Forestry is applied mathematics part 2: Pythagoras' theorem and SOHCAHTOA

I can tell it is only the second lecture of the first semester of first year for National School of Forestry students on their 'Measuring Trees and Forests' module because they are already all sat in the room when I arrive, right on time. Also, they hush as I enter. Neither of these things will last, thankfully. I find them slightly disconcerting. "Talk amongst yourselves" I say, and they do, kind of, but not with the lack of care that second and third years would have. It is not that familiarity breeds contempt, but that it takes time for them to grow into the role of adult, and, sadly, fee-paying learners. As soon as I move across from firing up the computer towards the whiteboard, I can feel their eyes on me. I know they are dreading the appearance of more scientific names of tree species to be tested on, but that is a challenge in another first year module. 'S O H C ...' I write, and the murmuring begins. "Sine" says one. "Cosine" another adds, confirming at least a couple of them are on the right track. "Opposite" returns the first. '... A H T ...' "Tangent" a chorus now. "Adjacent", it is the first one again, probably someone who did well at GCSE Maths, possibly even did it at A level, maybe even would admit to liking maths. I had better watch out, they will almost certainly know more than I do. '... O A'. Finished I step back to survey the whiteboard with them: S O H C A H T O

Climate smart forestry

The majority of ecologists either do not know, or quickly forget, that the first published record of sustainability originated from a book about forest management. In 1713, Hans Carl von Carlovitz wrote Sylvicultura Oeconomica to describe “the sustainable management of forest resources”. His intention was admittedly to manage the supply of timber, primarily for the silver mining industry. Nonetheless the concept of long-term management of resources to protect future yield as well as supplying present need can be attributed to him. The majority of foresters either do not know, or quickly forget, that part of the work of their professional body, the Institute of Chartered Foresters, is to “foster a greater public awareness and understanding of forestry in order to serve a variety of commercial, recreational, environmental and scientific interests.” To further this aim, the National School of Forestry, University of Cumbria, is participating in Timber Festival this summer. We hope to give people the opportunity to learn some forestry skills, but also to engage in public discussion of how sustainable forest management can be part of the solution to climate breakdown and biodiversity loss, while providing space for recreation, improving health and well-being, reducing flooding impacts and supplying the timber and other wood products we need. This article sets out how UK forestry currently contributes to combatting climate breakdown and biodiversity loss - the twin challenges of our time - and explains how managing commercial forest plantations protects rather than threatens our ancient semi-natural woodland

What ‘rewilding’ really means for forestry

The Forestry Commission was established 100 years ago to create a “strategic reserve of timber” after Lloyd George stated “Britain had more nearly lost the war for want of timber than of anything else”. The UK is 50% self-sufficient in food, but only 20% self-sufficient in wood, so we still want timber more than anything else. Any call to redirect subsidies to restore woodlands is welcome (Use farm subsidies to rewild quarter of UK, urges report, 21 May). The Rewilding Britain report states: “Commercial conifer plantations should not be eligible, except where they are removed and replaced with native woodland.” This approach is understandable if the aim is to increase habitat for wildlife. However, plantations are an excellent way to combat climate breakdown, because the growing trees sequester carbon and the forests store it, just like in more natural woodlands, but harvested wood products also provide a carbon substitution effect when used instead of concrete or steel. The report suggests healthier eating can release land from intensive agriculture, but conversely we should be using more, not less, wood. Any different approach in the way land is managed should include plantations, which can also be native trees to produce timber alongside the restoration and expansion of our most precious ancient semi-natural woodlands. Without this we are dependent on greenhouse gas emissions to import wood

So many ways – big and small – to capture carbon

The natural climate solutions approach proposed by scientists and activists including Michael Mann, Greta Thunberg and George Monbiot* is a vitally important component of our global approaches to tackling climate and ecological breakdown. But carbon sequestration by trees (the removal of carbon dioxide from the air via net photosynthesis), and carbon storage in forest ecosystems (especially soils) are only two of the methods by which sustainable forest management can combat climate change. The third method is the carbon substitution effect achieved by replacing fossil fuels, either directly as bioenergy, or indirectly through use of wood (for example as structural timber) instead of higher carbon footprint materials, such as concrete and steel. In the UK, with only 13% forest cover, we are less than 20% self-sufficient in wood products and thus need to increase all three methods of using forestry to mitigate climate change. Otherwise we are dependent on importing harvested wood from other parts of the world rather than helping restore their forests. Climate-smart forestry is an approach that considers how natural woodlands and commercial forest plantations need to adapt to climate change while maintaining, and increasing, their climate mitigation through individual trees, in the forest and by products from the forest. This needs to be achieved without reducing the other benefits to society that the forest habitat provides, such as flood mitigation, access for recreation and associated health and wellbeing. * Monbiot, George. The natural world can help save us from climate catastrophe. The Guardian 3rd April 2019 https://www.theguardian.com/commentisfree/2019/apr/03/natural-world-climate-catastrophe-rewilding Thunberg, Greta et al. A natural solution to the climate disaster. The Guardian 3rd April 2019 https://www.theguardian.com/environment/2019/apr/03/a-natural-solution-to-the-climate-disaste

Every sandwich needs a filling

As part of this month's focus on education, Dr Andrew Weatherall of the National School of Forestry, University of Cumbria, considers the importance of good placement opportunities for 'sandwich' year students. All final-year BSc students who have undertaken the optional sandwich placement year at the National School of Forestry, University of Cumbria, have job offers prior to graduation in 2019. These are students on BSc (Hons) Forest Management and BSc (Hons) Woodland Ecology and Conservation. The National School of Forestry also currently delivers an FdSc Forestry with a compulsory placement and a BSc Forestry top-up, to enable foundation degree students, on our course and similar ones, to progress through to BSc immediately or after some time working in the forest industry. We are proud of all our students, but it is clear that employers look for graduates with a combination of a good academic qualification and some relevant forestry experience. We do not consider our students to have completed their education when they graduate, but think they are ready to continue their learning on graduate schemes or in other early-career-development positions. It is also clear that applicants want to obtain a combination of education and experience from their university studies. Our data on current applicants for next year's intake shows that 86% of those applying for the BSc programmes (which can be chosen with or without sandwich placement) wish to take the 'with sandwich placement' option. In addition, as the FdSc students must take a placement on their course, this means that we will be looking for at least 17 placements for students commencing in September 2019

The use of digitally altered photographs to assess stakeholder woodland cover preferences in internationally important cultural landscapes; a case study in the English Lake District National Park.

This project explores the effectiveness of digitally manipulated photographs for evaluating peoples' preferences towards woodland cover in an internationally important cultural landscape. A photograph of a well known English Lake District view was digitally altered to produce six images with greater or lesser amounts of woodland cover. Using an online survey, respondents were asked to identify which image represented current levels and which their preferred levels of cover. The responses were then related to the personal data of the respondents. 506 usable responses indicated a strong preference for increased woodland cover. Accurate identification of the location and cover levels was related to proximity of domicile, age and frequency of visit. The nearer respondents lived to the Lake District the greater the preference for increased cover. Employment, domicile, age, gender, settlement type and voluntary organisation data were recorded. Women were less extreme in their preferences than men and farmers tended towards open field perceptions and preferences. Photomanipulation is shown to be an effective tool for assessing preferences for degree of woodland cover and could be well applied to more representative data gathering than online survey

Meiotic drive adaptive testes enlargement during early development in the stalk-eyed fly

The sex ratio (SR) X-linked meiotic drive system in stalk-eyed flies destroys Y-bearing sperm. Unlike other SR systems, drive males do not suffer fertility loss. They have greatly enlarged testes which compensate for gamete killing. We predicted that enlarged testes arise from extended development with resources re-allocated from the accessory glands, as these tend to be smaller in drive males. To test this, we tracked the growth of the testes and accessory glands of wild-type and drive males over 5–6 weeks post-eclosion before males attained sexual maturity. Neither of the original predictions is supported by these data. Instead, we found that the drive male testes were enlarged at eclosion, reflecting a greater allocation of resources to the testes during pupation. Testes grow at a higher rate during early adult development in drive males, but there was no evidence that this retards the growth of the accessory glands. Further experiments are proposed to investigate whether smaller accessory glands only arise in drive males post-copulation or when flies are subjected to nutritional stress. Our experimental findings support the idea that enlarged testes in drive males arise as an adaptive allocation of resources to traits that enhance male reproductive success

Management to conserve biodiversity is likely to increase soil carbon storage in upland Atlantic oakwoods in the United Kingdom

The objective of this research was to determine whether fencing to exclude grazing from upland woodlands to facilitate the natural regeneration of trees is likely to increase soil carbon storage. Permanent sample plots were established along a transect through Young Wood, the highest Atlantic oakwood in England, immediately prior to fencing and exclusion of sheep in autumn 2008. Plots outside the wood contained either heather (Calluna vulgaris), bilberry (Vaccinium myrtillus), gorse (Ulex europaeus), wavy hair grass (Deschampsia flexuousa) or mixtures of these species. The wood is 99% sessile oak (Quercus petraea) with woodland ground flora such as heath bedstraw (Galium saxatile). Soil samples were analysed for carbon and nitrogen content. Results indicated that more carbon is stored in soil under the oaks than in either heather, bilberry, gorse, grass or mixtures of these species. In conclusion, this study showed that fencing and excluding grazing to conserve Atlantic oakwoods at their altitudinal limit in the United Kingdom is likely to have a carbon mitigation benefit as well as protecting and enhancing the biodiversity for which the management was initially intended

Ground-based and LiDAR-derived measurements reveal scale-dependent selection of roost characteristics by the rare tree-dwelling bat Barbastella barbastellus

Bats use roosts for protection, sociality and reproduction. Lack of knowledge regarding the specific roost preferences of tree-dwelling bats means that roosts are regularly removed from woodland during felling and thinning interventions, even when woodlands are managed to promote biodiversity. The often-unintentional loss of roosts this way continues to constrain efforts to conserve many rare bat species. We investigated roost selection by the barbastelle Barbastella barbastellus in fragmented oak woodlands in southwest England. Twenty-nine bats were radio tracked to 44 tree roosts between 2007 and 2015. Twenty-four different characteristics of roosts were measured using a combination of ground-based field surveys and airborne light detection and ranging (LiDAR) imagery, and roost characteristics were compared with those of random trees to determine selection. Bats selected trees in ancient semi-natural broadleaved woodland over other woodland habitat types. Standing dead oak (Quercus spp.), while scarce, was positively selected over other tree types and supported significantly more suitable roost cavities. Roost selection was most strongly influenced by the number of cavities present on a tree and the openness of the canopy around the tree. The height of roost cavities and distance to water were also important features that influenced selection. Pregnant and lactating bats switched roosts less frequently than post-lactating and nulliparous bats and selected cavities higher on trees, most likely to facilitate the development of offspring and reduce the risk of predation. Old growth woodland is vitally important to barbastelles and so the preservation and restoration of these habitats should be a conservation priority. While standing dead trees supported more preferred roost cavities than other tree types, our findings indicate that any tree supporting a suitable cavity may be used as a roost, irrespective of the size, condition or species, and should be retained wherever possible. Promoting the natural succession of younger woodland will help to deliver additional sustained benefits in the future

Rewilding: continuing the debate

University of Cumbria experts Dr Andrew Weatherall, Dr Lisa Fenton and Dr Ian Convery contributed a write up of their panel discussion on rewilding from the recent Timber Fest (three days of music, art and performance held in the heart of the National Forest to celebrate 'the transformative impact of forests'). The article featured online in the August 2019 edition of The Ecologist