion Shortens The Lifespan Of Grassland Restoration Treatments, Dillon T. Fogarty, Michele Beadle, Craig R. Allen, Christine Bielski, Dirac Twidwell

Biology Student Work

An important question in restoration ecology is whether restored ecological regimes are more vulnerable to transitions back to a degraded state. In woody-invaded grasslands, high-intensity fire can collapse woody plant communities and induce a shift back to a grass-dominated regime. Yet, legacies from woody-dominated regimes often persist and it remains unclear whether restored regimes are at heightened vulnerability to reinvasion. In this study, we utilize a 17-year history of fire-based restoration in Nebraska's Loess Canyons Experimental Landscape to determine whether restored grassland regimes experience faster rates of Juniperus virginiana (eastern redcedar) reinvasion compared to the initial invasion process in adjacent …

Timber Talk, Vol. 63, No. 3, July 2025 (Special)

Timber Talk: Nebraska Forest Industry Newsletter

Timber Talk, Vol. 63, No. 3, July 2025 (Special)

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 …

Timber Talk, Vol. 63, No. 1, March 2025

Timber Talk: Nebraska Forest Industry Newsletter

Timber Talk, Vol. 63, No. 1, March 2025

Timber Talk, Vol. 63, No. 2, June 2025

Timber Talk: Nebraska Forest Industry Newsletter

Timber Talk, Vol. 63, No. 2, June 2025

Assessing The Potential For Bigleaf Maple Syrup Production In Humboldt County, Ca, David A. Reinhart, Juan A. Ramos-Cool, Liam H. Richardson

Undergraduate Scholarship

The bigleaf maple (Acer macrophyllum, Pursh) is the largest maple of the Pacific Northwest. While it has generally been treated as a nuisance in timber harvesting operations, a small amount of research has been conducted on its sugaring ability in Oregon, Washington, and British Columbia. This research has yet to reach further south in the species' range. This study aims to help a California landowner understand which maple trees on his property produce the most maple sap, to gauge what environmental factors contribute to maple sap production, and to find greater implications for the production of maple sap …

Two-Year Biomass And Productivity Data For Populus Trials In Mississippi, Courtney M. Siegert, Heidi Renninger, Austin Himes, Waqar Shafqat, Andrea Drager

CFR Publications

This dataset contains two years of biomass and productivity data for field trials of Populus in Mississippi.

How Forest Stand Conditions Influence Whitebark Pine And Clark’S Nutcracker: A Systematic Review, Bryan Mathew Cohen

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Whitebark pine (Pinus albicaulis), a keystone species of high-elevation ecosystems of western North America, is threatened with extinction due to disease (Blister rust), pests (Mountain pine beetle), and climate change. Regeneration of the species depends nearly exclusively on the seed-caching behavior of Clark’s nutcracker (Nucifraga columbiana, Family Corvidae). Because of this, conservation of whitebark ecosystems requires restoring stand structures that favor nutcrackers. Although there are increasing numbers of studies on the relationship between nutcrackers and whitebark pine, findings have not yet been synthesized, limiting knowledge for application to management. I did a systematic literature review to answer the following questions: …

The Role Of Floodplain Complexity In Wood Turtle Habitat Use, Laura S. Deming

Antioch University Dissertations & Theses

Wood turtles occupy cold, low-gradient riverine habitat throughout the northeastern United State and southeastern Canada. Stream alterations, such as dams, channel straightening, and floodplain development have diminished the natural hydrologic and sedimentation regimes that result in complex channel and floodplain geomorphology. Studies throughout the species’ range have quantified many aspects of their habitat, but none have quantified components of geomorphology of wood turtle sites. The goal of this study was to explore the role of stream channel and floodplain geomorphology in wood turtle habitat use, with specific objectives to (1) quantify components of stream channel and floodplain geomorphic complexity, (2) …

Sugar Maple (Acer Saccharum Marsh.) Tree-Ring Growth And Carbon Stable Isotope Responses To Nitrogen And Climate, Libbie Ring

Dissertations, Master's Theses and Master's Reports

This dendrochronological and stable carbon isotope study used tree rings from sugar maple (Acer Saccharum Marsh.) collected at long-term nitrogen (N) amended sites throughout Michigan to understand N amendment and deposition, climate, and growth relationships. Climate responses varied by site, however, we found importance in grouping sites by “productivity” which is related to inherent N and soil nutrients. Our results did not detect an overall effect of N amendments on growth during the treatment period. However, data shows N amendments benefiting larger diameter trees, while smaller diameter trees responded more positively without amendments, especially on more productive sites. Results …

Small Mammal Diet As An Indicator Of Lyme Disease And The Road To Endemicity In Michigan’S Upper Peninsula, Jacqueline E. Suits

Dissertations, Master's Theses and Master's Reports

Lyme disease is expanding in the Upper Midwest due to climate change, forest degradation, and shifting wildlife communities. Small mammals are key reservoir hosts, and their foraging behavior offers insight into environmental conditions that sustain pathogen transmission. We used DNA metabarcoding to investigate small mammal diets across seasonal, spatial, and infection gradients in Michigan’s Upper Peninsula. We identified dominant dietary plant and arthropod taxa, seasonal shifts, and slight variation by species, site, and Lyme infection status. Taxa associated with Lyme-positive individuals were primarily linked to moist, edge, and disturbed habitats, areas that also support ticks and disease spread. These results …

Impacts Of Southern Pine Beetle (Dendroctonus Frontalis Zimmerman) On Loblolly Pine (Pinus Taeda L.) Canopy And Water Use In The Homochitto National Forest, Mississippi, Usa, Sasha Goodnow, Yun Yang, Hui Liu, Ashley Schulz

Endeavors: Mississippi State Undergraduate Research Journal

Abiotic and biotic forest disturbances can have many impacts to forest ecosystem services, including to forest water use. Studies on impacts to forest evapotranspiration have been conducted on the mountain pine beetle (Dendroctonus ponderosae) in western North America, but not on the southern pine beetle (Dendroctonus frontalis), which is a native pest of loblolly pine (Pinus taeda) and shortleaf pine (Pinus echinata), in the southeastern United States. Stressed pine trees produce pheromones that attract southern pine beetles and, with enough stressed trees, beetle populations can quickly grow to epidemic levels and attack healthy trees, which results in widespread tree mortality. …