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

Gestionar contradicciones : los dilemas inherentes a la construcción posbélica del estado

Este documento es la traducción de un policy paper de Roland Paris y Timothy D. Sisk para la International Peace Academy (ahora, International Peace Institute, IPI). La publicación original en inglés es: Managing Contradictions: The Inherent Dilemmas of Postwar Statebuilding. IPA Policy Papers. Nueva York: IPA, 11/2007.La construcción del estado se ha convertido en un asunto central de las operaciones multi-dimensionales de paz llevadas a cabo en sociedades devastadas por la guerra. Pero los esfuerzos para construir instituciones estatales legítimas y efectivas están repletos de tensiones y contradicciones. Entenderlas es esencial para poder anticipar muchos de los problemas prácticos a los que se enfrentan las agencias internacionales en el proceso de la construcción del estado, así como para vislumbrar estrategias de construcción del estado mejor adaptadas y más efectivas de cara a misiones futuras

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

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)..

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

A Bio-Inspired Swellable Microneedle Adhesive for Mechanical Interlocking with Tissue

Achieving significant adhesion to soft tissues while minimizing tissue damage poses a considerable clinical challenge. Chemical-based adhesives require tissue-specific reactive chemistry, typically inducing a significant inflammatory response. Staples are fraught with limitations including high-localized tissue stress and increased risk of infection, and nerve and blood vessel damage. Here, inspired by the endoparasite Pomphorhynchus laevis which swells its proboscis to attach to its host’s intestinal wall, we have developed a biphasic microneedle array that mechanically interlocks with tissue through swellable microneedle tips, achieving ~ 3.5 fold increase in adhesion strength compared to staples in skin graft fixation, and removal force of ~ 4.5 N/cm2 from intestinal mucosal tissue. Comprising a poly(styrene)-block-poly(acrylic acid) swellable tip and non-swellable polystyrene core, conical microneedles penetrate tissue with minimal insertion force and depth, yet high adhesion strength in their swollen state. Uniquely, this design provides universal soft tissue adhesion with minimal damage, less traumatic removal, reduced risk of infection and delivery of bioactive therapeutics

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