University of New Hampshire

About: University of New Hampshire is a education organization based out in Durham, New Hampshire, United States. It is known for research contribution in the topics: Population & Solar wind. The organization has 9379 authors who have published 24025 publications receiving 1020112 citations. The organization is also known as: UNH.

Response of Early Successional Vertebrates to Historic Changes in Land Use

Abstract: Unlike other regions of North America, forested habitats in New England bave increased substantially in the past 100 years. The proportion of land in New Hampshire covered by forests was 47% in 1880 and 87% in 1980. This increase was largely the result of a region-wide abandonment of farms and the subsequent colonization of these lands by second-growth forests. I examined the sequence of farm abandonment, forest colonization and forest maturation that occurred in New Hampshire in relation to changes in the abundance and distribution of a group of forest mammals and birds that have undergone substantial declines. A modeled pattern of secondary succession resulted in the availability of approximately 195,000 ha of early seral habitats (10–25 years after abandonment) from 1905 to 1940. These habitats then mutured into closed-canopy forests by about 1960. Concurrent to the loss of early successional habitats, populations of New England cottontails (Sylvilagus transitionalis) decreased from an apparent continuous distribution throughout 60% of New Hampshire to fragmented populations that occupy less than 20% of the state Bobacts (Felis rufus) responded functionally (S. transitionalis in diet: 1951–1954 = 43%, 1961–1964 = 10%) and numerically (mean annual harvest of bobcats: 1951–1954 = 350, 1965–1969 = 36) to changes in cottontail abundance. Eighteen of 26 species of migratory passerines that nest in the forests of northern New England also declined during the period their populations were monitored (1934–1987). Eight (44%) of the species that declined are associated with early successional habitats, and these species consistently exhibited population declines during the 1950s. The reduction of early successional species may be extended in space and time by current land uses that fragment and isolate patches of habitat. Ownership patterns of forest lands in New England (excluding Maine) reveal 88% private ownership with an average holding of 10 ha. This suggests that large tracts of early successional habitats will be restricted to industrial and state/national forests. Although even-aged management of a portion of these forests may be prerceived as incompatible with area-sensitive and interior species, clustering of clearcuts and maintaining large tracts of mature habitats could sustain diverse populations of forest vertebrates. Resumen: A diferencia de otras regiones en Norte America, los habitats boscosos en Nueva Inglattera se han incrementado substancialmente en los ultimos 100 anos. La proporcion de tierra cubierta por bosques en New Hampshire fue del 47 % en 1880 y del 87% en 1980. Este incremento fue, en gran medida, el resultado de un abandono a nivel regional de granjas y la subsecuente colonizacion de estas tierras por un crecimiento secundario de bosques. Yo examine la secuencia del abandono de las granjas, la colonizacion de los bosques y la maduracion de los bosques que ha ocurrido en New Hampshire en relacion con los cambios en la abundancia y distribucion de un grupo de mamiferos y pajaros que han sufrido declinaciones substanciales. Un patron modelado de sucesion secundaria resulto en la disponibilidad de aproximadamente 195,000 ha de habitats serales tempranos (10–25 anos despues del abandono) entre 1905 y 1940. Subsecuentemente, hacia 1960, estos habitats, maduraron hacia bosques de canopeo cerrado. Conjuntamente con la pardida de habitats sucesionales tempranos, las poblaciones de conejos (Sylvilagus transitionalis) de Nueva Inglaterra decrecieron de una distribucion aparentemente continua a traves del 60% de New Hampshire, a una poblacion fragmentada que ocupa < 20% del estado. Los “bobcats” (Felis rufus) respondieron funcionalmente (S. transitionalis en dieta; 1951–54 = 43% versus 1961–64 = 10%) y numericamente (media anual de la captura de Linces: 1951–54 = 350, 1965–69 = 36) a cambios en la abundancia de conejos. Dieciocho de las 26 especies de paserinidos migratorios que anidan en los bosques del norte de Nueva Inglaterra tambien declinaron durante el periodo en que la poblacion fue monitoreada (1934–87). Ocho (44%) de las especies que declinaron estan asociadas con habitats sucesionales tempranos, y estas especies consistentemente exhibieron declinaciones durante los anos 50. La reduccion de especies sucesionales tempranas puede ser extendida (en espacio y tiempo) por los usos actuales de la tierra que fragmentan y aislan los patches de habitat. Los patrones de tenencia de tierra de bosques en Nueva Inglaterra (excluyendo Maine, 88% en manos privadas con una media de tenencia de 10 ha) sugieren que grandes extensiones de habitats sucesionales tempranos van a estar restringidos a usos industriales y reservas estatales/nacionales. Aunque un manejo con stands de la misma edad de porciones de estos bosques puede ser percibido como incompatible con especies sensibles al area y con especies interiores, el agrupamiento de areas taladas y el mantenimiento de grandes extensiones de habitats maduros pueden sustentar poblaciones diversas de vertebrados del bosque.

Bipolar Changes in Atmospheric Circulation During the Little Ice Age

Abstract: Annually dated ice cores from Siple Dome, West Antarctica, and central Greenland indicate that meridional atmospheric circulation intensity increased in the polar South Pacific and North Atlantic at the beginning (∼1400 A.D.) of the most recent Holocene rapid climate change event, the Little Ice Age (LIA). As deduced from chemical concentrations at these core sites, the LIA was characterized by substantial meridional circulation strength variability, and this variability persists today despite strong evidence for an end to LIA cooling. Thus, increased late 20th century storm variability may be in part a result of the continuation of these climatic fluctuations.

Biological responses to disturbance from simulated deep-sea polymetallic nodule mining

Abstract: Commercial-scale mining for polymetallic nodules could have a major impact on the deep-sea environment, but the effects of these mining activities on deep-sea ecosystems are very poorly known. The first commercial test mining for polymetallic nodules was carried out in 1970. Since then a number of small-scale commercial test mining or scientific disturbance studies have been carried out. Here we evaluate changes in faunal densities and diversity of benthic communities measured in response to these 11 simulated or test nodule mining disturbances using meta-analysis techniques. We find that impacts are often severe immediately after mining, with major negative changes in density and diversity of most groups occurring. However, in some cases, the mobile fauna and small-sized fauna experienced less negative impacts over the longer term. At seven sites in the Pacific, multiple surveys assessed recovery in fauna over periods of up to 26 years. Almost all studies show some recovery in faunal density and diversity for meiofauna and mobile megafauna, often within one year. However, very few faunal groups return to baseline or control conditions after two decades. The effects of polymetallic nodule mining are likely to be long term. Our analyses show considerable negative biological effects of seafloor nodule mining, even at the small scale of test mining experiments, although there is variation in sensitivity amongst organisms of different sizes and functional groups, which have important implications for ecosystem responses. Unfortunately, many past studies have limitations that reduce their effectiveness in determining responses. We provide recommendations to improve future mining impact test studies. Further research to assess the effects of test-mining activities will inform ways to improve mining practices and guide effective environmental management of mining activities.

Transnational Climate Change Governance

Abstract: The world of climate politics is increasingly no longer confined to the activities of national governments and international negotiations. Critical to this transformation of the politics of climate change has been the emergence of new forms of transnational governance that cut across traditional state-based jurisdictions and operate across public and private divides. This book provides the first comprehensive, cutting-edge account of the world of transnational climate change governance. Co-authored by a team of the world's leading experts in the field and based on a survey of sixty case studies, the book traces the emergence, nature and consequences of this phenomenon, and assesses the implications for the field of global environmental politics. It will prove invaluable for researchers, graduate students and policy makers in climate change, political science, international relations, human geography, sociology and ecological economics.

A Model for Spectral and Compositional Variability at High Energies in Large, Gradual Solar Particle Events

Abstract: Shocks driven by fast coronal mass ejections (CMEs) are generally believed to be the dominant accelerators in large, gradual solar energetic particle (SEP) events. A key challenge for this notion has been the highly variable spectral and compositional characteristics of these events above a few tens of MeV per nucleon. We have recently proposed that this variability results from the interplay of two factors: evolution in the shock-normal angle as the shock moves outward from the Sun; and a compound seed population, typically comprising at least suprathermals from the corona (or solar wind) and suprathermals from flares. We present here a simple analytical implementation of these ideas. Our calculations semiquantitatively reproduce key features of the observed variability, including spectral morphologies and energy dependence in Fe/O, 3He/4He, and mean ionic charges, in ways that are consistent with correlations in the data. The model makes a prediction for the average high-energy Fe/O enhancement that is borne out by 30 years of observations; the model also provides a quantitative explanation for the Breneman & Stone fractionation effect, a fundamental but previously unexplained aspect of SEP phenomenology. Our calculations must be bolstered by future efforts incorporating realistic CME-shock simulations and a rigorous treatment of particle transport. Suprathermal densities in the corona, as well as details of the injection process at shocks of arbitrary obliquity, require further investigation. Nevertheless, these first results suggest a comprehensive framework for understanding the complexity of high-energy variability in terms of shock physics for most, if not all, large SEP events.