Kveldssanger

Crikey, that's quite a broad area of decay (angle-wise). First image looks like a cheese string.

I shall read that. I am aware there was one, though never got around to reading it. That'll be one of the first things I do tomorrow!

The lack of funding really is rather scary, and wasn't there that leaked FC staff survey recently that showed hardly anyone was ready for the new Stewardship programme? It's impossibly difficult to successfully operate with declining budgets and more demands. Citizen science should be kept to simple things, I suspect. People don't report stuff out of malice (I hope!), though certainly they may be over-zealous. On an isolated levels that's OK, but if it becomes not so isolated then that's an issue.

24/03/16. Fact #179. Many studies undertaken by scientific researchers are – by a sort of default – quite limited, in terms of the study’s spatial scale. Whilst this is not necessarily a bad thing, when the point of the research is to use a specific area (such as a city) as a case study, it can limit the effectiveness of problems that occur across a very large geographical area. One such example would be Cameraria ohridella (horse-chestnut leaf miner) presence within the UK, where it is an invasive pest (having arrived in 2002) progressing across the UK that may aggressively defoliate Aesculus hippocastanum (horse chestnut) and thus cause serious tree health problems. An example of horse chestnut foliage being attacked by the leaf miner. Source: The Wild Diary. Because the pest is found in many areas of the UK, understanding its characteristics as a meta-population is important, but tricky (in terms of cost and time) if relying upon the standard method of research. To remedy this issue, a form of science known as ‘citizen science’ can be used, which directly involves members of the public, across very large areas, gathering data and relaying it back to scientific researchers, where the data can then be processed. And would you know it, the study looked at here employs such a form of science, with the aim of understanding: (1) more about how serious leaf damage is from Cameraria ohridella, when comparing leaf damage extent to how long the miner has existed within the local geographical area, and (2) whether parasitism of the leaf miner (by parasitic wasps) is higher in areas where the leaf miner has existed for longer periods of time. The research project was dubbed ‘Conker Tree Science‘ (and is still ongoing, in a slightly different format). In order to bring in accurate information from members of the public, which could be processed and transformed into conclusions, those aiding with the survey (around 875 people, for the first part) were asked to complete a few basic tasks. The first was to determine an average level of leaf mining damage upon foliage of the horse chestnut, with the aid of a very basic diagram (shown below). Such recording was undertaken during June – September of 2010, and alongside the numerical scoring the surveyors also submitted photos of the foliage inspected. This enabled an experienced individual to determine whether recording was accurate, and if not, bias would be accounted for in the data analyses. No bias was found, so the data gathered by the survey participants was considered to be accurate. Ranging from 0-4, with 0 being no damage and 4 being major damage, survey participants reported to what extent the horse chestnut they were inspecting was mined. Where a member of the public had stated the leaf was at least partly damaged, the researchers compared the location of the tree to how long Cameraria ohridella had been known to exist in the area. Of course, the time of year was factored into account, as leaf mining will progressively worsen as the larvae progress through their instar stages; as will it generally worsen as the summer progresses (there may be more than one life cycle of the pest in one summer). Furthermore, because the presence of the leaf miner may have been under-recorded prior to this study taking place (as people became used to its presence,a nd no longer recorded it), the researchers constructed a model that would predict where the miner should have progressed to in the years following 2002. Therefore, if reports came in from areas where there were no records of the leaf miner, the model would allow for comparisons to be made between mining severity and how long the miner had likely been present for in that locality. With regards to ascertaining whether parasitism increased with how long the leaf miner had been present within the local environment for, survey participants were also asked to take small cuttings of foliage during early July 2010 and seal those cuttings in a plastic bag for two weeks. After this time, a count for Cameraria ohridella, parasitic wasps, and any other insects (in case of contamination) was undertaken. In order to identify the different organisms, the researchers provided an identification key to all survey participants. Much of this part of the data collection was done by schoolchildren, with the aid of trained researchers. Following counting of all insects, the data was compared to that gathered by experts, in order to check for bias. No significant issues were found with regards to identifying the leaf miner, so the data gathered by the school children was used in the study without being corrected in any manner. For the parasitic wasps however, it was found that the school children failed to fully identify them in some instances (under-estimation). After collating the results and analysing them, the researchers found that the damage caused by Cameraria ohridella rose for the first three years; at which point, it begun to quickly ‘flatten’ (and thus, damage then remained rather constant, albeit significant). This is shown in the below graph. In this sense, in the fourth year, the leaf miner will most likely be causing maximum damage, and from here-on-in, such maximum damage will routinely occur (of course, it will still vary from year-to-year). Foliar damage associated with Cameraria ohridella, in relation to how long it had been present in the local area of the UK. As for whether parasitism of the leaf miner increased over time, the 2,208 cases of reared insects (1,810 of the cases were from school children) showed that the rate of parasitism increased aongside how long the leaf miner had been present in an area for. Consulting previous literature of parasitism on the leaf miner, the researchers suggest that initially pre-pupal stage generalist parasites will use the leaf miner as a host, though after a few years more specialised pupal stage parasites will succeed into the trophic system. However, once specialised parasites do arrive, it is not expected for there to be a continual rise in their population abundance, as research in mainland Europe has shown that parasitic wasp populations plateau after a some years. Therefore, parasitic wasps may not be able to greatly limit the damage caused by Cameraria ohridella. Such results are certainly interesting, though the manner in which they were obtained is equally so. What we can draw from this is that citizen science certainly has the ability to work, and across a large geographical area; all whilst costing little money and ‘outsourcing’ the time spent on data collection to willing volunteers. This can be good as it engages people with the scientific process, thereby removing it from its pedestal and giving science a form of accessibility. The act of engaging with school children was particularly pleasing to read about, as one never knows whether such research could evoke a greater interest in scientific research for some of those children. Granted, citizen science isn’t a ‘cure-all’ approach, as there are many limiations. The researchers remark that one main limitation in this study was the inability to directly sample wasp parasites, and thus specific species couldn’t be identified. Furthermore, the data is only as good as those collecting it, and because volunteers are unlikely to be amateur gall enthusiasts, data collection must be simple, swift, and succinct. There’s also the need to verify the data after it has been collected, unlike with scientific researchers who will know how to gather data prior to gathering it (and thus eliminating bias, ideally). Nonetheless, a good study, and hopefully citizen science can be used in the future for other projects! Source: Pocock, M. & Evans, D. (2014) The success of the horse-chestnut leaf-miner, Cameraria ohridella, in the UK revealed with hypothesis-led citizen science. PLoS One. 9 (1). e86226.

Always have a glass of milk after a gym session. Bit of a ritual, if I'm honest. Seems to help, as I can walk the day after I do squats. But no, in all seriousness, I have no clue whether it works. In terms of its macro-nutrient breakdown, it should do.

That's absolutely glorious! (not the pressing charges bit) :lol:

Would you ever be willing to travel down to south east Essex?

Sesia apiformis is the clearwing moth, and larvae tunnel within the fresher wood principally, before pupating and leaving the tree. I have not seen them bore into wood to any marked degree, though that's only personal experience. Likely they're feeding on the nutrient-rich sapwood, if anything. I do stand to be corrected though, as I haven't checked!

Aye it's Sesia apiformis.

Endangered magnolia species identified - BBC News Two new species of magnolia flower have been identified after being spotted on "Noah's Ark" online archive. Photographs of the endangered Magnolia dealbata, held by Bristol-based Arkive, were seen by a botanist at a Mexican university more than 5,500 miles away. The plants were tracked to Mexico's Serra Gorda Biosphere Reserve and identified. Lucie Muir, chief executive of Arkive, said they were "thrilled" by the discovery. After seeing pictures of the flowers, botanist Dr Jose Antonio Vazquez asked the original photographer for more images of the plant. Photographer Roberto Pedraza Ruiz said he then made several more trips to the forest "documenting the flowers and fruits of the trees until finally receiving confirmation that I had photographed not only one but two completely new species of magnolias". The first specimen was named Magnolia rzedowskiana, after emininet Mexican botanist, Dr Jerzy Rzedowski, while the second is to be named Magnolia pedrazae, in honour of its photographer. Mr Ruiz said: "This is without doubt the highest honour that a conservationist and nature photographer can receive." The Arkive website, run by the charity Wildscreen, hosts 16,000 images of flora and fauna. It claims to be the world's largest online encyclopaedia of life, receiving donations of images from wildlife film-makers, photographers, conservationists and scientists. Cool, eh!

Nah share it here. Not a derail - still on the topic of fungi. Gary, you haven't derailed it. Don't apologise.

Last image is upside-down!

I know what you mean Gary, and to be honest I agree. I am however responsible for these trees, and without an infinite arsenal of kit at my immediate disposal I have to go with what I think is best in the short and long term. I'm not felling the tree completely - it'll remain as a standing stem of quite some height, and will re-sprout. The decaying habitat remains. It sits between a very busy petrol station and a housing development, and is in falling distance of both. The one next to it went through a car, and I am simply not confident that justifying not doing anything is OK here, and if I were to prune it then it'd be on a two-year cycle (most probably) and would have to eventually be managed to more of a stem anyway. It's making the decision that balances everything (including risk perception, which is very much the case here for residents, though also ecology). Deadwood will be piled at the base, so nothing goes off site. In fact, the nutrients will go back into the soil from where the nutrients were taken. I have another case I found today, too. Even better. By a roundabout! Same course of action, really. Some cracking shots here. Hybrid black pop again. One next to it is nasty as well, so that's also becoming a low stem. Again, all wood piled around the base (or in a nearby hedgerow). Will probably seek to re-plant with a different tree species as well, nearby (probably a couple of common alder). That way, there's a continued regeneration (albeit, the poplar stems remain). If these were of a different species, with a stronger wood (inherently), then I would probably not do what I am doing here. No disrespect to poplars, but there are so many in completely the wrong locations, and they're all starting to fall apart after 40-60 years. Give it another 5-10 years as we'll be a hub of Rigidoporus ulmarius-infected poplars.

Some new images that are much better. On Guernsey. Holm oak is alive, and under the decayed areas are Armillaria boot laces. Madness! Probably a saprophytic fungus, therefore. I told the guy who found it to consider sending samples to Kew, if all else fails.

By all means do, if you get the time. We have quite a few large planes where I work, with many along very busy main routes. May have to discuss how they're managed in terms of recognising that massaria is a potential issue. Currently, I can't imagine there are swift ways of picking up on such decay? I'm talking a line of 100+ planes, in one example.

Fascinating. Sometimes I really do wonder exactly how such strategies of colonisation developed. Is the angle of decay always quite similar, in your experience, or are some branches suffering from narrow decay columns whilst others, like this, quite broad? Couldn't resist...

23/03/16. Fact #178. The pathogen Xylella fastidiosa has been hitting the headlines in the UK recently, because there is growing concern over the risk of it reaching the UK shores and not being caught quickly. This bacteria ultimately causes a leaf scorch that, over time, progresses throughout the crown of its host, and will eventually cause tree mortality. Because it’s not native to the UK, its introduction would potentially be very significant, given no native tree species have any form of resistance to it. Furthermore, as it may attack a huge variety of trees and plants, understanding a little more about its biology is certainly something that should be pursued. With that in mind, I thought I’d look at a study from the District of Colombia, Washington, USA that sought to investigate the population structure of the bacteria in an urban streetscene, with specific focus upon how the bacteria associated with the constituent tree species. Within the District’s street scape, infected trees of the species Morus alba, Platanus occidentalis, Quercus coccinea, Quercus palustris, Quercus phellos, Quercus rubra, and Ulmus americana had foliar samples taken from their structure, which were then taken into the laboratory and the constituent Xylella fastidiosa sequenced (DNA sequencing). Most samples were taken from trees displaying visible symptoms of infection, though some were also taken from trees, or locations upon an infected tree, where there were no symptoms (asymptomatic). The table below gives a breakdown of exactly what samples were taken from which trees. The number of samples taken from each tree species. Following DNA sequencing of all the samples, it was identified that there were five different ‘sequence types’ of the bacteria Xylella fastidiosa. These sequence types were almost exclusively unique to a specific tree genus, though one sequence type (ST-9), whilst found predominantly in oak, was also found in an elm sample (this specific sequence type has been found in elm before, and also sycamore). This near exclusivity of different sequence types occurred almost always, in spite of the fact that many study locations were comprised of infected trees of more than one of the species studied (for example, a site may have contained both mulberry and oak, or elm and sycamore, and so on). Curiously, the elm infected by a type found otherwise only on oak was not near to any oak tree. The host specificity of Xylella fastidiosa. This host specificity is important, because it means that a sequence type infected mulberry is highly unlikely to ever be pathogenic towards oak, for example. However, other studies have shown that ST-8, found here only on sycamore, could also be found on oak and elm. Therefore, certain sequence types may have the ability to infect more than one tree genus, though this is certainly not true for all sequence types. In this sense, a few comments can be made: (1) Monocultures are certainly to be avoided, for those tree species that are susceptible to Xylella fastidiosa. They can swiftly become very extensive inoculum bases for the bacteria as a group, and if they succumb to the infection then an entire swathe of trees can readily be wiped-out. By planting and maintaining healthy populations of an array of tree species of different genera, the impact of Xylella fastidiosa can be reduced (though only in urban areas – outbreaks in woodland settings would be far more impactful, because of a reduced diversity of tree species). (2) Management of the bacteria can be worked down to the sequence type level, and this may prove to be a double-edged sword in terms of management. In a positive light, because cross-contamination of a sequence type is likely to be quite infrequent, targeted management approaches can be created that are specific to the particular strain of the bacteria and specific to the area of infection. Of course, this is also concerning, because one control method for one sequence type may not necessarily work for another, and for those sequence types that do have more than one potential host genus, adaptations on the genetic level may enable it to branch-out to infect other tree genera as well, or become more adept as infecting peripheral species and genera in its current host range. This latter consideration may be one reason why limiting monocultures is important, as the build-up of the pathogen in a suitable inoculum base may potentially increase its pathogenicity. Source: Harris, J. & Balci, Y. (2015) Population Structure of the Bacterial Pathogen Xylella fastidiosa among Street Trees in Washington DC. PLoS One. 10 (3). p1-11.

Interesting shots. Is that a reaction zone stretching radially into (nearly) the core?

Foolish...

Beyond adorable!

hahah aye, I'd say so! To be honest, they get plenty of vegetables from when I cook (carrots, brocolli stalks, peppers), and also fruits (apples, oranges, bananas, kiwis).

22/03/16. Fact #177. Tree defoliators, namely insects, can cause serious damage when outbreaks are severe. In the urban environment, such outbreaks are considered to be more common, because of the urban heat island effect – this is because insects are ectotherms (they require an external heat source). Insects will, in theory, therefore fare much better in such urban environments, compared to nearby rural locations. Additionally, as the vigour of trees will change as a result of warmer urban climates, such alterations may have a positive (or negative) impact upon insect populations. For example, trees that fare less optimally may produce fewer secondary metabolites that dissuade defoliation, and emit fewer herbivore-induced plant volatiles that disrupt herbivory and attract predators and parasites of the insect defoliator. Of course, this has consequences for the host trees, as defoliation outbreaks may thus be more severe, more prolonged, more frequent, and thus more damaging. In order to add weighting to this statement, the authors of this study investigated how the oak scale insect Parthenolecanium quercifex fared in urban environments across Raleigh, North Carolina, USA, with a specific focus upon how urban temperatures influenced their abundance both directly (attraction to warmer areas, increased fecundity in females) and indirectly (rate of parasitism). Because the scale insect only has one generation per year, where the first instar stage of the insect feeds upon leaf phloem tissue before over-wintering upon the bark and developing through the second instar stage prior to pupating and becoming adults the following spring, it was not expected for increased temperature to improve generational turnover rates, but simply enable females to lay more eggs / lay eggs that have a lower mortality rate. Furthermore, as the scale insect is very similar to an array of other insect species and genera, understanding how urban temperatures influenced its biology could give an indicator as to how other insect species would fare in similar conditions. What the authors found, following a survey period, was that Parthenolecanium quercifex over-wintering in the second instar stage were 13x more abundant in warm locations than in cool ones (see the below figure). In addition to this, the ovisacs (where a single egg is layed) were 5.5x more abundant when deposited by the very same adult scale insects that were 13x more abundant, and these ovisacs gave way to first instar stage scale insects 7x greater than on trees in cold sites. Generations of scale insect that spent their entire life cycles in hot microclimates were also observed to, when placed in colder microclimates (in a greenhouse), still be found at higher abundances than scale insects that had spent their entire life cycle in cold microclimates. In this sense, scale insects may locally adapt (in a beneficial sense) to hotter locations, and it is suspected that the scale insect has this ability because populations are highly segmented and therefore site-specific adaptations can occur with relative ease (gene flow is ‘locked’ – meta-populations almost don’t exist beyond the level of but a single, or few, trees). Second instar stage scale insect abundance, in different urban locations, per 30.5cm of tree stem. Conversely, no correlation was identified between urban temperatures and the rate of parasitism upon the scale insect. A total of six parasites were studied, of which none were found to have a significantly increased rate of parasitism when temperatures were higher. In fact, rates were near identical in hot and cold sites, as shown in the graph below. It is suggested that this is because the scale insect’s natural enemies are simply found in less abundance in urban locations, because of the poorer habitat quality. By a similar token, females were not found to lag more eggs on trees in hotter microclimates, and nor was host tree ‘quality’ deemed to impact upon the abundance of scale insects. The rate of parasitism upon the scale insect Parthenolecanium quercifex. Parasites studied included Coccophagus lycimnia, Encyrtus fuscus, and Eunotus lividus. It was also mentioned that it is unlikely that stressed trees would be host to more scale insects, because scale insects would probably be found in lesser abundances where water and nutrients are lacking within the tree. Given urban trees typically struggle because of drought and a lack of nutrient availability, it is thus impropbable that tree quality is an influencing factor upon population levels of the scale insect. If it were then, because the scale insect is a sap-sucker that relishes nutrient-rich sap, a tree lacking this (because of drought and poor nutrient availability in the soil) would not be a able to support large numbers. Therefore, the increase in scale insects in hotter microclimates is likely to be independent of tree quality (condition). To conclude, the authors remark that scale insects are more abundant in urban locations where the microclimate is warmer. As a consequence, if temperatures continue to warm in the urban setting, or become more homogenous (at a higher temperature) across a large urbanised spatial scale, scale insect populations may markedly increase and therefore be potentially very damaging for urban trees. Because urban trees are exposed to so many adverse conditions, an increase in pest activity is certainly not something that will help their case for survival. Such a weakened nature may also leave them exposed to other pests and diseases, which do rely upon weakened hosts to establish in great abundance. Beyond the urban setting, if temperatures increase in rural locations, scale insects may also become more of an issue there. Granted, such rural locations are home to greater numbers of parasites (natural enemies), and thus an increase in numbers there may perhaps support an increase in parasitoid abundance as well. This is, however, just speculation. Source: Meineke, E., Dunn, R., Sexton, J., & Frank, S. (2013) Urban warming drives insect pest abundance on street trees. PLoS One. 8 (3). p1-7.

Not really, but pops are a hard one sometimes I find. Not worth the risk, unfortunately. Pruning it would put it back to where it would be an issue every few years, and cost-wise that's unfortunately not probably feasible. Monolith as a high stem and let it re-sprout from low down.

LOL! :lol:

Are they small fruiting bodies in those peeling bark areas in the bottom image? Silverleaf (Chondrostereum purpureum), maybe?