WorldCat Identities

Post, Eric

Overview
Works: 21 works in 22 publications in 1 language and 29 library holdings
Genres: Academic theses 
Roles: Thesis advisor, Contributor, Author
Publication Timeline
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Most widely held works by Eric Post
Report on expedition "Experimental assessment of the potential role of large herbivores in vegetation productivity response to global change" by Eric Post( Book )

2 editions published between 2002 and 2005 in English and held by 4 WorldCat member libraries worldwide

Greater Abundance of Betula nana and Early Onset of the Growing Season Increase Ecosystem CO2 Uptake in West Greenland by Sean M. P Cahoon( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Author Correction: Warming shortens flowering seasons of tundra plant communities by Janet S Prevéy( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

The response of Arctic vegetation to climate warming in an ungulate grazing system by Christian Pedersen( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

By monitoring plant emergence and phenological progression of plants in the permanent vegetation plots in 2004 and 2005, I investigated if herbivory could mitigate an advanced phenological progression of arctic plants as a response to climate warming. In 2004, the results indicated that a warmer climate advances the emergence of arctic plants. Furthermore, ungulate herbivory delayed plant emergence, but it appeared that the plants compensated a later emergence with a faster phenological progression. However, during the caterpillar outbreak in 2005, the relationships found in 2004 were offset by severe plant defoliation that caused fewer plant species to emerge during that year
Deer feeding selectivity for invasive plants by Kristine M Averill( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Warming shortens flowering seasons of tundra plant communities by Janet S Prevéy( )

1 edition published in 2018 in English and held by 2 WorldCat member libraries worldwide

On the sensitivity of root and leaf phenology to warming in the Arctic by Laura Radville( )

in Undetermined and held by 1 WorldCat member library worldwide

Taxonomic and ecologic implications of mammoth molar morphology as measured via computed tomography (CT) by Gregory Smith( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

Two Late Pleistocene species of Mammuthus, M. columbi and M. primigenius, prove difficult to identify on the basis of their third molar (M3) morphology alone due to the effects of dental wear. A newly-erupted, relatively unworn M3 exhibits drastically different characters than that tooth would after a lifetime of wear. On a highly-worn molar, the lophs that comprise the occlusal surface are more broadly spaced and the enamel ridges thicken in comparison to these respective characters on an unworn molar. Since Mammuthus taxonomy depends on the lamellar frequency (# of lophs/decimeter of occlusal surface) and enamel thickness of the third molar, given the effects of wear it becomes apparent that these taxonomic characters are variable throughout the tooth's life. Therefore, employing static taxonomic identifications that are based on dynamic attributes is a fundamentally flawed practice. To help resolve the relationship between M. columbi and M. primigenius, I quantified the proportions of the characters that comprise the occlusal surface of Mammuthus third molars. Using computed tomography (CT), I digitized a sample of teeth from both species, creating models of continual wear via the removal of slices from the occlusal surface to the base of the crown. At each time slice, I calculated the occlusal enamel percentage, enamel thickness, and lamellar frequency of the exposed surface of the tooth. I then examined the relationship between relative wear percentage and dental characters to determine if there was a separation between the two species of mammoth with wear. My results demonstrate a prevalence of intraspecific variation, making a consistent separation of species difficult. In the absence of accompanying cranial morphologies or molecular data, delineation of the North American mammoth species based solely on molar morphology remains challenging, if not impossible. Additionally, the scatter in enamel values in M. columbi molars is indicative of a less phenotypically stable organism, suggesting that M. primigenius was the mammoth with a more highly conserved niche
Global population dynamics and hot spots of response to climate change( )

1 edition published in 2009 in English and held by 1 WorldCat member library worldwide

Extrinsic modification of vertebrate sex ratios by climate variation( )

1 edition published in 1999 in English and held by 1 WorldCat member library worldwide

Reproductive morphology and histology of female Alaskan wolves by Andrea L Curatola( )

1 edition published in 2003 in English and held by 1 WorldCat member library worldwide

Against the Spring Wave : Ungulate Migration Phenology in a Changing Arctic by Christian John( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

Migration is a widespread adaptation to seasonal variability in resource distribution and availability. Through effects on resource phenology, composition, and abundance, climate change may disrupt the predictability of seasonal patterns of resource availability, with consequences for migratory timing and resource tracking by consumers. These impacts may be especially pronounced in the Arctic, where recent climatic warming is in excess of twice the global average. For long-distance migrants, the Green Wave Hypothesis has served as a broadly applicable framework for understanding the role of spatially propagating resource phenology in spring migration departure from wintering grounds, migratory rate, and timing of arrival at summer breeding grounds. While avian migrants and subarctic ungulates have been the focus of previous research on this topic, little focus has been placed to date on the impacts of climate change on ungulate migration phenology in the Arctic. Here, I use a framework based on the predictions of the Green Wave Hypothesis to investigate climatic effects on caribou (Rangifer tarandus) migration in a low-Arctic system. I begin in Chapter 2 by quantifying the spring wave in vegetation green-up phenology, finding that an unexpected trend in its direction of propagation is related to a suite of abiotic conditions including temperature, precipitation, and sea ice extent. Chapter 3 is an examination of caribou migration phenology, and the results presented therein suggest that the timing of arrival on the calving grounds is entrained by photoperiod, but is influenced secondarily by population density and timing of green-up
Carbon and water relations of contrasting Arctic plants: implications for shrub expansion in West Greenland( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

Wolverines and declining snowpack : response to comments by Jedediah F Brodie( )

1 edition published in 2011 in English and held by 1 WorldCat member library worldwide

Long-term changes in Artic tundra ecosystems ; papers of a Theme Issue( Book )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Mammoths, moose, and how animals might influence Earth's response to climate change by Eric Post( Visual )

1 edition published in 2002 in English and held by 1 WorldCat member library worldwide

Describes how populations of wild animals and the ecosystem changes they cause might influence the climate of the Northern Hemisphere. He discusses specifically extinct mammoths and mastodons in prehistoric times to moose, reindeer, and elk today
Nonlinear responses of wolverine populations to declining winter snowpack by Jedediah F Brodie( )

1 edition published in 2010 in English and held by 1 WorldCat member library worldwide

Phenology in a chancing Arctic : Linking trophic interactions across scales by Jeffrey Kerby( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

Phenology - the study of the timing of periodic biotic events or processes - is an integrative science that links the phenotypes of individual organisms with forces of global change. In recent decades is has evolved from an obscure pursuit of naturalists into a critical tool for evaluating the ecological consequences of climate change. Beyond simply reflecting climatic variability, phenology acts as a driver of ecological dynamics and a source of insight about an organisms' evolutionary history. The proximal drivers of phenology vary among species, sometimes resulting in asynchronous phenological responses to shared changes in climate. The match/mismatch hypothesis attributes changes in reproductive success to phenological asynchrony between trophic levels when asynchrony arises during sensitive periods of a consumer/predator life history progression. In chapter 2 I explore the genesis of this concept, review its contemporary relevance, and suggest avenues of future research that I explore in more detail in later chapters. No global region is warming faster than the Arctic, and widespread ecological perturbations have already been documented throughout high latitudes. Combining traditional field observations, novel phenological monitoring techniques, and data from a long-term study of tundra ecology, I examine how phenological dynamics link ecological processes across trophic levels and spatial scales in Arctic West Greenland. In chapter 3 I test predictions about how consumer reproductive strategies and directional changes in resource phenology interact to differentially affect the reproductive performance of two Arctic ungulate species. Sea ice loss is a broad scale abiotic driver of regional warming in the Arctic, but the indirect ecological consequences of these dynamics are poorly studied in terrestrial systems. In chapter 4 I identify a sea ice signal in the terrestrial phenological dynamics of plant phenology and herbivore reproductive performance. These findings suggest sea ice loss may have more wide reaching impacts on terrestrial Arctic ecology than are currently appreciated. Spatial patterns of phenological dynamics are relevant to ecological processes across multiple spatial scales, but often information on plant phenology is derived solely from localized vegetation plots or broad scale satellite derived metrics. In chapter 5 I explore landscape scale variability in plant phenology, its drivers, and evidence for scale dependency within and between years. I do so using a novel quantitative dataset derived from a network of time-lapse cameras distributed across the focal tundra landscape. Scale dependent dynamics were identified in metrics of phenological variability and landscape drivers of this variability, results that suggest traditional data sources may be insufficient to understand landscape-scale consequences of ongoing rapid changes in Arctic plant phenology
The biophysical and carbon-climate feedbacks of shrub expansion in the Arctic by Sean Cahoon( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

Recent warming in the Arctic has been twice the global average, leading to substantive changes in terrestrial ecosystem structure and function. Of primary concern is the vast amount of soil carbon (C) in the region, which, if mineralized, is expected to provide a significant positive feedback to global climate in the form of increasing atmospheric CO2 concentrations, and accelerate climatic warming. Alternatively, C uptake may be increasing in the region due to extended growing seasons and changes in plant community composition. The expansion of woody shrubs, for example, has been widely noted throughout the region, and is expected to impact ecosystem C budgets and alter soil C pools. However, the timing, magnitude and direction of changes in the C cycle in response to shrub expansion remain uncertain. Addressing the C cycle impacts of shrub expansion requires an examination of CO2 exchange processes at multiple spatiotemporal scales. At the broadest scale, Chapter 2 analyzes mid-summer CO2 exchange among herbaceous and woody tundra across 21 sites spanning 16° of latitude across the Arctic and Boreal zone. Variation in canopy temperature explained approximately half the variation in ecosystem respiration (ER), which, in turn, drives patterns of variation in net ecosystem CO2 exchange (NEE) across ecosystems, at least during the peak of the growing season. In addition, woody sites were slightly stronger sinks for atmospheric C; however, when soils were above 10° C, these sites became a net source for CO2. Meanwhile, herbaceous tundra remained a moderate C sink, regardless of soil temperature. These results indicate that an increase in shrub abundance may result in a net loss of C in the middle of the growing season if soils temperatures also rise. Identifying the primary drivers of CO2 uptake is a vital component of ecosystem C cycling, and may elucidate key physiological differences between shrubs and graminoids that confer a competitive advantage to a particular species. In Chapter 3, I combined leaf gas exchange with stable isotope analysis of two common arctic species, Betula nana and Poa pratensis, to reveal important difference in C uptake processes. I found greater drought sensitivity in the graminoid species, P. pratensis, which displayed reductions in stomatal conductance and photosynthesis during periods of high atmospheric vapor pressure deficits and low soil water content. Leaf [delta]13C and [delta]18O showed a negative relationship, indicating a strong stomatal influence on CO2 uptake. In contrast, Betula displayed less sensitivity to drought, and leaf [delta]13C and [delta]18O were not correlated with one another for this species. These key differences in C-H2O relations between co-existing species may confer an advantage to Betula if the climate becomes warmer and drier. Partitioning soil respiration (RS) into heterotrophic (RH) and autotrophic (RA) sources may provide valuable insight into the breakdown of soil organic matter (SOM) and short-term C flux from the rhizosphere. Chapter 4 presents a multi-year analysis of soil respiration (RS) partitioning among four common vegetation types in West Greenland. Although there were major differences in RS between vegetation types, the autotrophic proportion (RA / RS [almost equal to] 47%) was remarkably similar among vegetation types and between seasons. My comparative analysis suggests that RA / RS may be more conservative than what might be estimated based on global models, and that partitioning RS may be a useful diagnostic to identify ecosystems that are gaining or losing soil C. In Chapter 5, I examine the effect on the seasonal C cycle at the ecosystem scale of increasing abundance of Betula nana in West Greenland. Sites dominated by Betula were a stronger C sink than those dominated by graminoids due to higher gross ecosystem photosynthesis (GEP) and lower ER; however, water stress may have played a role in reducing mid-season GEP for both vegetation types. Vegetation along the transition between Betula and graminoid patches was commonly the strongest C sink, suggesting complementary in resource use. I detected a strong early season phenological influence on net C uptake, which coincided with recent warming in the region. A retrospective analysis revealed a net gain of 1.3 and 2.1 g C m-2 season-1 in Betula and graminoid tundra respectively, since 2002. These results suggest GEP has responded more strongly to recent warming than ER, resulting in an extended growing season that has increased net C uptake in West Greenland and provided a negative feedback. My research represents a comprehensive examination of C cycle processes across multiple scales in one of the most common types of Arctic tundra. However, there are clear gaps in our knowledge that remain unfilled. For instance, there may be important interactive effects between greater leaf area, litter input and changes in soil temperature associated with shrub expansion that will feedback to alter nutrient turnover and ultimately, plant productivity. My research has identified the importance of species-specific responses to climate perturbations and the need to focus future work on expanding, contracting and stable patch edges to elucidate physiological controls on vegetation change. The chapters presented herein represent a significant contribution to our understanding of how structural and physiological differences between woody and herbaceous species affect the magnitude of carbon-climate feedbacks in the Arctic
 
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English (20)