The vision of the Framework and NGSS requires important shifts in teaching approaches and instructional materials. We argue that this commitment to engaging learners in meaningful practice and ...supporting students' epistemic agency entails that we support coherence from the students' perspective. This coherence arises when students see their science work as making progress on questions and problems their classroom community has committed to address, rather than simply following directions from textbooks or teachers. We present an instructional model, storylines, to support this form of coherence. The storylines approach includes design principles for engaging students with phenomena and problems to elicit their own questions that teachers, with support of curriculum materials, use to guide the trajectory of their sensemaking. We describe how storylines organize cycles of engaging with phenomena, questions, and sensemaking to incrementally build, test, and revise explanatory models and design solutions. Storylines are supported by a collection of instructional routines and norms that provide strategies and tools to guide teachers' work with students around phenomena, questions, and sensemaking. The routines reflect strategies for eliciting questions from anchoring phenomena, navigation to engage students as partners in managing the direction of investigations, problematizing to help students find gaps in their work so far, and putting pieces together to support students in assembling what they have figured out. We present examples from elementary, middle, and high school storyline-based units awarded the NGSS design badge to illustrate the application of these design principles in the design and enactment of storyline-based units.
Biodiversity macroecology deals with the commonly measured variables of abundance, distribution, occupancy, and range size across two scales: the local (or α) and regional (γ). There are ca. 15 ...patterns consisting of the frequency distributions of the variables, variables as a function of area or sample size, and interrelationships between variables that appear to be very general if not close to universal. A number of links can be drawn between these patterns. In particular, I show that local communities can be seen as random samples of the regional pool, but only as a special form of sampling that is autocorrelated due to the spatial clumping of individuals within a species. I describe two distinct sets of mathematical machinery that can start with the regional species abundance distribution and then predict local species richness, local species abundance distributions, and β-diversity (in the form of species area relationships or decay of similarity with distance). I conclude by examining some of the implications of the fact that biodiversity patterns are linked by autocorrelated sampling.
New catalogue of Earth’s ecosystems McGill, Brian J.; Miller, Stephanie N.
Nature (London),
10/2022, Letnik:
610, Številka:
7932
Journal Article
Recenzirano
A tropical dry forest (Fig. 1a), distinguished by tall trees, many of which shed leaves during a relatively rain-free dry season, is in the same realm and biome as a tropical rainforest, but a ...different functional group (T1.2). ...although the emphasis on both vegetation structure and processes has always been implicit in the idea of biomes, IUCNGET brings this combination front and centre. IUCNGET has a model (see Fig. 1 of ref. 1) with five categories of processes (resource drivers, ambient environment/climate, disturbance regimes, biotic interactions and human activities) that generate the defining ecosystem properties (for example, vegetation structure, vegetation seasonality, productivity, biomass and diversity).
Background Reverse total shoulder arthroplasty (RTSA) has been indicated primarily for patients aged older than 65 years with symptomatic rotator cuff deficiency, poor function, and pain. However, ...conditions that benefit from RTSA are not restricted to an elderly population. This study evaluates a consecutive series of RTSA patients aged younger than 60 years. Methods We evaluated 36 shoulders (mean age, 54 years) at a mean follow-up of 2.8 years (range, 24-48 months). Of these shoulders, 30 (83%) had previous surgery, averaging 2.5 procedures per patient. The preoperative conditions compelling RTSA were as follows: failed rotator cuff repair (12), fracture sequelae (11), failed arthroplasty (5), instability sequelae (4), cuff tear arthropathy (CTA) (4), and rheumatoid arthritis (2). Follow-up examinations included range-of-motion and strength testing, as well as Single Assessment Numeric Evaluation, visual analog scale, Simple Shoulder Test, American Shoulder and Elbow Surgeons (ASES), and Constant scores. Preoperative and postoperative radiographs were reviewed for component loosening and scapular notching. Failure criteria were defined as undergoing revision, having gross loosening, or having an ASES score below 50. Results The mean Single Assessment Numeric Evaluation score improved from 24.4 to 72.0; the visual analog scale pain score improved from 6 to 2.1. The Simple Shoulder Test score improved from 1.4 to 6.2, and the ASES score improved from 31.4 to 65.8. Active forward elevation improved from 56° to 121°. The normalized postoperative mean Constant score was 54.3. In 9 patients (25.0%), we recorded an ASES score below 50, and these cases were considered failures. Conclusion RTSA can improve shoulder function in a younger, complex patient population with poor preoperative functional ability. This study's success rate was 75% at 2.8 years. This is a limited-goals procedure, and longer-term studies are required to determine whether similar results are maintained over time.
Disentangling the drivers of diversity gradients can be challenging. The Measurement of Biodiversity (MoB) framework decomposes scale-dependent changes in species diversity into three components of ...community structure: species abundance distribution (SAD), total community abundance, and within-species spatial aggregation. Here we extend MoB from categorical treatment comparisons to quantify variation along continuous geographic or environmental gradients. Our approach requires sites along a gradient, each consisting of georeferenced plots of abundance-based species composition data. We demonstrate our method using a case study of ants sampled along an elevational gradient of 28 sites in a mixed deciduous forest of the Great Smoky Mountains National Park, USA. MoB analysis revealed that decreases in ant species richness along the elevational gradient were associated with decreasing evenness and total number of species, which counteracted the modest increase in richness associated with decreasing spatial aggregation along the gradient. Total community abundance had a negligible effect on richness at all but the finest spatial grains, SAD effects increased in importance with sampling effort, and the aggregation effect had the strongest effect at coarser spatial grains. These results do not support the more-individuals hypothesis, but they are consistent with a hypothesis of stronger environmental filtering at coarser spatial grains. Our extension of MoB has the potential to elucidate how components of community structure contribute to changes in diversity along environmental gradients and should be useful for a variety of assemblage-level data collected along gradients.
Questions: Are patterns of intra- and inter-specific functional trait variation consistent with greater abiotic filtering on community assembly at high latitudes and elevations, and greater biotic ...filtering at low latitudes and elevations? Locations: Area de Conservación Guanacaste, Costa Rica; Santa Catalina Mountains, Arizona; Siskiyou Mountains, Oregon. Methods: We measured woody plant species abundance and a key functional trait associated with competition for resources and environmental tolerance (specific leaf area, SLA) along elevational gradients in low-latitude tropical (Costa Rica), mid-latitude desert (Arizona) and high latitude mediterranean (southern Oregon) biomes. We explored patterns of abiotic and biotic filtering by comparing observed patterns of community-weighted means and variances along elevational and latitudinal gradients to those expected under random assembly. In addition, we related trait variability to niches and explored how total trait space and breadth vary across broad spatial gradients by quantifying the ratio of intra- to inter-specific variation. Results: Both the community-wide mean and variance of SLA decreased with increasing latitude, consistent with greater abiotic filtering at higher latitudes. Further, low-elevation communities had higher trait variation than expected by chance, consistent with greater biotic filtering at low elevations. Finally, in the tropics and across latitude the ratio of intra- to inter-specific variation was negatively correlated to species richness, which further suggests that biotic interactions influence plant assembly at low latitudes. Conclusions: Intra- and inter-specific patterns of SLA variation appeared broadly consistent with the idea that the relative strength of biotic and abiotic drivers on community assembly changes along elevational and latitudinal gradients; evidence for biotic drivers appeared more prominent at low latitudes and elevations and evidence for abiotic drivers appeared more prominent at high latitudes and elevations.
Aim: Temperate tree species overwhelmingly responded to past climate change by migrating rather than adapting. However, past climate change did not have the modern human-driven patterns of land use ...and fragmentation, raising questions of whether tree migration will still be able to keep pace with climate. Previous studies using coarse-grained or randomized landscapes suggest that dispersal may be delayed but have not identified outright barriers to migration. Here, we use real-world fragmented landscapes at the scale of forest stands to assess the migration capacity of eastern tree species. Location: Eastern U.S.A. Time period: Present day to 2100. Major taxa studied: Eastern U.S. trees. Methods: We simulated dispersal over 100 years for 15 species common to the mid-Atlantic region and that are predicted to gain suitable habitat in the northeast. In contrast to previous studies, we incorporated greater realism with species-specific life histories and real-world spatial configurations of anthropogenic land use. We used simulation results to calculate dispersal rates for each species and related these to predicted rates of species habitat shift. Results: Our simulations suggest that land use in the human-dominated east-coast corridor slows species dispersal rates by 12–40% and may prevent keeping pace with climate. Species most impacted by anthropogenic land use were often those with the highest predicted species habitat shifts. We identified two major dispersal barriers, the Washington DC metropolitan area and central NY, that severely impeded tree migration. Main conclusions: Patterns of anthropogenic land use not only slowed migration but also resulted in effective barriers to dispersal. These impacts were exacerbated by tree life histories, such as long ages to maturity and narrow dispersal kernels. Without intervention, the migration lags predicted here may lead to loss in biodiversity and ecosystem functions as current forest species decline, and may contribute to formation of novel communities.
Coastal marshes are one of the world's most productive ecosystems. Consequently, they have been heavily used by humans for centuries, resulting in ecosystem loss. Direct human modifications such as ...road crossings and ditches and climatic Stressors such as sea-level rise and extreme storm events have the potential to further degrade the quantity and quality of marsh along coastlines. We used an 18-year marsh-bird database to generate population trends for 5 avian species (Rallus crepitans, Tringa semipalmata semipalmata, Ammodramus nelsonii subvirgatus, Ammodramus caudacutus, and Ammodramus maritimus) that breed almost exclusively in tidal marshes, and are potentially vulnerable to marsh degradation and loss as a result of anthropogenic change. We generated community and species trends across 3 spatial scales and explored possible drivers of the changes we observed, including marsh ditching, tidal restriction through road crossings, local rates of sea-level rise, and potential for extreme flooding events. The specialist community showed negative trends in tidally restricted marshes (-2.4% annually from 1998 to 2012) but was stable in unrestricted marshes across the same period. At the species level, we found negative population trends in 3 of the 5 specialist species, ranging from -4.2% to 9.0% annually. We suggest that tidal restriction may accelerate degradation of tidal marsh resilience to sea-level rise by limiting sediment supply necessary for marsh accretion, resulting in specialist habitat loss in tidally restricted marshes. Based on our findings, we predict a collapse of the global population of Saltmarsh Sparrows (A. caudacutus) within the next 50 years and suggest that immediate conservation action is needed to prevent extinction of this species. We also suggest mitigation actions to restore sediment supply to coastal marshes to help sustain this ecosystem into the future. Los humedales costeros son uno de los ecosistemas más productivos en el mundo. Consecuentemente, han sido utilizados intensivamente por los humanos durante siglos, resultando en la pérdida del ecosistema. Modificaciones humanas directas como caminos y zanjas, así como agentes climáticos estresantes como el incremento del nivel del mar y eventos de tormentas extremas tienen el potencial de degradar aun más la cantidad y calidad de humedales a lo largo de las costas. Utilizamos una base de datos de 18 años de aves de humedal para generar tendencias poblaciones de especies de aves (Rallus crepitans, Tringa semipalmata semipalmata, Ammodramus nelsonii subvirgatus, A. caudacutus, y A. maritimus) que se reproducen casi exclusivamente en marismas y que son potencialmente vulnerables a la degradación y pérdida de humedales como resultado de cambios antropogénicos. Generamos tendencias de la comunidad y de especies en 3 escalas espaciales y exploramos los posibles factores de los cambios observados, incluyendo la construcción de canales, la restricción de mareas por medio de caminos, tasas locales de incremento del nivel del el potencial de eventos de inundación extremos. La comunidad de especialistas mostró tendencias negativas en humedales restringidos por las mareas (-2.4% anualmente de 1998 a 2012), pero fue estable en humedales no restringidos. A nivel de especies, encontramos tendencias poblacionales negativas en 3 de las 5 especies especialistas que variaron entre -4.2% a 9% anualmente. Sugerimos que la restricción de mareas puede acelerar la degradación de la resiliencia de marismas al incremento del nivel del mar al limitar el aporte de los sedimentos necesarios para la acreción de marismas, lo cual resulta en la pérdida de habitat en marismas restringidas por las mareas. Con base en nuestros resultados, pronosticamos un colapso de la población global de A. caudacutus en los próximos 50 años y sugerimos que se requieren acciones de conservación inmediatas para prevenir la extinción de esta especie. También sugerimos acciones de mitigación para restaurar el aporte de sedimentos en los humedales costeros para ayudar a sostener este ecosistema en el futuro.
Ecosystem processes are driven by both environmental variables and the attributes of component species. The extent to which these effects are independent and/or dependent upon each other has remained ...unclear. We assess the extent to which climate affects net primary productivity (NPP) both directly and indirectly via its effect on plant size and leaf functional traits.
Using species occurrences and functional trait databases for North and South America, we describe the upper limit of woody plant height within 200 × 200 km grid‐cells. In addition to maximum tree height, we quantify grid‐cell means of three leaf traits (specific leaf area, and leaf nitrogen and phosphorus concentration) also hypothesized to influence productivity. Using structural equation modelling, we test the direct and indirect effects of environment and plant traits on remotely sensed MODIS‐derived estimates of NPP, using plant size (satellite‐measured canopy height and potential maximum tree height), leaf traits, growing season length, soil nutrients, climate and disturbances as explanatory variables.
Our results show that climate affects NPP directly as well as indirectly via plant size in both tropical and temperate forests. In tropical forests NPP further increases with leaf phosphorus concentration, whereas in temperate forests it increases with leaf nitrogen concentration. In boreal forests, NPP most strongly increases with increasing temperature and neither plant size nor leaf traits have a significant influence.
Synthesis. Our results suggest that at large spatial scales plant size and leaf nutrient traits can improve predictions of forest productivity over those based on climate alone. However, at higher latitudes their role is overridden by stressful climate. Our results provide independent empirical evidence for where and how global vegetation models predicting carbon fluxes could benefit from including effects of plant size and leaf stoichiometry.
Our results suggest that at large spatial scales plant size and leaf nutrient traits can improve predictions of forest productivity over those based on climate alone. However, at higher latitudes their role is overridden by stressful climate. Our results provide independent empirical evidence for where and how global vegetation models predicting carbon fluxes could benefit from including effects of plant size and leaf stoichiometry.
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