Thomas W. Swetnam (born 1955) is Regents' Professor Emeritus of Dendrochronology at the University of Arizona, studying disturbances of forest ecosystems across temporal and spatial scales. He served as the Director of the Laboratory of Tree-Ring Researchfrom 2000 to 2015.
Dendrochronology is the scientific method of dating tree rings to the exact year they were formed. As well as dating them this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from wood.
The University of Arizona is a public research university in Tucson, Arizona. Founded in 1885, the UA was the first university in the Arizona Territory. As of 2017, the university enrolls 44,831 students in 19 separate colleges/schools, including the University of Arizona College of Medicine in Tucson and Phoenix and the James E. Rogers College of Law, and is affiliated with two academic medical centers. The University of Arizona is governed by the Arizona Board of Regents. The University of Arizona is one of the elected members of the Association of American Universities and is the only representative from the state of Arizona to this group.
Swetnam received his bachelor's degree in biology and chemistry from the University of New Mexico and subsequently received his master's and PhD from the University of Arizona in watershed management and dendrochronology.
The University of New Mexico is a public research university in Albuquerque, New Mexico. Founded in 1889, UNM offers bachelor's, master's, doctoral, and professional degree programs in multiple fields. Its Albuquerque campus encompasses over 600 acres (2.4 km²), and there are branch campuses in Gallup, Los Alamos, Rio Rancho, Taos, and Los Lunas. UNM is categorized as an R1 doctoral university in the Carnegie Classification of Institutions of Higher Education
Watershed management is the study of the relevant characteristics of a watershed aimed at the sustainable distribution of its resources and the process of creating and implementing plans, programs, and projects to sustain and enhance watershed functions that affect the plant, animal, and human communities within the watershed boundary. Features of watershed that agencies seek to manage include water supply, water quality, drainage, stormwater runoff, water rights, and the overall planning and utilization of watersheds. Landowners, land use agencies, stormwater management experts, environmental specialists, water use surveyors and communities all play an integral part in watershed management.
He received the A.E. Douglass award from the University of Arizona, the W.S. Cooper award from the Ecological Society of America (with Julio Betancourt) and the Henry Cowles award from the American Association of Geographers (with James H. Speer). He was elected a Fellow of the American Association For the Advancement of Science in 2015. He received the Harold C. Fritts Lifetime Achievement Award from the Tree-Ring Society in 2016.
Henry Chandler Cowles was an American botanist and ecological pioneer. A professor at the University of Chicago, he studied ecological succession in the Indiana Dunes of Northwest Indiana. This led to efforts to preserve the Indiana Dunes. One of Cowles' students, O. D. Frank continued his research.
The American Association of Geographers (AAG) is a non-profit scientific and educational society aimed at advancing the understanding, study, and importance of geography and related fields. Its headquarters are located at 1710 16th St NW, Washington, D.C. The organization was founded on 29 December 1904 in Philadelphia as the Association of American Geographers, with the American Society of Professional Geographers later amalgamating into it in December 1948 in Madison, Wisconsin.pg. 1025 Currently, the association has more than 10,000 members from over 60 countries. AAG members are geographers and related professionals who work in the public, private, and academic sectors.
James H. Speer is a professor of geography and geology at Indiana State University. He is a past president of the Tree-Ring Society and the Geography Educator's Network of Indiana. He has been the organizer for the North American Dendroecological Fieldweek (NADEF) since 2003.
He has served on the following advisory and editorial boards:
Board of Trustees, Valles Caldera National Preserve (2000-2004); Arizona Forest Health Advisory Council (2003-2006); Arizona Climate Change Advisory Group (2005-2006); Associate Editor, International Journal of Wildland Fire, (1993–present); Editor, Tree-Ring Research (2000-2001); Associate Editor, Ecoscience (1994-1998); Associate Editor, Canadian Journal of Forest Research (1998); Editorial Board, Ecological Applications (1998-1999); Associate Editor, Dendrochronlogia, (2005–2012); Board of Trustees, The Nature Conservancy, New Mexico, 2016–present.
He has authored and co-authored approximately more than 120 scientific papers in journals and symposium proceedings, including the following frequently cited/significant papers:
The bibcode is a compact identifier used by several astronomical data systems to uniquely specify literature references.
In computing, a Digital Object Identifier or DOI is a persistent identifier or handle used to uniquely identify objects, standardized by the International Organization for Standardization (ISO). An implementation of the Handle System, DOIs are in wide use mainly to identify academic, professional, and government information, such as journal articles, research reports and data sets, and official publications though they also have been used to identify other types of information resources, such as commercial videos.
JSTOR is a digital library founded in 1995. Originally containing digitized back issues of academic journals, it now also includes books and other primary sources, and current issues of journals. It provides full-text searches of almost 2,000 journals. As of 2013, more than 8,000 institutions in more than 160 countries had access to JSTOR; most access is by subscription, but some of the site's public domain and open access content is available at no cost to anyone. JSTOR's revenue was $86 million in 2015.
The International Standard Book Number (ISBN) is a numeric commercial book identifier which is intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency.
Ecology is the branch of biology which studies the interactions among organisms and their environment. Objects of study include interactions of organisms with each other and with abiotic components of their environment. Topics of interest include the biodiversity, distribution, biomass, and populations of organisms, as well as cooperation and competition within and between species. Ecosystems are dynamically interacting systems of organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and niche construction, regulate the flux of energy and matter through an environment. These processes are sustained by organisms with specific life history traits. Biodiversity means the varieties of species, genes, and ecosystems, enhances certain ecosystem services.
The Holocene extinction, otherwise referred to as the Sixth extinction or Anthropocene extinction, is a current event, and is one of the most significant extinction events in the history of the Earth. This ongoing extinction of species coincides with the present Holocene epoch, and is mainly a result of human activity. This large number of extinctions spans numerous families of plants and animals, including mammals, birds, amphibians, reptiles and arthropods. With widespread degradation of highly biodiverse habitats such as coral reefs and rainforests, as well as other areas, the vast majority of these extinctions are thought to be undocumented, as no one is even aware of the existence of the species before they go extinct, or no one has yet discovered their extinction. The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background rates.
The Permian–Triassicextinction event, colloquially known as the Great Dying, the End-Permian Extinction or the Great Permian Extinction, occurred about 252 Ma ago, forming the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras. It is the Earth's most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all biological families and 83% of all genera became extinct. Because so much biodiversity was lost, the recovery of land-dwelling life took significantly longer than after any other extinction event, possibly up to 10 million years. Studies in Bear Lake County, near Paris, Idaho, showed a relatively quick rebound in a localized marine ecosystem, taking around 2 million years to recover, suggesting that the impact of the extinction may have been felt less severely in some areas than others.
Biodiversity refers to the variety and variability of life on Earth. Biodiversity typically measures variation at the genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near the equator, which is the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species. Marine biodiversity is usually highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future.
Human ecology is an interdisciplinary and transdisciplinary study of the relationship between humans and their natural, social, and built environments. The philosophy and study of human ecology has a diffuse history with advancements in ecology, geography, sociology, psychology, anthropology, zoology, epidemiology, public health, and home economics, among others.
The opisthokonts are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the "Fungi/Metazoa group", are generally recognized as a clade. Opisthokonts together with Apusomonadida and Breviata comprise the larger clade Obazoa.
The Younger Dryas impact hypothesis or Clovis comet hypothesis originally proposed that a large air burst or earth impact of one or more comets initiated the Younger Dryas cold period about 12,900 BP calibrated years ago. The hypothesis has been contested by research as recently as 2017, arguing that most of the conclusions cannot be repeated by other scientists, and criticized because of misinterpretation of data and previous lack of confirmatory evidence.
The evolution of fungi has been going on since fungi diverged from other life around 1.5 billion years ago, with the glomaleans branching from the "higher fungi" at ~, according to DNA analysis. Fungi probably colonized the land during the Cambrian, over , but terrestrial fossils only become uncontroversial and common during the Devonian, .
An ecological network is a representation of the biotic interactions in an ecosystem, in which species (nodes) are connected by pairwise interactions (links). These interactions can be trophic or symbiotic. Ecological networks are used to describe and compare the structures of real ecosystems, while network models are used to investigate the effects of network structure on properties such as ecosystem stability.
Malcolm K. Hughes is a meso-climatologist and Regents' Professor of Dendrochronology in the Laboratory for Tree-Ring Research at the University of Arizona.
The divergence problem is an anomaly from the field of dendroclimatology, the study of past climate through observations of old trees, primarily the properties of their annual growth rings. It is the disagreement between the temperatures measured by the thermometers and the temperatures reconstructed from the latewood densities or, in some cases, widths of tree rings in the far northern forests.
The Primatomorpha are a mirorder of mammals containing two orders: the Dermoptera or colugos and the Primates.
A nutrient cycle is the movement and exchange of organic and inorganic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus cycle, oxygen cycle, among others that continually recycle along with other mineral nutrients into productive ecological nutrition.
William F. Laurance is Distinguished Research Professor at James Cook University, Australia and has been elected as a Fellow of the Australian Academy of Science. He has received an Australian Laureate Fellowship from the Australian Research Council. He also has holds the Prince Bernhard Chair for International Nature Conservation at Utrecht University, Netherlands.
David John Beerling is the Director of the Leverhulme Centre for Climate change mitigation and Sorby Professor of Natural Sciences in the Department of Animal and Plant Sciences (APS) at the University of Sheffield, UK.
Thomas Thorstein Veblen is an American forest ecologist and physical geographer known for his work on the ecology of Nothofagus forests in the Southern Hemisphere and on the ecology of conifer forests in the southern Rocky Mountains of the U.S.A. He is an Arts and Sciences College Professor of Distinction at University of Colorado at Boulder, USA (2006).