James D Lewis

James D Lewis
Fordham University · Department of Biological Sciences

Ph.D.

About

113
Publications
23,769
Reads
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3,958
Citations
Education
September 1989 - December 1994
Duke University
Field of study
  • Botany
January 1988 - August 1989
Pennsylvania State University
Field of study
  • Ecology
August 1985 - May 1989
Pennsylvania State University
Field of study
  • Biology

Publications

Publications (113)
Article
Full-text available
Long-distance pollen dispersal is critical for gene flow in plant populations, yet pollen dispersal patterns in urban habitats such as green roofs have not been extensively studied. Pollen dispersal patterns typically are assessed either by fitting non-linear models to the relationship between the degree of pollen dispersal and distance to the poll...
Article
Soil fungi are vital to forest ecosystem function, in part through their role mediating tree responses to environmental factors, as well as directly through effects on resource cycling. While the distribution of soil fungi can vary with abiotic factors, plant species identity is also known to affect community composition. However, the particular in...
Article
Full-text available
Environmental educators have used guided-inquiry in natural and supportive learning environments for decades, but comparatively little programming and research has focused on experiences in urban environments, including in constructed ecosystems like green roofs, or impacts on older youth and adults. To address this gap, we designed a tiered, near-...
Preprint
Soil fungal communities vary spatially due to factors including variations in plant diversity and soil characteristics; however, the relative influences of these factors on composition and therefore function remain unclear. Small-scale variation in fungal communities may drive local variation in nutrient cycling and decomposition and may respond mo...
Article
Soil fungal communities vary spatially due to factors including variations in plant diversity and soil characteristics; however, the relative influences of these factors on composition and therefore function remain unclear. Small-scale variation in fungal communities may drive local variation in nutrient cycling and decomposition and may respond mo...
Article
Full-text available
Background: Authentic research experiences and mentoring have positive impacts on fostering STEM engagement among youth from backgrounds underrepresented in STEM. Programs applying an experiential learning approach often incorporate one or both of these elements, however, there is little research on how these factors impact youth's STEM engagement...
Article
Full-text available
We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of per...
Preprint
Full-text available
Background: Authentic research experiences and mentoring have positive impacts on fostering STEM engagement among youth from backgrounds underrepresented in STEM. Programs applying an experiential learning approach often incorporate one or both of these elements, however, there is little research on how these factors impact youth’s STEM engagement...
Preprint
Full-text available
Soil fungi are vital to forest ecosystem functions, in part through their role mediating tree responses to environmental factors, as well as directly through effects on resource cycling. While the distribution of these key taxa may vary with a suite of abiotic and biotic factors, the relative role of host species identity on soil fungal community c...
Preprint
Full-text available
Priority effects in host-associated microbiomes can influence not only community composition and structure, but also community functions, such as disease resistance. However, evidence for these priority effects remains scarce. Past studies suggest that amphibian protection from chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dend...
Article
A growing focus in microbial ecology is understanding how beneficial microbiome function is created and maintained through various assembly mechanisms. This study explores the role of both the environment and disease in regulating the composition of microbial species in the soil and on amphibian hosts. We compared the microbial communities of Pleth...
Preprint
Full-text available
We introduce the AusTraits database - a compilation of measurements of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 375 traits across 29230 taxa from field campaigns, published literature, taxonomic monographs, and individual taxa descriptions. Traits vary in scope from physiological measures of...
Article
Full-text available
A growing focus in microbial ecology is understanding of how beneficial microbiome function is created and maintained through both stochastic and deterministic assembly mechanisms. This study explores the role of both the environment and disease in regulating the composition of microbial species pools in the soil and local communities of an amphibi...
Article
Full-text available
Vacant spaces, such as unplanted, unmanaged, or infrequently accessed green roofs, may play a critical role in sustaining biodiversity in cities. Initial plant composition of these spaces likely is contingent on seed dispersal and growing medium, yet no studies have directly characterized the effects of location or growing medium depth on plant div...
Article
Premise: Pollen dispersal, the main component of overall plant gene flow, generally decreases with increasing distance from the pollen source, but the pattern of this relationship may differ among sites. Although site-based differences in pollen dispersal may lead to over- or underestimation of gene flow, no studies have investigated pollen disper...
Article
Full-text available
Premise: Pollen dispersal plays a critical role in gene flow of seed plants. Most often, pollen dispersal is measured using paternity assignment. However, this approach can be time-consuming because it typically entails genotyping all pollen donors, receptors, and offspring at several molecular markers. Methods: We developed a faster, simpler pr...
Article
Full-text available
Variation in the microbiome among individual organisms may play a critical role in the relative susceptibility of those organisms to infection, disease and death. However, predicting microbiome function is difficult because of spatial and temporal variation in microbial diversity, and taxonomic diversity is not predictive of microbiome functional d...
Article
Full-text available
Eucalypts are likely to play a critical role in the response of Australian forests to rising atmospheric CO2 concentration ([CO2]) and temperature. Although eucalypts are frequently phosphorus (P) limited in native soils, few studies have examined the main and interactive effects of P availability, [CO2] and temperature on eucalypt morphology, phys...
Article
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Despite a wealth of eco-physiological assessments of plant response to extreme drought, few studies have addressed the interactive effects of global change factors on traits driving mortality. To understand the interaction between hydraulic and carbon metabolic traits influencing tree mortality, which may be independently influenced by atmospheric...
Article
Full-text available
The field of ecology is poised to substantially contribute to the creation of a socially and environmentally equitable urban future. To realize this contribution, the field of ecology must create strategies that ensure inclusion of underrepresented minorities so that a broad array of experiences and ideas collectively address challenges inherent to...
Article
Full-text available
The role that mycorrhizal fungal associations play in the assembly of long-lived tree communities is poorly understood, especially in tropical forests, which have the highest tree diversity of any ecosystem. The lowland tropical rain forests of Southeast Asia are characterized by high levels of species richness within the family Dipterocarpaceae, t...
Article
The DARC (Duffy antigen receptor for chemokines) gene encodes the DARC protein, which serves multiple roles in the immune system, as a binding site for the malarial parasites Plasmodium vivax and Plasmodium knowlesi, a promiscuous chemokine receptor and a blood group antigen. Variation in DARC may play particularly significant roles in innate immun...
Article
Full-text available
Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing unce...
Article
Full-text available
Plant survivorship depends on biotic and abiotic factors that vary at local and regional scales. This survivorship, in turn, has cascading effects on community composition and the physical structure of vegetation. Survivorship of native plant species is variable among populations planted in environmentally stressful habitats like urban roofs, but t...
Article
Full-text available
Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere–atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing unce...
Article
Mycorrhizal fungi account for about 10% of identified fungal species, including essentially all of the Glomeromycota and substantial fractions of the Ascomycota and Basidiomycota. Several distinct types of mycorrhizal associations exist, including arbuscular, ericoid, orchid and ectomycorrhiza. Although arbuscular mycorrhiza evolved first, ectomyco...
Article
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Habitat fragmentation may lead to spatial genetic structuring of plant populations, but the magnitude of this effect differs among species. In this study, the effects of fragmentation on spatial genetic structure of Manilkara maxima , an ecologically important tree species endemic to the Atlantic forest of southern Bahia, Brazil, were examined. To...
Article
Full-text available
Rising atmospheric [CO2] is associated with increased air temperature, and this warming may drive many rare plant species to extinction. However, to date, studies on the interactive effects of rising [CO2] and warming have focussed on just a few widely distributed plant species. Wollemi pine (Wollemia nobilis W.G.Jones, K.D.Hill, & J.M.Allen), form...
Article
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Invasive insects may dramatically alter resource cycling and productivity in forest ecosystems. Yet, although responses of individual trees should both reflect and affect ecosystem-scale responses, relationships between physiological- and ecosystem-scale responses to invasive insects have not been extensively studied. To address this issue, we exam...
Article
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Fragmentation threatens biodiversity globally. Manilkara maxima (Sapotaceae) is listed by the IUCN as threatened and is an economically and ecologically important tree species endemic to the Atlantic forest of southern Bahia, Brazil, a biodiversity hotspot. The objectives of this study were to examine the effect of fragment size on density and gene...
Article
Full-text available
Total daily water use is a key factor influencing the growth of many terrestrial plants, and reflects both day-time and nocturnal water fluxes. However, while nocturnal sap flow (En) and stomatal conductance (gs,n) have been reported across a range of species, ecosystems and microclimatic conditions, the regulation of these fluxes remains poorly un...
Article
Full-text available
The fitness effects of mutations are context specific and depend on both external (e.g., environment) and internal (e.g., cellular stress, genetic background) factors. The influence of population size and density on fitness effects are unknown, despite the central role population size plays in the supply and fixation of mutations. We addressed this...
Conference Paper
Background/Question/Methods Global deforestation has led to the clearing of nearly two-thirds of the total forest cover on earth. Fragmented forests are now more common than contiguous expanses of intact forest, and forest fragmentation has been linked to reductions in genetic diversity of surviving populations. Fragmentation is particularly exte...
Article
Full-text available
The global hydrological cycle is predicted to become more intense in future climates, with both larger precipitation events and longer times between events in some regions. Redistribution of precipitation may occur both within and across seasons, and the resulting wide fluctuations in soil water content (SWC) may dramatically affect plants. Though...
Conference Paper
Fragmentation threatens biodiversity globally. Manilkara maxima (Sapotaceae) is an IUCN threatened, economically and ecologically important tree species endemic to the Atlantic forest of southern Bahia, Brazil, a biodiversity hotspot. The objectives in this study were to report the population genetics and examine the effect of fragment size on dens...
Article
Full-text available
The hydrological cycle is predicted to become more intense in future climates, with both larger precipitation events and longer times between events. Redistribution of precipitation may occur both within and across seasons, and the resulting wide fluctuations in soil water content may dramatically affect plants. Though these responses remain poorly...
Conference Paper
Background/Question/Methods Examining distribution patterns of tree species can help our understanding of why tropical forests have high diversity and guide conservation strategies. The Janzen – Connell hypothesis predicts that recruitment patterns of young life stages of tropical trees will be skewed away from reproductive trees and areas of hig...
Conference Paper
Full-text available
Background/Question/Methods The global hydrological cycle is predicted to become more intense, or extreme in future climates, with both larger precipitation events and longer times between events. The resulting wide fluctuations in soil water content (long droughts followed by flooding) may dramatically affect terrestrial ecosystems. Although eff...
Conference Paper
Background/Question/Methods Soil fungi play a critical role in regulating ecosystem carbon fluxes, and changes in soil fungal community composition may significantly alter ecosystem processes. Urbanization may alter fungal community composition through effects on soil, such as soil chemistry, yet little is known about the environmental drivers th...
Conference Paper
Background/Question/Methods Engaging urban teenagers in place-based environmental research improves long-term academic performance, understanding of the scientific process, and helps to create life-long environmental stewardship. Urban ecological research provides a unique opportunity to engage this demographic in place-paced research. Through a...
Conference Paper
Full-text available
Due to advances in technology allowing observations of low flow rates, we now have abundant evidence of nocturnal sap flow occurring in a range of species, ecosystems, and under various microclimatic conditions. This paper synthesises the conditions that facilitate nocturnal sap flow and evaluates possible mechanisms. The microclimatic variables wh...
Article
Full-text available
Climate change may alter forest composition by differentially affecting the responses of faster- and slower-growing tree species to drought. However, the combined effects of rising atmospheric CO2 concentration ([CO2]) and temperature on drought responses of trees are poorly understood. Here, we examined interactive effects of temperature (ambient,...
Article
Full-text available
Technological advancements have led to abundant evidence of nocturnal sap flow occurring in a range of species and ecosystems under varying microclimatic conditions. Here, we evaluate the physical factors that facilitate night-time water loss and explore potential advantages to this seemingly wasteful process. We discuss the microclimatic variables...
Article
Infection by eastern dwarf mistletoe (Arceuthobium pusillum) modifies needle and branch morphology and hastens white spruce (Picea glauca) mortality. We examined potential causal mechanisms and assessed the impacts of infection-induced alterations to host development and performance across scales ranging from needle hormone contents to bole expansi...
Conference Paper
Background/Question/Methods Atmospheric concentrations of carbon dioxide ([CO2]) over the past 650,000 years have ranged from 180 - 280 µmol mol-1, but in the past 150 years have risen rapidly to 389 µmol mol-1. This 40% increase is similar in magnitude to the increase in [CO2] projected for the 21st century, and understanding the factors that re...
Conference Paper
Background/Question/Methods Microstegium vimineum (Japanese stilt grass) is an invasive annual grass native to Asia. Although it is a C4 species, M. vimineum is frequently found in moist, shady habitats such as the understory of mesic forests. Despite these findings, the roles of light and moisture availability on M. vimineum physiology and growt...
Conference Paper
Background/Question/Methods The ectomycorrhizal eastern hemlock (Tsuga canadensis; hereafter “hemlock”) is subject to herbivory by the invasive hemlock woolly adelgid (Adelges tsugae) which is causing widespread mortality. In addition, a warming climate is predicted to reduce the importance value of hemlock in much of the eastern US, while creati...
Conference Paper
Background/Question/Methods We examined how forest fragmentation affected the population genetics of the threatened tree species Manilkara maxima from the Atlantic coastal region of southern Bahia, Brazil. Manilkara maxima is economically important as a source of timber and identified as one of the top five “extremely valuable” tree species for c...
Conference Paper
Background/Question/Methods Green roofs, rooftops that have growing media and plants on them, provide a number of benefits including increased biodiversity, decreased building energy use, storm water mitigation, increased rooftop lifespan, and mitigation of the urban heat island. Food production may also be a potential benefit of green roofs. In...
Article
Full-text available
Leaf structure and chemistry both play critical roles in regulating photosynthesis. Yet, a key unresolved issue in climate change research is the role of changes in leaf structure in photosynthetic responses to temperature and atmospheric CO2 concentration ([CO2]), ranging from pre-industrial to future levels. We examined the interactive effects of...
Article
1. Age-related reductions in stand biomass accumulation are frequently observed in old-growth forests. The phenomenon may be caused by reduced production, increased mortality or both. The relative importance of production and mortality is not well studied, so the mechanisms controlling age-related decline of stand biomass accumulation remain unclea...
Article
Full-text available
The response of nocturnal stomatal conductance (g(s,n)) to rising atmospheric CO(2) concentration ([CO(2)]) is currently unknown, and may differ from responses of daytime stomatal conductance (g(s,d)). Because night-time water fluxes can have a significant impact on landscape water budgets, an understanding of the effects of [CO(2)] and temperature...
Article
Full-text available
Trees adapted to mesic and xeric habits may differ in a suite of physiological responses that affect leaf-level carbon balance, including the relationship between photosynthesis (A) and respiration at night (R(n)). Understanding the factors that regulate physiological function in mesic and xeric species is critical for predicting changes in growth...
Conference Paper
Background/Question/Methods Climate change may alter forest composition by differentially affecting the responses of tree species to drought, which limits primary production of most terrestrial ecosystems for part or most of the year. However, the interactive effect of rising [CO2] and temperature on tree responses to drought is a key unresolved i...
Conference Paper
Background/Question/Methods A key unresolved issue in climate change research is the response of trees to alterations in CO2 and temperature ranging from the pre-industrial age to climate model projections for the future. Similarly, few studies have addressed the linkages between environmental effects on leaf structure (stomata, leaf thickness, s...
Article
Full-text available
Nearly 30 years ago, Whitehead and Jarvis and Whitehead et al. postulated an elegant mechanistic explanation for the observed relationship between tree hydraulic structure and function, hypothesizing that structural adjustments promote physiological homeostasis. To date, this framework has been nearly completely overlooked with regard to varying at...
Article
Full-text available
Nocturnal water flux has been observed in trees under a variety of environmental conditions and can be a significant contributor to diel canopy water flux. Elevated atmospheric CO(2) (elevated [CO(2)]) can have an important effect on day-time plant water fluxes, but it is not known whether it also affects nocturnal water fluxes. We examined the eff...