Kveldssanger

Pterocarya fraxinifolia, providing it with ample space to develop a truly majestic form. Gorgeous tree. Also Tilia tomentosa and Tilia henryana. Both absolutely wonderful trees, as individual specimens.

https://en.wikipedia.org/wiki/Andricus_quercuscalicis I believe it would be this, looking at the photo?

06/09/15. Fact #27. Increasingly, research is suggesting that fertilisation is, by-and-large, an unnecessary step in the transplanting process. Backfilling exclusively with native soil has shown to have no significant detraction in root growth over the two-year period following transplanting, when compared to soil that was amended with fertiliser. In the UK, fertilisation is in fact largely not required - soil conditions are typically of acceptable standards in their natural state. Ideally-speaking, soil analyses should be a necessary step in the planning phase of the wider transplanting process. One must understand the current state of the soil before seeking to amend the very same soil, as present properties will influence the dosage (and frequency of applications) needed to bring the soil up to an acceptable standard; assuming it is not at an acceptable standard, of course. And even then, some research papers indicate that fertiliser application has no lasting (or significant) benefits. Care must also be exercised in applying nitrogen-based fertilisers to soils, as application can disrupt the root-mycorrhizal fungi symbiosis; as is it critical that fertilisers are not applied after mid July (as a guideline) because the application will encourage soft, 'sappy' growth that will likely not have time to mature (lignify) before autumn, thus increasing the risk of frost damage if the oncoming winter is bitter. Further to this, the application of fertiliser is mostly ineffective if irrigation is not regular and sufficient, due to the root system being largely unable able to uptake the additional nutrients until the root system has adequately developed into the surrounding soil. Research suggests that only 2-5% of nitrogen applied at the time of planting is ever taken up by the plant. Sources: Davis, M. (2015) A Dendrologist's Handbook. UK: The Dendrologist. Day, S., Bassuk, N., & van Es, H. (1995) Effects of four compaction remediation methods for landscape trees on soil aeration, mechanical impedance and tree establishment. Journal of Environmental Horticulture. 13 (1). p64-71. Day, S. & Harris, J. (2007) Fertilization of red maple (Acer rubrum) and littleleaf linden (Tilia cordata) trees at recommended rates does not aid tree establishment. Arboriculture & Urban Forestry. 33 (2). p113-121. Ferrini, F. & Baietto, M. (2006) Response to fertilization of different tree species in the urban environment. Arboriculture & Urban Forestry. 32 (3). p93-99. Ferrini, F., Giuntoli, A., Nicese, F., Pellegrini, S., & Vignozzi, N. (2005) Effect of Fertilization and Backfill Amendments on Soil Characteristics, Growth, and Leaf Gas Exchange of English Oak (Quercus robus L.). Journal of Arboriculture. 31 (4). p182-190. Gilman, E. (2004) Effects of amendments, soil additives, and irrigation on tree survival and growth. Journal of Arboriculture. 30 (5). p301-310. Harris, J., Day, S., & Kane, B. (2008) Nitrogen fertilization during planting and establishment of the urban forest: a collection of five studies. Urban Forestry & Urban Greening. 7 (3). p195-206. Hipps, N. & Nicoll, F. (1997) Preconditioning Trees to Improve Outplanting Performance. In Claridge, J. (ed.) Research for Amenity Trees No. 6: Arboricultural Practice – Present and Future. UK: HMSO. Rivenshield, A. & Bassuk, N. (2007) Using organic amendments to decrease bulk density and increase macroporosity in compacted soils. Arboriculture & Urban Forestry. 33 (2). p140-146. Smalley, T. & Wood, C. (1995) Effect of backfill amendment on growth of red maple. Journal of Arboriculture. 21 (5). p247-250. Watson, G. & Himelick, E. (2013) The Practical Science of Planting Trees. USA: International Society of Arboriculture.

Is there ever scope to do any QTRAs in the Essex area?

I'll give you that one. Wide verges + limes = beautiful. Or lines of limes in old parks.

Maybe I like streets lined with limes.

These introductions also remind me of the old early 1900s "eh, the grey squirrel will never take on that much in the UK, don't get yer' knickers in a twist!". We all know how that went...

Indeed they do. Fun fact on timber production in this country: hardwoods grow best with a fast growth rate, with the ratio of earlywood to latewood being skewed in favour of latewood with regards to such fast growth - the UK's climate is suited to fast growth rates, thereby producing good quality timber will fewer vessels. Conversely, softwoods aren't of any decent value in this country as a timber crop (cedars, in particular) as the fast growth rate favours more earlywood formation, which means more tracheids (and lower quality timber as a result). (according to Peter Thomas in a talk he did at the Chelsea Physic Gardens).

I read somewhere that Turkey Oak was intended to be a timber crop, and was lauded to be "the next best thing". It never was. I also recall an account where someone acquired a woodland and bought it at a price that reflected the timber quality. They assumed it was English Oak, but turns out... ... ...it was Turkey Oak. Many tears were likely shed that day.

Don't bash the Turkey Oak. It's also useful for timber produ.... oh, wait...

Thinking about buying it, but not sure if the material is covered in other papers. Got Up by Roots and TLBG I-III, as well as Amenity Trees 8. Should be enough to cover most angles.

This one: Reducing Infrastructure Damage by Tree Roots: A Compenduim of Strategies

Gary, a few sources I linked here on beech a week or so ago explain this strategy somewhat. Remember it may only potentially cause significant decay to ensue. Branch attachments usually have good 'barriers' at the base, within the protection zone. Proper cladoptosis processes for the lower branches would reduce risk, assuming specialised opportunists didn't latch-on to the senescing branch and assimilate into the branch structure.

05/09/15. Fact #26. Yes, another one. Nice and short! The terminal bud of the central leader of a tree will usually be the dominant one, and thus will extend to form a shoot (and eventually become a branch / continue the trunk). In some species however, this apical dominance is not as rife, and lateral buds will grow rapidly to form long lateral branches. Take beech in a woodland setting, for instance. As it grows in the under-canopy, it will adopt such aforementioned characteristics, and develop a broad crown with long laterals. However, once canopy space is freed up (triggered by a mortality event to a former canopy tree(s) such as wind-throw, general old age, or otherwise), the 'leader' will grow rapidly and the tree will principally grow vertically in place of laterally. Such long laterals are subsequently shed due to the lack of need in retention, and this brings about trunk defects around 1-4m above ground level. And so, decay may begin... Source: Shigo, A. (1986) A New Tree Biology. USA: Shigo and Trees Associates.

Of course there is scope for this, but it's "too much effort" for most. People aren't trained (nor paid) to think 'outside' of the box unfortunately - only the norm is perpetuated, which is root severance, or tree removal. For all the spiel of "move the target, not the tree", it happens very infrequently. Anyway... Yes, one can 'bridge' over tree roots. Research for Amenity Trees 8 covers this, I do believe.

The Landscape Below Ground series? I, II, and III.

05/09/15. Fact 24. This one isn't wholly arb' related, though is to some extent (with regards to trees that flower and provide a nectar source for insects, including bees). I think it is absolutely worth the mention though, given how important ecosystem health is on the whole, and how the arb' industry and related industries can directly aid with insect population levels in particular. The paper being referenced is currently in press, and the source I used for this was Russia Today's website (linked here). Instead of paraphrasing the article, I will quote it all below - the message is short and clear, already. Bumblebees sickened by an intestinal parasite are apt to visit flowers containing nectar and pollen that have a medicinal effect, a new study reports, indicating the current decline in the bee population could be abated through beneficial plants. Iridoid glycosides, or secondary metabloites found in floral nectar, reduce common parasites in bees, previous research has found. In this case, scientists from the University of Vermont, Dartmouth College, and the University of Colorado-Boulder increased concentrations of two iridoid glycosides – aucubin and catalpol – in turtlehead, a wetland plant frequented by bees in eastern North America. Some plants were given high volumes of iridoid glycosides, while the other half's iridoid glycosides were diluted with sugar water. Parasitized bees -- afflicted with reproduction and foraging complications -- preferred the flower with the highest iridoid glycoside concentrations, the researchers found. Their results are being published in the journal Ecology. "We show that bees might be able to self-medicate, altering their foraging behavior when parasitized so as to maximize their consumption of beneficial plant secondary metabolite compounds," said senior author of the study, Rebecca Irwin, a faculty member at North Carolina State University who was formerly with Dartmouth, according to phys.org. The research team also found that bees would carry more pollen to other flowers from plants with the highest concentrations of nectar iridoid glycosides. "Secondary metabolites are commonly present in floral nectar and pollen, yet their functions are not well understood," said the study's lead author Leif Richardson, a former Dartmouth student now with the University of Vermont. "In this study, we show that these compounds could influence plant reproduction via complex suites of interactions involving not only pollinators but also their natural enemies." The numbers of bees, vital to the pollination process, are dwindling across the world thanks to habitat destruction, pesticide use, and disease. In May, the US Environmental Protection Agency announced new regulations on pesticide use that seek to protect managed bee populations during certain periods of the year. The proposal is part of the Obama administration's National Strategy to Promote the Health of Honey Bees and Other Pollinators. The administration wants to spend upwards of $82.5 million on honeybee research in the upcoming budget year, more than double the current allocation of $34 million. Source: Richardson, L., Bowers, M., & Irwin, R. (2015) Nectar chemistry mediates the behavior of parasitized bees: consequences for plant fitness. Ecology. In press.

Now that's a nasty one...

Very nice. Stalk(less) acorns are good for differentiation at this time of year. robur = stalked acorns petraea = stalk-less acorns

Interesting - thanks for that. Would a dissection of the bracket on the robinia aid with definitive identification?

04/09/15. Fact #23. Dedicated to Gary (impatience is a virtue!). One of my previous facts detailed the life processes of wood-decay fungi, though I'm interested in moving off at a slight tangent with that train of thought to explore the periphery of unspecialised parasites and their relationship with very young seedlings. Seedlings, until a certain age (species-specific, in part, though also driven by environmental conditions - may be from 5 days to 2+ weeks), lack the 'mature' tissue and resistance to pathogens that established ones have (this occurs when pectin begins to convert to calcium pectate within cell walls). This means seedlings are susceptible to unspecialised opportunists, particularly those within the soil. Depending upon the extent of soil-based inoculum, seedlings may in fact be killed before they even emerge from the soil (high inoculum potential). If the inoculum base is lower, seedlings may instead be killed post-emergence. In such instances, where localised humidity is high due to an abundance of seedlings creating a humid micro-climate and high rainfall (or artificial watering), fungal mycelium may spread across the surface from hypocotyl to hypocotyl - such rapid spread is aided by better aeration when compared to soil aeration. Such a concept is termed 'damping-off' disease. Source: Garrett, S. (1970) Pathogenic Root-Infecting Fungi. UK: Cambridge University Press.

Hahaha steady on, it's not midnight yet!

Lots more from the last few days: 1. Suspected P. fraxinea on R. pseudoacacia (not sure what else it could be) - 2. On a Prunus sp. - cannot for the life of me identify it - 3. Suspected P. squamosus on Aesculus sp. - 4. Some very cool A. kollari on Q. robur - 5. Some nibbled-at L. sulphureus on Prunus sp. (cherry) - 6. F. hepatica on Q. robur - Part 1 (on tree) | Part 2 (on ground*) | Part 3 (at office) | Part 4.1 (dissected) | Part 4.2 (more) * a stringy white rot also was present on the dead branch, further up from where the bracket was (as shown by photo of stringy wood fibers) The acidic taste of F. hepatica was definitely something new, when I cooked it. Even with a fair amount of garlic the taste was quite overpowering. Cold see it working with a game stew (pheasant, maybe rabbit, etc), though certainly not something I'd eat by itself again. Looks great when cooked mind you - really rich red-brown. 7. I. hispidus on F. excelsior - 8. I. hispidus on F. excelsior (directly opposite 7) - 9. L. sulphureus on Q. robur (two batches - five days apart) - 10. 9. L. sulphureus on a Q. robur log - Probably some more too, but I forget...

03/09/15. Fact #22. When cable installation works were being undertaken in the London Borough of Havering during the early to mid nineties (started in 1991, and finished by winter of 1993/94 I believe), a survey was undertaken to ascertain damage caused by the trenching works. As a precursor, the installation company (Bell Cable Ltd) stated they had a "tree protection policy". NJUG guidance states roots over 25mm diameter should be protected (as it is poor practice to not do so - unless there is absolutely no means of reconciling the root's presence, one would expect). So when the 1,154 mature trees that could potentially have been impacted by the trenching were surveyed, the surveyors found that: 1. Over 90% of all trees had at least one root of greater than 25mm severed 2. Over 20% had one or more roots severed of 100mm+ diameter 3. The largest root severed was 0.5m in diameter This meant that: 1. 6% (68) trees had to be felled due to the severe risk of retaining them 2. A further 17% (198) had to be crown reduced to lessen wind-throw potential - this number would have increased by another 300 had some trees not been pruned as part of the LA's cycle of maintenance at the time of cable installation Following the presentation of results, Bell Cable Ltd (the company that installed the cables) agreed to pay "substantial compensation" to the LA, including full costs of the investigation, remedial pruning works, felling, three replacement trees for each tree lost, and aftercare costs due to "the loss in amenity value". Conclusions (stated at the time): 1. utilise trenchless technology 2. hand-dig around larger roots if trenchless technology isn't an option 3. LAs should monitor the situation more closely Source: Crane, B. (1997) Damage to Tree Roots by Cable Trenching: a Case Study. In Claridge, J. (ed.) Research for Amenity Trees No. 6: Arboricultural Practice – Present and Future. UK: HMSO.

I am not actually too sure. Perhaps it means it needs specific measures of all other 7 (or 5, sans time and genetic coding)? Shigo didn't seem to elaborate.