Old-growth forests: what do we know about their ecology and management in the Southwest and Rocky Mountain Regions?

This paper reviews the science and management of old-growth forests and summarizes discussions among 30 participants at a workshop in Portal, Arizona, March 9-13, 1992. Concepts of old-growth forests -- the perceptions, values, definitions, characteristic features, ecological functions, and landscape importance -- vary widely. Because concepts are complex, scientists, resource managers, and the public will continue to bring old growth into clearer focus as knowledge is gained. Regardless of the concepts chosen for viewing old growth, on an ecological basis old-growth forests represent a stage in forest development characterized by certain structural, functional, and compositional features. Managers are concerned with how much old growth exists, where it is, and what condition it is in. Improved inventory procedures are needed, including both remote-sensing technology and conventional on-the-ground procedures. Where will tomorrows old growth be found, and how soon will younger stands attain old-growth conditions? Pathways of forest succession into old growth are poorly known for most forest types. We need better knowledge about how disturbances such as fire, insects, forest diseases, exotic organisms, pollution, and changing climate affect old growth and forest succession. Allocation is another problem for planners. How much old growth is enough? How many stands should be old growth at any given time, what are the sizes and shapes of the stands, and how should they be distributed over various forest habitat types? How should old-growth stands be connected by forest corridors, and how are their functions modified by their setting? These are difficult but researchable questions. Lacking clear answers to these questions, should managers find clues from pre-European settlement forests? Is it reasonable to attempt to restore forests to their natural conditions? Or have changes since settlement precluded returning to earlier conditions? In this paper, we review our knowledge of the influence old-growth stands on biogeochemical cycles and the roles of wildlife, decomposer organisms, cryptozoans of logs and snags, and other kinds of hidden diversity. To what extent are the legacy of old trees and other genetic reserves in old-growth forests carried into the future? We know little about how present old-growth influences the development of future forest generations. We conclude by looking at some tools for old-growth management. How can managers use fire or silviculture to assure future old-growth supplies, while at the same time meeting present and future extractive demands? Can younger stands be treated to hasten their development into old growth, or can existing old growth be altered without seriously compromising old-growth value

An Ecological Basis for Ecosystem Management

This report was prepared by the Southwestern Regional Ecosystem Management Study Team composed of management and research biologists. The USDA Forest Service Southwestern Regions Regional Forester, Larry Henson, and the Rocky Mountain Forest and Range Experiment Station Director, Denver Burns, chartered this team to recommend an ecological basis for ecosystem management. This report is not intended to provide details on all aspects of ecosystem management; it simply provides information and makes recommendations for an ecological basis for ecosystem management. The report is not a decision document. It does not allocate resources on public lands nor does it make recommendations to that effect. The report of this Study Team may be relied upon as input in processes initiated under the National Environmental Policy Act (NEPA), National Forest Management Act (NFMA), Endangered Species Act (ESA), Administrative Procedures Act (APA), and other applicable laws. The information contained in this report is general in nature, rather than site specific. Implementation of ecosystem management and allocation of resources on Forest Service administered lands is the responsibility of the National Forest System in partnership with Forest Service Research and State and Private Forestry. Implementation is done through Forest and project plans that are subject to the NEPA process of disclosing the effects of proposed actions and affording the opportunity for public comment. The Southwestern Region follows a planning process for projects called Integrated Resource Management (IRM). The opinions expressed by the authors do not necessarily represent the policy or position of the U.S. Department of Agriculture, the Forest Service, The Nature Conservancy, or the Arizona Game and Fish Department. The Study Team acknowledges the valuable input of more than 50 individuals from various agencies, universities, professional organizations, and other groups who provided thoughtful comments of an earlier draft of this document. Some of their comments are included in Appendix 3

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Cultural variations in wellbeing, burnout and substance use amongst medical students in twelve countries

High levels of stress, burnout, and symptoms of poor mental health have been well known among practicing doctors for a number of years. Indeed, many health systems have formal and informal mechanisms to offer support and treatment where needed, though this varies tremendously across cultures. There is increasing evidence that current medical students, our doctors of the future, also report very high levels of distress, burnout, and substance misuse. We sampled large groups of medical students in 12 countries at the same time and with exactly the same method in order to aid direct comparison. 3766 students responded to our survey across five continents in what we believe is a global first. Our results show that students in all 12 countries report very high levels of ‘caseness’ on validated measures of psychiatric symptoms and burnout. Rates of substance misuse, often a cause of or coping mechanism for this distress, and identified sources of stress also varied across cultures. Variations are strongly influenced by cultural factors. Further quantitative and qualitative research is required to confirm our results and further delineate the causes for high rates of psychiatric symptoms and burnout. Studies should also focus on the implementation of strategies to safeguard and identify those most at risk