240 research outputs found
Quantifying the impact of an extreme climate event on species diversity in fragmented temperate forests: the effect of the October 1987 storm on British broadleaved woodlands
1. We report the impact of an extreme weather event, the October 1987 severe storm, on fragmented woodlands in southern Britain. We analysed ecological changes between 1971 and 2002 in 143 200-m2 plots in 10 woodland sites exposed to the storm with an ecologically equivalent sample of 150 plots in 16 non-exposed sites. In both years, understorey species-richness, species composition, soil pH and woody basal area of the tree and shrub canopy were measured.
2. We tested the hypothesis that the storm had deflected sites from the wider national trajectory of an increase in woody basal area and reduced understorey species-richness associated with ageing canopies and declining woodland management. We also expected storm disturbance to amplify the background trend of increasing soil pH, a UK-wide response to reduced atmospheric sulphur deposition. Path analysis was used to quantify indirect effects of storm exposure on understorey species richness via changes in woody basal area and soil pH.
3. By 2002, storm exposure was estimated to have increased mean species richness per 200 m2 by 32%. Woody basal area changes were highly variable and did not significantly differ with storm exposure.
4. Increasing soil pH was associated with a 7% increase in richness. There was no evidence that soil pH increased more as a function of storm exposure. Changes in species richness and basal area were negatively correlated: a 3.4% decrease in richness occurred for every 0.1-m2 increase in woody basal area per plot.
5. Despite all sites substantially exceeding the empirical critical load for nitrogen deposition, there was no evidence that in the 15 years since the storm, disturbance had triggered a eutrophication effect associated with dominance of gaps by nitrophilous species.
6. Synthesis: Although the impacts of the 1987 storm were spatially variable in terms of impacts on woody basal area, the storm had a positive effect on understorey species richness. There was no evidence that disturbance had increased dominance of gaps by invasive species. This could change if recovery from acidification results in a soil pH regime associated with greater macronutrient availability
The nanostructural characterization of strawberry pectins in pectate lyase or polygalacturonase silenced fruits elucidates their role in softening
Este estudio investigó el papel de las pectinas en el reblandecimiento de la fresa, mediante plantas transgénicas con silenciamiento de los genes FaplC (liasa de pectato) y FaPG1 (poligalacturonasa). Los frutos transgénicos (FaPG1) presentaban más firmeza que los del control, Las pectinas de los frutos transgénicos tenían una mayor masa molecular y un mayor grado de polimerización, con cadenas más largas y estructuras más complejas, Los agregados de pectina, compuestos por homogalacturonano y rhamnogalacturonano I, también eran más comunes en estas muestras. Los resultados sugieren que la supresión de FaPG1 tiene un mayor efecto en la firmeza de la fresa al modificar significativamente la nanoestructura de las pectinas
Engaging communities in addressing air quality: a scoping review
Abstract
Background
Exposure to air pollution has a detrimental effect on health and disproportionately affects people living in socio-economically disadvantaged areas. Engaging with communities to identify concerns and solutions could support organisations responsible for air quality control, improve environmental decision-making, and widen understanding of air quality issues associated with health. This scoping review aimed to provide an overview of approaches used to engage communities in addressing air quality and identify the outcomes that have been achieved.
Methods
Searches for studies that described community engagement in air quality activities were conducted across five databases (Academic Search Complete, CABI, GreenFILE, MEDLINE, Web of Science). Data on study characteristics, community engagement approach, and relevant outcomes were extracted. The review process was informed by a multi-stakeholder group with an interest in and experience of community engagement in air quality. Thirty-nine papers from thirty studies were included in the final synthesis.
Conclusion
A range of approaches have been used to engage communities in addressing air quality, most notably air quality monitoring. Positive outcomes included increased awareness, capacity building, and changes to organisational policy and practice. Longer-term projects and further exploration of the impact of community engagement on improving air quality and health are needed as reporting on these outcomes was limited.
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Seasonal drivers of understorey temperature buffering in temperate deciduous forests across Europe.
Aim:Forest understorey microclimates are often buffered against extreme heat or cold, with important implications for the organisms living in these environments. We quantified seasonal effects of understorey microclimate predictors describing canopy structure, canopy composition and topography (i.e., local factors) and the forest patch size and distance to the coast (i.e., landscape factors). Location:Temperate forests in Europe. Time period:2017-2018. Major taxa studied:Woody plants. Methods:We combined data from a microclimate sensor network with weather-station records to calculate the difference, or offset, between temperatures measured inside and outside forests. We used regression analysis to study the effects of local and landscape factors on the seasonal offset of minimum, mean and maximum temperatures. Results:The maximum temperature during the summer was on average cooler by 2.1 °C inside than outside forests, and the minimum temperatures during the winter and spring were 0.4 and 0.9 °C warmer. The local canopy cover was a strong nonlinear driver of the maximum temperature offset during summer, and we found increased cooling beneath tree species that cast the deepest shade. Seasonal offsets of minimum temperature were mainly regulated by landscape and topographic features, such as the distance to the coast and topographic position. Main conclusions:Forest organisms experience less severe temperature extremes than suggested by currently available macroclimate data; therefore, climate-species relationships and the responses of species to anthropogenic global warming cannot be modelled accurately in forests using macroclimate data alone. Changes in canopy cover and composition will strongly modulate the warming of maximum temperatures in forest understories, with important implications for understanding the responses of forest biodiversity and functioning to the combined threats of land-use change and climate change. Our predictive models are generally applicable across lowland temperate deciduous forests, providing ecologically important microclimate data for forest understories
Journal of Microelectronic Research - May 2003
https://scholarworks.rit.edu/meec_archive/1012/thumbnail.jp
Combining biodiversity resurveys across regions to advance global change research
More and more ecologists have started to resurvey communities sampled in earlier decades to determine long-term shifts in community composition and infer the likely drivers of the ecological changes observed. However, to assess the relative importance of and interactions among multiple drivers, joint analyses of resurvey data from many regions spanning large environmental gradients are needed. In this article, we illustrate how combining resurvey data from multiple regions can increase the likelihood of driver orthogonality within the design and show that repeatedly surveying across multiple regions provides higher representativeness and comprehensiveness, allowing us to answer more completely a broader range of questions. We provide general guidelines to aid the implementation of multiregion resurvey databases. In so doing, we aim to encourage resurvey database development across other community types and biomes to advance global environmental change research
Transcript-Specific, Single-Nucleotide Polymorphism Discovery and Linkage Analysis in Hexaploid Bread Wheat (Triticum aestivum L.).
Summary Food security is a global concern and substantial yield increases in cereal crops are required to feed the growing world population. Wheat is one of the three most important crops for human and livestock feed. However, the complexity of the genome coupled with a decline in genetic diversity within modern elite cultivars has hindered the application of marker-assisted selection (MAS) in breeding programmes. A crucial step in the successful application of MAS in breeding programmes is the development of cheap and easy to use molecular markers, such as single-nucleotide polymorphisms. To mine selected elite wheat germplasm for intervarietal single-nucleotide polymorphisms, we have used expressed sequence tags derived from public sequencing programmes and next-generation sequencing of normalized wheat complementary DNA libraries, in combination with a novel sequence alignment and assembly approach. Here, we describe the development and validation of a panel of 1114 single-nucleotide polymorphisms in hexaploid bread wheat using competitive allele-specific polymerase chain reaction genotyping technology. We report the genotyping results of these markers on 23 wheat varieties, selected to represent a broad cross-section of wheat germplasm including a number of elite UK varieties. Finally, we show that, using relatively simple technology, it is possible to rapidly generate a linkage map containing several hundred single-nucleotide polymorphism markers in the doubled haploid mapping population of Avalon · Cadenza
A horizon scan of issues affecting UK forest management within 50 years
Forests are in the spotlight: they are expected to play a pivotal role in our response to society’s greatest challenges, such as the climate and biodiversity crises. Yet, the forests themselves, and the sector that manages them, face a range of interrelated threats and opportunities. Many of these are well understood, even if the solutions remain elusive. However, there are also emerging trends that are currently less widely appreciated. We report here the results of a horizon scan to identify developing issues likely to affect UK forest management within the next 50 years. These are issues that are presently under-recognized but have potential for significant impact across the sector and beyond. As the forest management sector naturally operates over long timescales, the importance of using good foresight is self-evident. We followed a tried-and-tested horizon scanning methodology involving a diverse Expert Panel to collate and prioritize a longlist of 180 issues. The top 15 issues identified are presented in the Graphical Abstract. The issues represent a diverse range of themes, within a spectrum of influences from environmental shocks and perturbations to changing political and socio-economic drivers, with complex emerging interactions between them. The most highly ranked issue was ‘Catastrophic forest ecosystem collapse’, reflecting agreement that not only is such collapse a likely prospect but it would also have huge implications across the sector and wider society. These and many of the other issues are large scale, with far-reaching implications. We must be careful to avoid inaction through being overwhelmed, or indeed to merely focus on ‘easy wins’ without considering broader ramifications. Our responses to each of the challenges and opportunities highlighted must be synergistic and coherent, involving landscape-scale planning. A more adaptive approach to forest management will be essential, encouraging continual innovation and learning. The 15 horizon scan issues presented here are a starting point on which to build further research, prompt debate and action, and develop evidence-based policy and practice. We hope that this stimulates greater recognition of how our forests and sector may need to change to be fit for the future. In some cases, these changes will need to be fundamental and momentous
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