Historical comparisons reveal multiple drivers of decadal change of an ecosystem engineer at the range edge

Biogenic reefs are important for habitat provision and coastal protection. Long‐term datasets on the distribution and abundance of Sabellaria alveolata (L.) are available from Britain. The aim of this study was to combine historical records and contemporary data to (1) describe spatiotemporal variation in winter temperatures, (2) document short‐term and long‐term changes in the distribution and abundance of S. alveolata and discuss these changes in relation to extreme weather events and recent warming, and (3) assess the potential for artificial coastal defense structures to function as habitat for S. alveolata. A semi‐quantitative abundance scale (ACFOR) was used to compare broadscale, long‐term and interannual abundance of S. alveolata near its range edge in NW Britain. S. alveolata disappeared from the North Wales and Wirral coastlines where it had been abundant prior to the cold winter of 1962/1963. Population declines were also observed following the recent cold winters of 2009/2010 and 2010/2011. Extensive surveys in 2004 and 2012 revealed that S. alveolata had recolonized locations from which it had previously disappeared. Furthermore, it had increased in abundance at many locations, possibly in response to recent warming. S. alveolata was recorded on the majority of artificial coastal defense structures surveyed, suggesting that the proliferation of artificial coastal defense structures along this stretch of coastline may have enabled S. alveolata to spread across stretches of unsuitable natural habitat. Long‐term and broadscale contextual monitoring is essential for monitoring responses of organisms to climate change. Historical data and gray literature can be invaluable sources of information. Our results support the theory that Lusitanian species are responding positively to climate warming but also that short‐term extreme weather events can have potentially devastating widespread and lasting effects on organisms. Furthermore, the proliferation of coastal defense structures has implications for phylogeography, population genetics, and connectivity of coastal populations.     

The amounts and properties of transported air at two norwegian stations as functions of wind direction and weather type

Based on monthly means of climatic variables during the period 1937–65, the climate at two Norwegian meteorological stations in January and July was classified by principal component analysis. The new variables were interpreted as pairs of alternating weather types, or airmasses. Four airmasses were identified, covering 20–30% of the transported air at each station. The significance, properties and amounts of air transported by each airmass was calculated and distributed according to wind direction. Differences between air circulation pattern and airmass distribution and properties during the summer and winter season were pointed out. One of the major differences is the tendency to form high pressure over inland areas in winter vs. low pressure in the summer season.     

The effect of the meteorological factors on the Alnus pollen season in Lublin (Poland)

Alder pollen seasons and the effect of meteorological conditions on daily average pollen counts in the air of Lublin (Poland) were analysed. Alnus pollen grains reach very high concentrations in the atmosphere of this city during the early spring period and the parameters of pollen seasons were very different in the particular years studied. The pollen season lasted on average one month. The highest variation was observed for the peak value and the Seasonal Pollen Index (SPI). The pollen seasons, which started later, had shorter duration. Peak daily average pollen counts and SPI value were higher during the shorter seasons. Similarities in the stages of pollen seasons designated by the percentage method depended on the start date of the pollen season. Season parameters were mainly correlated with thermal conditions at the beginning of the year. Regression analysis was used to predict certain characteristics of the alder pollen season. The highest level of explanation of the variation in Alnus pollen season start and peak dates was obtained in the model using mean temperature in February. The obtained regression models may predict 82% of the variation in the pollen season start date, 73% of the variation in the duration, and 62% in the peak date.     

The influence of weather on the flight altitude of nocturnal migrants in mid‐latitudes

By altering its flight altitude, a bird can change the atmospheric conditions it experiences during migration. Although many factors may influence a bird's choice of altitude, wind is generally accepted as being the most influential. However, the influence of wind is not clearly understood, particularly outside the trade‐wind zone, and other factors may play a role. We used operational weather radar to measure the flight altitudes of nocturnally migrating birds during spring and autumn in the Netherlands. We first assessed whether the nocturnal altitudinal distribution of proportional bird density could be explained by the vertical distribution of wind support using three different methods. We then used generalized additive models to assess which atmospheric variables, in addition to altitude, best explained variability in proportional bird density per altitudinal layer each night. Migrants generally remained at low altitudes, and flight altitude explained 52 and 73% of the observed variability in proportional bird density in spring and autumn, respectively. Overall, there were weak correlations between altitudinal distributions of wind support and proportional bird density. Improving tailwind support with height increased the probability of birds climbing to higher altitude, but when birds did fly higher than normal, they generally concentrated around the lowest altitude with acceptable wind conditions. The generalized additive model analysis also indicated an influence of temperature on flight altitudes, suggesting that birds avoided colder layers. These findings suggested that birds increased flight altitudes to seek out more supportive winds when wind conditions near the surface were prohibitive. Thus, birds did not select flight altitudes only to optimize wind support. Rather, they preferred to fly at low altitudes unless wind conditions there were unsupportive of migration. Overall, flight altitudes of birds in relation to environmental conditions appear to reflect a balance between different adaptive pressures.     

Sterilization the Sane “Pesticide”

Unpacking, an effective lesson-planning technique, can help students use scientific inquiry to understand the power behind hurricanes. Teachers identify a concept and then guide students to "unpack" it and look for new discoveries. The activity provides a means for students to develop the abilities to do scientific inquiry, demonstrate how it is applied, and develop understanding about the method. Additionally, students demonstrate abilities of technological design and understanding about science and technology. This activity promotes students' knowledge of the Earth's constant change, pattern recognition to enable prediction, statistical analysis and graphical display to reveal patterns in data, and the science behind hurricane rotation.     

The role of epiphytic Pseudomonas and Pantoea population diversity on prevalence of fire blight disease

Several microbial populations on plants interact with each other and their host through the actions of secreted metabolites. However, the role of diverse microorganisms and their metabolites on plant health has yet to be fully appreciated. Here, we investigated the population diversity of two dominant epiphytic bacterial genuses in different area and their role in biological control of fire blight disease. To do so, we isolated and calculated population diversity of different Pantoea spp. and Pseudomonas spp. using serial dilution methods. The growth inhibition of Erwinia amylovora in vitro by some of these bacteria indicated the ecological significance of secondary metabolites produced by these bacteria and discuss how they might contribute to biological control of fire blight disease. Although, we did not work on the ability of these bacteria on induction of disease resistance but it could be considered for future, because they represent very different but important types of secondary metabolites. We also described how the weather conditions in different geographical regions can effect on the population of these epiphytic bacterial phenotypes leading to plant health promotion. In conclusion, we demonstrated the role of Pantoea and Pseudomonas population diversity on prevalence of fire blight in different area of north-east of Iran.     

Avian responses to extreme weather across functional traits and temporal scales

Extreme weather, including heat waves, droughts, and high rainfall, is becoming more common and affecting a diversity of species and taxa. However, researchers lack a framework that can anticipate how diverse species will respond to weather extremes spanning weeks to months. Here we used high‐resolution occurrence data from eBird, a global citizen science initiative, and dynamic species distribution models to examine how 109 North American bird species ranging in migration distance, diet, body size, habitat preference, and prevalence (commonness) respond to extreme heat, drought, and rainfall across a wide range of temporal scales. Across species, temperature influenced species’ distributions more than precipitation at weekly and monthly scales, while precipitation was more important at seasonal scales. Phylogenetically controlled multivariate models revealed that migration distance was the most important factor mediating responses to extremely hot or dry weeks; residents and short‐distance migrants occurred less often following extreme heat. At monthly or seasonal scales, less common birds experienced decreases in occurrence following drought‐like conditions, while widespread species were unaffected. Spatial predictions demonstrated variation in responses to extreme weather across species’ ranges, with predicted decreases in occurrence up to 40% in parts of ranges. Our results highlight that extreme weather has variable and potentially strong implications for birds at different time scales, but these responses are mediated by life‐history characteristics. As weather once considered extreme occurs more frequently, researchers and managers require a better understanding of how diverse species respond to extreme conditions.     

不同天气条件下青头潜鸭越冬期行为的响应模式

2018年11—12月在河南民权国家湿地公园,采用定点观察法、扫描取样法对越冬青头潜鸭在不同天气条件下的行为响应模式进行研究。结果表明: 在晴天,静息、飞行、运动是青头潜鸭越冬期的优势行为(65.5%),觅食、修整是次要行为(31.9%);行为节律表现为上午觅食、中午静息、下午觅食修整;飞行通常发生在觅食高峰前,运动行为多与其他行为相伴,其时间分配与觅食呈正响应,与静息呈负响应。相较于晴天,阴雨天青头潜鸭增加了对静息和觅食的时间分配,静息、觅食和运动为阴雨天的主要行为(76.5%),修整、飞行为次要行为(20.3%);觅食和静息的高峰时段后移,傍晚时达到高峰,飞行和修整时间显著减少。与晴天相比,雾霭天青头潜鸭静息、觅食、运动和修整的时间分配增加,飞行行为减少;觅食高峰后移至中午和下午,静息高峰后移至下午;静息、运动和觅食为雾霭天的优势行为(70.6%),修整和飞行为次要行为(27.5%)。研究表明,不同天气条件下,民权湿地公园青头潜鸭的越冬期行为在时间分配、行为节律、优势行为方面存在一定的响应;阴雨天和雾霭天青头潜鸭会分配更多的静息和觅食时间,并通过增加能量摄入和减少耗能行为应对恶劣天气。     

Annual survival in female white-winged scoters and lesser scaup

Quantifying survival and understanding underlying sources of variation are important for developing population models and informing management decisions. We estimated apparent survival (i.e., true survival less permanent emigration) for adult female white-winged scoters (Melanitta fusca) and lesser scaup (Aythya affinis) breeding at a northern boreal forest site in western Canada, 2002–2008. We also evaluated variation in survival relative to indices of breeding status, individual quality, spring weather conditions, local small-mammal abundance, and overwinter climate. Breeding female scoters had higher apparent survival than did nonbreeding females, suggesting that breeders had higher survival or fidelity to the study area, or that more nonbreeders were transient birds that may have bred elsewhere in subsequent years. Apparent survival rate for breeding female scoters was unrelated to other individual and environmental covariates. Nest-trapped female scaup had higher apparent survival rates than did prenesting females captured in decoy traps, implying that more pre-nesters dispersed permanently or died after marking. Nesting female scaup with higher body condition or those in years when small mammals were more abundant had higher apparent survival; associations between survival and other environmental covariates were less certain. Overall, apparent survival rate of breeding adult female scoters was lower than reported for scoters from other North American locations or for other sea duck species, whereas estimates for nesting female scaup were comparable with those from other boreal and prairie-parkland locations. Our results indicate that for scaup in this region, factors influencing female body condition, such as maintaining high-quality habitat, areas with abundant food or low disturbance, could improve annual survival. © The Wildlife Society, 2019