Kveldssanger

The defence systems of the tree are typically activated by the presence of oxygen and / or compounds (enzymes, etc) secreted by pathogens. In relation to pruning cuts, leaving a stub is (currently) considered to be undesirable where a proper cut can be made, because the stub acts as a food source for any fungi (amongst other things). They can take advantage of this food source and gain extra energy to mount an attack on the natural barriers within the branch junction, that would not be available if the cut was finished to the industry standard.

That would really depend on the genetic properties of the ash, the environmental conditions within and directly surrounding the wood substrate, the genetic proeprties of the fungus, and the presence (and genetic properties) of any other decay-(or non-decay-)causing fungi and bacteria. The general point is that its presence on ash is less desirable. It wouldn't be possible to give a guideline, though I suppose where decay is upon the main stem there is potentially a greater 'window' before probable failure when compared to decay upon a smaller limb. Unless a very long-term study was done ascertaining average 'life expactancy' of ash with this fungal pathogen, we'd be in the realm of guess-work. If the ash successfully compartmentalises the decay, infection is likely non-fatal. If it doesn't, then fracture may occur and this may lead to the death of the individual - given this fungus principally degrades heartwood. However, if it acts as a canker pathogen, if the main trunk is girdled then it may kill the host - or initiate sprouting below the girdling point.

Went on a walk around some of the fields at the back of the house and walked past a line of mature ash, of which most were host to Inonotus hispidus. I thought, therefore, I'd post some information about the fungus. Again, this is all from my notes that I will be using for my Lvl 4, so it is thus set out in such a manner here. 31/10/15. Fact #68. Hosts: Most commonly found on Fraxinus spp. and Platanus x hispanica , though can also be found on other broadleaved species such as Malus spp. Juglans spp., Ulmus spp., Sorbus spp. and Acer pseudoplatanus. Colonisation strategy: Infection sets in via a branch stub, wound (either naturally or artificially-borne) or through tunnels made by wood borers. After entering exposed sapwood, Inonotus hispidus breaks out of the reaction zone formed by the tree by entering 'soft rot mode' and moves into the heartwood, where it colonises and begins to decay the host. However, it can colonise sapwood and has been observed in some young ash branches between 5-7 inches thick. Rot type: Most commonly a simultaneous white rot, though soft rot can also be observed during early stages of development. Canker development has also been observed in instances where a cambium strip has been destroyed. Selective white rot has also been observed in Tilia platyphyllos, which is likely due to Inonotus hispidus' inability to decay heavily-lignified lamellae and rays. Significance: The extent and mode of decay can vary greatly between host species, so ascertaining the potential significance of decay is species-specific. As heavily lignified cells are resilient to Inonotus hispidus, wood rays are usually degraded only in the later stages of decay. As a result, the heavily lignified rays of Platanus x hispanica have a greater innate resilience than the less lignified rays of Fraxinus spp., which can lose significant compression strength very rapidly (within weeks). Therefore, presence on Fraxinus spp. is more significant than on Platanus x hispanica, where co-existence can persevere for many years. Failure is usually a result of brittle fracturing. Part of host impacted: Both the main stem and large branches are the principal hosts for Inonotus hispidus, though smaller branches may also act as viable hosts. Treatment and prevention: Given decay can originate from wounding of the host, limiting pruning wound sizes and extent of pruning can reduce the potential for the onset of decay. Sources: Koyani, R., Sanghvi, G., Bhatt, I., & Rajput, K. (2010) Pattern of delignification in Ailanthus excelsa Roxb. wood by Inonotus hispidus (Bull.: Fr.) Karst. Mycology. 1 (3). p204-211. Lonsdale, D. (1999) Principles of Tree Hazard Assessment and Management (Research for Amenity Trees 7). London: HMSO. Mattheck C., Bethge, K., & Weber, K. (2015) The Body Language of Trees: Encyclopedia of Visual Tree Assessment. Germany: Karlsruhe Institute of Technology. Rayner, A. & Boddy, L. (1988) Fungal Decomposition of Wood: It's Ecology and Biology. UK: John Wiley & Sons. Schwarze, F. (2008) Diagnosis and Prognosis of the Development of Wood Decay in Urban Trees. Australia: ENSPEC. Watson, G. & Green, T (2011) Fungi on Trees: An Arborist's Field Guide. UK: The Arboricultural Association. Weber, K. & Mattheck, C. (2003) Manual of Wood Decays in Trees. UK: The Arboricultural Association.

Ivy gets a bad name for itself. Yes it can be annoying, but the fact it is full of wildlife is critical - particularly in urban environments where there is sometimes infrequent viable habitat for many insects and birds. Also great as a food source for the bees and birds. Ivy has its place.

Again taken from my notes, so there are various references and the reading may be a little disjointed at times. 31/10/15. Fact #67. Ecologically-speaking, there are thee distinct subsystems that can be found within most, if not all, environments: the plant subsystem, the herbivore and carnivore subsystem, and the decomposer subsystem. This post will focus exclusively on the decomposer subsystem. Put simply, the decomposition system is reliant upon, and therefore works in tandem with, both the plant and herbivore / carnivore subsystems. 'Decomposers' are usually the microflora, fungi and bacteria, or worms / nematodes, molluscs and arthropods (amongst other things, as well). Decomposers depend upon necromass (dead organic matter), typically in the form of plant remains, but also on the remains of dead animals, faeces, or shed skins. Relating to the field of arboriculture and forestry, the fungi are a very important decomposer, as are termites - particularly in woodlands. Decomposition will usually require more than one 'pass' through the subsystem, with different decomposers exploiting the different stages of the decomposition process. Some necromass 'types' will require more cycles through the decompositon process than others; this can vary with species for the same type of tissue, such as different species of leaf taking different times to ultimately decay fully. Dead remains of decomposers, such as fungal brackets that have desiccated, also contribute to necromass and require decomposition themselves, so there is an element of 'intra-system feedback'. The decomposition process will ultimately revert everything back to organic matter / humus, which is nutrient rich and available for utilisation by the plant-subsystem for uptake. Decomposition essentially 'mineralises' immobile nutrients locked within an organism, such as nitrogen, potassium or sulphur, and creates essential humus molecules. The decomposition process also releases carbon dioxide. As the decomposer subsystem directly breaks down dead plant material it directly regulates plant growth and (plant) community composition by determining the supply of available soil nutrients to existing plant communities on the site, thereby taking the process full-circle and back to the plant subsystem (which is the 'start' of the cycle). The amount and type of nutrients mineralised determines how the entire plant sub-system succeeds, which has knock-on effects for the herbivorous / carnivorous and decomposition sub-systems. We can therefore begin to see how the three are inter-woven, and a healthy system requires all three systems to be functioning optimally. If one suffers, the rest will (in time - of course, there may be lag periods). To finish off, and as a somewhat aside, the decomposition and herbivore subsystems vary in the sense that decomposition can, as established, be a process that happens more than once over, whereas herbivores only get one 'chance' at consuming a single leaf. However, both systems do compete somewhat for the uptake of carbon, though the herbivore / carnivore subsystem does still provide the decomposer subsystem with faeces and other necromass, whilst the decomposition subsystem does not directly provide herbivores / carnivores with anything (unless we enter the realm of fungivores, though I am sure there could be an entire post on that). Sources: Colpaert, J. & Tichelen, K. (1996) Decomposition, nitrogen and phosphorus mineralization from beech leaf litter colonized by ectomycorrhizal or litter‐decomposing basidiomycetes. New Phytologist. 134 (1). p123-132. Frankland, J. (1982) Biomass and nutrient cycling by decomposer basidiomycetes. In Frankland, J, Hedger, J, & Swift, M. (eds.) Decomposer basidiomycetes: their biology and ecology. UK: Cambridge University Press. Freschet, G., Cornwell, W., Wardle, D., Elumeeva, T., Liu, W., Jackson, B., Onipchenko, G., Soudzilovaskia, N., Tao, J., & Cornelissen, J. (2013) Linking litter decomposition of above‐and below‐ground organs to plant–soil feedbacks worldwide. Journal of Ecology. 101 (4). p943-952. Krivtsov, V., Bezginova, T., Salmond, R., Liddell, K., Garside, A., Thompson, J., Palfreyman, J., Staines, H., Brendler, A., Griffiths, B., & Watling, R. (2006) Ecological interactions between fungi, other biota and forest litter composition in a unique Scottish woodland. Forestry. 79 (2). p201-216. Pradhan, G. & Dash, M. (1987) Distribution and population dynamics of soil nematodes in a tropical forest ecosystem from Sambalpur, India. Proceedings: Animal Sciences. 96 (4). p395-402. Wardle, D., Bardgett, R., Klironomos, J., Setälä, H., van der Putten, W., & Wall, D. (2004) Ecological linkages between aboveground and belowground biota. Science. 304 (5677). p1629-1633. Wardle, D., Walker, L., & Bardgett, R. (2004) Ecosystem properties and forest decline in contrasting long-term chronosequences. Science. 305 (5683). p509-513.

Nope! Lost track of time today so nothing in the way of facts. Will do one or two tomorrow - will keep on the woodland theme, perhaps.

Taken from: Põlme, S., Bahram, M., Kõljalg, U., & Tedersoo, L. (2014) Global biogeography of Alnus‐associated Frankia actinobacteria. New Phytologist. 204 (4). p979-988. "The prominent roles of host phylogeny and spatial factors on Frankia community structure corroborate the results of a global study addressing Alnus-associated EcM fungal communities (P~olme et al., 2013). The Procrustes statistic revealed significant coupling of the two microbial communities, which probably results from the mutually shared host phylogeny effect as revealed by the partial Mantel test. Alternatively, the direct effects of symbionts on each other may be produced through their complementary effects on plant nutrition (Chatarpaul et al., 1989; Horton et al., 2013; Walker et al., 2013). As a result of N fixation, Alnus-dominated ecosystems are phosphorus-limited (Uliassi & Ruess, 2002). Therefore, the efficiency of mineral nutrition may play a role in indirect or direct selection of symbiotic EcM fungi and Frankia by the host tree (Walker et al., 2013)." The reference takes us here: Uliassi, D. D., & Ruess, R. W. (2002). Limitations to symbiotic nitrogen fixation in primary succession on the Tanana River floodplain. Ecology. 83(1), p88-103. A quick scan doesn't locate where the reference may have come from, though the entire article talks about P and N relationships.

Hahah. Your knowledge is not sparse!

Typo - I meant fungi, or more broadly just mycorrhizal species.

29/10/15. Fact #66. It is quite clear that within most derelict land soils the nitrogen supply is far too low to meet minimum plant requirements unless fertilizers or nitrogen fixing species are planted, though as fertiliser requires expenditure over and above the planting of the woodland and as benefits of fertiliser are somewhat contested, loking to plant nitrogen-fixing species is likely to have a more long-term and positive impact upon the soil. One genus that can be of great aid is Alnus spp., which have a close symbiosis with the Frankia genus (actinomycetes) that are found within the nodules of the fine roots. This relationship facilitates the nitrogen fixation process. Such fixation ensures that nitrogen supply can be improved in time, providing progressively improving soil conditions that brings about a more optimal state for more demanding species to then enter and thrive within. For instance, trials in the US have found that Juglans nigra stands have grown at a better rate when planted alongside Alnus glutinosa. Whilst an increase in growth rate varied between sites, at times not assisting with any significance, certain sites saw growth rates increase from 56%-351%. It should be noted however that Alnus-dominated environments tend to be phosphorus-lacking, so caution should perhaps be exercised with regards to a very heavy reliance upon Alnus spp. exclusively; though as the woodland starts to develop and new species establish the soil environment will respond to such development by containing a broader range of mycorrhizal bacteria species, which will on the whole supplement phosphorus uptake of plants. It is however understood that, even when nitrogen-fixing species occupy only a small part of the total woodland biomass, their effects are significantly beneficial. Curiously, Alnus spp. are viewed (by some) as "forest weeds" and are removed in certain instances. It is critical that this doesn't occur unless there is over-riding need to do so, as removal can trigger event chains that may cause imbalance within the entire developing woodland ecosystem. There is even a subtle symbiosis between nitrogen fixation by Alnus spp. and subsequent utilisation by Pinus spp. through commonly-shared ecotmycorrhizal mycelium, which may aid with growth of the latter as a result. This leads on to utilising Pinus sylvestris as a nurse species, particularly for when Quercus spp. are planted alongside. To round-off this post, the planting of species such as scots pine, aspen, and birch as nurse species, which colonise recently disturbed ground and are successional species, may also aid with site improvement. Improving soil condition and biomass accumulation (as well as being shade intolerant [thus being a more 'temporary' woodland feature] and offering dappled shade and shelter for climax species when such climax species are in their infancy), they will rarely succeed into the second generation once more dominant canopy species begin to reach the canopy layer; their selection has thus been shown to improve vitality and growth form of species such as oak and beech. Sources: Arnebrant, K., Ek, H., Finlay, R., & Söderström, B. (1993) Nitrogen translocation between Alnus glutinosa (L.) Gaertn. seedlings inoculated with Frankia sp. and Pinus contorta Doug. ex Loud seedlings connected by a common ectomycorrhizal mycelium. New Phytologist. 124 (2). p231-242. Balandier, P., Sinoquet, H., Frak, E., Giuliani, R., Vandame, M., Descamps, S., Coll, L., Adam, B., Prevosto, B., & Curt, T. (2007) Six-year time course of light-use efficiency, carbon gain and growth of beech saplings (Fagus sylvatica) planted under a Scots pine (Pinus sylvestris) shelterwood. Tree Physiology. 27 (8). p1073-1082. Bardgett, R. & Wardle, D. (2010) Aboveground-Belowground Linkages: Biotic Interactions, Ecosystem Processes, and Global Change. UK: Oxford University Press. Campbell, G. & Dawson, J. (1989) Growth, yield, and value projections for black walnut interplantings with black alder and autumn olive. Northern Journal of Applied Forestry. 6 (3). p129-132. Ekblad, A. & Huss-Danell, K. (1995) Nitrogen fixation by Alnus incana and nitrogen transfer from A. incana to Pinus sylvestris influenced by macronutrients and ectomycorrhiza. New Phytologist. 131 (4). p453-459. Gilman, E. (2004) Effects of amendments, soil additives, and irrigation on tree survival and growth. Journal of Arboriculture. 30 (5). p301-310. Granqvist, E., Sun, J., Op den Camp, R., Pujic, P., Hill, L., Normand, P., Morris, R., Downie, J., Guerts, R., & Oldroyd, G. (2015) Bacterial‐induced calcium oscillations are common to nitrogen‐fixing associations of nodulating legumes and nonlegumes. New Phytologist. 207 (3). p551-558. Mason, W. (2000) Silviculture and stand dynamics in Scots pine forests in Great Britain; implications for biodiversity. Forest Systems. 9 (1). p175-197. Põlme, S., Bahram, M., Kõljalg, U., & Tedersoo, L. (2014) Global biogeography of Alnus‐associated Frankia actinobacteria. New Phytologist. 204 (4). p979-988. Prévosto, B. & Balandier, P. (2007) Influence of nurse birch and Scots pine seedlings on early aerial development of European beech seedlings in an open-field plantation of Central France. Forestry. 80 (3). p253-264. Smalley, T. & Wood, C. (1995) Effect of backfill amendment on growth of red maple. Journal of Arboriculture. 21 (5). p247-247. Smith, S., Jakobsen, I., Grønlund, M., & Smith, F. (2011) Roles of arbuscular mycorrhizas in plant phosphorus nutrition: interactions between pathways of phosphorus uptake in arbuscular mycorrhizal roots have important implications for understanding and manipulating plant phosphorus acquisition. Plant Physiology. 156 (3). p1050-1057. Wheeler, C. (1971) The causation of the diurnal changes in nitrogen fixation in the nodules of Alnus glutinosa. New Phytologist. 70 (3). p487-495.

Got one coming up. It'll be copied over from my notes, so may read slightly note-like.

I have lots of stuff on tree planting - got quite a few good books on the topic. Anything in particular? Same with woodland management. Are you looking for specific areas of the practice?

No worries, on that front! No post today from me - had a BS 3998 course earlier and had some stuff to sort out since getting back. Any recommendations for facts? Got stuff on urban trees, pests / disease, phsyiology, woodland management, etc.

27/10/15. Fact #65. The width of a growth ring is dependant upon many factors - light duration (photoperiod), light intensity, temperature, moisture availability (and when the moisture is available), defoliation (by pests), disease, and so on. Where conditions are adverse for the particular species, growth will suffer. Where conditions are optimal, growth will be better. One may observe how the timing of rainfall, for example, impacts upon ring width, by comparing individuals in areas where rainfall is mainly in winter, and where rainfall is more common throughout the growth period (spring - summer). Where there is more rainfall during the growth period, there is a high probability that the width of the growth ring will be greater. It is important to note however that where the weather is more erratic - particularly where there is more rainfall during the growth period - yearly change in weather patterns can cause massive variation in ring width, compared to variation in ring width in areas where rainfall is always infrequent during the growth period. Where an entire annual ring is not laid down, it is known as a lens. A lens may be evident in individuals that have suffered drought conditions for extended periods - sometimes lenses may be almost non-existent, if drought conditions are that significant. Source: Morey, P. (1973) How Trees Grow. UK: Edward Arnold.

That's on my to-buy list, since you mentioned it a few weeks back to me. So many books to buy, so little space...

No, it is a cool little fact - absolutely! Do you recall where you got the fact from?

Helps with mine, too.

Interesting! I imagine the book I read was talking about on average (I presume!).

Good stuff. This one was spurred-on by a colleague in another department at work asking whether you can make a deciduous tree not lose its leaves during the autumn and winter months. Do pardon all the brackets! 26/10/15. Fact #64. Can a deciduous tree that loses its leaves during winter (we'll say an individual Quercus robur, for illustrative purposes) be made to not lose its leaves, by artificially controlling conditions so that the individual receives enough sunlight and is not subject to undesirable ambient temperatures? In short, probably not. Whilst the principal controlling stimulus behind winter bud set is the shortening day length (do not confuse this with the 'amount of light' a tree gets - shaded individuals are still, by-and-large, able to ascertain overall length of the day), particular species (such as for our Quercus robur) lay down their winter buds long before days even begin to shorten (so during periods where conditions are still 'optimal'). Therefore, there will come a point where it just is not possible for our oak to not lose its leaves, as those winter buds will require the winter conditions to aid with bud break again in spring (that 'over-wintering', so to speak), and as existing leaves cannot persist indefinitely (most cannot survive more than 2-3 years, even in coniferous species*) there will be a point where existing leaves are shed and new ones cannot form. Moving off at a tangent, it is also worth noting that the metabolism of our oak does not necessarily slow down as the days shorten and leaves are shed. Whilst both day length and temperature can impact upon its metabolic rate, this impact may at times increase metabolic rate - it is simply a case of cell division taking place in ways that do not see markedly increased growth; metabolism may raise to create organ(elles) used (in part) for both the onset of dormancy (and to survive the winter) and also for that all-important spring growth. Only when these processes have been completed will metabolism drop - it will only then raise again following the crucial wintering period, where the buds are exposed to cold temperatures. To wrap up, our oak will have also 'developed' an early-warning system (or systems) that provide it with ample time to fully prepare for dormancy. The system the oak will use, and was mentioned earlier, is day length. Measuring day length is more accurate than measuring temperature, as temperature will fluctuate far more significantly than day length - it will not give the oak as much of an accurate picture, and an accurate picture is critical for survival! Source: Villiers, T. (1975) Dormancy and the Survival of Plants. UK: Edward Arnold. * This is not from the source quoted, but from another book - unfortunately, I cannot recall which book.

Back to normal tomorrow, for those of you that care.

A packet of wotsits and a half-eaten cheese sandwich, I am guessing. The bread was stale.

I'm still waiting on a post from harrycarpenter. I can live in hope.

23/10/15. Fact #63. Much like the climate impacts upon trees, it also impacts upon fungi - though generally to a lesser extent. Straight away, therefore, we can observe how the climatedrives fungal presence. The climate infuences constituent species of trees, so therefore fungi 'follow' their suitable tree hosts. An indirect influence, if you will. On a more direct basis however, both rainfall and temperature will have an influence upon fungal presence and activity. As a pre-cursor, normally fungi can be found from June through to Deceber, with their activity 'peaking' during October. Within a woodland setting, fungi found growing on leaf litter can only manifest when leaf litter moisture content is over 50% and the average surface temperature is no lower than 4 degrees Celsius (the upper limit is a 'softer' cap than the lower limit, which is far less flexible). Therefore, when rainfall is lacking, or temperature is very low, fungi may cease to function - we may see this drop is activity during very dry periods of summer, with regards to rainfall (and one must remember temperatures in woodlands are much cooler, given the shafing effect of the canopy). As a general rule of thumb, the larger the sporophore the longer the lag period is between weather change and fungi activity. Smaller sporophores will appear first, and much larger ones later - larger sporopohores may in fact only be produced if such favourable conditions persist for long periods. Interestingly, one is more likely to find fungi operating within woodland settings than open grasslands (or other open settings). The canopy cover of the woodland modifies local micro-climate, and extends the period of time in which fungi can function by keeping temperatures cooler and humidity levels higher - both are favourable for fungal activity, as desiccation is essentially less of a risk. This applies for leaf litter fungi and wood-decay fungi. Source: Hudson, H. (1972) Fungal Saprophytism. UK: Edward Arnold.

The elfcup is incredible. Its turqoise colouration (and how it stains (?) the wood) is exquisite.