Cascading effects of a highly specialized beech-aphid–fungus interaction on forest regeneration

Specialist herbivores are thought to often enhance or maintain plant diversity within ecosystems, because they prevent their host species from becoming competitively dominant. In contrast, specialist herbivores are not generally expected to have negative impacts on non-hosts. However, we describe a cascade of indirect interactions whereby a specialist sooty mold (Scorias spongiosa) colonizes the honeydew from a specialist beech aphid (Grylloprociphilus imbricator), ultimately decreasing the survival of seedlings beneath American beech trees (Fagus grandifolia). A common garden experiment indicated that this mortality resulted from moldy honeydew impairing leaf function rather than from chemical or microbial changes to the soil. In addition, aphids consistently and repeatedly colonized the same large beech trees, suggesting that seedling-depauperate islands may form beneath these trees. Thus this highly specialized three-way beech-aphid–fungus interaction has the potential to negatively impact local forest regeneration via a cascade of indirect effects

Implementing GitHub Actions Continuous Integration to Reduce Error Rates in Ecological Data Collection

Accurate field data are essential to understanding ecological systems and forecasting their responses to global change. Yet, data collection errors are common, and data analysis often lags far enough behind its collection that many errors can no longer be corrected, nor can anomalous observations be revisited. Needed is a system in which data quality assurance and control (QA/QC), along with the production of basic data summaries, can be automated immediately following data collection. Here, we implement and test a system to satisfy these needs. For two annual tree mortality censuses and a dendrometer band survey at two forest research sites, we used GitHub Actions continuous integration (CI) to automate data QA/QC and run routine data wrangling scripts to produce cleaned datasets ready for analysis. This system automation had numerous benefits, including (1) the production of near real-time information on data collection status and errors requiring correction, resulting in final datasets free of detectable errors, (2) an apparent learning effect among field technicians, wherein original error rates in field data collection declined significantly following implementation of the system, and (3) an assurance of computational reproducibility—that is, robustness of the system to changes in code, data and software. By implementing CI, researchers can ensure that datasets are free of any errors for which a test can be coded. The result is dramatically improved data quality, increased skill among field technicians, and reduced need for expert oversight. Furthermore, we view CI implementation as a first step towards a data collection and analysis pipeline that is also more responsive to rapidly changing ecological dynamics, making it better suited to study ecological systems in the current era of rapid environmental change

allodb: An R package for biomass estimation at globally distributed extratropical forest plots

Allometric equations for calculation of tree above-ground biomass (AGB) form the basis for estimates of forest carbon storage and exchange with the atmosphere. While standard models exist to calculate forest biomass across the tropics, we lack a standardized tool for computing AGB across boreal and temperate regions that comprise the global extratropics. Here we present an integrated R package, allodb, containing systematically selected published allometric equations and proposed functions to compute AGB. The data component of the package is based on 701 woody species identified at 24 large Forest Global Earth Observatory (ForestGEO) forest dynamics plots representing a wide diversity of extratropical forests. A total of 570 parsed allometric equations to estimate individual tree biomass were retrieved, checked and combined using a weighting function designed to ensure optimal equation selection over the full tree size range with smooth transitions across equations. The equation dataset can be customized with built-in functions that subset the original dataset and add new equations. Although equations were curated based on a limited set of forest communities and number of species, this resource is appropriate for large portions of the global extratropics and can easily be expanded to cover novel forest types

Temporal population variability in local forest communities has mixed effects on tree species richness across a latitudinal gradient

Among the local processes that determine species diversity in ecological communities, fluctuation‐dependent mechanisms that are mediated by temporal variability in the abundances of species populations have received significant attention. Higher temporal variability in the abundances of species populations can increase the strength of temporal niche partitioning but can also increase the risk of species extinctions, such that the net effect on species coexistence is not clear. We quantified this temporal population variability for tree species in 21 large forest plots and found much greater variability for higher latitude plots with fewer tree species. A fitted mechanistic model showed that among the forest plots, the net effect of temporal population variability on tree species coexistence was usually negative, but sometimes positive or negligible. Therefore, our results suggest that temporal variability in the abundances of species populations has no clear negative or positive contribution to the latitudinal gradient in tree species richness

Age-Friendly Ecosystems: Expert Voices from the Field

(1) Background: With the growth of the age-friendly movement, age-friendly ecosystems (AFE) garnered more attention. The successful development of an AFE is contingent on unified efforts across different stakeholders; however, limited efforts were made to help create a common understanding of the necessary components of an AFE. (2) Methodology: In response, The John A. Hartford Foundation and The Age-Friendly Institute hosted a series of convenings of international experts to identify a working definition of the characteristics composing an AFE. The goal of these convenings was to provide a foundation on which to unite cross-sector age-friendly work. (3) Results: This paper discussed the findings of the convenings and provided a framework from which future age-friendly work must draw upon. (4) Conclusions: This paper presented a necessary change in how we conceive AFEs

Trends in use of the only Food and Drug Administration-approved commercially available fenestrated endovascular aneurysm repair device in the United States

BACKGROUND: Fenestrated endografts are customized, patient-specific, endovascular devices with potential to significantly reduce morbidity and mortality of short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. The Zenith fenestrated endovascular graft (ZFEN) for abdominal aortic aneurysms (Cook Medical, Bloomington, Ind), Food and Drug Administration-approved in 2012, remains the only fenestrated device available in the United States. This technology is among the most technically complex catheter-based procedures and, therefore, inherently associated with serious risk for device-related complications. We sought to define patterns of physician and hospital adoption of ZFEN. METHODS: Deidentified datasets containing numbers of physicians trained, orders by physicians and hospitals, and designs (fenestration/scallop configuration) was provided for U.S. ZFEN devices ordered (April 2012-August 2015). We evaluated the number of physicians trained, the number of devices ordered, hospital characteristics, and fenestration/scallop design configurations. Cook Medical assembled the datasets but played no role in study design, analysis, or interpretation of data. RESULTS: Between April 2012 and August 2015, 553 physicians attended formal ZFEN training sessions, 388 (70%) of whom ordered a total of 2669 devices. An increase in orders per month (nine in June 2012 and 91 in August 2015, 911% growth; P \u3c .001) and in number of physicians ordering per month (eight in June 2012 and 62 in August 2015, 675% growth; P \u3c .001) was observed. Teaching hospitals, representing all U.S. regions (Midwest 927, 35%; South 799, 30%; Northeast 547, 20%; West 396, 15%), accounted for 1703 (64%) ZFEN orders. Of 553 trained physicians, 165 (30%) ordered no devices, 116 (21%) ordered 1 device, 144 (26%) ordered 2-5 devices, 61 (11%) ordered 6-10 devices, 39 (7%) ordered 11-20, and 28 (5%) ordered \u3e 20 devices. For physicians contributing \u3e 6 months of data (n = 336), the average number of devices ordered per year was three (standard deviation, 4); 272 (81%) ordered \u3c /= 5 devices/year, 15 (4.5%) ordered 11-20 devices/year, and 3 (0.9%) ordered \u3e 20 devices/year. Of devices with design details available (2618 of 2669; 98%), most common designs were 2 small fenestrations/1 scallop (1443; 55%), 2 small fenestrations/1 large fenestration (568; 22%), 1 small fenestration/1 scallop (173, 6.6%), and 2 small fenestrations (169; 6.5%). The average number of target vessels incorporated in each design was 2.7/device; 2071 (79%) incorporated three, 398 (15%) incorporated two. CONCLUSIONS: Since 2012, ZFEN has demonstrated a ninefold increase in monthly orders, with 553 physicians trained. Unlike the experience of rapid dissemination seen with infrarenal endografts, only 28 (5%) physicians have ordered \u3e 20, whereas 165 (30%) have ordered none, and 272 (81%) ordered \u3c /= 5 devices/year. Assuming that volume, in general, correlates with outcomes, this adoption pattern raises questions whether fenestrated technology should be regionalized to high-volume centers

Appendix C. Supplemental tables describing environmental variables in each forest stand, tests for phylogenetic trait conservation, and comparisons of native and introduced species.

Supplemental tables describing environmental variables in each forest stand, tests for phylogenetic trait conservation, and comparisons of native and introduced species

Appendix B. Supplemental figures showing patterns for each forest stand, environmental coefficients, and results from alternative models.

Supplemental figures showing patterns for each forest stand, environmental coefficients, and results from alternative models

Appendix A. Detailed description and likelihood function for the Bayesian hierarchical hurdle model.

Detailed description and likelihood function for the Bayesian hierarchical hurdle model

Supplement 1. All python/STAN code, including Bayesian hierarchical model, used in the analysis.

<h2>File List</h2><div> <p><a href="Supplement_Model_REPORT.txt">Supplement_Model_REPORT.txt</a> (MD5: ea2e3f2c6f17b80e7d3b55eff718d9d3) </p> </div><h2>Description</h2><div> <p>Supplement_Model_REPORT.txt contains all Python/STAN code needed to replicate the analysis and hierarchical model.</p> </div