Twenty-five years of vegetation change along a putative successional chronosequence on the Tanana River, AlaskaThis article is one of a selection of papers from The Dynamics of Change in Alaska’s Boreal Forests: Resilience and Vulnerability in Response to Climate Warming.

2010 ◽  
Vol 40 (7) ◽  
pp. 1273-1287 ◽  
Author(s):  
Teresa N. Hollingsworth ◽  
Andrea H. Lloyd ◽  
Dana R. Nossov ◽  
Roger W. Ruess ◽  
Brian A. Charlton ◽  
...  
Keyword(s):  
Plant Community ◽  
Boreal Forests ◽  
Vegetation Change ◽  
Turning Points ◽  
Community Change ◽  
Ecosystem Structure ◽  
Mature Trees ◽  
Successional Stage ◽  
Long Term Ecological Research

Along the Tanana River floodplain, several turning points have been suggested to characterize the changes in ecosystem structure and function that accompany plant community changes through primary succession. In the past, much of this research focused on a presumed chronosequence that uses space for time substitutions. Within this chronosequence, permanent vegetation plots repeatedly measured over time provide an excellent test of the turning points model. We analyzed both canopy and understory vegetation data collected since 1987 in the Bonanza Creek Experimental Forest at the Bonanza Creek Long Term Ecological Research site to address the following questions: (i) Do long-term changes in the densities of seedling, sapling, and mature trees and shrubs of the dominant woody taxa at each successional stage support the turning points model? (ii) How does the entire plant community change with time at each hypothesized turning point? (iii) Do we see evidence of directional and synchronous shifts in species composition across successional stages? We conclude that some aspects of vegetation change during the last 25 years were consistent with the turning points model; however, many changes were not consistent, indicating the potential roles of biological, environmental, landscape, and climate controls in vegetation patterns.

scholarly journals Spores and soil from six sides: interdisciplinarity and the environmental biology of anthrax (Bacillus anthracis)

2017 ◽  
Author(s):  
Colin J. Carlson ◽  
Wayne M. Getz ◽  
Kyrre L. Kausrud ◽  
Carrie A. Cizauskas ◽  
Jason K. Blackburn ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Disease Ecology ◽  
Seasonal Pattern ◽  
Interdisciplinary Approach ◽  
Ecosystem Structure ◽  
Environmental Biology ◽  
Environmental Persistence ◽  
Long Term Ecological Research ◽  
Anthrax Spores

AbstractEnvironmentally Transmitted Diseases Are Comparatively Poorly Understood And Managed, And Their Ecology Is Particularly Understudied. Here We Identify Challenges Of Studying Environmental Transmission And Persistence With A Six-Sided Interdisciplinary Review Of The Biology Of Anthrax (Bacillus Anthracis). Anthrax Is A Zoonotic Disease Capable Of Maintaining Infectious Spore Banks In Soil For Decades (Or Even Potentially Centuries), And The Mechanisms Of Its Environmental Persistence Have Been The Topic Of Significant Research And Controversy. Where Anthrax Is Endemic, It Plays An Important Ecological Role, Shaping The Dynamics Of Entire Herbivore Communities. The Complex Eco-Epidemiology Of Anthrax, And The Mysterious Biology OfBacillus AnthracisDuring Its Environmental Stage, Have Necessitated An Interdisciplinary Approach To Pathogen Research. Here, We Illustrate Different Disciplinary Perspectives Through Key Advances Made By Researchers Working In Etosha National Park, A Long-Term Ecological Research Site In Namibia That Has Exemplified The Complexities Of Anthrax’S Enzootic Process Over Decades Of Surveillance. In Etosha, The Role Of Scavengers And Alternate Routes (Waterborne Transmission And Flies) Has Proved Unimportant, Relative To The Long-Term Persistence Of Anthrax Spores In Soil And Their Infection Of Herbivore Hosts. Carcass Deposition Facilitates Green-Ups Of Vegetation To Attract Herbivores, Potentially Facilitated By Anthrax Spores’ Role In The Rhizosphere. The Underlying Seasonal Pattern Of Vegetation, And Herbivores’ Immune And Behavioral Responses To Anthrax Risk, Interact To Produce Regular “Anthrax Seasons” That Appear To Be A Stable Feature Of The Etosha Ecosystem. Through The Lens Of Microbiologists, Geneticists, Immunologists, Ecologists, Epidemiologists, And Clinicians, We Discuss How Anthrax Dynamics Are Shaped At The Smallest Scale By Population Genetics And Interactions Within The Bacterial Communities Up To The Broadest Scales Of Ecosystem Structure. We Illustrate The Benefits And Challenges Of This Interdisciplinary Approach To Disease Ecology, And Suggest Ways Anthrax Might Offer Insights Into The Biology Of Other Important Pathogens.Bacillus Anthracis,And The More Recently EmergedBacillus CereusBiovarAnthracis, Share Key Features With Other Environmentally-Transmitted Pathogens, Including Several Zoonoses And Panzootics Of Special Interest For Global Health And Conservation Efforts. Understanding The Dynamics Of Anthrax, And Developing Interdisciplinary Research Programs That Explore Environmental Persistence, Is A Critical Step Forward For Understanding These Emerging Threats.

The demographic structure of European aspen (Populus tremula) populations in managed and old-growth boreal forests in eastern Finland

2007 ◽  
Vol 37 (6) ◽  
pp. 1070-1081 ◽  
Author(s):  
Tarja Latva-Karjanmaa ◽  
Reijo Penttilä ◽  
Juha Siitonen
Keyword(s):  
Protected Areas ◽  
Boreal Forests ◽  
Large Scale ◽  
Populus Tremula ◽  
Managed Forests ◽  
Mature Trees ◽  
Old Growth ◽  
European Aspen ◽  
Eastern Finland

European aspen ( Populus tremula L.) is a keystone species for biodiversity in boreal forests. However, large aspen have largely been removed from managed forests, whereas regeneration and the long-term persistence of mature trees in protected areas are matters of concern. We recorded the numbers of mature (≥20 cm diameter) aspen in old-growth and managed forests in eastern Finland, based on a large-scale inventory (11 400 ha, 36 000 living and dead trees). In addition, saplings and small aspen trees were surveyed on thirty-six 1 ha sample plots. The average volumes of mature living and dead aspen were 4.0 and 1.3 m3/ha in continuous old-growth forests and 0.2 and 0.6 m3/ha in managed forests, respectively. These results indicate that large aspen trees in managed forests are a legacy of the past, when forest landscapes were less intensively managed. We conclude that the long-term persistence of aspen in protected areas can only be secured by means of restoration measures that create gaps large enough for regeneration to occur. More emphasis should be given to sparing aspen during thinning and to retaining mature aspen during regeneration cutting in managed forests.

Alaska's Changing Boreal Forest

2006 ◽  
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Spatial Scales ◽  
Historical Context ◽  
Major Change ◽  
Frozen Ground ◽  
Long Term Ecological Research ◽  
Temporal And Spatial ◽  
Animal Communities

The boreal forest is the northern-most woodland biome, whose natural history is rooted in the influence of low temperature and high-latitude. Alaska's boreal forest is now warming as rapidly as the rest of Earth, providing an unprecedented look at how this cold-adapted, fire-prone forest adjusts to change. This volume synthesizes current understanding of the ecology of Alaska's boreal forests and describes their unique features in the context of circumpolar and global patterns. It tells how fire and climate contributed to the biome's current dynamics. As climate warms and permafrost (permanently frozen ground) thaws, the boreal forest may be on the cusp of a major change in state. The editors have gathered a remarkable set of contributors to discuss this swift environmental and biotic transformation. Their chapters cover the properties of the forest, the changes it is undergoing, and the challenges these alterations present to boreal forest managers. In the first section, the reader can absorb the geographic and historical context for understanding the boreal forest. The book then delves into the dynamics of plant and animal communities inhabiting this forest, and the biogeochemical processes that link these organisms. In the last section the authors explore landscape phenomena that operate at larger temporal and spatial scales and integrates the processes described in earlier sections. Much of the research on which this book is based results from the Bonanza Creek Long-Term Ecological Research Program. Here is a synthesis of the substantial literature on Alaska's boreal forest that should be accessible to professional ecologists, students, and the interested public.

Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

2011 ◽  
Vol 34 (1) ◽  
pp. 87-93
Author(s):  
Yong-Chan Cho ◽  
Chang-Seok Lee ◽  
Hyun-Je Cho ◽  
Kyu-Song Lee ◽  
Pil-Sun Park
Keyword(s):  
Vegetation Change ◽  
Ecological Research ◽  
Long Term Ecological Research

Enhanced Seasonal Exchange of CO2 by Northern Ecosystems Since 1960

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1085-1089 ◽  
Author(s):  
H. D. Graven ◽  
R. F. Keeling ◽  
S. C. Piper ◽  
P. K. Patra ◽  
B. B. Stephens ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Atmospheric Carbon Dioxide ◽  
Ecosystem Models ◽  
The North ◽  
Ecological Changes ◽  
Term Change ◽  
Major Shift ◽  
Underlying Mechanisms ◽  
Global Carbon

Seasonal variations of atmospheric carbon dioxide (CO2) in the Northern Hemisphere have increased since the 1950s, but sparse observations have prevented a clear assessment of the patterns of long-term change and the underlying mechanisms. We compare recent aircraft-based observations of CO2 above the North Pacific and Arctic Oceans to earlier data from 1958 to 1961 and find that the seasonal amplitude at altitudes of 3 to 6 km increased by 50% for 45° to 90°N but by less than 25% for 10° to 45°N. An increase of 30 to 60% in the seasonal exchange of CO2 by northern extratropical land ecosystems, focused on boreal forests, is implicated, substantially more than simulated by current land ecosystem models. The observations appear to signal large ecological changes in northern forests and a major shift in the global carbon cycle.

scholarly journals Connectivity: insights from the U.S. Long Term Ecological Research Network

Ecosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
Author(s):  
David M. Iwaniec ◽  
Michael Gooseff ◽  
Katharine N. Suding ◽  
David Samuel Johnson ◽  
Daniel C. Reed ◽  
...  
Keyword(s):  
Research Network ◽  
Ecological Research ◽  
Long Term Ecological Research ◽  
The U.S

Calcareous nannoplankton ecology and community change across the Paleocene-Eocene Thermal Maximum

Paleobiology ◽  
10.1666/12050 ◽  
2013 ◽  
Vol 39 (4) ◽  
pp. 628-647 ◽  
Author(s):  
Leah J. Schneider ◽  
Timothy J. Bralower ◽  
Lee R. Kump ◽  
Mark E. Patzkowsky
Keyword(s):  
Nutrient Availability ◽  
Multivariate Analyses ◽  
Geochemical Modeling ◽  
Community Change ◽  
Open Ocean ◽  
Data Set ◽  
Long Term Effect ◽  
Term Change ◽  
Thermal Maximum

The Paleocene-Eocene Thermal Maximum (PETM; ca. 55.8 Ma) is thought to coincide with a profound but entirely transient change among nannoplankton communities throughout the ocean. Here we explore the ecology of nannoplankton during the PETM by using multivariate analyses of a global data set that is based upon the distribution of taxa in time and space. We use these results, coupled with stable isotope data and geochemical modeling, to reinterpret the ecology of key genera. The results of the multivariate analyses suggest that the community was perturbed significantly in coastal and high-latitudes sites compared to the open ocean, and the relative influence of temperature and nutrient availability on the assemblage varies regionally. The open ocean became more stratified and less productive during the PETM and the oligotrophic assemblage responded primarily to changes in nutrient availability. Alternatively, assemblages at the equator and in the Southern Ocean responded to temperature more than to nutrient reduction. In addition, the assemblage change at the PETM was not merely transient—there is evidence of adaptation and a long-term change in the nannoplankton community that persists after the PETM and results in the disappearance of a high-latitude assemblage. The long-term effect on communities caused by transient warming during the PETM has implications for modern-day climate change, suggesting similar permanent changes to nannoplankton community structure as the oceans warm.

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