Kveldssanger

Will look at that later - got work soon. Else, I'll read it in my lunch break. I read something about why somewhere, though cannot remember the source. Will try to find...

If you're referring to the fact from today, I doubt the authors are suggesting anything different. The comment the authors made was purely with regards to coppicing ability, and the suspected origins. Only when the vascular system is so horrendously wounded that it ceases to function properly, or is removed due to snapping of the trunk, from fire, browsing damage,or otherwise, will dormant buds activate and perhaps trump incremental growth for that single point in time where incremental growth is of lesser importance. If your point is with regards to the use of clonal propagation in a historic sense by early woody angiosperms, I am afraid I cannot really elaborate (though again I do imagine that incremental growth is the most critical aspect; at least initially - competition for light would have been a driver for such incremental growth until the canopy was occupied, though if the canopy was not occupied due to high shade tolerance then perhaps such species could remain smaller and focus more on reproduction after a while). If you're interested in reading the article from where that comment came see here.

^ That would be too easy. The analogous nature of the films would therefore not exist as they do.

Question - are there any papers that look into phenology of trees and fungi, in the sense that where trees are at their weakest point phenologically the potentially-infecting fungi will be at their best (or in a good state at least, to readily establish)?

27/08/15. Fact #16. Bit of a short one, and again quite odd, but certainly something to bring up in conversations about vegetative propagation (does such a conversation ever occur!?). The ability for trees to be coppiced and subsequently re-sprout derives from the tree's natural response to wounding / significant stress (snapping of main stem, uprooting, fire damage, browsing damage, drought, flooding, pests, disease, etc). Such a trait is initially believed to have originated in early woody angiosperms, where the shady, disturbed, wet habitats made clonal reproduction the most advantageous means of species continuation. Such examples of clonal reproduction can be seen today, albeit likely infrequently. In southern England, clonal Prunus avium accounted for 48% and 65% on managed and unmanaged sites, respectively. Such expanses but pale in comparison to a case of Populus tremuloides extent in Utah (USA) however - the 'pando' colony of trembling aspen comprises of 47,000 stems and covers 43ha of land (!!!!). Source: Buckley, P. & Mills, J. (2015) Coppice Silviculture: From the Mesolithic to the 21st Century. In Kirby, K. & Watkins, C. (eds.) Europe's Changing Woods and Forests: From Wildwood to Managed Landscapes. UK: CABI.

I spoke to some colleagues who work in another department today about my job, letting them know what I do day-to-day. I started going on about how leaves lobe to become more 'aerodynamic' in the wind, and hazards associated with trees, and they actually were very receptive. If you show you care when speaking, that passion will come through and people will respond accordingly. Keep up the good work, armybloke! Jules, you make great points. I think Shigo went on to say that man looks for continuous patterns in nature (linear / bell-shaped curves, for example), but nature never works by our laws and preferences. Therefore, the photosynthesis comment can indeed only be what one would 'expect'. Wouldn't burning wood and measuring joules of energy be a means of determining energy stored within the wood? We're thieving buggers - the trees are being all charitable, and we just make it harder for them to live via fragmentation and pollution and then cut them down.

Is this the beginnings of honey fungus on oak? And what's this on willow? Brain not working today...

Nice pics. I have seen I. hispidus on Malus sp. before, and potentially a tiny P. squamosus that was desiccated.

Potentially, I'd say. Depends on how confident you are.

26/08/15. Fact #15. This one is so obscure I thought it'd be rather interesting to share. Not sure how many of you bear witness to the glory of a Prunus padus covered in ermine silk and the thousands of caterpillars that come alongside, though I can say it's certainly not nice to stand under. On that note...: There are times when a host plant may directly or indirectly mediate an inter-specific competition between two (or more) species. One example of this is when Prunus padus (bird cherry) facilitates indirect inter-specific competition between Yponomueta evonymella (bird cherry ermine moth) and Rhopalosiphum padi (bird cherry aphid). Both species will commonly feed on the same tree at the same time of year, and the resulting competitive effects are indirectly mediated by the host tree. Individual Prunus padus trees will differ from one another in regards to their suitability as a food source for Rhopalosiphum padi, and these host tree differences are consistent (they do not change year-on-year) - essentially, trees with high Rhopalosiphum padi counts in one year will always have high counts. This was proven through studies in Scotland and Finland, where it was shown that trees with an abundance of Rhopalosiphum padi eggs had a low number of Yponomueta evonymella larval shields. As a precursor to the following, the former lays eggs within the angle of the bud and shoot, whilst the latter oviposits on the shoot itself. And now it gets interesting. Yponomueta evonymella lay their larval shields on the shoots, and such shields are 13mm long. Therefore, a space of at least 13mm is needed, though realistically 20mm is required on the shoot for oviposition to be "comfortable". Therefore, trees with narrow bud spacings are not suitable for Yponomueta evonymella oviposition. Conversely, as Rhopalosiphum padi lay their eggs within the shoot-bud angle, narrowly-spaced buds (which entails buds being more abundant on the whole; therefore meaning more egg-laying sites on the tree) are preferential. Further, trees defoliated by Yponomueta evonymella always re-foliate (assuming the tree doesn't die) during summer. The leaves subsequently senesce at a later date than those from non-defoliated trees, meaning Rhopalosiphum padi egg-laying is not particularly practical given the lack of 'mineralised' nitrogen (which aphids require as a food source) provided by the later senescing leaves of trees where Yponomueta evonymella has defoliated and caused re-foliation. Basically, where leaves senesce at the 'expected' time nitrogen availability is high, though where the leaves senesce later (following Yponomueta evonymella defoliation) the nitrogen is still 'locked' within the leaf when it comes to Rhopalosiphum padi egg-laying time. And we're not finished yet, as trees heavily attacked by Rhopalosiphum padi respond to such attack by... growing buds more densely along the shoots! Therefore, either heavy feeding by Rhopalosiphum padi makes the tree less desirable for Yponomueta evonymella, or defoliation (and subsequent refoliation and later leaf senescence) by Yponomueta evonymella makes the tree less desirable for Rhopalosiphum padi. Therefore, we see higher populations of one or the other on specific Prunus padus. In older Prunus padus, the suitability of which species they are more able to support has long been decided (I would imagine very early on in the life of the tree would such species suitability be determined - perhaps even pre-natally). As research indicates the type of defoliation drives different colonisation habits of both species, perhaps identifying where the fate of the tree is decided is the next step for researchers. I would suggest that genetic traits drive early colonisation abundances, and from there the tree is 'shaped' into a host for (predominantly, though most exclusively) one of the two insects. Source: Leather, S. & Bland, K. (1999) Naturalists' Handbook 27: Insects on cherry trees. UK: The Richmond Publishing Co. Ltd.

I am inclined to agree, though a better leaf shot would be preferable. BL c'spur (C. persimilis 'Prunifolia') has very small thorns up to 2cm, I believe. The normal C. crus-galli has much larger ones.

Hah talk about timing. Did it earlier at work and sent them an email about it too.

I can agree with that. I've had a few residents say the only things trees are good for is "making a mess". The fact they quite literally support ecosystems by providing oxygen doesn't even register.

Might shoot the AA an email and ask if they'll consider a livestream (or playback / DVD option). Won't be too hard. I'm sure you'll be a little rusty when it comes to reading after such long days... ... ...yeah that was rather poor.

24/08/15. Fact #14. Given UKTC's discussions over big urban trees and their benefits, I thought I'd share a fact from a recent study into the perceptions residents have with regards to urban trees. It seems to be that the amenity benefits of trees are markedly more recognisable than other benefits by residents of urban / sub-urban areas. When homeowners of a new development (all of which had trees in their front garden) were surveyed, the 38 respondents identified 55 benefits of trees, of which 36 where aesthetic, 10 environmental, 2 economical, 2 social, 3 none (!!!), and 2 'other'. 49 disadvantages were also recognised among the respondents. 16 residents stated the visual or physical obstruction caused by trees was detrimental, 13 stated leaf shedding was an issue, 7 outlined concerns over risk of damage to property or person, 2 were wary over future maintenance needs, and 11 respondents identified no disadvantages. Now here's where it gets more interesting. When residents were informed that the trees in their gardens would reach height x in maturity, 30 of the 38 respondents (79%) stated they would look to restrict the height of their tree. A further three said they would remove their tree. Only five were happy to allow their tree to grow unrestricted. There was a strong association between the disadvantages individuals listed and their probability of restricting tree height (or removing the tree entirely), with the most significant association being that of the tree causing obstruction (light, view, literal obstruction) and pruning work. Small trees under 6m were the stated preference of 23 residents, medium trees of 6-9m were preferred by 13 residents, and only one resident admitted to preferring trees of a large size (9m+). One respondent did not mind. I could go on ad nauseum, though that wouldn't be right! Instead, I'll round up by saying the authors did an i-Tree analysis of two potential scenarios on pollutant removal 10 years into the future: (1) leaving all trees to grow unrestrained for the 10 years and (2) seeing the 79% of trees continually pruned and a further three removed (totaling to 87%), as desired by the respondents, and ascertaining their value after 10 years. The analysis concluded that 149% and 88% of pollutants would be filtered out respectively, after the 10 years had passed, when compared to the value the trees provided at the time the survey was undertaken. Source: Andrew, C. & Slater, D. (2014) Why some UK homeowners reduce the size of their front garden trees and the consequences for urban forest benefits as assessed by i-Tree ECO. Arboricultural Journal. 36 (4). p197-215.

Nice fact, Alec!

Shigo suggests that above 40 degrees Celsius, air temperature causes a sudden and massive loss in photosynthetic capacity. The graph you have copied here is a more gradual slope up to the 28-35 range, and then a very swift drop by 40.

I'll binge read Rust Diseases of Willows and Poplars whilst the conference is on, bemoaning my lack of time to juggle many things at once. If only they set up a live feed and I could pay to watch from my laptop... or even release a DVD. Apparently this year's Big Barn Conference is meant to come out on DVD...

Great addition to the discussion there, Julian. Generational turnover is indeed a driver of species and sub-species development. I do wonder that as forest patches become more fragmented whether associated genetic drift will reduce the likelihood of new species developing. It can work the other way too however, with fragmented pockets of a species slowly evolving into a new sub-species (ultimately it would depend on the starting genetic pool of a species, and wouldn't work for vegetative propagation - perhaps genuses and species that reproduce primarily vegetatively don't therefore have as many species and sub-species respectively?). I wonder if there is any research on such a topic... As for today's fact, it's going back to the basics and is again from Shigo's Modern Arboriculture (still reading it!). 23/08/15. Fact #13. Photosynthesis, which is an autotrophic means of energy synthesis, involves the conversion of solar radiation (that comes in waves or particles: photons) to sugars (glucose). In the rawest sense, the photon strikes an electron within the chlorophyll molecule, the electron gets excited as a result, and in the process of it returning to an unexcited state the energy it gives off is captured and utilised to split a water molecule and to then bond the split molecule to a carbon dioxide molecule, producing glucose. The two principal drivers of photosynthesis (excluding plant vigour and vitality - genetic trait and situational trait respectively) are light and temperature. Efficient photosynthesis can occur, at least on paper, when light availability is akin to 1,500 foot candles and temperature is between 28-35 degrees Celsius. Once temperature reaches 40 degrees or above, regardless of light availability, efficiency is significantly impacted. Interestingly, only 0.1%* of the sun's solar energy is captured by plants (for any given increment of time - a second, a minute, an hour...). Of this 0.1%, 50% is captured by trees. Source: Shigo, A. (1991) Modern Arboriculture. USA: Shigo & Trees, Associates. *I believe the 0.1% would be of 1.08x10(to the power of 14) kW, going by this source. That means 108,000,000,000 kW (one hundred and eight billion) of energy is utilised by plants per second, of which 54,000,000,000 kW (fifty four billion) is used by trees (someone please double-check this!).

Myerscough College, Capel Manor College, Writtle College, Otley College, Treelife, and some other colleges and consultancies. I believe Edinburgh offers some forestry courses, and Cambridge and Oxford will by default provide courses I would imagine. Myerscough and Treelife and probably the two most popular, alongside Capel Manor.

^ Agreed. There are certainly many who can differentiate native species of tree and common introduced ones, though many exist who can't. I would say one should also have at least a moderate understanding of fungal fruiting bodies, etc. Having never done the practical side, I cannot relate too much, though it is certainly refreshing when the arborists I speak with have a sound awareness of tree physiology, pests & diseases, etc. What happens if a customer asks you to look at "that tree" down the end of the garden that has a fruiting body on it, and you don't know what species of tree (or fungus) it is? The answer isn't always "just fell it" - it is situational and requires knowledge that extends beyond pure knowledge of how to correctly prune and fell trees.

You are correct - that is what I am saying. Obviously I can only take the word of those in Aus' saying that they declined bribes, though given locals out there have accepted compensation and then don't speak out (so to speak), one can put two-and-two together and get four instead of five. On the topic of media and the lack of reporting on certain things, or the over-reporting of a particular agenda, check out this video (saw it a few months ago and it's very good, from memory - only a short video): youtube.com/watch?v=-bYAQ-ZZtEU

The documentaries at the start go some way to explaining contamination of the water table, as well as gas leaks from the ground, through rivers, lakes, etc. Many VOCs are also released into the air in the process that can only be seen via infra-red means, though I do believe that this country (the UK) is not mandating the use of infra-red sensors to ascertain VOC release from fracking operations. Contamination has taken place in Australia without a shadow of a doubt. There are videos documenting this, with many bore holes that locals utilise becoming so laden with toxic compounds that they can no longer drink the water, bathe in it, or use it for any other means. Fracking also requires a lot of water, and naturally-occurring aquifers have been shown to dissipate at up to six times the rate they can sustain themselves, again in Australia. As only one well has been drilled over in the UK (as far as I am aware), data from the UK is sparse. Data from AUS and USA is not sparse however, and we need to be analysing that if we are to begin to understand what fracking will do to our country as well. As a side note, fracking companies in AUS have given compensation to residents impacted, though if they accepted the compensation they also agree to a gagging order. No longer can they talk about fracking whatsoever. Those that didn't take the money (100,000+ Australian Dollars) are free to talk. That's another reason why there is little direct 'social data' from those impacted.

An article was scanned in this thread earlier that mirrors what I have read before - the 'chemicals' added to fracking 'water' may include those that can otherwise not be disposed of with financial ease. As only 40% of the water sent down for fracturing actually comes back up, the remaining 60% permeates into the rock formations and any underground water reservoirs / the water table. Potentially as easy way of ridding waste chemicals. If this is indeed a driver, direct profit may not be simply the only influence. Sometimes it's very hard to base arguments in absolute fact when information is held back so readily by the same companies one is looking to liaise with about proposed developments. I'm sure if the fracking industry was honest, there would be no manner in which any well construction could be justified.

Some may argue we simply vote for which wolf (we can choose wolf 1 or wolf 2) we want to rule us... It is indeed a matter of opinion. That is, assuming, nothing arises to the contrary of it simply being an opinion. When does something become an 'observable opinion', per se?