Forest Biology Commons^™

Impacts Of Native And Nonnative Plant Species On Avian Community Diversity, Matty John Mackay, Steven Van Dang, Brandon Lee Corn

SPARK Symposium Presentations

Avian communities play an essential role in maintaining a healthy ecosystem dynamic by regulating insect populations, assisting in plant pollination, and seed dispersal. These contribute to the overall health of natural ecosystems and mitigate ecological disruptions that would arise in their absence. However, the introduction of non-native invasive plant species can interrupt the balance avian communities bring to ecosystems by reducing availability of food sources, altering habitat structures, increasing competition among individuals, and disrupting ecological relationships through rapid invasion of ecological spaces. Point count observations of birds at Shelby Bottoms Park, Nashville, Tennessee in areas dominated by non-native privet and …

Warming Induces Unexpectedly High Soil Respiration In A Wet Tropical Forest, Tana E. Wood, Colin Tucker, Aura M. Alonso-Rodríguez, M. Isabel Loza, Iana F. Grullón-Penkova, Molly A. Cavaleri, Christine S. O'Connell, Sasha C. Reed

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Tropical forests are a dominant regulator of the global carbon cycle, exchanging more carbon dioxide with the atmosphere than any other terrestrial biome. Climate models predict unprecedented climatic warming in tropical regions in the coming decades; however, in situ field warming studies are severely lacking in tropical forests. Here we present results from an in situ warming experiment in Puerto Rico, where soil respiration responses to ⁺4 ^oC warming were assessed half-hourly for a year. Soil respiration rates were 42-204% higher in warmed relative to ambient plots, representing some of the highest soil respiration rates reported for any …

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 …}

Vascular Epiphyte Population Dynamics Within Human-Modified Landscapes Of Guadalupe, Cerro Punta, Chiriquí, Panamá, Lucine Tashjian

Independent Study Project (ISP) Collection

Epiphytes are plants that grow on other plants non-parasitically, and globally, epiphytes compose a very large and diverse group. They are especially abundant and species-rich in the tropics- particularly, in tropical montane forest ecosystems. Human population growth in the tropics, however, has resulted in significant declines in forest cover with land being converted largely for agricultural purposes. Studies on epiphytes have traditionally been undertaken in pristine, undisturbed forest ecosystems, yet terrestrial land conversion has increased the need to understand the value of human-modified ecosystems for epiphytic populations and biodiversity conservation. This study sought to understand the relationship between human modification …

Mushroom Composition Across An Elevational Gradient During The 2024 Wet Season In Mazumbai Forest Reserve, Tanzania, Christopher Brady

Independent Study Project (ISP) Collection

Mushrooms are key bioindicators that contribute greatly to ecological health, and their diversity is indicative of a healthy ecosystem. However, even with the vital role they play in ecological health, there are few studies which measure the diversity of mushrooms in Mazumbai Forest Reserve (MFR), Tanzania, Africa, and none which focus on diversity along the elevational gradient within the reserve (1300-1900m). This study measures the diversity and equitability of mushrooms growing in six elevational zones within MFR during the rainy season of 2024. A species checklist of mushrooms growing in MFR during the 2024 rainy season was created, tracking the …

Tropical Tree Carbon Storage At Drago Dos Forest In Boca Del Drago, Panama, Ben Dwyer

Independent Study Project (ISP) Collection

Currently, anthropogenic carbon emissions pose a significant, global threat, contributing to Global Warming and Climate Change (CC). Today, the most effective carbon sinks are natural. Trees are highly effective carbon sinks that sequester large amounts of atmospheric carbon dioxide (CO2), most greatly in tropical areas. However, tropical tree carbon storage needs to be more accurately estimated to provide valuable information toward mitigating CC and its negative environmental effects. This study aimed to estimate CO2 sequestration at a tropical forest in Boca Del Drago, Panama, and compare it to that of a nearby mangrove forest. It was hypothesized that the tropical …

Variation In The Growth Parameters And Biomass Of Rhizophora Mangle Seedlings With Distances From Playa Estrella, Bocas Del Toro, Panama, Thiny Tep

Independent Study Project (ISP) Collection

Mangrove is a salt-tolerant, intertidal, tropical tree or shrub and make up a rich community of various organism. On the Caribbean coast of Panama, in Bocas del Toro, mangrove forests cover 28 km² and are dominated by R. mangle, followed by L. racemosa and A. germinans. Simultaneously, Isla Colón, the most populated and developed among all islands in the Bocas del Toro Archipelago, is a tourist center. Unfortunately, tourism comes at the price of environmental degradation via alteration of natural habitats, solid and wastewater pollution. Therefore, this study aims to gain a preliminary understanding on how the …

Troop Composition And Behavior Of Mantled Howler Monkeys (Alouatta Palliata) In Mangroves And Forested Islands South Of David, Panama, Slate Hyacinthe

Independent Study Project (ISP) Collection

The mantled howler monkey, Alouatta palliata, is one of the most commonly studied and widely distributed primate species in Central America. They have been reported to inhabit mangrove environments in Panama, but few studies have undertaken to describe their demography and behavior in these particular ecosystems. For my study, I spent 12 days studying A. palliata populations in both the mangrove and forested island ecosystems (Isla Parida and Isla Boca Brava) south of David. Seven groups were found in the mangrove environments, and 11 groups were found on the island environments. The mangrove groups were significantly smaller and at a …

A Comparative Plague Study Of Cacao Fungal Disease In Cacao Pods Within Monocultures And Indigenous Agroforests In Ecuador’S Napo Province, Seamus Mccarthy

Independent Study Project (ISP) Collection

This study analyzes the composition of three major fungal diseases in Theobroma cacao fruits compared between monocultures and chakra agroforests in the Napo province of Ecuador with the goal of noting similarities and differences in the disease composition between the two systems, as well as investigate possible variation within this poorly understood category of agroforest to better structure future studies. Cacao pods on sampled trees were counted and fungal infections identified visually and by touch. Chakra systems were selected in the communities of Cinco de Enero and Seis de Marzo to the Southwest of Tena, Ecuador. Monoculture data was collected …

Community Participation And Perspectives Of Ambondrolava Mangrove Restoration Project, Nadine Shannon

Independent Study Project (ISP) Collection

Madagascar’s mangrove forests are intertidal ecosystems that provide numerous valuable ecosystem services but are nonetheless under pressure from large amounts of deforestation. On the southwestern coast of Madagascar, the village of Ambondrolava practices community led management of the mangrove and its resources. This research project studied the evolution of the mangrove area using GIS data, and investigated, through interviews, the relationship between the local community of Ambondrolava and the organizations that manage the mangrove ecosystem. From 2000 to 2018, the zone of the mangrove has experienced a net loss in area every year, despite reforestation efforts. Most community members interviewed …

Laguncularia Racemosa Top-Layer Sediment Microorganism Makeup In Relation To Differing Levels Of Perceived Anthropogenic Impact In Bocas Del Drago, Bocas Del Toro, Panama, Gabrielle Glendening

Independent Study Project (ISP) Collection

As mangrove forests are destroyed by human factors across the earth, many crucial ecological processes that take place in these systems of trees are obstructed. One of the most important roles played by mangroves is their ability to sequester carbon in the sediment, as this storage of carbon helps diminish atmospheric warming. Many sediment microorganisms help in this process of carbon sequestration and play various other vital roles in mangrove ecosystems. Microorganisms in marine sediments can be used to assess the health of the surrounding environment. Past research has found significant differences in sediment microorganism composition, abundance, and diversity in …

Observational Study Of Woolly Monkey Behavior And Vocalizations: Behavioral Time Allotment And Vocalization Habits Of A Small Population Of Poeppig’S Woolly Monkey (Lagothrix Lagotricha Poeppigii) In The Ecuadorian Amazon, Marina Smith-Hanke

Independent Study Project (ISP) Collection

Poeppig’s woolly monkey (Lagothrix lagotricha poeppigii), a species of primate native to the Amazonian regions of western Brazil, eastern Ecuador, and northeastern Peru, is classified as endangered by the IUCN. These large, frugivorous primates are threatened by habitat loss and climate change as a result of human interference. Deforestation, hunting, petroleum mining, and illegal trafficking are all huge threats to this species. As a result of these pressures, their populations have decreased by at least 30% over the past three generations. However, as keystone seed dispersers, they are essential for Amazonian ecosystem health; without their seed dispersal services, a loss …

The Role Of Frugivorous Birds As Seed Dispersers: Feeding Selection And Preference Of Madagascar’S Avian Frugivores In Analamazaotra Forest, Thaddeus Bashaw

Independent Study Project (ISP) Collection

Madagascar is a country rich in floral and faunal diversity. However, anthropogenic habitat destruction and climate change increasingly threaten its biodiversity. Endozoochorous plants that dependent on frugivory for seed dispersal are under threat due to increasing rates of localized extinctions of frugivorous lemurs, the primary seed dispersers of the island. While lemurs are the islands most abundant frugivores, other frugivorous vertebrates like birds and bats likely play a significant role in seed dispersal, although this role is still poorly understood. This study, conducted in Analamazaotra forest, compares the rates of visitation and consumption of six endemic fruiting tree species by …

A Quantitative Study Of Orchids And Their Proximate Environments Over An Elevational Gradient On The Northern Slope Of Montagne D’Ambre, Hazel Schrader

Independent Study Project (ISP) Collection

This research investigated change in orchid populations and their proximate environments on the Northern slope of Montagne d’Ambre, a subhumid forest in Northern Madagascar. Orchid density, way of life (epiphyte or terrestrial), phenology, and associations were recorded over 100m elevation gradients and between forest types (primary, secondary, dry, and humid forests at the same altitude). Additionally, orchid preferences for certain heights in the forest and DBH of host trees were analyzed. The establishment of 50X20m plots in 100m elevation gradients combined with ground survey yielded significant results demonstrating change along with elevation as well as forest types. Orchid density increased …

A Ladder Of Endemicity: A Pioneering Study Of Anuran Communities Along An Elevational Gradient In The Eastern Andean Cloud Forests, Ecuador, Ella Halbert

Independent Study Project (ISP) Collection

Per unit of area, Ecuador is home to the most herpetofauna of any region on Earth, yet many ecosystems are under researched. Positioned between the Eastern Andes and the Amazon rainforest, the Río Pastaza Basin of Ecuador has been the recent focus of anuran biodiversity surveys and is home to many endemic species. This study aimed to determine how the anuran community composition of a vertical transect in the Llanganates National Park varied between elevations. A 7-day expedition was conducted along a new trail up Abitagua Range spanning 1,050 m in elevation. Each night, visual encounter surveys were employed to …

Assessing And Mapping The Spatial-Temporal Change In Forest Phenology Of Arabuko-Sokoke Forest Using Moderate Resolution Satellite, Bailey Ytterdahl

Independent Study Project (ISP) Collection

This study focuses on coastal forests in Kenya that have some of the highest variety of flora and fauna, specifically Arabuko Sokoke Forest. Arabuko Sokoke Forest is located 110 miles north of Mombasa and 18 kilometers south of Malindi. This forest is known to be a worldwide biodiversity hotspot that is home to endemic and rare plants and animals. Within the Arabuko Sokoke Forest ecosystem, there are two main issues that challenge the conservation of the area. First, there has been more competition for land, primarily for agriculture and development. Second, there is an increase demand for forest resources due …

Hot But Not Dry: Modest Changes In Water Relations For An Epiphytic Bromeliad In A Tropical Dry Deciduous Forest, Saúl Hernández-Robinson, Eric A. Graham, Olivia Hernández-González, Roberth Us-Santamaría, José Luis Simá, Fernando Arellano-Martín, José Luis Andrade

All Faculty Scholarship for the College of the Sciences

Premise of research. Epiphytic bromeliads endure intense seasonal environmental changes in the canopy of dry tropical deciduous forests. The analysis of the physiological responses of these epiphytes to environmental changes can be useful in assessing their plasticity, vulnerability, and adaptations to such extreme habitats.

Methodology. We measured microenvironmental variables and water relations for plants of the epiphytic bromeliad Tillandsia brachycaulos in three microhabitats within the canopy of a dry tropical forest. We measured individual plants for seasonal and spatial differences in light, leaf temperature, osmotic potential, cell wall elasticity, and relative capacitance as indications of their physiological responses …

Shifting Public Perception: Climate Change Means Living With Fire And Smoke, Robert Froembling

Seattle Journal of Technology, Environmental, & Innovation Law

The urgency to prepare for the climate crisis has never been greater. We are currently living in the sixth mass extinction and the effects are only going to accelerate. We will inherit more wildfires, larger wildfires, and more frequent wildfires.

This piece is not meant to stoke fear in its readers or be depressing, but to shift public perception on what our future holds by evaluating the laws and science presented to us. This piece will look at regional and federal regulations and assess the increased rate of forest fires and the grave public health concerns from stagnant smoke specifically …

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 …

Optimizing Water Quality And Temperature Parameters To Increase Survival Rates Of Anotheca Spinosa (Anura: Hylidae) Eggs At The El Valle Amphibian Conservation Center, Morgan Oestereich

Independent Study Project (ISP) Collection

Amphibians globally are facing extinction due to the fungus Batrachochytrium dendrobatidis (Bd). This has resulted in a worldwide push for increased conservation efforts. These efforts include those of the El Valle Amphibian Conservation Center (EVACC) in El Valle de Antón, Panama, where captive assurance colonies of many native amphibian species are housed. Among these species is Anotheca spinosa, a species of tree frog native to mountainous regions of Central America. This study was performed to analyze the relationship between water quality parameters and egg survival and reproductive success of EVACC’s captive population of A. spinosa and assess how related husbandry …

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 …

Island Invasion: The Silent Crisis In Hawaii, Sophia Janssen

Pomona Senior Theses

Keeping out invasive species may, upon first review, seem like a trivial environmental cry from ecologists and deep environmentalists; a belated wish to return to an undeveloped world where nature was pristine. However invasive species create problems that impact all of us and can have far more severe consequences than changing a stunning landscape. These problems are heightened in islands like Hawaii, where the fragile ecosystems have developed over centuries of evolution and adaptation. The introduction of a disease-carrying mosquito can put the people of Hawaii at risk to many vector-born illnesses and create an epidemic, taking human life. The …

Efficacy Of Herbivore Exclusion On Planted Tree Seedling Vitality On A Reclaimed Surface Mine In Eastern Kentucky, Zachary J. Hackworth

Theses and Dissertations--Forestry and Natural Resources

Conventional Appalachian surface-mine reclamation techniques repress natural forest regeneration, and tree plantings are often necessary for reforestation. Reclaimed Appalachian surface mines harbor a suite of mammal herbivores that forage on recently planted seedlings. Anecdotal reports across Appalachia have implicated herbivory in the hindrance and failure of reforestation efforts, yet empirical evaluation of herbivory impacts on planted seedling vitality in this region remains relatively uninitiated. First growing-season survival, height growth, and mammal herbivory damage of black locust (Robinia pseudoacacia L.), shortleaf pine (Pinus echinata Mill.), and white oak (Quercus alba L.) are presented in response to varying intensities …

The Role Of Environmental Filtering In Structuring Appalachian Tree Communities: Topographic Influences On Functional Diversity Are Mediated Through Soil Characteristics, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Identifying the drivers of community assembly has long been a central goal in ecology, and the development of functional diversity indices has provided a new way of detecting the influence of environmental gradients on biotic communities. For an old-growth Appalachian forest, we used path analysis to understand how patterns of tree functional diversity relate to topography and soil gradients and to determine whether topographic effects are mediated through soil chemistry. All of our path models supported the idea of environmental filtering: stressful areas (high elevation, low soil moisture, low soil nutrients) were occupied by communities of low functional diversity, which …

Fungi Of Forests: Examining The Diversity Of Root-Associated Fungi And Their Responses To Acid Deposition, Donald Jay Nelsen

Graduate Theses and Dissertations

Global importance of forests is difficult to overestimate, given their role in oxygen production, ecological roles in nutrient cycling and supporting numerous living species, and economic value for industry and as recreational zones. Fitness of the forest-forming trees strongly depends on microbial communities associated with tree roots. In particular, fungi impact tree fitness: mycorrhizal species provide water and nutrients for the trees in exchange for C, endophytic fungi play key roles in host defense against pathogenic organisms, and saprotrophic fungi decompose dead organic matter and facilitate nutrient cycling. In addition, pathogenic fungal species strongly affect forest fitness. Despite their importance, …

The Use Versus Availability Of Wood Extraction At The Baga Ii Forest Reserve Border Adjacent To Kizanda Village In The West Usambara Mountains, Tanzania, Rebecca Halter

Independent Study Project (ISP) Collection

Tropical forests, especially in developing countries, continue to face serious threats of deforestation due to human pressures and poor management. These forests are at risk of disappearing and taking their water catchment and ecosystem services with them. Kizanda Villagers’ illegal woodfuel and polewood extraction poses a threat to the future health and existence of the Baga II Forest. This study, conducted from April 5th to April 19th, 2016, aimed to examine the use versus availability of tree species along the forest border. Twenty disturbance transects, each 4 meters wide, were conducted perpendicular to the Baga II forest border. The transects …

On Underestimation Of Global Vulnerability To Tree Mortality And Forest Die-Off From Hotter Drought In The Anthropocene, Craig D. Allen, David D. Breshears, Nate G. Mcdowell

United States Geological Survey: Staff Publications

Patterns, mechanisms, projections, and consequences of tree mortality and associated broadscale forest die-off due to drought accompanied by warmer temperatures—‘‘hotter drought’’, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortalityrelevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases …

Monitoring The Influence Of Acid Deposition On Soil And Implications To Forest Health In The Daniel Boone National Forest, Tyler M. Sanderson

Theses and Dissertations--Forestry and Natural Resources

Combustion of fossil fuels has contributed to many environmental problems including acid deposition. The Clean Air Act (CAA) was created to reduce ecological problems by cutting emissions of sulfur and nitrogen. Reduced emissions and rainfall concentrations of acidic ions have been observed since the enactment of the CAA, but soils continue to receive some acid inputs. Soils sensitive to acid deposition have been found to have low pH, a loss of base cations and a shift in the mineral phase controlling the activity of Al³⁺ and/or SO₄^2-. If inputs continue, soil may be depleted of base …

Carbon Dynamics In The Future Forest: The Importance Of Long-Term Successional Legacy And Climate–Fire Interactions, E. Louise Loudermilk, Robert M. Scheller, Peter J. Weisberg, Jian Yang, Thomas E. Dilts, Sarah L. Karam, Carl Skinner

Environmental Science and Management Faculty Publications and Presentations

Understanding how climate change may influence forest carbon (C) budgets requires knowledge of forest growth relationships with regional climate, long-term forest succession, and past and future disturbances, such as wildfires and timber harvesting events. We used a landscape-scale model of forest succession, wildfire, and C dynamics (LANDIS-II) to evaluate the effects of a changing climate (A2 and B1 IPCC emissions; Geophysical Fluid Dynamics Laboratory General Circulation Models) on total forest C, tree species composition, and wildfire dynamics in the Lake Tahoe Basin, California, and Nevada. The independent effects of temperature and precipitation were assessed within and among climate models. Results …