Kveldssanger

I bet you were petrified... ... ... :001_tt2::thumbup1:

These devils are also cultivating Amanita muscaria. Clearly they will be using the fungus for nefarious purposes, such as contacting Gaia to obtain April's lottery numbers.

He was obviously disgusted then, as his back is to the door!

It is frequently remarked how deadwood is highly valuable for bacteria, bats, birds, insects, and fungi, but all too often do we forget that fairies also benefit greatly from deadwood of the standing kind. Today, I actually came across a fairy home at the base of an oak tree, and in light of this monumental discovery I thought the first thing I’d do it write about it in the most serious of manners. Below, I have included the best photos of what is classed as a fairy door, though in this instance there seems to have been some form of ecological succession, as the fairies seem to have also begun to landscape the surrounding area. Frighteningly fabulous. What may this be? Is it a gateway to the kingdom of Hades? Is it a public restroom? Perhaps neither; for it is a fairy door. A rather quaint little abode, though as it is exposed on its south-western side, I expect the heating bills are quite high. A well-trained gateway of ivy greets all visitors who are under 20cm in height. A well-laid table, with utensils that may actually be a form of antiquated javelin. A gnome stands a silent vigil, though doubles-up as a riddlemaster. A selection of choice firewood ensures the heating bills may actually not be so high after all.

Nah that's cool - the post isn't going anywhere! Yeah after four and a half years I thought it'd be unfair to drag it out any longer, so I am now set to spend the rest of my life with Modern Arboriculture. :laugh1:

It's a slippery slope!

There are many new research articles out on DED breeding, and as you're probably aware Gary I did a post on it here: https://arboriculture.wordpress.com/2016/03/10/breeding-for-dutch-elm-disease-ded-resistance/ Those books looks good - added to my list of stuff to buy when I have some funds spare. Blew my budget on a damn ring this month!

Yeah, I'd never have guessed that! Nice shot - from the Heath?

I confess I don't think I know, then. I checked my shots of I. hispidus last night as I considered much the same as Sean, though I cannot think of what else guttates and has such an underside. Postia can guttate, but it looks too big to be one of those.

Gonna have to get some sleep, first. Perhaps it'll come to me, in a dream...!

Hmm... I know P. dryadeus exudates liquid on the upper surface, though I haven't seen enough to know whether they do below, as well. I notice a few brown specks, which suggests perhaps a Ganoderma, though I wouldn't rule out Perenniporia either with this as I cannot actually see whether those brown specs are spores or just little insect mines or what have you.

Chicken, due to the insects?

Aye, back on point (but thanks for the reply). My immediate reaction was P. squamosus, though I don't think you'd be that kind to give us such an easy one!

11/03/16. Fact #171. The cuticle is the primary barrier against uncontrolled foliar water loss, and is comprised of a continuous cutin membrane, waxes, and polysaccharides. The cuticle ultimately controls the transfer of water on both an intra-ceullular level and on an atmospheric level, thereby aiding with the reduction of water loss through the epidermis (Riederer & Schreiber, 2001; Watson, 2006). In conifers, water loss is controlled not only by very thick waxy cuticles, but by the leaf area being segmented into a massive abundance of smaller single leaf areas – this segmentation of the leaf ‘mass’ is known as a xerophytic adaption (Watson, 2006). Further, and as previously established, sun leaves will also be smaller in order to reduce surface area and, subsequently, transpirational loss (Givnish, 1988; Nobel, 1976). The stomata, found below the cuticle layer, facilitate the rate of transpiration. They are usually less abundant on the upper epidermis than on the underside, as upper epidermis abundance would provide more risk of significant water loss by the leaf. Stomata begin to close when hydration levels of the soil begin to fall, thus ensuring that necessary water is retained within the plant. However, as stomata are required for gas exchange, their full closure halts any gaseous exchanges. To combat this however, the cuticle layer can provide for limited gas exchange so leaf operations can continue; albeit at a reduced level (Boyer et al., 1997). Stomata control moisture loss through the two guard cells that surround and regulate each stomatal pore. To optimize the trade-off between carbon dioxide induction (which also occurs via the stomata) and transpirational water loss, stomata sense and respond to a range of environmental signals that include ambient carbon dioxide concentration and soil moisture levels. As moisture levels drop, stomata will reduce their size in response via the closure of the guard cells (Doheny-Adams et al., 2012). Abscisic acid will regulate such stomatal closure under drought conditions, and the flow of positively-charged potassium ions out of the guard cells will facilitate their closure by drawing out water alongside through osmotic processes (Karban, 2015). In very drastic drought conditions, leaves may control water loss by abscising from the tree, thus reducing potential transpirational area and also reducing the overall water demand of the tree. Juglans ssp. for instance are known to shed leaves in times of severe drought, and such an act is defined as vulnerability segmentation (Tyree et al., 1993). Typically, leaves will be shed from the lower crown primarily, as their role is of lesser criticality than the upper crown’s leaves, and the increased competition for light in the lower canopy means retaining such leaves may be impractical (Achten et al., 2010). As a side note, buds will form within leaf axils as soon as leaves begin to develop. Therefore, if leaves are shed, new leaves can readily be grown again, and the same process will begin once more (Shigo, 1986). This adaption essentially means trees can continue to live following intentional or unintentional (herbivory, pruning, etc) defoliation – this is of direct benefit to the tactic of leaf shedding in drought conditions. Additional means of controlling water loss include altering the angle at which the leaves face the sun (such as with Fraxinus excelsior), through the growth of small hairs that trap air and make it more difficult for water to escape in dry conditions or conversely aid with water release by keeping the leaf surface clear of moisture build-up during times of very high humidity, and by adopting one of two leaf macro-morphological adaptations: (1) grow rather thin leaves in times where conditions are adverse, shedding them once conditions improve, and / or (2) growing leaves that are small and covered with a leathery cuticle, thereby persisting through the adverse conditions and increasing photosynthetic rates once conditions improve again (Davis, 2015). References Achten, W., Maes, W., Reubens, B., Mathijs, E., Singh, V., Verchot, L., & Muys, B. (2010) Biomass production and allocation in Jatropha curcas L. seedlings under different levels of drought stress. Biomass and Bioenergy. 34 (5). p667-676. Boyer, J., Wong, S., & Farquhar, G. (1997) CO2 and water vapor exchange across leaf cuticle (epidermis) at various water potentials. Plant Physiology. 114 (1). p185-191. Davis, M. (2015) A Dendrologist’s Handbook. UK: The Dendrologist. Doheny-Adams, T., Hunt, L., Franks, P., Beerling, D., & Gray, J. (2012) Genetic manipulation of stomatal density influences stomatal size, plant growth and tolerance to restricted water supply across a growth carbon dioxide gradient. Philosophical Transactions of the Royal Society of London B: Biological Sciences. 367 (1588). p547-555. Givnish, T. (1988) Adaptation to sun and shade: a whole-plant perspective. Functional Plant Biology. 15 (2). p63-92. Karban, R. (2015) Plant Sensing & Communication. USA: University of Chicago Press. Nobel, P. (1976) Photosynthetic Rates of Sun versus Shade Leaves of Hyptis emoryi Torr. Plant Physiology. 58 (2). p218-223. Riederer, M. & Schreiber, L. (2001) Protecting against water loss: analysis of the barrier properties of plant cuticles. Journal of Experimental Botany. 52 (363). p2023-2032. Shigo, A. (1986) A New Tree Biology. USA: Shigo and Trees Associates. Tyree, M., Cochard, H., Cruiziat, P., Sinclair, B., & Ameglio, T. (1993) Drought‐induced leaf shedding in walnut: evidence for vulnerability segmentation. Plant, Cell & Environment. 16 (7). p879-882. Watson, B. (2006) Trees – Their Use, Management, Cultivation, and Biology. India: The Crowood Press.

Hampstead is just a glorious outlier for fungal ecology, it seems! It helps that it has had continuity of landscape for many centuries, in some manner of the word. Such long-term existence of a generally 'green' has enabled for fungi to succeed and establish over many generations, and the massive presence of mature and veteran trees certainly helps. Slightly off topic here, but is there a long-term plan at the Heath to ensure there are enough veteran trees of the future?

Wahey! Nice fungus, actually - rather rare, no?

Evidently white spores, with a grifola / merip-esque morphology. I had a look through Roger Phillips' mushrooms polypore section, and Podoscypha multizonata stood out immediately. I noted the flash would brighten the actual colours, so I was looking for a slightly duller but richer colouration. (did I pass the test?)

I try to where I can - that and keeping trees as standing stems, wherever possible (complete with stubs). I'm experimenting with the idea of planting daffodils around standing stems of dead trees and high stumps, in an attempt to make them more amenable along streets verges.

Nice link - thanks, Jon.

Podoscypha multizonata?

Interesting, 'aint it! I'll look to do more of these, as I wrote that for my Lvl 4 though really want to look at other P&Ds as well. Got so many things I want to do it's just hard to find the time. Writing a lot on the benefits of trees right now, and have amassed 20,000 words for economic impacts and ecological impacts. In time, I'll share some of that. Plenty more things to look at there - hence why I'm hoarding books, in part.

For the sake of my sanity, can we please rule out chicken of the woods right now, else I might actually have a nervous breakdown.

10/03/16. Fact #170. Following on from the mass mortality of elms across the UK’s landscape in recent decades (and also an earlier spate of the disease during the first half of the last century), there has been a huge desire to breed resistant stock, in an attempt to have elms grace the landscape once more. However, such a pursuit has been very slow in terms of substantial progress, and it is only in more recent years that more significant developments have begun to manifest in breeding resistance against Ophiostoma novo-ulmi. In fact, not all of these advancements have been in the UK – research across Europe and the US has really helped shape the way forward for the elm, given the disease was responsible for the loss of elms across both continents (Lamb, 1979; Venturas et al., 2014). Because resistance to Ophiostoma novo-ulmi (DED) is considered to be largely polygenic (qualitative) – in the sense that resistance does not follow a major gene pattern, but instead by the effective production of phenolic compounds and signalling metabolites (compartmentalisation processes), xylem morphology (length, width), and so on – breeding resistant stock is automatically very difficult (Aoun et al., 2009; Ďurkovič et al., 2014; Martín et al., 2013a; Martín et al., 2013b). Therefore, for resistance to be identified, understanding what genetic markers to look for is necessary, and research is ongoing in this regard (Perdiguero et al., 2015). However, because the main manner in which polygenic resistance is cultivated is through vegetative propagation, there is huge risk of a future strain of Ophiostoma novo-ulmi, or even another pathogen, creating the same problem that arose over the last few decades with regards to elm mortality (Martín et al., 2013b). A small genetic pool across many individuals is not to be desired, and can spell disaster very quickly – as was the case for Ulmus minor, which had a history of vegetative propagation across the English landscape and suffered great losses as a result of DED. With regards to identifying resistant individuals therefore, research has indeed been completed via the growing of cuttings from different mother trees for a variety of species (including Ulmus glabra, Ulmus laevis, Ulmus minor, and Ulmus pumila), and then inoculating the cuttings with Ophiostoma novo-ulmi (Solla et al., 2005). Results have shown that some cuttings of particular species will display complete resistance to the pathogen, though many cuttings of other species will not. The reason behind evident resistance is largely considered to be down to xylem width and length, with individuals that possess longer and broader vessels showing greater susceptibility to the pathogen (Pouzoulet et al., 2014). This may not exclusively be in the wood structure either, as leaf xylem structure also impacts upon resistance – ‘Dodoens’ is marked as a potentially important cultivar, in this regard (Ďurkovič et al., 2014). An Ulmus ‘Dodoens’ at Royal Botanic Gardens, Kew, taken in 2012. Source: Davis Landscape Architecture. To advance this displayed resilience of some cuttings, hybridisation projects have been undertaken that may even see resistant European elm individuals crossed with resistant Asian ones – this broadens the genetic resources an individual will have access to (Brunet et al., 2013; Santini et al., 2012; Solla et al., 2014). If such resultant individuals display resistance in the laboratory, then they will be propagated vegetatively and then be subjected to further testing in a more naturalised environment (Santini et al., 2010). Such a means of testing for resistance has produced some clones that may potentially be used in an ornamental setting or forestry setting, including ‘Ademuz’, ‘Majadahonda’, and ‘Morfeo’ (Martín et al., 2015). It is, at this point, important to recognise that the resistance of different clones may in fact vary across regions of the world, and that cultivars will also differ in their response to the pathogen – some will initially display low resistance but soon recover and exhibit few signs the following year, and some perhaps vice versa (Buiteveld et al., 2015). Furthermore, current research has only really focussed on trailing resistance in young specimens. Little evidence is available to show how these new cultivars will fare in the longer term (such as over many decades). Concerningly, research by Hodgetts et al. (2015) in the UK found that freshly-imported ‘Morfeo’ clones were host to Candidatus phytoplasma ulmi, which is a pathogen that is controlled in the UK and therefore requires infected stock to be destroyed under a Plant Health Notice. Despite this, many older and pre-existing clones were not found to be host to the pathogen. Therefore, risk may also exist with regards to the movement of cultivars, which evidently may harbour exotic pathogens that may threaten the UK’s tree species. On a similar note, Ulmus americana ‘Princeton’ (a DED-resistant cultivar) has been discontinued by some nurseries (including Barcham) because of its high susceptibility to Candidatus phytoplasma ulmi. Very recent research has also identified specific genetic markers in Ulmus minor that may suggest resistance (Perdiguero et al., 2015). Such identification, the authors allege, may aid significantly with the quest in finding disease-resistant cultivars, and such markers may also be transferable across species. At the same time, the genomics of the pathogen Ophiostoma novo-ulmi, now fully mapped, is paving the way for innovative research that seeks to identify specific markers that identify pathogenicity (Bernier et al., 2015). Research into the pathogen itself may therefore yield beneficial results in understanding how to breed for resistance, though only time will tell in this regard. Even in spite of the cultivation of many individuals that display levels of resistance to DED, the fact that vegetative propagation is the main means of continuing to provide resistant elms means there is huge risk of elm populations lacking genetic diversity. Such populations are fragile, and can readily be wiped-out by a pathogen in a very quick period of time. Of course, looking to re-introduce elm to the landscape through means of cultivation is a noble pursuit, particularly when man was the main cause of the second DED outbreak in the UK, though it is perhaps naive to think that a similar thing could not happen again – and by planting clones, a similar mass-mortality event has a much higher likelihood of occurring. Hybridisation of elms is therefore potentially a way forward, in place of cloning. However, then we run the risk of a loss of true native progeny, and crossing species that would never otherwise have the ability to cross may be ethically obstructive for some. Pessimism aside, understanding what drives resistance is important, and DED has triggered a great deal of research into finding resistant elms. The benefits of such research – very importantly – does not stop with elms, as research techniques can be replicated for other areas of disease research. Technological advancements and continued investigatory work into DED will therefore continue to yield good results, though potentially with greater magnitude. Judging by current research, finding truly resistant cultivars is indeed a possibility, and planting a large mix of them when they do arise may be the best way forward. References Aoun, M., Rioux, D., Simard, M., & Bernier, L. (2009) Fungal colonization and host defense reactions in Ulmus americana callus cultures inoculated with Ophiostoma novo-ulmi. Phytopathology. 99 (6). p642-650. Bernier, L., Aoun, M., Bouvet, G., Comeau, A., Dufour, J., Naruzawa, E., Nigg, M., & Plourde, K. (2015) Genomics of the Dutch elm disease pathosystem: are we there yet?. iForest-Biogeosciences and Forestry. 8 (2). p149-157. Brunet, J., Zalapa, J.E., Pecori, F., & Santini, A. (2013) Hybridization and introgression between the exotic Siberian elm, Ulmus pumila, and the native Field elm, U. minor, in Italy. Biological Invasions. 15 (12). p2717-2730. Buiteveld, J., van der Werf, B., & Hiemstra, J.A.. (2015) Comparison of commercial elm cultivars and promising unreleased Dutch clones for resistance to Ophiostoma novo-ulmi. iForest-Biogeosciences and Forestry. 8 (2). p158-164. Ďurkovič, J., Čaňová, I., Lagaňa, R., Kučerová, V., Moravčík, M., Priwitzer, T., Urban, J., Dvořák, M., & Krajňáková, J. (2013) Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease. Annals of Botany. 111 (2). p215-227. Ďurkovič, J., Kačík, F., Olčák, D., Kučerová, V. , & Krajňáková, J. (2014) Host responses and metabolic profiles of wood components in Dutch elm hybrids with a contrasting tolerance to Dutch elm disease. Annals of Botany. 114 (1). p47-59. Hodgetts, J., Flint, L., & Fox, A. (2015) First report of ‘Candidatus phytoplasma ulmi’ (16SrV-A) associated with Ulmus cultivar Morfeo (elm) in the United Kingdom. New Disease Reports. 32 (1). p26. Lamb, R. (1979) World Without Trees: Dutch elm disease and other human errors. UK: Wildwood House. Martín, J., Solla, A., Ruiz-Villar, M., & Gil, L. (2013) Vessel length and conductivity of Ulmus branches: ontogenetic changes and relation to resistance to Dutch elm disease. Trees. 27 (5). p1239-1248. Martín, J., Solla, A., Venturas, M., Collada, C., Domínguez, J., Miranda, E., Fuentes, P., Burón, M., Iglesias, S., & Gil, L. (2015) Seven Ulmus minor clones tolerant to Ophiostoma novo-ulmi registered as forest reproductive material in Spain. iForest-Biogeosciences and Forestry. 8 (2). p172-180. Martín, J., Witzell, J., Blumenstein, K., Rozpedowska, E., Helander, M., Sieber, T., & Gil, L. (2013b) Resistance to Dutch elm disease reduces presence of xylem endophytic fungi in elms (Ulmus spp.). PLoS One. 8 (2). e56987. Perdiguero, P., Venturas, M., Cervera, M., Gil, L., & Collada, C. (2015) Massive sequencing of Ulmus minor’s transcriptome provides new molecular tools for a genus under the constant threat of Dutch elm disease. Frontiers in Plant Science. 6 (541). p1-12. Pouzoulet, J., Pivovaroff, A., Santiago, L., & Rolshausen, P. (2014) Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine. Frontiers in Plant Science. 5 (253). p1-11. Santini, A., Pecori, F., Pepori, A., & Brookes, A. (2012) ‘Morfeo’Elm: a new variety resistant to Dutch elm disease. Forest Pathology. 42 (2). p171-176. Solla, A., Bohnens, J., Collin, E., Diamandis, S., Franke, A., Gil, L., Burón, M., Santini, A., Mittempergher, L., Pinon, J., & Broeck, A. (2005) Screening European elms for resistance to Ophiostoma novo-ulmi. Forest Science. 51 (2). p134-141. Solla, A., López-Almansa, J., Martín, J., & Gil, L. (2014) Genetic variation and heritability estimates of Ulmus minor and Ulmus pumila hybrids for budburst, growth and tolerance to Ophiostoma novo-ulmi. iForest-Biogeosciences and Forestry. 8 (4). p422-430. Santini, A., Pecori, F., Pepori, A., Ferrini, F., & Ghelardini, L. (2010) Genotype× environment interaction and growth stability of several elm clones resistant to Dutch elm disease. Forest Ecology and Management. 260 (6). p1017-1025. Venturas, M., López, R., Martín, J., Gascó, A., & Gil, L. (2014) Heritability of Ulmus minor resistance to Dutch elm disease and its relationship to vessel size, but not to xylem vulnerability to drought. Plant Pathology. 63 (3). p500-509.

It's not Auricularia auricula-judae going moldy, is it?

Odd! The link works for me. Try accessing it from here. https://scholar.google.co.uk/scholar?q=+Occurrence+and+decay+patterns+of+common+wood-decay+fungi+in+hazardous+trees+felled+in+the+Helsinki+City&btnG=&hl=en&as_sdt=0%2C5