Previous Spring Research Articles

Sustainability of Organic Fertilizers Use in Dryland Mediterranean Agriculture

Organic fertilization is a key issue in European Union (EU) regulations, particularly in the context of promoting a circular nutrient economy, maintaining soil quality, and sequestering carbon to face climate change. In a rainfed system in Northeastern Spain, an experiment was set up (split-plot design). It included five pre-sowing N fertilization treatments: control, mineral, pig slurry, and composted sewage sludge (two rates). The average N rates were 0, 30, 141, 176, and 351 kg N ha−1, respectively. They were combined with mineral N topdressings (0, 50, and 100 kg N ha−1). Three crops were grown: barley (nine years), wheat (three years), and rapeseed (one year). In the driest years (c. 350 mm rainfall), the yields averaged 2.5, 2.0, and 1.9 Mg ha−1, respectively. The maximum yields were for barley (6.5 Mg ha−1) and wheat (5.5 Mg ha−1). The avoidance of a significant increase in soil residual NO3−-N, plus the control of soil build up of available P, micronutrients, and Cd, defines the fertilization strategies. (i) With a previous spring drought season, no fertilization is needed in the following year, if devoted to winter cereals. (ii) In rainier seasons, pig slurry or composted sewage sludge (lowest rate) applied at sowing is sufficient; however, 50 kg of mineral-N ha−1 at the topdressing can be applied. The study found that pig slurry favors K, Mg, Cu, and Zn availability, while composted sewage sludge enhances Fe availability. Although it is possible to reduce N inputs from organic fertilizers, organic C build-up will be constrained.

Association Between Draft Order and Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers: An 18-Year Study

Background: The Major League Baseball (MLB) draft is a common route for players to enter professional baseball in the United States. Players taken in earlier rounds are typically higher-performing players. When looking at pitchers specifically, higher performance at the amateur level may be associated with an increased frequency of adaptive change in the throwing elbow. Purpose: To determine whether pitchers taken in earlier rounds of the MLB draft have a greater frequency or extent of pathological change in the elbow, as measured by dynamic stress ultrasound. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Dynamic stress ultrasounds (SUSs) were performed over 18 years on the dominant and nondominant arms of 651 professional pitchers. The 383 drafted players were grouped according to the round in which they were drafted (rounds 1-5, 6-10, 11-20, 21+). Groups were compared with respect to “relative” ulnar collateral ligament (UCL) thickness (dominant-nondominant), relative ulnohumeral joint laxity (joint space distance under stress minus joint space at rest), and the presence of pathology (calcifications, tears, hypoechoic foci, osteophytes). In addition, a subgroup analysis was done to compare the progression of SUS findings over 3 years in players for which data were available. Results: Draft round groups did not differ by age, number of previous spring training, or handedness. Comparing baseline measurements, there was no significant relationship between draft round and relative UCL thickness (P = .932), relative laxity (P = .996), or presence of pathology detectable on SUS (P = .642). However, increased relative UCL thickness was significantly associated with the presence of pathology on SUS (odds ratio, 1.45; 95% CI, 1.26-1.69; P < .001). Longitudinally, there was no significant relationship between draft round and 3-year progression of relative laxity, relative UCL thickness, or clinical progression of pathology. Conclusion: Higher-performing pitchers are drafted earlier in the MLB draft. This may be attributable to peak pitch velocity, in-game performance, visibility gained during player showcases, or any number of other sport-specific variables. However, despite this, there was no significant relationship between draft round and adaptive changes to the elbow or specific properties of the UCL on stress ultrasound.

The strengthened role of new predictors of Indian Ocean Dipole (IOD) during the recent decades of weakened ENSO-IOD relationship

Indian Ocean Dipole (IOD) is the major interannual ocean-atmosphere interaction phenomena in the Indian Ocean (IO) and is influenced by external forcing such as El Nino Southern Oscillation (ENSO). Meanwhile, its co-occurrence and stronger relationship with ENSO have decreased during recent decades. The IOD variability also reduced after 2000, accompanied by a shift of the western pole to central IO extending further southward. The study reports that the boreal fall (SON, September, October, November) season IOD has an intensified relationship with the previous winter Subtropical Indian Ocean dipole (SIOD) and spring season equatorial north tropical Atlantic (NTA) SST anomalies., while the ENSO relationship is reduced from its pre-2000 value. It is found that the persistent warming (cooling) in the western side of positive (negative) SIOD during the previous winter induces easterly (westerly) wind anomalies in the equatorial IO during the following summer and fall, leading to positive (negative) IOD events. These IOD events have the western pole shifted to south-central IO instead of the canonical northwestern warming. The spring season NTA SST anomalies induce stronger summer season circulation and SST gradient in the equatorial Pacific, like ENSO. During the SON season, this pattern is associated with cooling and easterly wind anomalies in the tropical eastern IO and IOD. These two patterns explain the major mode of IOD variability after 2000. While the IOD associated with NTA have co-occurring ENSO during summer and fall, the SIOD-induced IOD events are independent of ENSO in the Pacific. Thus, these two predictors provide long-lead predictability (2–3 seasons ahead) of IOD for both ENSO co-occurring and non-ENSO IOD events. However, the IOD predictability of seasonal prediction models mainly depends on the ENSO-IOD relationship, resulting in reduced IOD skills for many of them after 2000. The models such as COLA-CCSM4, which has improved skill have stronger than observed ENSO-IOD relationship than the pre-2000 period. A linear regression model including SIOD and NTA SST indices of the previous winter and spring season respectively as predictors simulates IOD with a skill of around 0.65 during the recent period, indicating the necessity of seasonal prediction models to capture the variability in the southern IO and NTA and their teleconnections for better prediction of IOD in the recent period of reduced ENSO skill.

Interannual variation in spring weather conditions as a driver of spring wildflower coverage: a 15-year perspective from an old-growth temperate forest.

Spring ephemerals are wildflowers found in temperate deciduous forests that typically display aboveground shoots for a period of 2 months or less. Early spring, before the canopy leaves out, marks the beginning of the aboveground growth period where ephemerals acquire nutrients and resources via aboveground tissues. Several studies have shown that spring ephemeral reproduction is affected by spring temperature, but few have looked at how weather conditions of the current and previous seasons, including precipitation and temperature, influence aboveground growth. Here, we examine the response of a spring ephemeral community in a temperate hardwood forest to weather conditions during their current and previous growing seasons. For 15 years we estimated percent cover of each species within our community. We highlighted five dominant spring ephemerals within this community: wild leek (Allium tricoccum), cutleaf toothwort (Cardamine concatenata), spring beauty (Claytonia virginica), squirrel corn (Dicentra canadensis) and trout lily (Erythronium americanum). We compared changes in cover on both a community and species level from 1 year to the next with average precipitation and temperature of the year of measurement as well as the year prior. We found precipitation and temperature influence a change in cover at the community and species level, but the strength of that influence varies by species. There were few significant correlations between plant cover in the current year and temperature and precipitation in the 30 days preceding measurement. However, we found significant correlations between plant cover and precipitation and temperature during the previous spring; precipitation and cover change were positively correlated, whereas temperature and cover change were negatively correlated. Overall, cooler, wetter springs lead to an increase in aboveground cover the next year. Learning how individual species within a forest plant community respond to weather conditions is a crucial part of understanding how plant communities will respond to climate change.

Quantifying winter survival of alfalfa [Medicago sativa (L.)

AbstractWinter injury of alfalfa [Medicago sativa (L.)] in the northern United States decreases its economic and ecosystem benefits. Therefore, continued improvement in alfalfa cultivar winter survival (WS) is crucial for sustaining the productivity of this perennial crop. The North American Alfalfa Improvement Conference (NAAIC) standard test for WS recommends measuring the WS of spaced plants established in rows the previous spring. Measurement of WS of alfalfa grown in sward plots used by plant breeders would increase data collection and better reflect the potential for WS when grown in production fields. We conducted trials at seven location‐year environments spanning from Wisconsin to South Dakota in the northern United States. These trials involved six check cultivars and followed protocols from the NAAIC standard test. The objectives were to determine (1) if WS and biomass yield assessment from sward plots were similar to those from the standard spaced planted row ratings and (2) if location‐dependent environmental conditions affected the usefulness of alternative approaches for measuring WS. Estimation of WS using spaced plants and sward measurements was highly correlated, while correlations between the WS of the spaced planted rows and biomass yields were less. The number of locations required for spaced and sward plantings to determine cultivar differences was at least two, with four replications per location. Measuring WS from swards can enhance data collection and its relevance to on‐farm alfalfa production, as sward plots serve a dual purpose by allowing both WS testing and evaluation of yield, making them a practical choice in comparison to the exclusive use of spaced plants in rows for WS testing. Availability of sward‐plot WS descriptions of alfalfa cultivars will enhance decision making by producers.

Effects of Irrigation Projects on the Classification of Yellow River Terrace Landslides and their Failure Modes: A Case Study of Heitai Terrace

The study of the classification and failure modes of Yellow River terrace landslides under the influence of irrigation projects is of key importance to alleviate the paradox between the rapid evolution of terrace landscapes caused by landslides and the survival of local residents. However, such studies remain controversial, despite it being widely recognized that a rise in groundwater level caused by irrigation is a key factor associated with landslide failure modes. In this paper, we take the Heitai terrace as a case study. Using aerial images and field investigations, we classify landslides in the Heitai loess layer into type A landslides (not related to groundwater) and type B1 and B2 landslides (related to groundwater). We analyze the failure modes and disaster-causing characteristics of each type of landslide, and our results indicate that the attenuation in soil strength is a key factor common to both type A and type B landslides, based on which type A landslides with small volume and short sliding distance are able to block the previous spring discharge, causing a rise in localized groundwater, which further contributes to type B landslides; the location of previous type B1 landslides with a large volume and long sliding distance and type A landslides may be more susceptible to type B2 landslides with a small volume and short sliding distance, where there are low confining pressures during the lower soil shear process. Therefore, we believe that the inevitable interaction effects between the failure modes of landslides during landslide evolution, which govern the geomorphological evolution of the Heitai terrace, are unavoidable. Combining these data with numerical analyses, we further demonstrate that a rise in groundwater level and discontinuous attenuation of soil strength caused by changes in soil properties during irrigation together control terrace landslides and their failure modes. From the results of interferometric synthetic aperture radar time-series monitoring of Yellow River terrace activity with and without irrigation projects, and electrical resistivity tomography groundwater detection, we conclude that in the future, Heitai terrace will continue to experience a high intensity of landslide activity, and conditions for the most catastrophic type of landslide (type B1) will remain, including the high localized groundwater caused by previous landslides, and the discontinuous attenuation of soil strength caused by the deterioration in soil properties. In this context, we believe that slope-cutting engineering will be one of the most economical means to achieve future landslide-type transformation on the Heitai terrace; this will mitigate the process of geomorphological evolution and improve the human living environment.

Increasing winter temperatures explain body size decrease in wintering bird populations of Northern Europe—But response patterns vary along the spatioclimatic gradient

AbstractAimRecent evidence has shown changes in body size and shape of individuals, which are suggested to be a result of global warming caused by climate change. Here, we explored the spatiotemporal changes in wing length and body mass of 24 wintering bird species in Northern Europe and how these relate to temperature anomaly.LocationFinland and Sweden, Europe.Time Period50 years, 1970 to 2020.Major Taxa StudiedBirds, 24 species.MethodsWe used site‐specific, long‐term winter ringing data containing wing length and body mass measurements from across Sweden and Finland for 24 bird species. We modelled wing length and body mass change over time, in relation to the spatioclimatic gradient and as response to temperature anomalies (of [i] the same winter as the ringing took place, [ii] the previous winter and [iii] the previous spring) by accounting for phylogenetic relatedness between species and their species‐specific responses to each predictor of interest.ResultsWe show that across all species, body size has decreased since the 1970s, with a negative relationship between wing length and temperature anomalies of previous winters, suggesting carry‐over effects likely linked to body size‐related survival or dispersal. Body mass was negatively related to the temperature anomaly of the same winter, indicating more immediate effects related to reduced fat reserves during mild winters.Main ConclusionsOur results highlight a climate‐driven decrease in body size across several species and its association with positive anomalies in winter temperature in the high latitudes. However, the responses are not spatially uniform and there is considerable species‐specific variation, emphasizing the importance of conducting multispecies studies when investigating responses to climate change. The mechanisms of decreasing wing length and body mass seem to differ and underline the immediate and carry‐over effects of temperature warming during the nonbreeding season.

Westward extension of summer atmospheric circulation over the North Pacific after the 1990s

This paper documents the westward extension of the summer atmospheric circulation over the North Pacific (NP circulation) around the 1990s and investigates the possible reason, based on the North Pacific index. The NP circulation was centered in the Northeast Pacific during 1961–1983 and in the central North Pacific during 1994–2016. Further results show that the westward movement of the NP circulation was closely linked with an intensification of the relationship between the NP circulation and the previous spring sea surface temperature of the midlatitude North Pacific (SST_NP) after the 1990s. The spring SST_NP anomalies exerted considerable impacts on surface heat flux (i.e., sensible heat flux and latent heat flux) and vertical motion anomalies over the central North Pacific during the following summer, facilitating a westward shift in the summer NP circulation. Additionally, the interannual variability of the sea level pressure over the central North Pacific increased after the 1990s, which was likely a contributing factor to the westward extension of the NP circulation.摘要本文研究了20世纪90年代前后夏季北太平洋大气环流 (NP circulation) 向西扩展, 并探讨了其可能的原因. 结果表明, 在1961–1983年期间NP中心主要位于东北太平洋, 而在1994–2016年期间NP中心发生西移, 至北太平洋中部. 进一步分析指出, 90年代以后NP活动中心的西移和春季中纬度北太平洋海温(SST_NP) 与NP关系的加强有关. 春季SST_NP异常通过引起后期夏季北太平洋中部地表热通量(即感热通量和潜热通量)和垂直运动异常, 有利于NP活动中心向西移动. 此外, 20世纪90年代以后, 北太平洋中部海平面气压的年际变率增加, 这可能是NP向西扩展的另一原因.

Climate effect on the growth and hydraulic traits of two shrubs from the top of a Mediterranean mountain

Increasing mean global temperatures in conjunction with increases in the frequency and severity of drought events affect plant growth and physiology, particularly in more arid and mountainous ecosystems. Thus, it is imperative to understand the response of plant growth to climatic oscillations in these regions. This study used dendrochronological and wood anatomical traits of two shrub species growing over 1500 m.a.s.l. in the Serra da Estrela (Portugal), Juniperus communis and Cytisus oromediterraneus, to analyze their response to temperature and water availability parameters. Results showed an increase in shrub growth related to the increase over time of the mean minimum and maximum monthly temperature in Serra da Estrela. Warming seems to promote shrub growth because it lengthens the growing season, although J. communis responds mainly to spring maximum temperature while C. oromediterraneus is influenced by fall maximum temperature. Hydraulic traits of J. communis and C. oromediterraneus were negatively influenced by winter drought. Additionally, there were species-specific differences in response to changes in water availability. J. communis radial growth was significantly affected by spring drought conditions, while C. oromediterraneus radial growth was significantly affected by spring precipitation. C. oromediterraneus hydraulic traits were also significantly affected by drought conditions from the previous spring and fall. This study shed light on specific differences in the response to climate between two co-occurring shrub species in the top of an understudied Mediterranean mountain, which could have implications in the future distribution of woody species within this region.

Can lightning indicate genesis frequency of tropical cyclones over the South China Sea?

AbstractThe present study identifies a significant negative correlation of the South China Sea (SCS) summer–fall (JJASON) tropical cyclone (TC) genesis with the previous boreal spring (MAM) total lightning flash rate east of the Philippines during 1996–2013. The increased lightning flash rate east of the Philippines signifies an enhancement in deep convection, which induces cyclonic wind anomalies to the west via a Gill‐type atmospheric response and results in an increase in convection and cloud cover over the SCS during spring. The atmospheric changes lead to a decrease in sea surface temperature (SST) and ocean heat content (OHC) in the SCS by reducing downward short‐wave radiation and enhancing oceanic upwelling. The negative SST and OHC anomalies persist from spring to summer–fall and induce unfavourable thermodynamic anomalies, suppressing the SCS TC genesis during JJASON. Thus, the spring total lightning flash rate east of the Philippines, as an indicator of deep convection, may serve as a precursor of the SCS TC genesis.

Oxidative physiology of two small and highly migratory Arctic seabirds: Arctic terns (Sterna paradisaea) and long-tailed jaegers (Stercorarius longicaudus).

Arctic ecosystems are changing rapidly. The tundra supports nesting migratory seabirds that spend most of their year over the ocean. Migrations are demanding, but it is unclear how physiological capability may equip organisms to respond to their changing environments. For two migratory seabird species nesting in Alaska, USA, the Arctic tern (n = 10) and the long-tailed jaeger (n = 8), we compared oxidative physiology and aerobic capacity measured during incubation and we recorded individual movement paths using electronic tracking tags. Within species, we hypothesized that individuals with longer-distance migrations would show higher oxidative stress and display better aerobic capacity than shorter-distance migrants. We examined blood parameters relative to subsequent fall migration in jaegers and relative to previous spring migration in terns. We present the first measurements of oxidative stress in these species and the first migratory movements of long-tailed jaegers in the Pacific Ocean. Arctic terns displayed positive correlation of oxidative variables, or better integration than jaegers. Relative to physiological sampling, pre-breeding northward migration data were available for terns and post-breeding southward data were available for jaegers. Terns reached a farther maximum distance from the colony than jaegers (16 199 ± 275km versus 10 947 ± 950km) and rate of travel northward (447 ± 41.8km/day) was positively correlated with hematocrit, but we found no other relationships. In jaegers, there were no relationships between individuals' physiology and southward rate of travel (193 ± 52.3km/day) or migratory distance. While it is not clear whether the much longer migrations of the terns is related to their better integration, or to another factor, our results spark hypotheses that could be evaluated through a controlled phylogenetic study. Species with better integration may be less susceptible to environmental factors that increase oxidative stress, including thermal challenges or changes in prey distribution as the Arctic climate changes rapidly.

FCoSE: A Fast Compound Graph Layout Algorithm with Constraint Support.

Visual analysis of relational information is vital in most real-life analytics applications. Automatic layout is a key requirement for effective visual display of such information. This article introduces a new layout algorithm named fCoSE for compound graphs showing varying levels of groupings or abstractions with support for user-specified placement constraints. fCoSE builds on a previous compound spring embedder layout algorithm and makes use of the spectral graph drawing technique for producing a quick draft layout, followed by phases where constraints are enforced and compound structures are properly shown while polishing the layout with respect to commonly accepted graph layout criteria. Experimental evaluation verifies that fCoSE produces quality layouts and is fast enough for interactive applications with small to medium-sized graphs by combining the speed of spectral graph drawing technique with the quality of force-directed layout algorithms while satisfying specified constraints and properly displaying compound structures. An implementation of fCoSE along with documentation and a demo page is freely available on GitHub at https://github.com/iVis-at-Bilkent/cytoscape.js-fcose.

Modeling Phenological Phases of Winter Wheat Based on Temperature and the Start of the Growing Season

The phenological phases of field crops have shifted to earlier times in the Czech Republic in recent decades; additionally, they have shown correlations with temperatures from previous spring months. Using a thermal time model called PhenoClim, the correlations between temperatures and phenophases allow us to evaluate the strongest predictors (i.e., maximum temperature) and indicators of base temperatures and growing degree days for the selected phenophases of winter wheat (Triticum aestivum L.). With the help of this model, it is possible to explain 0.6–0.82% of the phase variability and to estimate the onset of phenophases for the selected time period and stations (with the RMSE values of 9.4 days for jointing, 4.3 days for heading, and 5.3 days for full ripeness). To further refine the modeled onsets of phenophases, we used satellite data, specifically the normalized difference vegetation index and the enhanced vegetation index 2 from MODIS; based on these vegetation indices, the start of the growing season (SOS) was determined. After including SOS to model PhenoClim, we modeled the onsets of phenophases, with average accuracies ranging from 6.2 to 15.2. By combining the thermal time model and remote sensing data, specifically the data concerning the determination of SOS, we can refine the modeling of the onset of full ripeness in some locations.

Attack by a Turkey: Learning to Write History from Bernard Bailyn

Attack by a Turkey: Learning to Write History from Bernard Bailyn

Does the timing of short-term biowaste compost application affect crop growth and potential nitrate leaching? The case studies of processing tomato and cauliflower under field conditions

The feasibility of municipal solid waste compost (MSWC) as a substitute for mineral nitrogen (N) fertiliser was tested for a spring-summer (i.e., processing tomato) and an autumn-winter (i.e., cauliflower) vegetable crop grown in Mediterranean open field conditions. Two different doses (10 and 20 t dm C ha–1) and two distribution timings for each dose (i.e., early application at about nine months before processing tomato transplanting and five months before cauliflower transplanting: C10_early and C20_early; late application at about one month before processing tomato and cauliflower transplanting: C10_late and C20_late) were compared in a two-year field experiment. An unfertilised control and a 100% mineral N fertilisation (MIN, 200 kg N ha–1 for processing tomato and 150 kg N ha–1 for cauliflower) were added to the experiment. The application of MSWC significantly reduced the aboveground DM accumulation compared to the MIN in both crops, and it was inadequate to ensure a high yield for spring-summer and autumn-winter vegetables. However, the timing of compost application seems to play an essential role in reducing the reduction of crop growth due to compost application. In both tomato and cauliflower, when the MSWC was applied a few months earlier than the transplanting (i.e., in the previous summer in tomato and the previous spring in cauliflower), the DM and yield reduction was less apparent than in soil where compost was applied immediately before transplanting. Despite the lowest N-uptake associated with the MSWC application, the N-NO3 concentration in the soil solution was reduced by MSWC. In addition to the amendment effect, compost use may positively impact lowering N leaching risks in the groundwater. Combining the use of MSWC applied early before the crop season with mineral N fertiliser, it is possible to gain high yield, increase soil organic carbon and reduce groundwater contamination risk both in spring-summer and autumn-winter vegetable crops. Highlights- Biowaste compost decreased the aboveground biomass accumulation and yield in processing tomato and cauliflower. - Biowaste compost alone did not meet the N requirement in processing tomato and cauliflower. - Biowaste compost distribution in the summer before the processing tomato growing season alleviated its depressive effect in reducing DM and yield. - Biowaste compost distribution in the spring before the cauliflower growing season alleviated its depressive effect in reducing DM and yield. - Biowaste compost decreased the N-NO3 concentration in soil solution compared to mineral fertilisation with a positive effect in reducing N leaching risks in the groundwater.

Seroprevalence and incidence of Puumala orthohantavirus in its bank vole (Myodes glareolus) host population in northeastern France: Between-site and seasonal variability

Given the difficulty of measuring pathogen transmission in wildlife, epidemiological studies frequently rely on cross-sectional seroprevalence. However, seropositivity indicates only exposure to a pathogen at an unknown time. By allowing to obtain repeated test results from individuals sampled multiple times over an extended period, longitudinal data help reduce this uncertainty. We used capture-mark-recapture data on bank vole (Myodes glareolus) individuals collected at four sites over ten years in northeastern France to investigate the impact of environmental variables on seroprevalence and incidence of Puumala orthohantavirus (PUUV). PUUV causes a chronic infection without apparent symptoms, that may however impair survival of its rodent host in the wild. Viral transmission between rodents may occur through direct contact or via the environment. Principal component analysis was used to deal with multicollinearity among environmental variables. Incidence and seroprevalence were investigated with either generalized estimating equations or Poisson regression models depending on the number of observations for each season. In spring, only the factor site was found to be significant for seroprevalence, while a principal component including meteorological conditions of the previous winter and the normalized difference vegetation index (NDVI) of both the previous winter and spring had a significant effect on incidence. In autumn, only the factor site was significant for incidence, while two principal components, including either the meteorological conditions of the autumn and previous spring or NDVI of the autumn significantly affected seroprevalence. We discuss these results in light of the particular demography of small mammals. We encourage other researchers to investigate the relationships between demographic parameters of wild host populations and the environment, by using both incidence and seroprevalence.

Response rate and content differences between web and mail surveys

AbstractThe Florida Fish and Wildlife Conservation Commission (Commission) conducts an annual harvest survey of licensed wild turkey (Meleagris gallopavo) hunters to determine the proportion of license holders that hunt and the estimated total harvest. The harvest survey is traditionally conducted with a mailed postcard, which is increasingly costly and time‐consuming to administer. The Commission has considered using a less costly and less protracted web‐based survey. From 2012 through 2014, we conducted web and mail surveys of licensed turkey hunters to compare response rates and reported rate of hunting participation. The average response rate differed between mail and web survey respondents (25.5% and 16.5%, respectively). Rates of hunting participation also differed between the survey modes; 40.5% and 61.4%, respectively, of mail and web survey respondents said that they hunted during the previous spring season. When hunting participation rates were extrapolated to the total number of license holders in the state, the projected average number of hunters across the 3 years was 17,356 (52%) greater from the web survey than the mail survey. Demographic weighting (age class, sex, ethnicity, median household income, or urbanicity) failed to account for the difference in reported hunting participation between survey modes. Our results indicated that respondents of the 2 survey modes differed fundamentally in either their hunting behavior or in their propensity to respond to the surveys, both of which have ramifications when management decisions are based on the results of harvest surveys. Although a mixed‐mode survey may be a feasible option to reduce cost and still obtain accurate harvest estimates, we caution against abruptly switching from mail to web surveys given the vastly different outcomes.

The Impact of Fire on Nectar Quality and Quantity for Insect Pollinator Communities

Grassland insect pollinators have undergone population declines due to habitat loss and degradation. Patch-burning is a management method used to reduce woody plant encroachment and maintain grassland habitats. However, the impacts of fire on the quality and quantity of floral resources (nectar volume, total sugar, and sucrose concentration) available to insect pollinators are understudied. Evaluating how time since last fire and season of fire impact nectar quality and quantity is vital to understanding the overall impact of fire on insect pollinator communities. For this study, 10 flowering forb species (Asclepias viridis, Baptisia alba, Cirsium undulatum, Desmodium canadense, Monarda citriodora, Monarda fistulosa, Oenothera speciosa, Penstemon tubaeflorus, Ruellia humilis, Spiranthes cernua) were selected in The Nature Conservancy's Joseph H. William's Tallgrass Prairie Preserve in an area managed with patch-burning and cattle grazing. Study sites were burned in spring 2018, summer 2018, summer 2019, and spring 2020, with three replicates of each treatment (for 12 total burn units). In each unit, we collected nectar from flowering individuals of each plant species with microcapillary tubes to measure standing crop or the nectar in flowers at any given time that is available to insect pollinators. Total volume of nectar and sucrose concentration were recorded, and total mg of sugar was calculated. Desmodium canadense flowering individuals were only located in units burned the previous spring, whereas P. tubaeflorus flowering individuals were only located in units burned the previous summer. For the eight remaining species, total volume of nectar, total mg of sugar, and sucrose concentration varied with different burn regimens for different species. Cirsium undulatum inflorescences with crab spiders (Thomisidae) had higher volumes of nectar and higher amounts of sugar available. This study highlights how a patch-burn approach with different fire return intervals may benefit insect pollinators at the community level by providing a wide range of nectar qualities and quantities to support insect pollinators with different nutritional needs.

Increased summer electric power demand in Beijing driven by preceding spring tropical North Atlantic warming

By using electric power data, observational station temperature data in Beijing, CN05.1 temperature data, ERA5 atmospheric reanalysis data, and ERSST.v3b sea surface temperature (SST) data, it is found that summer (July–August) electric power demand in Beijing is remarkably positively correlated with the previous spring (March–April) tropical North Atlantic (TNA) SST anomaly (SSTA). The possible physical mechanism of the TNA SSTA affecting summer electric power in Beijing is also revealed. When a positive SSTA occurs in the TNA during spring, anomalous easterlies prevail over the tropical central Pacific, which can persist to the following summer. Trade winds are thus enhanced over the northern Pacific, which favors a strengthening of upwelling cold water in the tropical central-eastern Pacific. As a result, a negative SSTA appears in the central-eastern Pacific in summer, which means a La Niña event is triggered by the previous TNA SSTA through the Bjerknes feedback. During the La Niña event, an anomalous anticyclonic circulation occupies the northwestern Pacific. The southerly anomalies at the western edge of this anomalous anticyclone strengthen the transportation of warm and humid airflow from the low latitudes to North China, where Beijing is located, causing higher summer temperatures and increased electricity usage for air conditioning, and vice versa. The results of this study might provide a new scientific basis and clues for the seasonal prediction of summer electric power demand in Beijing.摘要本文利用北京市电力负荷资料, 北京市站点观测温度资料, CN05.1温度资料, ERA5大气再分析资料及ERSST v3b海表温度资料, 发现3–4月副热带北大西洋海温异常和北京市夏季电力呈很好的正相关关系, 并揭示了副热带北大西洋海温异常影响北京市夏季电力的可能物理机制. 春季副热带北大西洋海温异常偏暖, 热带中太平洋出现东风异常并持续至夏季, 太平洋信风增强, 热带中东太平洋冷水上翻增强, 通过Bjerkness正反馈机制激发了La Niña事件. La Niña事件时, 西北太平洋反气旋环流异常, 将低纬度暖湿气流输送至北京地区, 引起北京市夏季温度增高, 电力负荷需求增加. 反之亦然. 研究结果可为北京市夏季电力负荷需求的季节预测提供新的科学依据和线索.

Effects of spring Arctic sea ice on summer drought in the middle and high latitudes of Asia

Based on data observed from 1979 to 2017, the influence of Arctic sea ice in the previous spring on the first mode of interannual variation in summer drought in the middle and high latitudes of Asia (MHA) is analyzed in this paper, and the possible associated physical mechanism is discussed. The results show that when there is more sea ice near the Svalbard Islands in spring while the sea ice in the Barents–Kara Sea decreases, the drought distribution in the MHA shows a north–south dipole pattern in late summer, and drought weakens in the northern MHA region and strengthens in the southern MHA region. By analyzing the main physical process affecting these changes, the change in sea ice in spring is found to lead to the Polar–Eurasian teleconnection pattern, resulting in more precipitation, thicker snow depths, higher temperatures, and higher soil moisture in the northern MHA region in spring and less precipitation, smaller snow depths, and lower soil moisture in the southern MHA region. Such soil conditions last until summer, affect summer precipitation and temperature conditions through soil moisture–atmosphere feedbacks, and ultimately modulate changes in summer drought in the MHA.摘要本文分析了亚洲中高纬度地区 (MHA) 年际尺度夏季干旱的主模态时空变化特征, 以及影响第一模态的主要影响因子和可能的物理过程. 结果显示该区域夏季干旱第一模态主要呈现一个南北偶极性的分布. 而影响MHA夏季干旱的主要影响因子为前春北极海冰. 当春季斯瓦尔巴群岛附近海冰偏多, 而巴伦支海-喀拉海海冰减少时, 通过冰-气相互作用, 使得MHA北部春季降水增加, 雪深加厚, 土壤湿度偏高, 而南部则相反. 然后这样的土壤湿度条件从春季持续到夏季, 通过土壤湿度-大气反馈影响夏季MHA降水和温度变化, 最终对夏季干旱主模态产生影响.