Climatic and Non-climatic Controls Shaping Early Postglacial Conifer History in the Northern Greater Yellowstone Ecosystem, USA

Climatic and Non-climatic Controls Shaping Early Postglacial Conifer History in the Northern Greater Yellowstone Ecosystem, USA PDF Author: Teresa R. Krause
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 15

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Book Description
Mountain ecosystems are characterized by their complex vegetation responses to past climate variability because of the interplay between large-scale climate changes and local-scale biotic and abiotic conditions. This study reconstructs the early postglacial expansion of conifer populations in the northern Greater Yellowstone Ecosystem (GYE). The objective is to examine how climate change and non-climatic factors, including species characteristics, edaphic conditions and disturbance, governed postglacial vegetation changes. Spruce populations expanded first at 13 300 cal a BP, concurrent with soil development and warming summers. Subalpine fir populations expanded after 12 300 cal a BP and probably lagged spruce expansion due to differences in climatic tolerances and/or its poorer seed dispersing capacity. Pine species expanded nearly synchronously after 11 300 cal a BP in response to elevated summer temperatures and increased fire activity. Douglas-fir populations expanded last after 10 200 cal a BP during the early Holocene summer insolation maximum and cooler winters. The sequence and timing of conifer expansions in the northern GYE are consistent with the regional conifer history, indicating strong vegetation responses to millennial-scale climate change associated with the seasonal cycle of insolation across spatial scales. Nonetheless, non-climatic factors, including landscape stabilization and subsequent soil development, seed dispersing characteristics and fire, still shaped local-scale patterns of conifer expansion.

Climatic and Non-climatic Controls Shaping Early Postglacial Conifer History in the Northern Greater Yellowstone Ecosystem, USA

Climatic and Non-climatic Controls Shaping Early Postglacial Conifer History in the Northern Greater Yellowstone Ecosystem, USA PDF Author: Teresa R. Krause
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 15

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Book Description
Mountain ecosystems are characterized by their complex vegetation responses to past climate variability because of the interplay between large-scale climate changes and local-scale biotic and abiotic conditions. This study reconstructs the early postglacial expansion of conifer populations in the northern Greater Yellowstone Ecosystem (GYE). The objective is to examine how climate change and non-climatic factors, including species characteristics, edaphic conditions and disturbance, governed postglacial vegetation changes. Spruce populations expanded first at 13 300 cal a BP, concurrent with soil development and warming summers. Subalpine fir populations expanded after 12 300 cal a BP and probably lagged spruce expansion due to differences in climatic tolerances and/or its poorer seed dispersing capacity. Pine species expanded nearly synchronously after 11 300 cal a BP in response to elevated summer temperatures and increased fire activity. Douglas-fir populations expanded last after 10 200 cal a BP during the early Holocene summer insolation maximum and cooler winters. The sequence and timing of conifer expansions in the northern GYE are consistent with the regional conifer history, indicating strong vegetation responses to millennial-scale climate change associated with the seasonal cycle of insolation across spatial scales. Nonetheless, non-climatic factors, including landscape stabilization and subsequent soil development, seed dispersing characteristics and fire, still shaped local-scale patterns of conifer expansion.

Early Postglacial Vegetation Development in the Greater Yellowstone Ecosystem

Early Postglacial Vegetation Development in the Greater Yellowstone Ecosystem PDF Author: Teresa Rose Krause
Publisher:
ISBN:
Category : Paleobotany
Languages : en
Pages : 1104

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Book Description
The last glacial-interglacial transition in the western US (20,000-8000 years ago) was a period of rapid environmental change. In the Greater Yellowstone Ecosystem (GYE), much research has focused on postglacial vegetation changes; however, questions still remain regarding the relative trade-off between climate and nonclimatic factors, such as edaphic conditions, disturbance, and biotic interactions, in driving early postglacial vegetation development at finer spatial and temporal scales in the region. This study reconstructed vegetation development in the GYE from the time of ice retreat to the early Holocene insolation maximum (17,000-8000 years ago) at sub-regional and regional scales using fossil pollen data from three sites in the northern GYE and across a regional network of 13 previously published records. Fossil pollen data from lake sediments were compared to independent measures of climate (paleoclimate model simulations, stable isotope data), edaphic conditions (lithologic and geochemical data), and fire activity (charcoal data) to better understand climatic and nonclimatic drivers of early postglacial vegetation development. Climate was the primary driver of early postglacial vegetation development in the GYE. Increasing summer insolation and its direct effects on summer temperature and effective moisture directed changes in vegetation from pioneering herb and shrub communities to spruce parkland during the late-glacial period to subalpine forest and eventually open Douglas-fir forest by the early Holocene summer insolation maximum. Nonetheless, fire activity, site-specific edaphic conditions, and biotic interactions mediated vegetation responses to climate change. Elevated regional fire activity between 12,500 and 10,000 cal yr BP, driven by increasing summer temperatures and fuel biomass, facilitated important ecosystem changes from an Engelmann spruce and subalpine fir dominated system to one dominated by whitebark and lodgepole pine. Site-specific edaphic conditions, namely erosional processes associated with newly deglaciated terrain, inhibited early conifer expansion, and important competitive interactions between lodgepole pine and whitebark pine after the early Holocene limited the range of whitebark pine at middle elevations in the GYE. This research provides new insight into how ecosystems and plant species have responded to past climate change and is critical for better understanding local responses to regional climate change predicted in the coming decades.

Plants and Their Environments

Plants and Their Environments PDF Author:
Publisher:
ISBN:
Category : Botany
Languages : en
Pages : 372

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Book Description


Postglacial Vegetation Dynamics at High Elevation from Fairy Lake in the Northern Greater Yellowstone Ecosystem, Montana, USA

Postglacial Vegetation Dynamics at High Elevation from Fairy Lake in the Northern Greater Yellowstone Ecosystem, Montana, USA PDF Author: James V. Benes
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Book Description
The postglacial vegetation and fire history of the Greater Yellowstone Ecosystem is known from low and middle elevations, but little is known about high elevations. Paleoecologic data from Fairy Lake in the Bridger Range, southwestern Montana, provide a new high-elevation record that spans the last 15,000 yr. The records suggest a period of tundra-steppe vegitation prior to ca. 13,700 cal yr BP was followed by open Picea forest at ca. 11,200 cal yr BP. Pinus-Pseudotsuga parkland was present after ca. 9200 cal yr BP, when conditions were warmer-drier than presernt. It was replaced by mixed-conifer parkland at ca. 5000 cal yr BP. Present-day subalpine forest established at ca. 2800 cal yr BP. Increased avalanche or mass-wasting aactivity during the early late-glacial period, the Younger Dryas chronozone, and Neoglaciation suggest cool, wet periods. Sites at different elevations in the region show (1) sunchronous vegetation responses to late-glacial warming; (2) widespread xerothermic forests and frequent fires in the early-to-middle Holocene; and (3) a trend to forest closure during late-Holocene colling. Conditions in the Bridger Range were, however, wetter than other areas during the early Holocene. Across the Northern Rockies, postglacial warming progressed from west to east, reflecting range-specific responses to insolation-driven changes in climate.

Ecological Dynamics on Yellowstone's Northern Range

Ecological Dynamics on Yellowstone's Northern Range PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309083451
Category : Science
Languages : en
Pages : 199

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Book Description
Ecological Dynamics on Yellowstone's Northern Range discusses the complex management challenges in Yellowstone National Park. Controversy over the National Park Service's approach of "natural regulation" has heightened in recent years because of changes in vegetation and other ecosystem components in Yellowstone's northern range. Natural regulation minimizes human impacts, including management intervention by the National Park Service, on the park ecosystem. Many have attributed these changes to increased size of elk and other ungulate herds. This report examines the evidence that increased ungulate populations are responsible for the changes in vegetation and that the changes represent a major and serious change in the Yellowstone ecosystem. According to the authors, any human intervention to protect species such as the aspen and those that depend on them should be prudently localized rather than ecosystem-wide. An ecosystem-wide approach, such as reducing ungulate populations, could be more disruptive. The report concludes that although dramatic ecological change does not appear to be imminent, approaches to dealing with potential human-caused changes in the ecosystem, including those related to climate change, should be considered now. The need for research and public education is also compelling.

Yellowstone’s Wildlife in Transition

Yellowstone’s Wildlife in Transition PDF Author: P. J. White
Publisher: Harvard University Press
ISBN: 0674076435
Category : Nature
Languages : en
Pages : 321

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Book Description
The world's first national park, Yellowstone is a symbol of nature's enduring majesty and the paradigm of protected areas across the globe. But Yellowstone is constantly changing. How we understand and respond to events that are putting species under stress, say the authors of Yellowstone's Wildlife in Transition, will determine the future of ecosystems that were millions of years in the making. With a foreword by the renowned naturalist E. O. Wilson, this is the most comprehensive survey of research on North America's flagship national park available today. Marshaling the expertise of over thirty contributors, Yellowstone's Wildlife in Transition examines the diverse changes to the park's ecology in recent decades. Since its creation in the 1870s, the priorities governing Yellowstone have evolved, from intensive management designed to protect and propagate depleted large-bodied mammals to an approach focused on restoration and preservation of ecological processes. Recognizing the importance of natural occurrences such as fires and predation, this more ecologically informed oversight has achieved notable successes, including the recovery of threatened native species of wolves, bald eagles, and grizzly bears. Nevertheless, these experts detect worrying signs of a system under strain. They identify three overriding stressors: invasive species, private-sector development of unprotected lands, and a warming climate. Their concluding recommendations will shape the twenty-first-century discussion over how to confront these challenges, not only in American parks but for conservation areas worldwide. Highly readable and fully illustrated, Yellowstone's Wildlife in Transition will be welcomed by ecologists and nature enthusiasts alike.

Influence of Bioclimatic Variables on Treeline Conifer Distribution in the Greater Yellowstone Ecosystem

Influence of Bioclimatic Variables on Treeline Conifer Distribution in the Greater Yellowstone Ecosystem PDF Author: Anne M. Schrag
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 13

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Book Description
Aim: Tree-line conifers are believed to be limited by temperature worldwide, and thus may serve as important indicators of climate change. The purpose of this study was to examine the potential shifts in spatial distribution of three tree-line conifer species in the Greater Yellowstone Ecosystem under three future climatechange scenarios and to assess their potential sensitivity to changes in both temperature and precipitation. Location: This study was performed using data from 275 sites within the boundaries of Yellowstone and Grand Teton national parks, primarily located in Wyoming, USA. Methods: We used data on tree-line conifer presence from the US Forest Service Forest Inventory and Analysis Program. Climatic and edaphic variables were derived from spatially interpolated maps and approximated for each of the sites. We used the random-forest prediction method to build a model of predicted current and future distributions of each of the species under various climatechange scenarios. Results: We had good success in predicting the distribution of tree-line conifer species currently and under future climate scenarios. Temperature and temperature-related variables appeared to be most influential in the distribution of whitebark pine (Pinus albicaulis), whereas precipitation and soil variables dominated the models for subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii). The model for whitebark pine substantially overpredicted absences (as compared with the other models), which is probably a result of the importance of biological factors in the distribution of this species. Main conclusions: These models demonstrate the complex response of conifer distributions to changing climate scenarios. Whitebark pine is considered a 'keystone' species in the subalpine forests of western North America; however, it is believed to be nearly extinct throughout a substantial portion of its range owing to the combined effects of an introduced pathogen, outbreaks of the native mountain pine beetle (Dendroctonus ponderosae), and changing fire regimes. Given predicted changes in climate, it is reasonable to predict an overall decrease in pinedominated subalpine forests in the Greater Yellowstone Ecosystem. In order to manage these forests effectively with respect to future climate, it may be important to focus attention on monitoring dry mid- and high-elevation forests as harbingers of long-term change.

Yellowstone's Destabilized Ecosystem

Yellowstone's Destabilized Ecosystem PDF Author: Frederic H. Wagner
Publisher: Oxford University Press
ISBN: 0198033796
Category : Science
Languages : en
Pages : 386

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Book Description
Wagner, one of our most distinguished wildlife biologists, is a strong critic of ecological practices in the national parks. This book provides an assessment of the ecological history of Yellowstone's northern range, since before the park existed, showing the impact of US Park Service policies on the health of the areas they oversee. He demonstrates that elk had been historically rare throughout the region and that overgrazing by elk has seriously degraded the landscape and altered the structure of the area. This is a major contribution to reconstructing the ecology of this region over the course of the past 500 years. It is also a critique of US Park Service management policies and their stewardship of the nation's most cherished natural areas. Wagner's book will generate substantial attention and debate both in the scientific and policy/management communities.

Ensuring Greater Yellowstone's Future

Ensuring Greater Yellowstone's Future PDF Author: Susan Gail Clark
Publisher: Yale University Press
ISBN: 0300145039
Category : Travel
Languages : en
Pages : 316

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Book Description
Drawing on extensive conservation experience in the greater Yellowstone region, Susan G. Clark outlines the leadership and policy issues associated with managing greater Yellowstone's natural resources and asseses the successes and failures of those who have worked there toward sustainability over the past 40 years.

The Ecology of Large Mammals in Central Yellowstone

The Ecology of Large Mammals in Central Yellowstone PDF Author: Robert A. Garrott
Publisher: Academic Press
ISBN: 0080921051
Category : Science
Languages : en
Pages : 712

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Book Description
This book is an authoritative work on the ecology of some of America's most iconic large mammals in a natural environment - and of the interplay between climate, landscape, and animals in the interior of the world's first and most famous national park.Central Yellowstone includes the range of one of the largest migratory populations of bison in North America as well as a unique elk herd that remains in the park year round. These populations live in a varied landscape with seasonal and often extreme patterns of climate and food abundance. The reintroduction of wolves into the park a decade ago resulted in scientific and public controversy about the effect of large predators on their prey, a debate closely examined in the book. Introductory chapters describe the geography, geology and vegetation of the ecosystem. The elk and bison are then introduced and their population ecology described both pre- and post– wolf introduction, enabling valuable insights into the demographic and behavioral consequences for their ungulate prey. Subsequent chapters describe the wildlife-human interactions and show how scientific research can inform the debate and policy issues surrounding winter recreation in Yellowstone. The book closes with a discussion of how this ecological knowledge can be used to educate the public, both about Yellowstone itself and about science, ecology and the environment in general. Yellowstone National Park exemplifies some of the currently most hotly debated and high-profile ecological, wildlife management, and environmental policy issues and this book will have broad appeal not only to academic ecologists, but also to natural resource students, managers, biologists, policy makers, administrators and the general public. - Unrivalled descriptions of ecological processes in a world famous ecosystem, based on information from 16 years of painstaking field work and collaborations among 66 scientists and technical experts and 15 graduate studies - Detailed studies of two charismatic North American herbivore species – elk and bison - Description of the restoration of wolves into central Yellowstone and their ecological interactions with their elk and bison prey - Illustrated with numerous evocative colour photographs and stunning maps