Unravelling perceptions of Eurasian beaver reintroduction in Great Britain

This is the final version. Available from Wiley via the DOI in this record.Data Accessibility: Due to ethical concerns resulting from the permissions given by participants for use of data in this research, supporting data cannot be made openly available. Data are held by the corresponding author.International Union for the Conservation of Nature (IUCN) guidelines state that anticipated impacts must be considered in wildlife reintroduction, including the impacts on humans. Further, since reintroduction projects can be halted by resulting human–wildlife conflicts or human–human conflicts about wildlife, the perceptions of stakeholders and publics are of great importance. Eurasian beaver (Castor fiber) reintroduction is being debated in Great Britain at a devolved level. A decision has already been taken in Scotland to allow beavers already present to remain, while a number of reintroduction trials are taking place in England (both fenced and unfenced). There are also proposals for a reintroduction trial in Wales. We use a sub‐set of results from a nationwide survey (n = 2,759) to identify four social areas that we propose decision‐makers should consider in the debate: key stakeholder perceptions; engagement methods; attitudes towards legal protection and management responsibilities; and support for management techniques. In this paper, we investigate the complex social dimensions of wildlife reintroduction and we argue that emphasis should be placed on the need to recognise societal perceptions of potential management solutions, beyond perceptions of reintroduction itself. This is paramount in order to develop a management strategy that is more likely to garner social support and reduce potential future conflicts, should beaver reintroduction proceed.Natural Environment Research Council (NERC

Operational Trials of Cut-To-Length Harvesting of Poplar in a Mixed Wood Stand

Cut-to-length harvesting systems offer an alternative to conventional mechanical systems for thinning mixedwood stands. We evaluated the performance of a single-grip harvester and forwarder in a poplar-dominated mixedwood stand in Southern Ontario to quantify the effect of tree size and tree form on harvester productivity and harvesting cost, and to assess the damage caused by the harvesting operation to advance regeneration and residual trees. A single-tree selection silvicultural system was used. Individual trees were assigned a form index based on their visual estimates of limb size and stem form. The cut-to-length harvester produced 23.1 m3 per productive machine hour (PMH). Forwarder productivity was 17.2 m3/PMH. The results indicate a significant and positive relationship between harvester productivity and tree size (dbh) and tree form. Tree size (dbh) has the greatest influence on the unit cost of harvesting. At an average 27 cm dbh and extraction distance of 200 m, the stump-to-landing cost was approximately 10 US$/m3. As tree size increased, the unit cost of wood produced decreased. Damage to residual trees and advance regeneration was minimal. The results suggest that single-grip cut-to-length harvesting systems can be effective in managing poplar-dominated mixedwood stands

Sediment and nutrient storage in a beaver engineered wetland

This is the final version of the article.Available from Wiley via the DOI in this record.Beavers, primarily through the building of dams, can deliver significant geomorphic modifications and result in changes to nutrient and sediment fluxes. Research is required to understand the implications and possible benefits of widespread beaver reintroduction across Europe. This study surveyed sediment depth, extent and carbon/nitrogen content in a sequence of beaver pond and dam structures in South West England, where a pair of Eurasian beavers (Castor fiber) were introduced to a controlled 1.8 ha site in 2011. Results showed that the 13 beaver ponds subsequently created hold a total of 101.53 ± 16.24 t of sediment, equating to a normalised average of 71.40 ± 39.65 kg m2. The ponds also hold 15.90 ± 2.50 t of carbon and 0.91 ± 0.15 t of nitrogen within the accumulated pond sediment. The size of beaver pond appeared to be the main control over sediment storage, with larger ponds holding a greater mass of sediment per unit area. Furthermore, position within the site appeared to play a role with the upper‐middle ponds, nearest to the intensively‐farmed headwaters of the catchment, holding a greater amount of sediment. Carbon and nitrogen concentrations in ponds showed no clear trends, but were significantly higher than in stream bed sediment upstream of the site. We estimate that >70% of sediment in the ponds is sourced from the intensively managed grassland catchment upstream, with the remainder from in situ redistribution by beaver activity. While further research is required into the long‐term storage and nutrient cycling within beaver ponds, results indicate that beaver ponds may help to mitigate the negative off‐site impacts of accelerated soil erosion and diffuse pollution from agriculturally dominated landscapes such as the intensively managed grassland in this study.The Mid-Devon Beaver Project is led by Mark Elliott from Devon Wildlife Trust, monitored by the University of Exeter,and funded by Devon Wildlife Trust, University of Exeter and Westland Countryside Stewards. Further support came from NERC grant: NERC/PE/2016_087 and the Wellcome Trust

Buoyancy-induced flow and heat transfer in compressor rotors

The buoyancy-induced flow and heat transfer inside the compressor rotors of gas-turbine engines affects the stresses and radial growth of the compressor disks, and it also causes a temperature rise in the axial throughflow of cooling air through the center of the disks. In turn, the radial growth of the disks affects the radial clearance between the rotating compressor blades and the surrounding stationary casing. The calculation of this clearance is extremely important, particularly in aeroengines where the increase in pressure ratios results in a decrease in the size of the blades. In this paper, a published theoretical model—based on buoyancy-induced laminar Ekman-layer flow on the rotating disks—is extended to include laminar free convection from the compressor shroud and forced convection between the bore of the disks and the axial throughflow. The predicted heat transfer from these three surfaces is then used to calculate the temperature rise of the throughflow. The predicted temperatures and Nusselt numbers are compared with measurements made in a multicavity compressor rig, and mainly good agreement is achieved for a range of Rossby, Reynolds, and Grashof numbers representative of those found in aeroengine compressors. Owing to compressibility effects in the fluid core between the disks—and as previously predicted—increasing rotational speed can result in an increase in the core temperature and a consequent decrease in the Nusselt numbers from the disks and shroud

Should individual animals be given names in wildlife reintroductions?

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: This manuscript is a perspective piece drawing on case study examples. It does not include data.Individual animals are often given names by humans. For example, names are attributed to domestic animals to acknowledge their closeness to people, some research studies use names to identify differences between individuals in a study group, or zoos often use names to tell stories that attract public or media attention. Publicly naming individual animals can provide opportunities in conservation, but there are also risks. In this perspective we exemplify such opportunities and risks in the context of wildlife reintroductions. We draw on examples and observations from our experience researching Eurasian beaver Castor fiber reintroduction in England, to encourage careful thinking before publicly attributing a name to an individual in reintroduction projects. Naming individuals in reintroduction can: be a low-cost engagement tool; help people relate to unfamiliar reintroduced species; encourage local ownership of reintroduction projects; enable an effective tool for communicating information about the species and ways to coexist; or support creative or cultural expression. Yet naming individuals in reintroduction could: risk misrepresentation of natural species characteristics; make it challenging to normalise the sense that the reintroduced species is a wild animal; unintentionally imply that humans have ownership or power over the animal; cause distraction from establishing viable populations due to focus on the individual; or result in human investment in individual animals, which may have influence on reintroduction outcomes if that animal later comes to harm or dies (naturally or otherwise). Synthesis and Applications. We argue there is more to the act of naming individuals than may first appear. If considering doing so, we call for careful thought about whether it is appropriate and how to go about it. While we intentionally refrain from concluding whether ‘to name or not to name’, we call for careful, informative, message framing that takes advantage of the opportunities and is prepared for future circumstances, when naming of individuals does take place. Read the free Plain Language Summary for this article on the Journal blog

Determination of tip transfer function for quantitative MFM using frequency domain filtering and least squares method

Magnetic force microscopy has unsurpassed capabilities in analysis of nanoscale and microscale magnetic samples and devices. Similar to other Scanning Probe Microscopy techniques, quantitative analysis remains a challenge. Despite large theoretical and practical progress in this area, present methods are seldom used due to their complexity and lack of systematic understanding of related uncertainties and recommended best practice. Use of the Tip Transfer Function (TTF) is a key concept in making Magnetic Force Microscopy measurements quantitative. We present a numerical study of several aspects of TTF reconstruction using multilayer samples with perpendicular magnetisation. We address the choice of numerical approach, impact of non-periodicity and windowing, suitable conventions for data normalisation and units, criteria for choice of regularisation parameter and experimental effects observed in real measurements. We present a simple regularisation parameter selection method based on TTF width and verify this approach via numerical experiments. Examples of TTF estimation are shown on both 2D and 3D experimental datasets. We give recommendations on best practices for robust TTF estimation, including the choice of windowing function, measurement strategy and dealing with experimental error sources. A method for synthetic MFM data generation, suitable for large scale numerical experiments is also presented

Positive coexistence of water voles and beaver: water vole expansion in a beaver engineered wetland

This is the final version. Available on open access from the Mammal Society via the DOI in this recordWater voles (Arvicola amphibius) are critically endangered in Great Britain and there is a pressing need for successful conservation strategies. Meanwhile, another semi-aquatic rodent, the Eurasian beaver (Castor fiber) is being restored to much of its native range including Great Britain. Beavers are known as ecosystem engineers and keystone species, creating wetland habitats. As part of the River Otter Beaver Trial in South-West England, free-living beavers were reintroduced in a location where water vole were present and being surveyed. Here, we present survey data showing the expansion of water vole into newly beaver engineered wetland areas. We propose that complex beaver wetlands may benefit water vole populations by creating new habitat and providing refuge from predation, warranting further investigation as a nature recovery option

A wireless sensor network-based approach to large-scale dimensional metrology

In many branches of industry, dimensional measurements have become an important part of the production cycle, in order to check product compliance with specifications. This task is not trivial especially when dealing with largescale dimensional measurements: the bigger the measurement dimensions are, the harder is to achieve high accuracies. Nowadays, the problem can be handled using many metrological systems, based on different technologies (e.g. optical, mechanical, electromagnetic). Each of these systems is more or less adequate, depending upon measuring conditions, user's experience and skill, or other factors such as time, cost, accuracy and portability. This article focuses on a new possible approach to large-scale dimensional metrology based on wireless sensor networks. Advantages and drawbacks of such approach are analysed and deeply discussed. Then, the article briefly presents a recent prototype system - the Mobile Spatial Coordinate-Measuring System (MScMS-II) - which has been developed at the Industrial Metrology and Quality Laboratory of DISPEA - Politecnico di Torino. The system seems to be suitable for performing dimensional measurements of large-size objects (sizes on the order of several meters). Owing to its distributed nature, the system - based on a wireless network of optical devices - is portable, fully scalable with respect to dimensions and shapes and easily adaptable to different working environments. Preliminary results of experimental tests, aimed at evaluating system performance as well as research perspectives for further improvements, are discusse