Forest Biology Commons^™

A Delicate Balance: The Effects Of Habitat Type On Frog Communities: A Three-Pronged Study Examining The Effects Of Differing Habitat Characteristics On Anuran Diversity At El Centro De Investigación Sumak Kawsay In Situ, Ecuador, Zane Libke

Independent Study Project (ISP) Collection

We conducted 60 hours of visual encounter surveys and 3 hours of calling surveys on 6 different habitat types near Sumak Kawsay in situ Reserva (SKIS) near Mera, Pastaza, Ecuador. We defined habitat types defined by two variables: type of forest and proximity to water. The aim of the study was to determine what effect each variable has on anuran community composition. We compared the effectiveness of the two survey methods as well. High anuran community dissimilarity was found between each habitat type surveyed, indicating that both forest type and proximity to water are important factors that shape species richness …

Diversity And Abundance Of Soil Microbes Differ Along A Forest-Pasture Transect, Hannah Suli, Ashley Schumann, Cleo Bickley, Jasmine Rodriguez

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

No abstract provided.

Diffuse Light And Wetting Differentially Affect Tropical Tree Leaf Photosynthesis, Z. Carter Berry, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

‐Most ecosystems experience frequent cloud cover resulting in light that is predominantly diffuse rather than direct. Moreover, these cloudy conditions are often accompanied by rain that results in wet leaf surfaces. Despite this, our understanding of photosynthesis is built upon measurements made on dry leaves experiencing direct light.

‐Using a modified gas exchange setup, we measured the effects of diffuse light and leaf wetting on photosynthesis in canopy species from a tropical montane cloud forest.

‐We demonstrate significant variation in species‐level response to light quality independent of light intensity. Some species demonstrated 100% higher rates of photosynthesis in diffuse light …

Warming Up: Climate Change Related Shifts Of Mycorrhizal Fungal Communities In High Latitude Ecosystems, Megan Rae Devan

Biology ETDs

This dissertation examines how climate change affects mycorrhizal fungal communities in boreal and arctic ecosystems. In chapter one, I revealed that increases in fire severity and related increases in deciduous tree dominance result in greater Ascomycota relative abundance (RA) and subsequent declines in Basidiomycota RA. In chapter two I analyzed the effects of post-fire mycorrhizal fungal communites on host growth. There were trends at the fungal genus level that were largely reflected at the guild level across all hosts; however, there were some fungal genera that had the opposite effect on different host species. In chapter three, I found host …

Herpetological Assemblages In Tropical Dry Forests Of The Azuero Peninsula, Panama: An Evaluation Of Reforestation, Tyler Kovacs

Masters Theses, 2010-2019

Tropical dry forests are considered one of the most endangered tropical ecosystems making reforestation increasingly necessary to restore Panama’s unique ecoregion. The isolated dry ecoregion surrounding the Bay of Parita in Panama has a long history of deforestation and cattle grazing. Successful reforestation of this land is important to restore ecosystem health and biodiversity. In Panama, reforestation ranges from monocultures of exotic teak (Tectona grandis) to passive regeneration. Faunal recovery within these reforestation systems may vary due to different habitat characteristics. In this study, amphibian and reptile communities were compared in two types of reforestation systems and protected riparian forests …

Amphibian And Reptile Community Responses To Forest And Riparian Disturbance, Jacquelyn Christine Guzy

Graduate Theses and Dissertations

Riparian zones are transitional, semi-terrestrial areas regularly influenced by freshwater. These areas serve as dispersal corridors for many animal and plant species and ultimately function as important reservoirs of biodiversity in altered landscapes. While much of the riparian habitat in the United States has been affected by anthropogenic activities, management actions may mitigate potentially negative influences of these activities. For example, Streamside Management Zones (i.e., riparian buffers; SMZs) are commonly implemented within managed forests to protect water quality, but may also provide habitat for riparian-associated wildlife. Yet, little research has rigorously addressed the value of SMZs for wildlife, particularly cryptic …

Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson

Graduate Theses and Dissertations

Earlywood (EW) and latewood (LW) ring-width chronologies have become an increasingly important proxy in paleoclimate reconstructions. These subannual variables can provide estimates of past hydroclimate variability for seasonal windows that total ring-widths cannot resolve. The strength of the relationship between EW and LW series may influence what type of paleoclimate information is embedded within the tree-ring series. High correlations (> 0.70) between EW and LW are recorded for much of the continent but the magnitude of correlation varies greatly across space and species boundaries. Using four LW chronologies from shortleaf pine, the North American conifer species displaying the lowest EW-LW …

Mammals Of The Northern Andes: An Analysis Of Camera Trap Data And Observation In Angochagua, Ecuador, Risa Berman

Independent Study Project (ISP) Collection

The high Andes of Ecuador are home to a diverse community of mammals, many of which are threatened. These include the Andean bear, Andean fox, puma, and mountain tapir. This study used camera traps, direct observation, and indirect observation over three weeks to monitor the wildlife in the mountains of the Parroquia of Angochagua. The five species observed during this period were Andean bear, Andean fox, dog, mountain paca, and mouse. While this short study did not completely survey the mammalian community of the area, it confirmed the presence, diet, sociality, temporal habits, elevational range, and habitat preferences of the …

Trends In Nectar Production And Concentration Of Hummingbird-Pollinated Flowers: An Investigation Of Three Flowers Of The Ecuadorian Cloud Forest: Palicourea Demissa, Mezobromelia Capituligera, And Kohleria Affinis, Grace Palmer

Independent Study Project (ISP) Collection

Nectar concentration and sugar production both impact and are impacted by pollinator activity through a complex system of coevolution. Additionally, a variety of morphological and environmental factors influence the nectar properties of animal-pollinated flowering plants. Nectar concentration and nectar production rate (NPR) of three hummingbird-pollinated plants, Palicourea demissa, Mezobromelia capituligera, and Kohleria affinis, were measured. These flowers occur and were studied in the southern section of the Chocó-Andean subtropical montane rainforest, in the Pichincha province of Ecuador. Flowers were bagged for 24 hours and sampled at approximate two-hour time intervals for 12 or 24 hours. Nectar concentration and sugar production …

A Survey Of Beetle Diversity (Order Coleoptera) On Lizard Island, John Mccormack

Independent Study Project (ISP) Collection

The beetles (order Coleoptera) of Lizard Island, a small granitic island on the mid shelf of the Great Barrier Reef, have never been assessed in the scientific literature. Prior to our work, only a single beetle genus had been documented on the island (Caryotrypes Decelle, 1968), based on a single specimen collected in 1993 (Reid & Beatson 2013). We conducted a survey of Lizard Island in April 2019 to determine which beetle families are present on the island and which families are the most diverse. The survey also assessed the beetle diversity in different habitats on the island and two …

The Ecology And Behavior Of Spring Migrating Indiana Bats (Myotis Sodalis), Piper Lee Roby

Theses and Dissertations--Animal and Food Sciences

Migration of animals has been studied for decades and has included everything from large terrestrial and pelagic mammals traveling thousands of kilometers to many types of birds flying through several countries to insects going through multiple life cycles in a single migration. The migration of bats has been studied in broad terms to gather coarse information such as distance traveled, connecting summer and winter habitat, and a general understanding of timing. However, only recently have researchers begun to understand the specifics of bat migration including physiology and fine resolution behavior.

Using nine years of spring migration data collected on VHF …

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 …

Spatiotemporal Variability In Winter Severity: Consequences For White-Tailed Deer Populations And Habitat Sustainability, Grace Parikh

Dissertations, Master's Theses and Master's Reports

Winter in the northern Great Lakes presents a suite of challenging conditions for animals, in terms of limited food availability and increased energetic cost of locomotion and thermoregulation. Variable winter severity is liable to cause interannual fluctuations in habitat viability and use by animals, in addition to modulating physiological responses in animals to conserve energy. For example, white-tailed deer (Odocoileus virginianus) congregate at high densities under eastern hemlock (Tsuga canadensis) or northern white-cedar (Thuja occidentalis) stands, which provide forage, thermal cover, reduced snow depth, and enhanced vigilance. However, a suite of climatic, edaphic, and …

Plant Community Response To Novel Silvicultural Treatments In Great Lakes Northern Hardwoods, Stefan F. Hupperts

Dissertations, Master's Theses and Master's Reports

The objective of this dissertation is to assess plant community response across a range of silvicultural disturbances and test ecological hypotheses to better inform ecologists and forest managers. To provide context for the utility of revising silvicultural systems, I review natural disturbance regimes and historical practices that have shaped contemporary Great Lakes northern hardwood forests (Chapter 2). Further, I identify important ways to expand the silvicultural toolbox and better emulate natural disturbance regimes. Building on this theoretical underpinning, I investigate the initial regeneration and plant community response to two novel silvicultural experiments: the Northern Hardwood Experiment for Enhancing Diversity (NHSEED) …

An Ecological Survey Of Forest Succession In A Northeast Ohio Ecosystem Following An Emerald Ash Borer Infestation, Joseph Haas

Williams Honors College, Honors Research Projects

This paper will be an ecological survey of a selected 28 acre piece of land in northeast Ohio impacted by the Emerald Ash Borer. This invasive species arrived in North America in 2002 and has since spread throughout the country wreaking havoc on the ash tree population. The purpose of this study is to determine what tree species are replacing the native ash trees in the succession of the forest. In order to achieve this goal, a section of the selected land will be blocked off and subdivided into manageable sections to facilitate data collection, namely the location of the …

Testing The Competition-Colonization Trade-Off And Its Correlations With Functional Trait Variations Among Subtropical Tree Species, Yue Bin, Guojun Lin, Sabrina E. Russo, Zhongliang Huang, Yong Shen, Honglin Cao, Juyu Lian, Wanhui Ye

School of Biological Sciences: Faculty Publications

The competition-colonization trade-off, by which species can partition spatial niches, is a potentially important mechanism allowing the maintenance of species diversity in plant communities. We examined whether there was evidence for this trade-off among tree species in a subtropical forest and how it correlated with eight functional traits. We developed and estimated a metric for colonization ability that incorporates both fecundity and seed dispersal based on seed trap data and the sizes and distributions of adult trees. Competitive ability was estimated as survival probability under high crowding conditions based on neighborhood models. Although we found no significant relationship between colonization …

Understory Community Assembly Following Wildfire In Boreal Forests: Shift From Stochasticity To Competitive Exclusion And Environmental Filtering, Bo Liu, Han Y. H. Chen, Jian Yang

Forestry and Natural Resources Faculty Publications

Understory vegetation accounts for the majority of plant species diversity and serves as a driver of overstory succession and nutrient cycling in boreal forest ecosystems. However, investigations of the underlying assembly processes of understory vegetation associated with stand development following a wildfire disturbance are rare, particularly in Eurasian boreal forests. In this study, we measured the phylogenetic and functional diversity and trait dispersions of understory communities and tested how these patterns changed with stand age in the Great Xing'an Mountains of Northeastern China. Contrary to our expectation, we found that understory functional traits were phylogenetically convergent. We found that random …

Mule Deer Impede Pando’S Recovery: Implications For Aspen Resilience From A Single-Genotype Forest, Paul C. Rogers, Darren J. Mcavoy

Ecology Center Publications

Aspen ecosystems (upland Populus-dominated forests) support diverse species assemblages in many parts of the northern hemisphere, yet are imperiled by common stressors. Extended drought, fire suppression, human development, and chronic herbivory serve to limit the sustainability of this keystone species. Here we assess conditions at a renowned quaking aspen (Populus tremuloides) grove—purportedly the largest living organism on earth—with ramifications for aspen biogeography globally. The “Pando” clone is 43 ha and estimated to contain 47,000 genetically identical aspen ramets. This iconic forest is threatened in particular by herbivory, and current management activities aim to reverse the potential for …

Does Environment Filtering Or Seed Limitation Determine Post-Fire Forest Recovery Patterns In Boreal Larch Forests?, Wen H. Cai, Zhihua Liu, Yuan Z. Yang, Jian Yang

Forestry and Natural Resources Faculty Publications

Wildfire is a primary natural disturbance in boreal forests, and post-fire vegetation recovery rate influences carbon, water, and energy exchange between the land and atmosphere in the region. Seed availability and environmental filtering are two important determinants in regulating post-fire vegetation recovery in boreal forests. Quantifying how these determinants change over time is helpful for understanding post-fire forest successional trajectory. Time series of remote sensing data offer considerable potential in monitoring the trajectory of post-fire vegetation recovery dynamics beyond current field surveys about structural attributes, which generally lack a temporal perspective across large burned areas. We used a time series …

Perma/Culture: Imagining Alternatives In An Age Of Crisis By Molly Wallace And David Carruthers, Bryant Scott

The Goose

Review of Molly Wallace and David Carruthers' Perma/Culture: Imagining Alternatives in an Age of Crisis.

Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd

Graduate Theses and Dissertations

The natural flow regime exerts primacy over lotic ecosystem patterns and processes. However, little work has examined the influence of flow regime on instream and riparian carbon (C) dynamics in minimally-impacted, temperate forested systems. To date, most research efforts have focused on characterizing C movement and transformations across biomes and land use categories; however, flow regime represents an overlooked, finer level of detail that may drive differences in ecosystem function. My dissertation objective was to measure C fixation and movement within and across multiple environmental spheres (e.g. within stream channels, between stream surfaces and the atmosphere, and from riparian soils …

Forest Drought Resistance Distinguished By Canopy Height, Wei Fang, Peipei Xu, Tao Zhou, George Hendrey, Xiang Zhao

Publications and Research

How are the survival and growth of trees under severe drought affected by their size? While some studies have shown that large trees are more vulnerable to drought than smaller trees, others found that small trees are the more vulnerable. We explored the potential relationships between canopy height and forest responses to drought indicated by tree mortality, tree ring width index (RWI), and normalized difference vegetation index (NDVI) in the southwestern United States (SWUS) in 2002. In that year many trees had zero tree ring growth due to mortality and dieback, presumably related to drought-stress. With RWI data from a …

Dynamic Responses Of Tree-Ring Growth To Multiple Dimensions Of Drought, Wei Fang, Shan Gao, Ruishun Liu, Tao Zhou, Chuixiang Yi, Ruijie Liu, Xiang Zhao, Hui Luo

Publications and Research

Droughts, which are characterized by multiple dimensions including frequency, duration, severity and onset timing, can impact tree growth profoundly. Different dimensions of drought influence tree growth independently or jointly, which makes the development of accurate predictions a formidable challenge. Measurement-based tree-ring data have obvious advantages for studying the drought responses of trees. Here, we explored the use of abundant tree-ring records for quantifying regional response patterns to key dimensions of drought. Specifically, we designed a series of regional-scaled “natural experiments”, based on 357 tree-ring chronologies from Southwest USA and location-matched monthly water balance anomalies, to reveal how tree-ring growth responds …

Mitigating Bioiversity Loss Of Native Plants, Jamie Ana Grigonis

Student Theses 2015-Present

Growing up harvesting from my own vegetable garden and going from nursery to nursery with my mother, it has been extremely evident that plant biodiversity is more than just privet along driveways and carnations in window boxes. Plant biodiversity is often overlooked but crucial to having a healthy and thriving environment. Without certain plants, our ecosystems will crumble and this needs to be addressed now while it’s still at a level we can grow from. In my internship I am working alongside the director of the Thain Family Forest at the New York Botanical Gardens in order to get a …

Juvenile Amphibian Response To Oak And Maple Leaf Litter, Benjamin Breslau

Honors Scholar Theses

The composition of tree species within New England forests has changed significantly in recent decades, with an increase in maple (Acer spp.) abundance and a decrease in oak (Quercus spp.) abundance. Changing forest structure results in changing leaf litter composition of the forest floor, which influences the ground-dwelling amphibians that live in the litter. To better understand how changes to forest composition alters amphibian habitat quality, we recorded the growth and survival of 27 juvenile wood frogs (Lithobates sylvaticus or Rana sylvatica) and 27 juvenile American toads (Anaxyrus americanus) in response to leaf litter …

Avian Foraging Response To Jack Pine (Pinus Banksiana) Volatile Chemicals, Katie Bjornen

All NMU Master's Theses

Birds benefit trees and other plants by removing herbivores that damage the plant and impede its growth. They can significantly increase the growth and biomass of the trees by foraging on the herbivores that harm plants, and the prey items eaten in turn benefits foraging birds by providing sustenance. This interaction becomes complex when tree volatile chemical communication is added. Trees regularly release volatile organic chemicals (referred to as VOCs) as part of metabolism. The particular VOCs released by a tree can depend on several factors, including water availability, time of year, and damage type (e.g., mechanical damage or insect …

Comparative Study Of Photosynthesis Rates Between Native Red Maple And Invasive Norway Maple In The Eastern Deciduous Forest, Evan M. Bourtis, Lindsey R. Heckman

The Review: A Journal of Undergraduate Student Research

Invasive species, such as the Norway Maple, are often able to outcompete native species, such as the Red Maple by performing more efficiently in the environment compared to the native species. In this study, we examined if the Norway maple was able to outcompete the Red Maple in the Eastern Deciduous Forest because the Norway Maple had a higher rate of photosynthesis. The study found that the Norway Maple leaves had a slightly higher rate of carbon dioxide consumption than Red Maple leaves and that the Red Maple leaves had a higher rate of oxygen production compared to the Norway …

Bifurcated Response Of A Regional Forest To Drought, Wei Fang, Chuixiang Yi, Guangwei Mu, George Hendrey, Sergio M. Vicente-Serrano, Tao Zhou, Shan Gao, Peipei Xu

Publications and Research

Several lines of evidence suggest that forest growth in many regions is declining as a consequence of changing climate. To predict the fate of forests in the future, a quantitative understanding of how the key climate variables (insolation, precipitation and temperature) interact with forests to cause the decline is a pressing need. Here we use a regionally-averaged tree-ring width index (RWIr ) to quantify forest growth in the Southwest United States (SWUS). We show that over a period of 100 years, SWUS RWIr bifurcated into forest stands with enhanced (healthy) and reduced (declining) branches when regressed on shortwave-radiation and temperature, …

Food Habits Of Sympatric Pitvipers From The West Gulf Coastal Plain, Usa, Christopher M. Schalk, Toni Trees, Joshua B. Pierce, D. Craig Rudolph

Faculty Publications

Widespread species that occupy multiple communities exhibit geographic variation in their natural history due to the ecological context of the local community. An animal’s food habitats are a central component to understanding its natural history and ecological role within its community—information that is critical to understanding resource needs of a species, mechanisms of species coexistence, and energy flow in food webs (Litvaitis 2000; Schalk et al. 2014). This information is also crucial for predicting the response of populations to changes in resource availability and, if necessary, inform mitigation strategies (Holycross and Mackessy 2002)

Phosphorus Limitation Of Aboveground Production In Northern Hardwood Forests, Shinjini Goswami, Melany C. Fisk, Matthew A. Vadeboncoeur, Mariann Garrison-Johnston, Ruth D. Yanai, Timothy J. Fahey

All Materials

Forest productivity on glacially derived soils with weatherable phosphorus (P) is expected to be limited by nitrogen (N), according to theories of long-term ecosystem development. However, recent studies and model simulations based on resource optimization theory indicate that productivity can be co-limited by N and P. We conducted a full factorial N × P fertilization experiment in 13 northern hardwood forest stands of three age classes in central New Hampshire, USA, to test the hypothesis that forest productivity is co-limited by N and P. We also asked whether the response of productivity to N and P addition differs among species …