78 research outputs found
Abiotic drivers of Chihuahuan Desert plant communities
Within grasslands, precipitation, fire, nitrogen (N) addition, and extreme temperatures influence community composition and ecosystem function. The differential influences of these abiotic factors on Chihuahuan Desert grassland communities was examined within the Sevilleta National Wildlife Refuge, located in central New Mexico, U.S.A. Although fire is a natural disturbance in many grasslands, fire during drought temporarily increased forb cover and decreased grass cover for several years. The seasonal timing of fire was not important, rather community recovery was more influenced by the persistent drought conditions. N deposition is increasing worldwide due to human activities, and although additional N increases productivity and decreases diversity in most terrestrial systems, community responses were variable in Chihuahuan Desert grasslands. During above-average precipitation, N addition greatly increased aboveground productivity but did not influence belowground productivity or community composition. During average or below-average precipitation, no effects of N addition on the grassland community occurred. Although human activities provide grasslands with extra N, soil microorganisms help plants naturally acquire N. The activity of soil microbes, and in turn nutrient availability for plants, responded to rainfall events and the proximity to plants and varied throughout the monsoon growing season. Lastly, shrub encroachment is converting grasslands to shrublands and may possibly be reversed by extreme climate events. Following an extreme cold event at the boundary between Chihauhuan Desert grass- and shrublands, shrubs were damaged but not killed by cold temperatures. Therefore a single cold event might not be influential enough to reverse shrub encroachment. Many factors, including fire, N addition, and shrub encroachment, influence Chihauhaun Desert grasslands, but the magnitude of influence is strongly regulated by precipitation. Some factors, such as fire seasonality and N addition, were not influential during drought and only changed communities when water limitations were alleviated, while other factors, such as extreme cold temperatures, influence communities regardless of soil water status. As humans continue to change abiotic factors and natural environments, it is important to understand how plant communities respond to changing conditions
The ABC\u27s of HIV: When Just Say No Is Not Enough-Queer Critique of AIDS Policy
This paper will critique the United States\u27 AIDS policy, both domestic and international. I demonstrate how queer theorists have used Jacques Lacan\u27s concepts of jouissance and the unconscious desire to suggests ways in which the current policy has dangerous implications for real people, for public health, and human rights. I reveal how the problem of rising HIV infection is not due to the lack of availability of safer-sex information, but rather it is a problem of execution: the Religious Right\u27s ideology inscribed in our public health policy. Finally, I wish to expose how people in this country and others are increasingly denied the necessary information and services to prevent HIV transmission. These people are not even given the choice of execution because they are sheltered from the information necessary to make that choice to prevent one\u27s self from HIV/AIDS. I hope to demonstrate how our ultra, socially conservative administration and its constituency preclude effective HIV/AIDS treatment and prevention
Spatiotemporal dynamics of lianas during 50 years of succession to temperate forest
Although they are important components of forest communities, the general ecology and spatiotemporal patterns of temperate lianas during forest regeneration are largely unknown. The dependence of lianas on other plants for physical support makes them a potentially important driver of community dynamics. We examined 50 years of vegetation data from an old-field succession study to determine the dynamics and community controls on liana expansion within the Piedmont region of New Jersey, USA. Four lianas, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp., occurred in enough abundance for detailed analyses. In general, liana cover peaked during mid-succession (20–30 years post-abandonment) when community composition was mostly herbaceous with scattered trees and shrubs. Liana cover began to decrease as trees became dominant and the canopy closed. Temporal patterns of cover dynamics of abundant species indicated three early- and one late-successional liana species within the community. In contrast to cover, frequency of lianas increased throughout succession, indicating that liana populations persisted despite dramatic declines in cover for the three early-successional species. Temporal dynamics between native and nonnative lianas were similar but spatially distinct as cover of native species dispersed and expanded near the forest edge while the nonnative species preferentially grew far from the forest. These dynamics indicate that successional processes may ultimately lead to the decline of most lianas. However, the persistence of lianas as high numbers of suppressed individuals suggests that they may rebound quickly following canopy disturbance
Witches, Wizards and Potions: The Christian Nature of the Harry Potter Best Selling Novels
The magic in Harry Potter is not “sorcery” or invocational magic; it is incantational magic. Most of the objections of the Harry Potter novels are from people who have not read the books. The author, J. K. Rowling is more interested in alchemy than magic and uses Christian symbols and careful naming throughout the books, thereby delivering difficult truths to a postmodern audience in a way that they accept as givens, ideas they would otherwise laugh at. Harry\u27s devotion to the truth and to what is right leads him to disregard the pain he may encounter in pursuing these great ends. He emulates courage, love and persistence in his fight against evil
An Organizational Analysis of the Processing Services Division, Thomas Cooper Library, University of South Carolina
This report presents results of an organizational analysis conducted of the Processing Services Division of Thomas Cooper Library at the University of South Carolina. The authors reviewed a selection of the recent literature relevant to technical services. The authors also compiled and analyzed the recent history, organization structure, mission, goals, and objectives for Thomas Cooper Library and the Processing Services Division. The report presents results from twelve interviews with Division staff, management, and Library administration; an exploration of catalog use statistics; and a staff time allocation study. Recommendations were made regarding the organizational structure, incorporating a team approach, physical space considerations, training and development, and use of metrics
Indexes: The Heart of Research
This article, originally a presentation at ACL’s 2023 conference, will delineate the enduring value of indexes for librarians and researchers alike, giving some examples of how indexes have evolved in a technology-driven age
Flying Solo
This article is designed to assist solo librarians in thinking through their libraries, responsibilities,clientele, support personnel, and work habits in order to determine best practices to maximize their professional and personal effectiveness
Grassland productivity limited by multiple nutrients
Terrestrial ecosystem productivity is widely accepted to be nutrient limited1. Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)2,3, the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized4,​5,​6,​7,​8. However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment
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