One-sided edge responses in forest birds following restoration treatments

Abstract. We studied the effects of the edge between two forest types on the probability of occurrence of seven species of birds and found that four responded to the edge on only one side. Over 4 years, we measured the responses of forest birds to the edge between ponderosa pine forest undergoing restoration and neighboring untreated stands. Of the seven species analyzed, one occurred most frequently near the edge. Of the remaining six, none responded to the edge in the treated forest, but four responded in the untreated forest. Relatively few studies have examined abundance changes on both sides of an edge between distinct habitats that support similar bird communities, and predictive models of edge effects used for mapping animal responses to habitat change often assume that animal abundance will change on both sides of this sort of edge, declining near the edge in the habitat in which the species is most abundant and increasing near the edge in the habitat in which the species is less abundant. One-sided edge effects, such as those we have documented, may lead to markedly different predictions of the effects of habitat change on bird abundance in heterogeneous landscapes. , Resumen. Estudiamos los efectos de borde entre dos tipos de bosque en la probabilidad de ocurrencia de siete especies de aves y encontramos que cuatro respondieron al borde de un solo lado. Durante cuatro años medimos las respuestas de aves de bosque al borde entre un bosque de pino ponderosa bajo restauración y rodales colindantes sin tratar. De las siete especies analizadas, una presentó mayor frecuencia cerca del borde. De las seis restantes, ninguna respondió al borde en el bosque tratado, pero cuatro mostraron una respuesta al bosque sin tratar. Relativamente pocos estudios han examinado los cambios en la abundancia en ambos lados de un borde entre habitats distintos que albergan comunidades de aves similares. Además, los modelos predictivos de efecto de borde utilizados para mapear las respuestas de animales al cambio de hábitat a menudo asumen que la abundancia animal cambiará en ambos lados de este tipo de borde, disminuyendo cerca del borde en el hábitat en el cual la especie es más abundante e incrementado cerca del borde en el habitat en el cual la especie es menos abundante. Los efectos de borde de un solo lado, tales como los que documentamos, pueden llevar a predicciones marcadamente diferentes de los efectos de cambio de habitat en la abundancia de aves en paisajes heterogéneos

Linking ecosystem health indicators and collaborative management: A systematic framework to evaluate ecological and social outcomes

Collaborative management has gained popularity across the United States as a means of addressing the sustainability of mixed-ownership landscapes and resolving persistent conflicts in public lands management. At the same time, it has generated skepticism because its ecological and social outcomes are seldom measured. Evaluating the success of collaborative efforts is difficult because frameworks to assess on-the-ground outcomes are poorly developed or altogether lacking. Ecosystem health indicators are valuable tools for evaluating site-specific outcomes of collaboration based on the effects of collaboration on ecological and socioeconomic conditions. We present the holistic ecosystem health indicator, a promising framework for evaluating the outcomes of collaborative processes, which uses ecological, social, and interactive indicators to monitor conditions through time. Finally, we draw upon our experience working with the Diablo Trust, a community-based collaborative group in northern Arizona, USA, to illustrate the development of an indicator selection model generated through a stakeholder-driven process

Plant community responses to livestock grazing: an assessment of alternative management practices in a semi-arid grassland

One of the most prevalent land-use practices in the American Southwest, and one of the most contentious issues among land-use policymakers, is the grazing of domestic livestock. In an effort to contribute scientific understanding to this debate, we have designed experiments comparing the effects of alternative grazing regimes on plant communities. In a semiarid grassland of northern Arizona, we have implemented a replicated study of four treatments: (1) low-intensity, long-duration grazing rotations; (2) highintensity, short-duration rotations (Holistic Resource Management-style grazing); (3) very high intensity, short duration grazing (to simulate herd impact); and (4) livestock exclosure. Beginning in 1997, we conducted annual surveys of the plant communities with Modified-Whittaker plots. Preliminary results suggest that interannual variability affecting all study plots is high, and that these alternative management strategies do not have dramatic short-term effects on the plant community. Comparisons of native and exotic species richness, as well as ground cover of grasses and forbs, showed no consistent pattern due to treatment over a 3-year period. Our results suggest that the effects of alternative livestock management styles in the semiarid grasslands studied are modest, at least in the short-term, and that future plant monitoring programs would greatly benefit from a multiscale sampling design

Assessing impacts of alternative livestock management practices: raging debates and a role for science

Grazing of domestic livestock is the most pervasive and persistent human impact on the grasslands and shrublands of the Colorado Plateau. Impacts on ecosystem function and biological diversity arc thought to be great, but few studies have attempted to characterize such effects and compare the impacts of alternative livestock management practices. The dearth of pertinent, defensible information has contributed to the polarization of ranching and environmental interests, and has exacerbated what is one of the most contentious social issues in the southwestern USA. We discuss the role of ecological science in deriving and disseminating information that will help focus and perhaps resolve the impasse over grazing impacts and other natural resource issues. Specifically, we describe results of our involvement in "management teams" that include ranchers, environmentalists, public servants, and interested citizens, and how this collaborative process has helped shape an experimental research program that would be impossible to execute without the involvement of divergent interests in the grazing debate. Claims of various interest groups are reformulated as testable hypotheses, and a research design is presented

Reframing the grazing debate: Evaluating ecological sustainability and bioregional food production

The semi-arid grasslands of the Colorado Plateau are productive, diverse, and extensive ecosystems. The majority of these ecosystems have been altered by human land use, primarily through the grazing of domestic livestock, yielding a plethora of environmental and social consequences that are tightly interconnected. From an agroecological perspective, untangling these issues requires both an understanding of the role of livestock grazing in bioregional food production and the effect of that grazing on ecological sustainability. To address the former, we discuss the importance of cattle ranching as a bioregional food source, including estimates of meat production and water use in Arizona. To address the latter, we present data from a long-term project addressing changes in native plant community composition, under a range of alternative livestock management strategies. Our study site near Flagstaff, AZ includes four different management treatments: (1) conventional low-intensity, long-duration grazing rotations; (2) high-intensity, short-duration rotations; (3) very high-impact, very short-duration grazing (to simulate herd impact); and, (4) livestock exclosure. Preliminary results suggest belowground properties are responding more quickly to grazing treatments than aboveground properties. Particular response variables, such as cyanobacteria and diatoms, show a marked short-term response to very high-impact, short-duration grazing, but long-term implications are as yet unknown

Analysis of small-diameter wood supply in northern Arizona - Final report

Forest management to restore fire-adapted ponderosa pine ecosystems is a central priority of the Southwestern Region of the USDA Forest Service. Appropriately-scaled businesses are apt to play a key role in achieving this goal by harvesting, processing and selling wood products, thereby reducing treatment costs and providing economic opportunities. The manner in which treatments occur across northern Arizona, with its multiple jurisdictions and land management areas, is of vital concern to a diversity of stakeholder groups. To identify a level of forest thinning treatments and potential wood supply from restoration byproducts, a 20-member working group representing environmental non-governmental organizations (NGOs), private forest industries, local government, the Ecological Restoration Institute at Northern Arizona University (NAU), and state and federal land and resource management agencies was assembled. A series of seven workshops supported by Forest Ecosystem Restoration Analysis (ForestERA; NAU) staff were designed to consolidate geographic data and other spatial information and to synthesize potential treatment scenarios for a 2.4 million acre analysis area south of the Grand Canyon and across the Mogollon Plateau. A total of 94% of the analysis area is on National Forest lands. ForestERA developed up-to-date remote sensing-based forest structure data layers to inform the development of treatment scenarios, and to estimate wood volume in three tree diameter classes of 16" diameter at breast height (dbh, 4.5' above base). For the purposes of this report, the group selected a 16" dbh threshold due to its common use within the analysis landscape as a break point differentiating "small" and "large" diameter trees in the ponderosa pine forest type. The focus of this study was on small-diameter trees, although wood supply estimates include some trees >16" dbh where their removal was required to meet desired post-treatment conditions.4 There was no concurrence within the group that trees over 16" dbh should be cut and removed from areas outside community protection management areas (CPMAs)..

Independent large scale duplications in multiple M. tuberculosis lineages overlapping the same genomic region

Mycobacterium tuberculosis, the causative agent of most human tuberculosis, infects one third of the world's population and kills an estimated 1.7 million people a year. With the world-wide emergence of drug resistance, and the finding of more functional genetic diversity than previously expected, there is a renewed interest in understanding the forces driving genome evolution of this important pathogen. Genetic diversity in M. tuberculosis is dominated by single nucleotide polymorphisms and small scale gene deletion, with little or no evidence for large scale genome rearrangements seen in other bacteria. Recently, a single report described a large scale genome duplication that was suggested to be specific to the Beijing lineage. We report here multiple independent large-scale duplications of the same genomic region of M. tuberculosis detected through whole-genome sequencing. The duplications occur in strains belonging to both M. tuberculosis lineage 2 and 4, and are thus not limited to Beijing strains. The duplications occur in both drug-resistant and drug susceptible strains. The duplicated regions also have substantially different boundaries in different strains, indicating different originating duplication events. We further identify a smaller segmental duplication of a different genomic region of a lab strain of H37Rv. The presence of multiple independent duplications of the same genomic region suggests either instability in this region, a selective advantage conferred by the duplication, or both. The identified duplications suggest that large-scale gene duplication may be more common in M. tuberculosis than previously considere

Human papillomavirus infection in “young” versus “old” patients with squamous cell carcinoma of the head and neck

Background Human papillomavirus (HPV) represents a potential risk factor for squamous cell cancer of the head and neck (SCCHN). We evaluated the prevalence of HPV DNA in patients with SCCHN diagnosed at the University of Michigan from 1994–1996. Methods Patients were stratified by age at diagnosis as “young” (50 years; median, 66). Fourteen “young” and 14 “old” were matched for tumor site, and 4 additional “old” patients were included. Specimens were analyzed by polymerase chain reaction for HPV DNA using 2 sets of consensus primers. HPV sequences were confirmed by Southern blot hybridization and typed with type-specific probes. Results Overall, 15 of 32 (46.9%) samples contained HPV sequences. HPV 16 was detected in 9 of 15 (60%), HPV-18 in 1 of 15 (6.6%), and 5 of 15 (33.3%) remained untyped by multiple methods. When stratified, 7 of 14 (50%) “young” were HPV-positive compared with 8 of 18 (44.4%) “old” ( p = .76). Survival in patients with HPV-positive SCCHN was significantly longer than that for HPV-negative patients. Conclusions The incidence of HPV in “young” versus “old” is not significantly different, suggesting similar roles for both groups. Patients with HPV-positive tumors may have a survival advantage relative to patients with HPV-negative tumors. © 2000 John Wiley & Sons, Inc. Head Neck 22: 649–657, 2000.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35115/1/2_ftp.pd

Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians

Effects of co-administered dexamethasone and diclofenac potassium on pain, swelling and trismus following third molar surgery

BACKGROUND: The apparent interactions between the mechanisms of action of non-steroidal anti-inflammatory drugs (NSAIDS) and steroids suggest that co-therapy may provide beneficial inflammatory and pain relief in the absence of side effects. The aim of the study was to compare the effect of co-administered dexamethasone and diclofenac potassium (diclofenac K) with diclofenac K alone on the postoperative pain, swelling and trismus after surgical removal of third molars. PATIENTS AND METHODS: A prospective randomized double-blind study was conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Nigeria. A total of 100 patients were randomly allocated to two treatment groups of dexamethasone (prophylactic 8 mg and postoperative 4 mg IV) and diclofenac K (50 mg Oral before and after surgery), and diclofenac K alone (as with first group). The overall analgesic efficacy of the drug combinations was assessed postoperatively by determination of pain intensity using a category rating scale. Facial swelling was measured using a tape measure placed from tragus to gonion to tragus, while interincisal mouth-opening of patients was measured using a vernier calibrated caliper pre-operatively and post-operatively. RESULTS: Co-administration of dexamethasone and diclofenac K was significantly superior to diclofenac alone for the relief of pain (P < 0.05), and facial swelling up to post-operative 48 hour (P < 0.05). However, there was no significant difference for trismus relief between the two medication protocols (P > 0.05). CONCLUSION: This study illustrates enhanced effects of co-administered dexamethasone and diclofenac K on short-term post-operative pain and swelling, compared to diclofenac potassium alone in third molar surgery