Kveldssanger

Good. Why on earth was it not put there to begin with? Reeks of laziness and a lack of desire to care for important heritage features in the planning stages.

First time I have seen any fungus whatsoever on Acer saccharinum. Usually a rather sterile species, I find! Cool shots I got earlier on today, and I'm still pretty delighted at finding this (I seriously have been looking at every silver maple I come across, in the hope of finding something). I suspect it's G. australe, though I haven't a tamed mycologist at hand to confirm.

That's for the kind words, David! Means a great deal. I always find it better not just to 'scrape by' with anything - I just do what I want to do until I get bored or figure I need to stop. As for Confistulina, that's really awesome! I have seen some similar-looking fruiting bodies though much smaller - perhaps they would also be the asexual stage? I had a quick look on Wikipedia and am I right in thinking that the anamorph stage is not currently accepted as a means of classifying a species taxonomically (as in, it's seen that only one 'over-riding' teleomorphic name, in this case F. hepatica, would be used to cover all stages of the fungus' life)? Interesting that the authors suggest it is a new genus, however. I admit I got lost after the first page - too many words I don't know!

23/02/16. Fact #157. Such strategists have their spores colonise the (now dysfunctional) sapwood after a wound exposes what would otherwise have been functional sapwood. Such strategists are adapted to a wood environment with high oxygen content and (initially) high moisture levels (Boddy, 2001; Rayner, 1993; Rayner & Boddy, 1988; Schwarze et al., 2000). Cankers may also facilitate the establishment for spores of such strategists, in particular instances (Shigo, 1986). Sapwood-exposed strategists are typically rapid in colonisation rate, though do not begin to cause decay until the wood dries out (Schwarze et al, 2000); by this point, non-decay-causing organisms have likely already begun to colonise, and may in fact aid with fungal succession and wood degradation (Rayner, 1993; Schwarze et al., 2000; Shigo, 1991). As such, there is a (brief) ‘latent’ period in between infection and decay. During this delay, the fungus will take advantage of readily-available food sources such as sugars, using the energy to fuel its rapid colonisation habit. Such rapid establishment means the tree does not have enough time to properly compartmentalise the attack around the wounded area (Rayner & Boddy, 1988; Schwarze et al., 2000). Some of these strategists also deploy offensive mechanisms to further damage the tree, such as via the secretion of toxins to kill or damage parenchyma cells. The decay column that manifests following fungal establishment is largely axial in spread, progressing vertically from the wound site with – at least initially – little radial spread. The decayed area will be surrounded by a discoloured margin, where the tree has deposited tyloses, suberin, and phenols, in an attempt to compartmentalise the decay process by shutting down and clogging its vascular tissues (Boddy, 2001; Dujesiefken & Liese, 2015; Shigo, 1991; Weber & Mattheck, 2003). Discolouration and decay extent both vary depending upon the species of fungus and the tree species’ characteristics (intrinsic), as well as the environment in which the host tree resides (extrinsic) (Rayner, 1993; Rayner & Boddy, 1988). On this Aesculus x carnea, which has suffered major windthrow within its crown that thus exposed large tracts of sapwood, Polyporus squamosus has colonised. In certain instances, numerous unspecialised strategists may colonise a tree in different regions, surrounding either the same wound or, if the tree has many wounds, various ones (Boddy, 2000). This can lead to intricate patterns of decay and barrier zones between each different hyphal network, at times with barriers being visibly breached on numerous occasions. Ultimately, it is critical that invading pathogens create and retain their own zones within the wood structure, protecting the hyphal network from both tree defence mechanisms, mycoparasites, and other invading pathogens (Boddy & Rayner, 1983; Shain, 1979; Shigo, 1986). Furthermore, such strategists possess a wide range of ‘sub-colonisation’ strategies, varying from the ruderal (saprophytic) mold fungi (Hyphomycetes) to the combative (parasitic) Basidiomycetes (Schwarze et al., 2000). Ruderal strategists do not typically degrade wood but merely discolour it, though may initiate decay that may, as already suggested, initiate succession by higher-tier Basidiomycetes of the same site. This is because ruderal strategists tend to enter early, colonise, and exit, before conditions become undesirable (due to lowering nutrient availability, competition from other decay organisms, desiccation of substrate, etc). They are largely non-selective with regards to species preference (Boddy, 2001). As a partial aside, unspecialised opportunists will also attack incredibly 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 (Garrett, 1970). Such a concept is termed ‘damping-off’ disease. References Boddy, L. (2000) Interspecific combative interactions between wood-decaying basidiomycetes. FEMS Microbiology Ecology. 31 (3). p185-194. Boddy, L. (2001) Fungal community ecology and wood decomposition processes in angiosperms: from standing tree to complete decay of coarse woody debris. Ecological Bulletins. 49 (1). p43-56. Boddy, L. & Rayner, A.. (1983) Origins of decay in living deciduous trees: the role of moisture content and a re-appraisal of the expanded concept of tree decay. New Phytologist. 94 (4). p623-641. Dujesiefken, D. & Liese, W. (2015) The CODIT Principle: Implications for Best Practices. USA: International Society of Arboriculture. Garrett, S. (1970) Pathogenic Root-Infecting Fungi. USA: Cambridge University Press. Mattheck C., Bethge, K., & Weber, K. (2015) The Body Language of Trees: Encyclopedia of Visual Tree Assessment. Germany: Karlsruhe Institute of Technology. Rayner, A. (1993) New avenues for understanding processes of tree decay. Arboricultural Journal. 17 (2). p171-189. Rayner, A. & Boddy, L. (1988) Fungal Decomposition of Wood: It’s Ecology and Biology. UK: John Wiley & Sons. Schwarze, F., Engels, J., & Mattheck, C. (2000) Fungal Strategies of Wood Decay in Trees. UK: Springer. Shain, L. (1979) Dynamic responses of differentiated sapwood to injury and infection. Phytopathology. 69 (10). p1143-1147. Shigo, A. (1986) A New Tree Biology. USA: Shigo and Trees Associates. Shigo, A. (1991) Modern Arboriculture. USA: Shigo and Trees Associates. Weber, K. & Mattheck, C. (2003) Manual of Wood Decays in Trees. UK: The Arboricultural Association.

I'll be honest. Mind = blown.

22/02/16. Fact #156. There exist four different colonisation strategies of a living tree by wood-decay fungi: heart rot (heartwood-exposed), unspecialised opportunism (sapwood-exposed), specialised opportunism (sapwood-intact), and active pathogenesis (Boddy, 2001; Rayner, 1993; Rayner & Boddy, 1988; Schwarze et al., 2000). Over the coming week or so, I’ll be looking at each strategy. We shall begin with heart rot. Heart rot In simple terms, this strategy involves colonisation of heartwood – via an entry point where heartwood becomes exposed – and subsequent decay of such heartwood (or core) of the host, where parenchyma (living) cells are lacking and conditions are very gaseous (Boddy, 2001; Rayner & Boddy, 1988; Schwarze, 2008). Colonisation is considered to be through heartwood-exposed wound surfaces, or alternatively via exposed heartwood from dead or diseased areas of the tree that are old enough to contain heartwood. Entry via such mechanisms can be divided into two distinct segments: top-rot (colonisation originates at the crown and progresses downwards) and butt-rot (colonisation originates at the root collar-butt interface and works upwards). For butt-rots, colonisation can further be divided, with entry being via root-mycelium contact, or by fungal spores (Rayner & Boddy, 1988). Rarely do butt rots cause hollows more than a few feet up into the trunk (Shigo, 1986). Such strategists are particularly stress-tolerant, predominantly because conditions for decay are initially very unsuitable deep within the heartwood of the host. The lack of oxygen, high levels of carbon dioxide, undesirable moisture levels (particularly if bacterial wetwood is present – this will occur if bacteria are the pioneer invaders of a site, and not fungal pathogens), and abundance of inhibiting compounds (tannins), mean decay will be a very slow process and may take many years to even initiate substantially. Species that adopt this strategy therefore are largely non-combative, very slow with regards to their decay and colonisation of the heartwood, and may well be species-specific; or at least show certain levels of host species-preference (Boddy, 2001; Boddy & Rayner, 1983; Cartwright & Findlay, 1958; Rayner & Boddy, 1988; Shigo, 1986; Weber & Mattheck, 2003). The predominant reason behind such frequently-observed selectivity is suspected to be due to the fact that different species of host possess vastly different characteristics with regards to heartwood formation and properties, and by limiting host preference the fungal species directly reduce their potential fungal competitor range to, in some instance, almost zero (Rayner & Boddy, 1988). Species-specificness ultimately varies between heart rot strategists, therefore; a continuum, of sorts (Rayner & Boddy, 1988). Genus-specific strategists include Fistulina hepatica (Quercus spp.), Phellinus pomaceus (Prunus spp.), and Porodaedalea pini (Pinus spp.), whilst generalist strategists include Armillaria spp. and Heterobasidion annosum. Rayner and Boddy (1988) also note that Laetiporus sulphureus may colonise seemingly unrelated species such as Castanea spp., Quercus spp., Salix spp., and Taxus spp. This oddly-shaped Fistulina hepatica, a heart rot strategist, was found (by me) at the base of a very mature Quercus robur. In spite of their largely non-combative ability, both with regards to colonisation of wood and competition against other fungi, their intricate specialisms that have optimised them for heartwood decay enable them to create large individual territories amongst the expansive heartwood extent within their host. Mycoparasites (fungal parasites that predate upon other fungi) may however be a potentially limiting factor, in certain instances, where such fungal parasites establish within the decaying wood zone(s) and attack the wood-decaying fungi present – as may fungal viruses (Badalyan et al., 2004; Boddy, 2000; Boddy & Rayner, 1983; Shigo, 1986). Research by Highley et al. (1983) also suggests that the lack of difference in performance under low oxygen and high carbon dioxide regime levels for heart rot strategists means they may have evolved to become so specialised by adapting to species-specific heartwood traits (pH, volatiles, extractives, etc) – such as with Laetiporus sulphureus and its ability to tolerate tannin-rich and acetic acid-rich wood, which correlates with the low pH of Quercus spp. heartwood, and its high tannin levels (Hintikka 1969, Hintikka 1971, Rayner & Boddy, 1988). In this image (taken by me) a mature Pinus nigra, with major storm damage upon its stem, has been colonised by the heart rot strategist Porodaedalea pini. Heart rot is typically non-fatal for trees (at least, in the direct sense – the tree may die as a result failure induced by the decay), in the sense that it is considered to be more economically destructive to foresters than it is the health and longevity of the tree (Rayner, 1993, Rayner & Boddy, 1988). Because such strategists largely lack the ability to invade intact sapwood, their extent is confined to the heartwood of the host, thereby enabling the tree to continue in its metabolic pursuits without marked hindrance. However, death can be caused when heartrot strategists that are able to attack sapwood (through suspected active pathogenesis – Phellinus pomaceus), for the purpose of creating fruiting bodies (on sites where exposed heartwood does not exist) and for means of continued colonisation (Mattheck et al., 2015; Rayner & Boddy, 1988), do so extensively – to the point that the stem may be girdled, or the sapwood significantly damaged. Such a means of sapwood attack is through the development of a canker, initiated by the creation of a thick mycelial pad, which serves to force bark outwards and thus enable for an exit point (Rayner & Boddy, 1988). References Badalyan, S., Innocenti, G., & Garibyan, N. (2004) Interactions between xylotrophic mushrooms and mycoparasitic fungi in dual-culture experiments. Phytopathologia Mediterranea. 43 (1). p44-48. Boddy, L. (2000) Interspecific combative interactions between wood-decaying basidiomycetes. FEMS Microbiology Ecology. 31 (3). p185-194. Boddy, L. (2001) Fungal community ecology and wood decomposition processes in angiosperms: from standing tree to complete decay of coarse woody debris. Ecological Bulletins. 49 (1). p43-56. Boddy, L. & Rayner, A.. (1983) Origins of decay in living deciduous trees: the role of moisture content and a re-appraisal of the expanded concept of tree decay. New Phytologist. 94 (4). p623-641. Cartwright, K. & Findlay, W. (1958) Decay of Timber and its Prevention. 2nd ed. London: HMSO. Highley, T., Bar-Lev, S., Kirk, T., & Larsen, M. (1983) Influence of O2 and CO2 on wood decay by heartrot and saprot fungi. Phytopathology. 73 (4). p630-633. Hintikka, V. (1969) Acetic acid tolerance in wood – the litter decomposing Hymenomycetes. Karstenia. 10 (1). p177-183. Hintikka, V. (1971) Tolerance of some wood decomposing basidiomycetes to aromatic compounds related to lignin degradation. Karstenia. 12 (1). p46-52. Mattheck C., Bethge, K., & Weber, K. (2015) The Body Language of Trees: Encyclopedia of Visual Tree Assessment. Germany: Karlsruhe Institute of Technology. Rayner, A. (1993) New avenues for understanding processes of tree decay. Arboricultural Journal. 17 (2). p171-189. Rayner, A. & Boddy, L. (1988) Fungal Decomposition of Wood: It’s Ecology and Biology. UK: John Wiley & Sons. Schwarze, F., Engels, J., & Mattheck, C. (2000) Fungal Strategies of Wood Decay in Trees. UK: Springer. Shigo, A. (1986) A New Tree Biology. USA: Shigo and Trees Associates. Weber, K. & Mattheck, C. (2003) Manual of Wood Decays in Trees. UK: The Arboricultural Association.

Yes it was, David. That OPM rash image is scarred into the back of my eyelids.

I remember Glynn talking about this back last summer when he did a talk at Barcham. Will have to watch this later on tonight.

Good points about the car. I'd also be interested to know what type of cars the people were in when they died - were they the 'trailer' ones you get quite often in the US, hatchbacks, minis, etc? As for street trees having a 50% chance, I take it you mean it can either go on to the street or not? If it's on the inside of a bend it has a chance greater than 50%, and the outside of a bend lower than 50% chance. On a crossroads, it could be up to nearer 100%, and maybe even 100% for a roundabout or central island (that US crossroads lack, I guess?).

I was 97% sure you'd have to double take! Interesting article, David. I had heard about using heat, though never actually 'seen' it. Looks very hi-tech.

They trying to teach that tree to swim, there?

21/01.16. Fact #155. I have written a lot about trees in the urban environment, and I can certainly continue to write about them forever more, though when I stumbled upon the study I am to write about below I thought it would be interesting to touch upon vegetation beyond the realm of trees. Of course, the benefits trees provide, and the issues they create, are well understood, and there will always be a torrent of new research articles dealing with their presence in the urban setting. However, I am not aware of such an abundance of research for shrubs and other types of vegetation that may exist within urban environments. This is probably not all too surprising given trees are simply bigger and more noticable than other types of vegetation, though when we work with trees we also will generally work with shrubs, grasses, and so on. Combined, or even exclusively, such vegetation (and the form adopted – formal or ‘wilded’) will impact upon the lives of residents, and understanding exactly how is always going to be vital to their successful incorporation into an urban landscape. In this instance, the residents of two German cities (Berlin and Cologne) are the focus. In Cologne, the authors asked passers-by (a total of 108 were questioned) on a main arterial road (see the below image) just outside of the inner portion of the city how they perceived roadside vegetation (with regards to what they valued in terms of the functions the vegetation provides), what types of roadside vegetation they knew about and preferred, amongst other related topics (including how they thought vegetation established within the urban environment). The passers-by were stopped and questioned over the course of three weekdays from the morning through to the evening, during summer. All answers were written down either by them, or by the authors. 56% of passers-by who answered the questions were below 30 years of age, and 58% were male. This was the site used by the authors for their Cologne study. We can see vegetation occupying different ‘tiers’, with some higher canopy trees with smaller shrubs beneath (some appear to be coniferous, in the foreground). The Berlin study was somewhat different, and whilst it also was conducted along a similar main arterial road on a summer day (which had wilded vegettion growing along the pathways, below the trees – see the image below), it asked different questions. Principally, the questionnaire provided to the passers-by was standardised, though some open-ended questions did feature. For example, the main bulk of the questionnaire was asking the individuals what type of vegetation cover they thought would work best on the arterial road they were walking down (no vegetation, maintained vegetation, wilded vegetation, or no preference). However, individuals could give reasons as to why they chose the answer they did, and were also asked what they thought about the current ‘wild’ appearance of the roadside vegetation. This was the exact location of the Berlin survey. All passers-by who stopped to answer the questions thus, in response to the open-ended question asking for their thoughts on the street’s current view, formed their opinion from this vista. For the Berlin study, 40% of respondents were beloe 30 years of age, and gender distribution was almost equal. 74% of the individuals lived either near to the street or in an inner city borough of Berlin, and 78% were familiar with the street to some degree. Results In Cologne, just over half (52%) of the respondents considered trees to be the main vegetation type that feature along roads. The remaining 48% therefore detailed shrubs, perennials, and grasses – some individuals were specific to the species, as well. Furthermore, a wide array of landscaping features were also identified by the respondents, with flower beds, tree pits, and planting tubs being but three examples. In terms of how the individuals thought the vegetation had become established, the vast majority (87%) considered artificial planting to be the cause (be it through public or private hands). Only 13% suggested that natural regeneration could have led to the street vistas of Cologne. A great number of the surveyed individuals also valued roadside vegetation as important, and for a variety of reasons (see the below table). Responses ranged from their presence being good for amenity to being beneficial for improving air quality, though most answers related to the vegetaton’s amenity value. So positive were the answers that many had a desire to see a greater amount of roadside vegetation of all types, of which some answers pushed a greater number of ‘wilded’ scenes more akin to a rural and naturalised scene. The reason for this ‘wilded’ desire varied, though answers included for the benefit of insects such as bees, to simpy being more interesting to the eye and making the streets more “lively”. This table compares how respondents valued different ecosystem services, across the two cities. For respondents in Berlin, 48% considered the current ‘wild’ appearance of the street undesirable, and suggested it should be more formal in character (dubbed ‘urban devotees’). Conversely, 43% liked the vegetation as it was (dubbed ‘wilderness enthusiasts’). The remaining 8% did not mind, or were undecided. Therefore, there is certainly a similar mix of individuals who like ‘wilded’ streets and those who don’t. Unspurprisingly, it was the wilderness enthusiasts that most routinely saw the vegetation on the street as greatly improving the landscape’s character, because they considered the street to have a greater association with nature (a total of 40% of all respondents responded in such a manner). On the other hand, the ~30% of individuals who didn’t like the ‘wilded’ vegetation were more frequently from the urban devotee group (and this group cited the poor safety and amenity of the ‘wilded’ area as their reasons for such an opinion). The below table shows the disparity of opinion. A breakdown of how urban devotees and wilderness enthusiasts valued the current ‘wilded’ streetside vegetation. Across both sities, neither age or gender were significant in determining how an individual viewed vegetation cover. Concluding remarks From the results detailed, there is no question that there is a wide range of opinion regarding what vegetation types are most valued by individuals, and the form that these vegetation types adopt (formal or ‘wilded’). It is entirely evident that there will always be a significant minority of people who do not appreciate the vegetation cover an urban area possesses, and it is also evident that people will value vegetation presence for different reasons (though mostly, it is for the aesthetic benefit provided – even then, what is considered as aesthetic beauty differs from person to person). Despite this, more vegetation (in general) on streets was in demand. It is nonetheless curious that a good portion of those surveyed valued ‘wild’ vegetation (particularly in Berlin, and likely because individuals were more routinely exposed to such vegetation cover), though perhaps still considered this ‘wilded’ character as originating from man’s intervention. Only a small selection of respondents understood that the vegetation on streets may also regenerate naturally. By a similar token, the fact that many respondents recognised that trees are not the only type of urabn vegetation cover that may grace street scenes is suggestive of a need to incorporate complex landscaping vistas into urban sites – simply having canopy cover is not ‘enough’, perhaps. At the same time however, the desire of many for safe and formal landscapes may mean that constituent vegetation is maintained to some degree. Perhaps there is scope to have both more formal and ‘wilded’ vegetation types, assuming a street can accomodate such diversity (this requires size and desire). Source: Weber, F., Kowarik, I., & Säumel, I. (2014) A walk on the wild side: Perceptions of roadside vegetation beyond trees. Urban Forestry & Urban Greening. 13 (2). p205-212.

A newly-forming sporophore?

Caught some probably the day it started forming - 12th May 2015. Early April though, that be very early!

I think it would be fair if there was a time limit (Amazon give you two weeks once you buy a film from them to watch online), and if you attend the event you only get to see it once as well! For some, the £180 + travel expenses is likely too much, though I don't doubt paying £20-50 would be appealing if it could be streamed online for a period of time. My only concern with having indefinite access is that people can just pass their access key on to someone else when they have watched it once or twice. At least with a video you can pause it.

Hope to see you there! Totally understand you on this one. Very unfortunate are the circumstances you have found yourself in lately, so hope you're well on that front (the same applies to Sean). If, by the time of the arb conference the AA do, you're able to get to seminars again, I shall see you there. I'm looking to get down to the ATF one in Dorset as well, this July.

I sent them an email to ask. I wouldn't like to take photos during the talks, solely as I'm more intent on listening (as you said), though I'm thinking more about selling the recording as a digital file either in its entirety or as individual presentations (so people can choose what ones they want to purchase). Travel can be a right bugger for some, and it's lucky we're based near to London (where these talks are held). If the concern is about copyright issues, there are means of having a video play within a browser that you enter a key to play, and the key only works for a limited time.

Shame, but understandable. Too much to do in a small space of time, sometimes. It doesn't help that the tickets are quite expensive, but I suppose the trade-off comes when you fly-in experienced professionals to talk about what they have learned. I would still like to see events like this live-streamed or recorded (and sold / streamed for a small fee), as the information presented is always so important that it's a shame it's limited to only a small group.

URL Link to the seminar Overview Programme of presentations Anyone else booking themselves down on this? Got my place sorted. Would be good to see others there. Certainly looks like a good one.

Didn't spot any, but we were walking around quite a bit and I had to keep darting off from the group to get photos. Planning on going back soon to explore on my own. Got more shots to sort, but again just your standard brackets.

19/02/16. Fact #154. We hear a lot about how residents perceive trees in the research ‘community’, though less frequently do we read reports that assess the views held by industry professionals. This is strange because arborists, planners, landscape architects, and other professionals have a potentally massive impact upon the manner in which individual trees and landscapes containing trees are managed. Recognising the views held by such individuals is therefore very important, and could even facilitate introspection by those within the industry. Furthermore, are views even uniform across the industry, or do they vary across professions and spatial areas? Thankfully, such questions can begin to be answered as a result of this study, by assessing Australian industry professionals (principally arborists) and their perceptions of trees and the conflicts associated with their presence. For the study, the authors interviewed a total of 52 professionals through advertising within the industry (and then via word of mouth across organisations), in the cities of Adelaide, Brisbane, Hobart, Melbourne, Sydney, and Townsville. These cities were selected as they cover a wide geographical area, and are home to large yet varied tree populations in differing climatic regions of the country. The vast majority who responded and were subsequently interviewed identified themselves as arborists (arboriculturalists), though a few did respond by labelling themselves as landscape architects, horticulturalists, or environmental planners. The interviews with the professionals had some sort of structure, though were ‘open’ enough to permit conversation away from a typical question and answer scenario. This, the authors recognised, allowed the interviewees to discuss matters they felt were important to them, and this had the benefit of ensuring interviews were fruitful in terms of the data collected. However, a general trend was present within the interviews, in the sense that details regarding how the professionals thought about and interacted with trees were obtained, as were thoughts on other ‘tree professions’, ‘non-tree professions’, legal frameworks, and residents. Alongside the interviews, a survey was sent out to residents across the same cities, of which 736 survey responses were obtained. This survey investigated how residents chose what trees to plant, and offered them to add any other comments they desired to their response (about anything tree-related, including industry professionals). Once all interviews had been completed and surveys returned, they were analysed by the authors for trends. Before going on, it’s necessary to point out that the authors found five distinct ‘groups’ amongst the interview data, with public and private sector workers being very distinct from each other, though the city the individual was based within and their actual profession also were found to cause distinct difference in opinion in particular instances. Gender was not a driver behind varying opinions, nor was location (on the whole). Further results are detailed below. How arborists view residents Probably not surprisingly, a common trend amongst all interviewed professionals was their perception of residents hating trees (or some types of tree). However, the rationale behind such thoughts differed across the 52 individuals. Another general theme was that residents put too much weighting on the risks trees pose, thereby over-playing the ‘risk factor’. Further themes amongst the data, though generally variable across the groups and held in particular abundance by arborists from Adelaide, Brisbane, and Hobart, was that older people viewed trees with less fondness, and that residents would readily scapegoat trees without evidence of the trees causing a problem. However, it was Melbourne arborists that felt trees were most actively removed because of the perception residents held about them causing fires (scapegoating). This may be as a result of the ‘Black Saturday’ fire some ten months prior, which scourged parts of Melbourne. In this image, wildfire encroaches upon a residential property in Melbourne. Source: Wikimedia Commons. Other opinions aired by over 20% of the 52 individuals (indicating a sort of ‘theme’) included things such as residents needed to be educated about trees, immigrants don’t like ornamental trees, people dislike trees because of the mess they make, people on low incomes don’t like trees, but that most people actually still love trees. However, opinions that were very much varied between professionals interviewed (and were, at times, contradictory) included whether the affluent demand tree care, whether conflicts arise between neighbouring land owners with regards to trees, and whether ‘tree Nazis‘ are annoying. Therefore, whilst trends amongst the responses are evident, there is still a wide pool of thought held by individuals within the industry. How residents perceive professionals Curiously, residents surveyed made very little mention of arborists, but instead saw the management of trees as something simply done by the council (as a whole) or by the planners (part of the council). Only one respondent, who was an arborist himself, referred to arborists being part of the management of publicly-owned trees. It was also found that residents saw local councils as an enemy to trees, and particularly by the so-called ‘tree Nazis’. One individual, for example, lamented over the council’s removal of healthy trees along a street. Other individuals commented that councils plant the wrong trees in the wrong places and then refuse to remove ones in a supposedly ‘wrong’ place, failing to educate the public about trees, not planting a young tree near to one set to be removed and instead doing the re-planting afterwards, and making grotesque forms from trees following aggressive pruning management (all whilst refusing to allow protected trees on private land to suffer a similar fate). Residents were also critical of urban planners, saying that they failed to ensure tree plantings were incorporated into new developments, and should see trees more as ornaments that complement the landscape in place of something much the opposite. How professionals perceive trees Planners and other professionals who held a more strategic position (in place of actually being an arborist) were found to hold more ‘abstract’ views of trees. For intance, they saw trees as helping to reduce energy costs (associated with cooling in the summer). Their stance was also much less emotional than other professionals, in the sense that they formed their views on trees from more analytical (niche?) thought processes. However, planners were found to not consider street trees as important for biodiversity as much as other industry professionals did, though did see trees in other urban settings as important. Perhaps their isolation from working ‘with’ trees has led to such a perspective, because it cannot be argued that there is an abundance of data highlighting how critical street trees are for biodiversity. As more of a collective however (totalling to 40% of all interviewees), professionals considered a mix of native and exotic tree species to be important, citing that pragmatism is key in the selection and management of the urban forest. Interestingly, this also translates over into residential (privately-owned) trees (albeit likely for different reasons), where residents were found to not discriminate for or against either native or exotic tree species. A mix of natives and exotics is therefore present across the six cities, outside of the publicly-owned realm. A line of large and mature eucalypts in Canberra, Australia. Note the womnderful shading beneath. The linked source has some more great photos. Source: Treelogic. However, a diversity of thought was evident with regards to the risk management of trees. Around 33% of professionals considered risk to be appropriately measured and managed, whilst 40% saw both local governments and residents as exaggerating the risk a tree poses (that could be classed as ‘risk averse’). 10% of the interviewed professionals also considered that such risk management lead to the loss of large trees, in spite of the fact larger trees are usually held in higher regard by residents, whilst 40% (mostly professionals working for local government) saw managing old trees as highly important but nonetheless challenging. As touched upon earlier, there was also a trend held by professionals (particularly if they were based near to where natural wildfire and storm events occurred) that trees are unfairly scapegoated. 75% of professionals in Melbourne saw the removal of trees following on from wildfire as abhorrent and as a “gross over-reaction” to the situation. Similarly, Queensland professionals thought residents unfairly blamed trees following on from storms, and the public must be educated more about the ‘true’ risk of trees. A large beech tree that fell following high winds. Source: Cazort. Quite intiguingly, many professionals also saw engineers as people who hated trees, and developers as people who try to “corrupt” arborists. Not only this, but professionals saw electricity organisations as doing a bad job of maintaining trees beneath lines (and focussing too intently on just keeping their service operating without hindrance). Such thoughts probably exist the world over, within the industry! However, private arborists (not employed by councils) were found to be in a difficult situation, because their income depended upon work by developers (in part), and even though they felt they were placed in positions they did not necessarily like, turning down work for moral reasons was not always feasible. One canny individual did however suggest that developers will tend to employ arborists who are lenient to the developers, thus making their operations easier by getting trees removed more readily. Whether such arborists have so much of a dilemma about removing otherwise probably healthy trees is open to debate. …so what? On the whole, it is evident that there is a vast opinion pool amongst professionals within the industry, though common themes are pervasive across individuals found in all six cities. The fact that many professionals consider the risks associated with trees to be over-played is important, as it highlights a need for residents and other laymen to be informed of the real risk trees pose (and even local councils). Whether this would actually impact upon their fears is open to question, though there is no doubt that they should at least be presented with such information. Such an action may in fact help to reduce the evident gap between professionals and residents with regards to their view of trees. Professionals, throughout the survey, were identified to view trees more positively. Such a stance can only be because of the greater level of knowledge possessed, as there is absolutely no argument relating to the great benefits (and importance) of trees, particularly in the ecological and environmental senses. Furthermore, there is a need for planners to recognise that residents do not hold them in high regard. Communication between such professionals and the residents would therefore be a good idea, in an attempt to at least construct the beginnings of a more harmonious relationship between the two groups. However, perhaps there is also need for developers and electricity companies to quell their pursuits, and foster a healthier partnership with professionals (particularly arborists) who consider them to be abusing their (perhaps inherently advantageous, thanks to the law and the flow of money) position. Of course, many more conclusions can be drawn, though I’d be here all night discussing this one if I didn’t stop somwhere! Source: Kirkpatrick, J., Davison, A., & Harwood, A. (2013) How tree professionals perceive trees and conflicts about trees in Australia’s urban forest. Landscape and Urban Planning. 119 (1). p124-130.

Great photos. David is correct. To confirm? Microscopy of the spores.

There has to be another way to balance this desire with maintaining good quality and honest posting by users. If you want an example of the absurdity that is a rep-based forum community, take a look at the bodybuilding.com forums. A noble intention turned sour the minute people realised they could monopolise rep points and 'neg' people into the 'red', giving the impression such 'red' users are not to be taken seriously. Plus, it's a good way to thought police, and police different thought aside from that which is the norm and will be met with "good post, mate!". Perhaps we can have something along the lines of 'superusers', who have shown to contribute to discussions and provide value to a conversation or the community as a whole. This would be enacted by only the mods, of course (or even just Steve). A little tag or something. Perhaps also a FAQ sticky at the top of different forums with a run-down of pointless and easy questions asked in such abundance that every new time they are asked it makes children cry across a seven mile radius.

No, please no. It was the worst thing about a large forum I used to use. It made people control their posts and such forth. Very bad idea and no need for it. This forum doesn't need a currency (because that's exactly what rep points become).

18/02/16. Fact #153. In spite of Ted Green remarking that he is “stating the obvious” in this chapter of his, it’s nonetheless good to be reminded of the benefits of open-grown trees and how they compare to closed-canopy trees of a similar age. Despite certain similarities, there really are many differences in today’s age, and we’ll explore some of them here. Before that however, it is interesting to note that the utilisation of open-grown trees during ‘ancient’ times was not uncommon. Orchard trees, for example, demonstrate man’s understanding of open-grown trees producing a much greater abundance of fruit than closed canopy trees. Open-grown individuals Morphologically, a tree that has grown without any marked competition will be vastly different to a tree that has grown amongst its competitive peers. Due to a reduced competition for light, and also because of the greater effect of wind upon its structure, an open-grown tree will be shorter, have a fatter trunk, a wider crown (perhaps with vastly-spreading and near-horizontal limbs), and a more significant anchorage root system. This ensures it is well adjuested to its setting (principally in allowing for optimal photosynthesis whilst retaining structural stability). Amazingly, investigations into the rooting systems of open-grown veteran trees by the Ancient Tree Forum revealed roots with a 2.5cm diameter at a distance of 50m from the base of the tree. A mature open-grown oak pollard, complete with an absurdly broad crown with many near-horizontal limbs. Certainly an effective means of balancing photosynthetic needs with stability! On a biodiversity level, we must also recognise that roots are host to a massive array of mycorrhizal associations. If an open-grown tree has a huge rooting system, associations with the tree (directly) will be potentially vast, though perhaps isolated somewhat (assuming no other trees are about). Shed roots may also support organisms of the decmposition subsystem (fungi, in particular). Looking at the above-ground structure of an open-grown tree, we can also observe associations with a great number of species. For instance, the large limbs and vast canopy area of an open-grown tree will provide habitat for many insect species, and entire trophic systems surrounding their presence (from parasitic wasps to mites, and from birds to fungi and bacteria). Similarly, the very large and broad main stem will have a vast quantity of substrate (wood, cavities, hollows, and so on) available for saproxylic species and nesting birds, which will typically revel in the warmer conditions. The herbaceous plant species surrounding the tree will also provide support for insects, including saproxylic beetles. Closed-canopy individuals Because trees growing within a woodland or forest have to compete for all types of resource (light, water, nutrients, rooting space, branching space), their form will be vastly divorced from the open-grown tree. Investing most of its resources into growing towards the light, stems will be thin, lack taper, and rooting systems will be largely insufficient to support the tree structurally (which is evident when woodland edge trees fall following localised tree felling). However, root grafts (between a single species) and mycorrhizal relationships between individuals (across different species) may ensure that edge trees, which have larger canopies, support trees (via grafted roots and mycorrhizae) in more sheltered but still very local settings. By that same token, older trees may support younger individuals (particularly of the same species). In time, deadwood within woodland stands may build up to significant quantities. As a stand ages, there is a progressive ‘self-thinning’ of the stand, eventually leading to only some (usually mature and quite large) trees remaining. This accumulation of deadwood ensures that the decomposition subsystem can mineralise nutrients, allowing these remaining trees to utilise these resources once again. The same can also be said for leaf litter, which is of far greater quantity within a closed stand (and retained, courtesy of a more sheltered micro-climate). For these reasons, and compiled both with the fact trees will ‘trade’ resources in a sort of peer-to-peer economy and their sheltered setting, rooting systems may be less expansive (compared to open-grown trees). Buttressing may also be lacking, unlike in open-grown individuals. A stand of beech (Fagus sylvatica) last pollarded before 1830. We can see how the crowns of each individual are much more upright and narrow, and the stems have less taper than they would in an open setting. There is however a great abundance of leaf litter on the floor, though an unfortunate lack of coarse woody debris (excluding standing deadwood). The decomposition associated with woodland stands will also be far quicker, given the cooler and moister conditions. As fungi tend to operate most effectively in such settings, the mineralisation of locked-away nutrients will be a much swifter process, when compared to the decomposition of deadwood on and around an open-grown tree. For instance, a large stem of a fallen tree within a woodland may decay in a few deacdes, whilst a fallen and significantly-sized limb of an open grown tree may take up to a century to fully decay. Clearly it’s not possible to compare and contrast trees in different setting in any short space of time, though I felt that this brief entry by Ted Green in the below book was a rewarding read, if not to simply cement existing knowledge. Source: Green, T. (2007) Stating the obvious: the biodiversity of an open-grown tree – from acorn to ancient. In Rotherham, I. (ed.) The History, Ecology, and Archaeology of Medieval Parks and Parklands. UK: Wildtrack Publishing.