Kveldssanger

I don't think fact number 200 could have been much cooler!

09/05/16. Fact #200. Most cultures will have their important trees. Historically, perhaps more so, as cultures are so diluted today that the only thing worshipped with any ferocity is money and power (a generalisation, yes). An interesting relationship of trees and a culture is that of the ceiba tree and the Mayans (in the Mayan language, the ceiba was called the ‘yaxche‘, which translates to ‘the first [blue-green] tree’), and thus we have to go back a good few thousand years for this factoid. We must first understand that, back in time, trees were so critically important. They provided food for humans and livestock, shade and protection from the harsh elements of nature, had medicinal properties and were thus used to treat illnesses, and were harvested for their timber, which could be used for construction (or burned as firewood). Therefore, there was a very strong connection between man and trees, and this was the case for the Mayans and the ceiba tree. The ceibas provided food through their edible fruits, of which the fine silk-like thread from the mature fruits could be harvested and spun into cloth, and the seeds crushed to make oil. The species also had wood soft enough to carve into canoes, and, in addition, numerous parts of the tree could be harvested for their medicinal benefits. For example, the leaves of the ceiba could treat skin burns, swellings, and rashes, whilst the bark could heal ulcerations, encourage ‘menstrual flow’ and expel placentas, amongst other more earthly ailments such as treating gonorrhea. The sap was also used as a weight-gainer (quick, someone inform the supplement industry!). A parakeet feasting upon the fruit of the ceiba. We can also see the silky threads that would have been spun to make cloth. Source: The Internet Bird Collection. The ceibas were also important for locating water sources. In dry regions, ceibas were found where there was water near to the surface, and therefore their presence indicated that sustaining a human population nearby was at least somewhat feasible. Often, settlements were built around the ceibas, meaning the trees had a particular status, which obviously fostered the relationship they had with the Mayans. Beyond growing in arid regions, their abundant presence in the forest was also a reason for them being so revered – their commonality is probably a factor that allured the Mayans into worshiping the tree. In fact, in forest settings, other trees would be cleared and ceibas retained, sometimes also the younger ones, and settlements were constructed around them. The Mayans revered the ceibas so much that they made stone carvings of the trees (known as tree stones or stelae). Where these tree stones were placed in temples, they were situated in the central regions atop the pyramid, and around the tree stone would, at times, sit four ceiba trunks. In this sense, the tree stones and surrounding trunks suggested great power and status (in the religious and political sense). Despite this (arguably very masculine) power display, the ceibas were actually considered to be quite feminine. The trees had maternal characteristics, such as how it was seen to care for deceased children by feeding them milk from its fruits, which actually resembled female breasts (in the eyes of the Mayans). The swollen trunk of the ceiba, particularly when growing within the forest, also had similarities to a pregnant woman. Some Mayan groups also claimed to be descendants from the ceiba tree. There is also cross-over (pardon the pun) with the Mayan view of the ceibas and Christianity. In Mayan culture, the ceiba was sometimes depicted as a cross (usually in a green colour). When the Spanish invaded the Americas many centuries ago, this depiction actually enabled for the ‘easier’ conversion of Mayans to Christianity. The ceiba cross, green in colour. Source: Travelblog. In modern times, whilst the culture has been diluted, ceibas are still respected. Generally only much older trees are revered in modern day, whilst younger ones are ignored. Unfortunately, however, even at times the older trees are ignored. For those communities situated within the lowlands, the ceiba is more respected than it is in the highlands. Despite this, young ceibas are still felled in the lowlands to allow for agricultural practices to take place – an act that may have been hugely frowned upon (or perhaps banned) in historic times. The link with Christianity still exists, too, as the ceiba is linked with the Catholic Church and can therefore be found within the grounds of churches across the land (a bit like yew trees in churchyards across the UK). Source: Anderson, K. (2003) Nature, culture, & big old trees: live oaks and ceibas in the landscapes of Louisiana and Guatemala. USA: University of Texas Press.

That oak does indeed look shot! Hopefully it bounces back. Considered mulching it?

Man has always had a direct link to the landscape, though that link, whilst it is always there, may not be in the form that it once was. Keeping with the wood pasture theme, which I am really enjoying learning about through books and journal articles, I thought we’d look at how the manner in which we approach the ecosystem has changed over the centuries (quite briefly). Of course, what is written below doesn’t stop just at wood pasture – it has cross-over to other ecosystems, where the reasons for interaction with the landscape have altered through space and, more pertinently, time. Historically, wood pastures were managed for economic purposes. The grazing of animals on grasslands containing trees (and the feeding of the livestock with cuttings from pollarded trees, and a tree’s fruit crop), such as cattle and pigs, was for the direct benefit of communities, who relied upon the produce of the livestock (milk, meat, and so on) in order to make a living, and to generally therefore survive. Of course, the wood pastures needed to be conserved, so that they did not disappear, due to over-grazing. In this sense, they were actively conserved (by replanting dying and dead trees, and limiting grazing intensity), though largely because, without actively conserving them, the livelihood of many tens of thousands of people would be challenged. A by-product of this conservation of wood pastures, for the benefits created from grazing livestock, was that the sites were very rich in biodiversity – birds, fungi, insects, and plants, for example. The complex mosaic of niches within the wood pasture, ranging from open and disturbed soils through to the (perhaps sizeable) groves surrounded by the mantle and fringe vegetation, meant that a large number of organisms could viably frequent the site. However, for all of the biodiversity present as a result of the careful management and conservation of wood pastures throughout history, biodiversity was not the reason for management – until recently. The shift, in Europe, probably begun when wood pasture became disliked (for hope of a better word), during the 19th-20th century (varies depending upon the country). Foresters wanted to maximise output from the trees (coppice – sometimes with standards), and farmers wanted to maximise agricultural output. Therefore, the two practices, initially married, were divorced from one another (somtimes farmers were forced to stop grazing their livestock in wood pasture!). Wood pastures were thus either cleared of trees entirely, or alowed to regenerate into forest. With this came a decline in the richness of biodiversity and, eventually, this loss of biodiversity caused a rather evident of panic amongst conservationists. Ironically, therefore, the rationale behind creating and maintaining wood pasture became largely ecologically-driven, in place of economically-driven (though, particularly in Spain and Romania, wood pastures remain, are these are generally economically viable). Regardless of reason however, the status of wood pastures essentially went full-circle. A fantastic wood pasture in Estonia. Source: Ideas for Sustainability. Of course, this new found love for wood pastures does not necessarily mean that they can ever exist in the manner in which they did before. First and foremost, wood pastures are extensively grazed, and thus, for operations to be self-supporting financially, they must cover large expanses of land (unless the wood pasture is maintained for subsistence purposes, or grants are provided as a means of financial support). As farmers in Europe are generally in ‘the game’ for profit (they must make a living), managing livestock in wood pastures is probably not going to be all too popular, as it’d probably signal a marked drop in profits and / or a marked increase in labour input (at least, initially). Scope does exist to harvest edible mycorrhizal mushrooms from the wood pasture, such as truffles, though this is a specialised pursuit that is far from the current farming status quo of Europe. Furthermore, European culture has changed. Gone are the days of communities being self-sufficient, and instead many Europeans now work a job (that they may even hate) and buy their food from the supermarket (or even order it online). Therefore, is there even the desire to re-introduce wood pastures, for anything other than ecological reasons, or to supply the market with a niche animal product (such as Iberian ham from the black Iberian pig, in the holm oak dehesas of Spain). With this change in culture there has also been a change in learning priorities, and unfortunately many today seem to be fixated with knowing pointless facts about sports teams and celebrities. Functional and practical knowledge is largely gone. As a consequence, the management of wood pastures will be left to an expert few, where knowledge has either been gained academically, or via being passed-down through the generations (usually limited to rural areas where grazing still takes place). However, as more people now live in cities than in rural areas, and this trend will likely continue as rural areas are swallowed up by urban sprawl, or people move into cities for economic reasons, this tradition of passing practical knowledge on and keeping up the family tradition of extensive livestock grazing within wood pasture may very well become ever more the stuff of legend. The black Iberian pig grazing amongst a landscape of holm oak, in a Spanish dehesa. Source: Andrew Petcher. Society is simply in a different place than it once was. For this reason, the conservation of wood pasture is to be far from mainstream. People are certainly aware of nature (of which wood pastures feature), though more and more awareness comes from watching on the television and less from direct experience, and with this comes a discord. There is less emotional and cultural attachment to nature, and as a result, less of an impetus to associate with nature. Why help with the recreation of wood pasture when you can watch about its conservation on television, utter some lamentations, and then switch the channel and soon relegate it to a mere memory? That’s even assuming people watch such programs, in large numbers, in the first place. This probably turned out far more dystopian than I ever intended for it to come out as, though hopefully this illustrates how social changes have led to landscape management changes, with specific focus upon wood pastures in Europe. This is obviously applicable to other landscape types as well, of course. The principle generally carries across. Source (of inspiration): Hartel, T. & Plieninger, T. (2014) The social and ecological dimensions of wood-pastures. In Hartel, T. & Plieninger, T. (eds.) European wood-pastures in transition: A social-ecological approach. UK: Earthscan.

Hahah maybe one day! Slowing down with them a bit as I'm trying to do so many things at once at the moment - read books, write these, explore landscapes, spend time with the missus, and writing other bits and bobs. Hopefully the length isn't too bad. I try to put pretty images in where I can, of course.

Cheers for 40k views. And this won't become a thread that only ever talks about wood pasture.

08/05/16. Fact #199. Man has always had a direct link to the landscape, though that link, whilst it is always there, may not be in the form that it once was. Keeping with the wood pasture theme, which I am really enjoying learning about through books and journal articles, I thought we’d look at how the manner in which we approach the ecosystem has changed over the centuries (quite briefly). Of course, what is written below doesn’t stop just at wood pasture – it has cross-over to other ecosystems, where the reasons for interaction with the landscape have altered through space and, more pertinently, time. Historically, wood pastures were managed for economic purposes. The grazing of animals on grasslands containing trees (and the feeding of the livestock with cuttings from pollarded trees, and a tree’s fruit crop), such as cattle and pigs, was for the direct benefit of communities, who relied upon the produce of the livestock (milk, meat, and so on) in order to make a living, and to generally therefore survive. Of course, the wood pastures needed to be conserved, so that they did not disappear, due to over-grazing. In this sense, they were actively conserved (by replanting dying and dead trees, and limiting grazing intensity), though largely because, without actively conserving them, the livelihood of many tens of thousands of people would be challenged. A by-product of this conservation of wood pastures, for the benefits created from grazing livestock, was that the sites were very rich in biodiversity – birds, fungi, insects, and plants, for example. The complex mosaic of niches within the wood pasture, ranging from open and disturbed soils through to the (perhaps sizeable) groves surrounded by the mantle and fringe vegetation, meant that a large number of organisms could viably frequent the site. However, for all of the biodiversity present as a result of the careful management and conservation of wood pastures throughout history, biodiversity was not the reason for management – until recently. The shift, in Europe, probably begun when wood pasture became disliked (for hope of a better word), during the 19th-20th century (varies depending upon the country). Foresters wanted to maximise output from the trees (coppice – sometimes with standards), and farmers wanted to maximise agricultural output. Therefore, the two practices, initially married, were divorced from one another (somtimes farmers were forced to stop grazing their livestock in wood pasture!). Wood pastures were thus either cleared of trees entirely, or alowed to regenerate into forest. With this came a decline in the richness of biodiversity and, eventually, this loss of biodiversity caused a rather evident of panic amongst conservationists. Ironically, therefore, the rationale behind creating and maintaining wood pasture became largely ecologically-driven, in place of economically-driven (though, particularly in Spain and Romania, wood pastures remain, are these are generally economically viable). Regardless of reason however, the status of wood pastures essentially went full-circle. A fantastic wood pasture in Estonia. Source: Ideas for Sustainability. Of course, this new found love for wood pastures does not necessarily mean that they can ever exist in the manner in which they did before. First and foremost, wood pastures are extensively grazed, and thus, for operations to be self-supporting financially, they must cover large expanses of land (unless the wood pasture is maintained for subsistence purposes, or grants are provided as a means of financial support). As farmers in Europe are generally in ‘the game’ for profit (they must make a living), managing livestock in wood pastures is probably not going to be all too popular, as it’d probably signal a marked drop in profits and / or a marked increase in labour input (at least, initially). Scope does exist to harvest edible mycorrhizal mushrooms from the wood pasture, such as truffles, though this is a specialised pursuit that is far from the current farming status quo of Europe. Furthermore, European culture has changed. Gone are the days of communities being self-sufficient, and instead many Europeans now work a job (that they may even hate) and buy their food from the supermarket (or even order it online). Therefore, is there even the desire to re-introduce wood pastures, for anything other than ecological reasons, or to supply the market with a niche animal product (such as Iberian ham from the black Iberian pig, in the holm oak dehesas of Spain). With this change in culture there has also been a change in learning priorities, and unfortunately many today seem to be fixated with knowing pointless facts about sports teams and celebrities. Functional and practical knowledge is largely gone. As a consequence, the management of wood pastures will be left to an expert few, where knowledge has either been gained academically, or via being passed-down through the generations (usually limited to rural areas where grazing still takes place). However, as more people now live in cities than in rural areas, and this trend will likely continue as rural areas are swallowed up by urban sprawl, or people move into cities for economic reasons, this tradition of passing practical knowledge on and keeping up the family tradition of extensive livestock grazing within wood pasture may very well become ever more the stuff of legend. The black Iberian pig grazing amongst a landscape of holm oak, in a Spanish dehesa. Source: Andrew Petcher. Society is simply in a different place than it once was. For this reason, the conservation of wood pasture is to be far from mainstream. People are certainly aware of nature (of which wood pastures feature), though more and more awareness comes from watching on the television and less from direct experience, and with this comes a discord. There is less emotional and cultural attachment to nature, and as a result, less of an impetus to associate with nature. Why help with the recreation of wood pasture when you can watch about its conservation on television, utter some lamentations, and then switch the channel and soon relegate it to a mere memory? That’s even assuming people watch such programs, in large numbers, in the first place. This probably turned out far more dystopian than I ever intended for it to come out as, though hopefully this illustrates how social changes have led to landscape management changes, with specific focus upon wood pastures in Europe. This is obviously applicable to other landscape types as well, of course. The principle generally carries across. Source (of inspiration): Hartel, T. & Plieninger, T. (2014) The social and ecological dimensions of wood-pastures. In Hartel, T. & Plieninger, T. (eds.) European wood-pastures in transition: A social-ecological approach. UK: Earthscan.

Bloody hell. The stupidity of people never ceases to amaze.

06/05/16. Fact #198. Within many urban environments, one can come across vacant parcels of land. Such land parcels may be in residential, commercial, or industrial areas, and oftentimes they will be home to, because of the lack of disturbance and management of the land, plants. Some of these plants will, of course, be trees (of varying ages – depends on how long the land has been vacant for). In certain cities, the amount of vacant land may be particularly high, with declining fortunes of landowners, a worsening economy, and a change in demographics, being three drivers of the abandonment of land. In Detroit, USA, for example, around 32% of all urban land is currently vacant.Of course, in many aspects, this is not good, though is there a silver lining to such vacant plots? The study investigated in this post (referenced at the bottom) seeks to establish just that, in terms of ascertaining how valuable vacant land plots are as green infrastructure. The study area for the investigation was the city of Roanoke, Virginia, USA. This city was chosen as it has a wide variety of different vacant land parcels, of which many are old industrial (manufacturing / factory) plots that were abandoned as the economy declined and technologies changed. In total, the vacant areas of land were split into five different categories, as shown in the below table. Overall, 114 vacant plots, both under public and private ownership, were sampled. The five types of vacant land, as defined by the authors. Of these land types, an area amounting to nearly 30% of the entire city was considered to be classed as vacant. Granted, some areas are intentionally vacant, as they are floodplains, wetland areas, and so on. The table shown below gives more of an indication of what land types there are in the city, and how much of the total city area they comprise. Total land area of the different vacant land types. Within these vacant plots, there was a total of 210,000 trees (an average of 30.6% canopy cover, in these vacant areas); of which nearly 41% of the trees were quite small (below 15.2cm in diameter). The total number of trees are split as follows: (1) derelict: 25,725; (2) natural: 26,514; (3) post-industrial: 7,488; (4) transportation-related: 28.923, and; (5) unattended with vegetation: 121,613. Because of the species of trees found on the vacant sites (see below), it can be recognised that this data means many trees are young. This, in turn, means that the ecosystem services (filtering air pollutants, sequestering carbon, catching rainwater, cooling the urban environment, and so on) provided by the trees are rather limited, though as the authors note there is scope for the services to increase in time, as the trees mature. Of course, there are older trees within these vacant plots, and nearly 6% of all of the trees had a DBH of over 76.cm, though the population is heavily skewed in favour of young trees. It is also worth noting that the invasive tree of heaven (Ailanthus altissima) features rather readily, and this may be undesirable on an ecological level. In fact, invasive non-native plants are perhaps more likely to be able to colonise vacant land plots than native ones, in many instances – particularly on brownfield sites. A breakdown of the tree species found within the vacant plots. The three main species are American elm (16.5%), tree of heaven (12.3%), and box elder (6.7%). Combined, the trees within the vacant plots do however have many benefits. First and foremost, they have a very positive impact upon air quality, by filtering out harmful pollutants that, as a result, has a monetary value attributed to it (as shown below). For example, nearly 30 metric tons of moderately-sized particulate matter is removed by the vegetation every year, and this equates to financial benefits of $450,000 (nearly $16,000 per metric ton). The removal of pollutants by trees growing within vacant land parcels. The bars represent total pollution removal per year, whilst the triangles relate to the financial benefits. Beyond the removal of air pollutants, the trees growing within vacant land also have a marked benefit when it comes to the sequestration of carbon. As carbon dioxide is considered by some (but not all) scientists as being a marked cause of climate change, some will promote the utilisation of trees for their assimilative capacity when it comes to storing carbon. In the study area, the 210,000 trees were found to sequester a gross total of 2,090 tons of carbon each year, which has a monetary value of $164,000. Granted, not all species are equal in this regard, and it is the American elm and the tree of heaven that top the charts for carbon sequestration (see the below graph), with the elm being far above anything else in this regard. Curiously, whilst the box elder is the third most common tree species within vacant plots, it does not rank third for carbon sequestration. When the authors looked at total carbon storage, which is what carbon has been stored over the trees’ lifetimes, a total of nearly 100,000 tons had been stored, which is valued at $7.6m. This value does however vary across vacant land types, with much of the carbon being stored in areas unattended that possess vegetation, though this may very likely be down to the fact that this land type has over half of the total 210,000 trees. The total amount of caron sequestered, each year, by some of tree species found within vacant plots. Each metric ton of carbon sequestered is valued at $78.5. These vacant land-borne trees also reduce the expenditure incurred by residents of the city, and particularly when it comes to heating or cooling of property. Each year, the trees reduced, by over $210,000, the expenses paid to heat and cool property. Such savings translate into indirect benefits for limiting air pollution, as this reduces cost is associated with reduced energy bills. This obviously means less energy was used, which implies that individuals emit (via consumption) fewer total pollutants, each year. There also exists a structural value to the vegetation within these vacant plots, and for the city’s trees this amounts to $169m. Again, it is the unattended land that possesses vegetation that bears most of this value ($111m), as such land has by far the most trees, though other land types also have important financial values. The below table details exactly this. The structural value of the trees within each land type, compared with the number of trees and the total cover of trees within each land type. What I find particularly interesting about this study is that it suggests that we need to adopt a broader approach to how we view vacant areas of alnd within the city. Often, people will refer to areas of abandoned land within industrial and residential areas as wastelands, though according to this research they are anything but. Even though post-industrial and derelict land types themselves feature only to a small degree within the urban environment, they can certainly support tree populations, and the longer these areas remain void the better, from an environmental standpoint. Granted, there is a pursuit to re-build the economy after the banks managed to royally muck it all up and run off with billions in bailouts from the taxpayer, so such sites may be ear-marked for development if there is the justification, though at the same time there is huge opportunity to almost re-wild inner-city areas. Can there be a balance between the economy and the environment, therefore? If these sites are developed, perhaps there exists scope to retain some areas of trees. It’s also important to recognise the value these trees have by merely existing, and whilst it’s not a value that can be ‘cashed in’, it is nonetheless a value that should be properly recognised. Source: Kim, G., Miller, P., & Nowak, D. (2015) Assessing urban vacant land ecosystem services: Urban vacant land as green infrastructure in the City of Roanoke, Virginia. Urban Forestry & Urban Greening. 14 (3). p519-526.

A welcome addition to what I wrote, so thanks for that. Interesting on the larch appeals, and clarification on the nature of a hedge within England - i.e. deciduous specimens.

A beefsteak would probably have fallen away, no? My first hunch was Pseudoinonotus dryadeus or Ganoderma resinaceum, with a leaning to the former because of the atop texture (the rippled and mottled greeny surface).

04/05/16. Fact #197. Currently, I am on chapter 6 of Vera’s book Grazing Ecology and Forest History, and there’s a great sub-chapter (6.2.2) that explores the relationship between the Eurasian jay (Garrulus glandarius) and the oak. I learned a lot from reading this specific segment of the book, and thus hope that others also find the following information useful. Firstly, one can certainly recognise that oak trees in Europe (Quercus petraea and Quercus robur) do not generally regenerate in woodland. Whilst acorns do germinate, after a period of usually less than a decade, they cease to be, as they are out-competed by shade-tolerant species, such as hornbeam (Carpinus betulus) and beech (Fagus sylvatica). Instead, oaks oft regenerate amongst thorny scrub (in grasslands, grazed areas, and within mantle and fringe vegetation bordering woodland), be the scrub comprised of hawthorn (Crataegus spp.), blackthorn (Prunus spinosa), holly (Ilex aquifolium), gorse (Ulex europaeus), or otherwise. In many an instance, one can perhaps wonder how the young oaks reached and regenerated within such scrub, and most notably so if there are no sizeable oaks within the immediate area. One explanation for this is, as explained by Vera, and courtesy of an array of sources, the Eurasian jay. As an oak releases its fruit crop (acorns) into the harsh environment during September to November, the jay will collect many of the acorns (the healthy, ripe, good-sized ones, generally-speaking), and bury them at a distance from the tree that may vary from tens of metres to a few miles. When a jay collects only one or two acorns, it may bury them only a short distance from the point at which it gathered them from, but if the jay carries five or six acorns (in its gullet, throat, and beak – the largest being in its beak), then the acorns may be buried thousands of metres away. All of the acorns collected in one ‘trip’ will be buried in close proximity to one another, at a maximum spacing distance of around 15m (usually 0.5-2m spacings). At the level of a single jay, this dispersal of acorns may be relatively small, but when amplified to a group of jays 65 strong, research has indicated that (over the course of four weeks) up to 500,000 acorns may be dispersed. This dispersal is also very significant at distances from nearby oaks, with approximately 5,000 acorns per hectare when the nearest fruit-producing oak is around 200m away. A Eurasian jay with an acorn within its beak. Source: Phil Winter. Jays also have a strong preference of burying their acorns in open areas with loose soil. Usually, this will be open areas outside of forests within grasslands and amongst thorny scrub (this explains why oaks may pop up amongst thick scrub), though if substantial forest clearings manifest (due to tree mortality – normally courtesy of windthrow and the forest edge effect), then they too may be alluring sites in which the jay may cache its treasure. Interestingly, open areas complete with loose soil and areas of thick scrub are akin to medieval wood pastures, where grazing would have occurred. This young oak is growing amongst bramble and gorse, within a heathland area, and beyond the direct reach of a parent oak (meaning the acorn didn’t just fall into this spot). Thus, it is likely that it was buried by a jay. Once the acorn has been buried by the jay, it will cover the site with soil and leaves, in order to hide it from sight. In order to re-find it, the jay will remember the vertical structures of vegetation in the immediate area – their memory of where they have planted acorns is, in fact, very good. Interestingly, a jay will only be able to find acorns it has buried – it will not be able to locate acorns buried by other jays, unless that other jay is also present at the time of digging up the acorn. Typically, the acorns they bury will be eaten throughout the year, though the months of April through to August mark the period when fewest acorns are dug up and eaten. This drop in predation by the jay fits in well with the period of acorn germination, with the stem emerging during May and the first few leaves unfolding in June. This development of the small leaf crown co-incides with when jays will begin to search for acorns with a little more intent, as it is during this time that they will be feeding and training their young to fend for themselves. When a seedling (that is still green in the stem, and thus not lignified) is found from an acorn that the parent jay had buried, it will pull it up and eat the acorn, before depositing the little seedlng back into the ground rather crudely. Its young will, actually rather hilariously, mirror this behaviour, though with far less finesse, and pull up not only oak seedlings but anything else they find as well. This removal of the acorn does however not have a huge impact upon the oak seedling, as the strong and extensive tap root developed rapidly after germination means that the little oak seedling is securely anchored into the ground and can fend for itself, even if the acorn (provides energy for seedling growth) is lacking. Essentially, the uprooting is a trade-off that the oak tolerates well, so to be able to grow in the full sunlight conditions the jay opts to bury its acorns in (and where they will grow best, as the oak is not shade tolerant). Research has even shown that many oaks bear the scar of early uprooting by a jay, though since that time they have developed into healthy young trees. Importantly, this disturbance event only happens once (usually), as jays will only uproot small seedling that they buried. Jays are very ‘untrusting’ of ‘foreign’ or ‘alien’ acorns and oak seedlings, and thus will avoid them, by-and-large. The symbiotic nature of the relationship between the oak and the jay is cemented when one recognises that both benefit very well from the association. As remarked above, the oak is able to regenerate in ideal conditions, though as the jay selects only the healthiest and larger acorns there’s also a direct filter placed upon acorn populations, that ensures only the strongest acorns ever have a good chance of germinating. Furthermore, the wide dispersal of acorns by the jay ensures that oak populations can spread quite markedly, with small satellite groves emerging at sometimes great distances from the parent tree. On the side of the jay, the provisioning of an important food source is critical, as without acorns the jay, in Europe, may have to find other significant sources of food with good nutritional value. Of course, it is also important that the right conditions are available for the jay – this means open areas of grassland, or mantle and fringe vegetation. Closed forests are not suitable for the jay, and it will thus not bury its acorns there. In fact, even though forest stands of oak produce 10-times more acorns than sparsely-populated open-grown oak pasture landscapes, the density of acorns within the soil buried by jays is 50-times greater within the open landscapes. Such landscapes are generated by grazing, according to Vera, and whilst modern grazing has been created by man (up until the decline on grazing, in recent times), historically the wild boar (Sus scrofa) would have provided good conditions (due to its disturbance of the soil in grasslands, which were created by large roaming herbivores – the auroch, deer, and wild horse, for example) for where the jay could bury its acorn collection. Source: Vera, F. (2000) Grazing Ecology and Forest History. UK: CABI Publishing.

04/05/16. Fact #197. Currently, I am on chapter 6 of Vera’s book Grazing Ecology and Forest History, and there’s a great sub-chapter (6.2.2) that explores the relationship between the Eurasian jay (Garrulus glandarius) and the oak. I learned a lot from reading this specific segment of the book, and thus hope that others also find the following information useful. Firstly, one can certainly recognise that oak trees in Europe (Quercus petraea and Quercus robur) do not generally regenerate in woodland. Whilst acorns do germinate, after a period of usually less than a decade, they cease to be, as they are out-competed by shade-tolerant species, such as hornbeam (Carpinus betulus) and beech (Fagus sylvatica). Instead, oaks oft regenerate amongst thorny scrub (in grasslands, grazed areas, and within mantle and fringe vegetation bordering woodland), be the scrub comprised of hawthorn (Crataegus spp.), blackthorn (Prunus spinosa), holly (Ilex aquifolium), gorse (Ulex europaeus), or otherwise. In many an instance, one can perhaps wonder how the young oaks reached and regenerated within such scrub, and most notably so if there are no sizeable oaks within the immediate area. One explanation for this is, as explained by Vera, and courtesy of an array of sources, the Eurasian jay. As an oak releases its fruit crop (acorns) into the harsh environment during September to November, the jay will collect many of the acorns (the healthy, ripe, good-sized ones, generally-speaking), and bury them at a distance from the tree that may vary from tens of metres to a few miles. When a jay collects only one or two acorns, it may bury them only a short distance from the point at which it gathered them from, but if the jay carries five or six acorns (in its gullet, throat, and beak – the largest being in its beak), then the acorns may be buried thousands of metres away. All of the acorns collected in one ‘trip’ will be buried in close proximity to one another, at a maximum spacing distance of around 15m (usually 0.5-2m spacings). At the level of a single jay, this dispersal of acorns may be relatively small, but when amplified to a group of jays 65 strong, research has indicated that (over the course of four weeks) up to 500,000 acorns may be dispersed. This dispersal is also very significant at distances from nearby oaks, with approximately 5,000 acorns per hectare when the nearest fruit-producing oak is around 200m away. A Eurasian jay with an acorn within its beak. Source: Phil Winter. Jays also have a strong preference of burying their acorns in open areas with loose soil. Usually, this will be open areas outside of forests within grasslands and amongst thorny scrub (this explains why oaks may pop up amongst thick scrub), though if substantial forest clearings manifest (due to tree mortality – normally courtesy of windthrow and the forest edge effect), then they too may be alluring sites in which the jay may cache its treasure. Interestingly, open areas complete with loose soil and areas of thick scrub are akin to medieval wood pastures, where grazing would have occurred. This young oak is growing amongst bramble and gorse, within a heathland area, and beyond the direct reach of a parent oak (meaning the acorn didn’t just fall into this spot). Thus, it is likely that it was buried by a jay. Once the acorn has been buried by the jay, it will cover the site with soil and leaves, in order to hide it from sight. In order to re-find it, the jay will remember the vertical structures of vegetation in the immediate area – their memory of where they have planted acorns is, in fact, very good. Interestingly, a jay will only be able to find acorns it has buried – it will not be able to locate acorns buried by other jays, unless that other jay is also present at the time of digging up the acorn. Typically, the acorns they bury will be eaten throughout the year, though the months of April through to August mark the period when fewest acorns are dug up and eaten. This drop in predation by the jay fits in well with the period of acorn germination, with the stem emerging during May and the first few leaves unfolding in June. This development of the small leaf crown co-incides with when jays will begin to search for acorns with a little more intent, as it is during this time that they will be feeding and training their young to fend for themselves. When a seedling (that is still green in the stem, and thus not lignified) is found from an acorn that the parent jay had buried, it will pull it up and eat the acorn, before depositing the little seedlng back into the ground rather crudely. Its young will, actually rather hilariously, mirror this behaviour, though with far less finesse, and pull up not only oak seedlings but anything else they find as well. This removal of the acorn does however not have a huge impact upon the oak seedling, as the strong and extensive tap root developed rapidly after germination means that the little oak seedling is securely anchored into the ground and can fend for itself, even if the acorn (provides energy for seedling growth) is lacking. Essentially, the uprooting is a trade-off that the oak tolerates well, so to be able to grow in the full sunlight conditions the jay opts to bury its acorns in (and where they will grow best, as the oak is not shade tolerant). Research has even shown that many oaks bear the scar of early uprooting by a jay, though since that time they have developed into healthy young trees. Importantly, this disturbance event only happens once (usually), as jays will only uproot small seedling that they buried. Jays are very ‘untrusting’ of ‘foreign’ or ‘alien’ acorns and oak seedlings, and thus will avoid them, by-and-large. The symbiotic nature of the relationship between the oak and the jay is cemented when one recognises that both benefit very well from the association. As remarked above, the oak is able to regenerate in ideal conditions, though as the jay selects only the healthiest and larger acorns there’s also a direct filter placed upon acorn populations, that ensures only the strongest acorns ever have a good chance of germinating. Furthermore, the wide dispersal of acorns by the jay ensures that oak populations can spread quite markedly, with small satellite groves emerging at sometimes great distances from the parent tree. On the side of the jay, the provisioning of an important food source is critical, as without acorns the jay, in Europe, may have to find other significant sources of food with good nutritional value. Of course, it is also important that the right conditions are available for the jay – this means open areas of grassland, or mantle and fringe vegetation. Closed forests are not suitable for the jay, and it will thus not bury its acorns there. In fact, even though forest stands of oak produce 10-times more acorns than sparsely-populated open-grown oak pasture landscapes, the density of acorns within the soil buried by jays is 50-times greater within the open landscapes. Such landscapes are generated by grazing, according to Vera, and whilst modern grazing has been created by man (up until the decline on grazing, in recent times), historically the wild boar (Sus scrofa) would have provided good conditions (due to its disturbance of the soil in grasslands, which were created by large roaming herbivores – the auroch, deer, and wild horse, for example) for where the jay could bury its acorn collection. Source: Vera, F. (2000) Grazing Ecology and Forest History. UK: CABI Publishing.

Of course I have an agenda to push, but I am not trying to minimise an alternate argument by suggesting there are more 'impactful' issues out there.

My family owns land in Essex with unchanged hedgerows from around the Elizabethan times (so I am told), though the land was traditionally managed extensively with the grazing of cattle. Nowadays, it's meadow grass that is cut and collected once per year for fodder. In this time, the hedgerows have also been left to develop, and support a great thicket of blackthorn, hawthorn, rose, bramble, elder, and so on (they also support regeneration of oak, from the many healthy mature oaks we have). I cannot say that the same is evident in many other hedgerows around - scraggly, thin, waning hedgerows in marked decline, brought about by the aggressive management of the land. The post-war era battered hedgerows. The promise of re-planting them was never fulfilled, and frankly by that point the damage had been done anyway. Centuries-old hedgerows ripped out cannot be replaced overnight - the complexity of the landscape will take many hundreds of years to even substantially recover, and as of yet that process hasn't begun - in fact, the reverse is evident. Don't minimise the problem. A classic belittling tactic by those who look to project their own agenda onto others.

Indeed. Consider that was over a decade ago, so I wonder what developments have been made since.

A paper you might find interesting - https://www.researchgate.net/profile/Thomas_Sieber2/publication/226036501_Latent_infections_of_Fomes_fomentarius_in_the_xylem_of_European_beech_%28Fagus_sylvatica%29/links/00463533188b7ad796000000.pdf

Very nice. A little hub, of sorts, for Fomes.

03/05/16. Fact #196. Whilst overhanging branches of a tree are not deemed trespass but instead nuisance, the case of Earl of Lonsdale v Nelson [1823], which dealt with trespass and not nuisance is perhaps a peculiar beginning. However, during the case’s hearing, the judge remarked that nuisances could be abated by the individual suffering from the nuisance without notice to the person causing the nuisance, though notably not when overhang was onto a public roadway or the overhang was from a tree whose owner would routinely tend to their trees themselves. The judge also remarked that permitting branches to overhang into a neighbouring property was a “most unequivocal act of negligence”, though caution must be exercised here as labelling overhang as negligent is lurking at the threshold of what could be considered appropriate for the situation. Instead, such overhang is referred to as nuisance, as outlined in the judge’s preceding comments. Building upon this ruling, the case of Rylands v Fletcher [1868], even though not to do with trees, set the precedent for foreseeability, and therefore because boundary trees will foreseeably encroach, via their branching crown (and roots), onto neighbouring land, the tree owner must, in readily recognising this, ensure the nuisance associated with their encroachment is abated. If not, if anything “mischievous” were to arise (including solely from the overhang detracting from the neighbour’s enjoyment of his or her land), the tree owner would be held liable. The case of Earl of Lonsdale v Nelson [1823] was, at the Court of Appeal, considered in some detail during the case of Lemmon v Webb [1894], where the claimant, who owned a few large trees, consisting of oaks and elms, growing amongst a hedgerow on his property, filed a claim against Webb for damages when Webb cut off some of the branches to his boundary line without prior warning. In this instance, there was absolutely no question that Webb did indeed have the power to cut back the overhang, though discussions did take place of whether Lemmon had to be informed of such an action. Initially, Lemmon won the case with regards to this matter, though at appeal that was overturned. However, the judge at appeal did recognise that, particularly if trespass must occur for overhang to be removed, then the owner of the trees be informed prior to the works being carried out – though the judge did not mandate such a course of action, and thus there is no actual need to inform the owner of the trees if a neighbour seeks to remove overhang. All that is required is they prune the tree with “reasonable care”, and the removed wood (and leaves, flowers, etc – depends upon the time of year) is offered back to the tree’s owner as it was removed from the tree (who has the right to refuse them back, if they so desire). Such a precedent was established in the Mills v Brooker [1919] case. Overhanging branches from a red horse chestnut (Aesculus x carnea). Some lower ones have been pruned back. Later, in Smith v Giddy [1904], a slightly different angle of approach could be seen. The claimant was contesting how Giddy’s trees were overhanging onto his property and impacting adversely upon the growth of his fruit trees. The judge ruled, in the case prior to it going to appeal (of which the outcome is not known), that if the trees are not doing any damage, then it may be up to the claimant (plaintiff) to abate the nuisance by cutting back to the boundary line. Only when overhang is actually causing damage is there a need for action on behalf of the grower of the trees, as in such a case one cannot expect the neighbour to fund such remedial works to ensure his or her property is once again free to a damaging agent. More recently, courts seem only to rule that a tree is a nuisance if harm is being caused (stemming back from the case of Lemmon v Webb). Elliott v Islington LBC [1991] did come close to ruling a tree can be a nuisance merely for overhanging a property, though ultimately did not accept such a precedent. Instead, where overhang is not causing harm, it can be removed by the neighbour. Such a stance was also adopted by the judge in Perrin & Anor v Northampton Borough Council & Ors [2006], where it was ruled that “the owner of the land who has suffered the encroachment has a right to remove the overhanging boughs“, and also ruled in Delaware Mansions Limited & Others v Lord Mayor & Citizens of The City of Westminster [2001], where the judge remarked that overhang can be abated by the neighbouring land owner. In terms of who can remove overhang, Read v J Lyons & Co [1947] stated that, and as subsequently re-affirmed by Hunter v Canary Wharf Ltd [1997], action of nuisance abatement can be undertaken by any person or persons who are the owner(s) of occupier(s) of the land affected by overhang. Overhang cannot however be removed by guests, lodgers, employees, or family members who do not have exclusive possession of the land affected. In the latter case of Hunter v Canary Wharf Ltd [1997], it was also ruled that nuisance can be divided into three categories: (1) nuisance by encroachment on a neighbour’s land, (2) nuisance by direct physical injury to a neighbour’s land, and (3) nuisance by interference with a neighbour’s quiet enjoyment of land. The encroachment of branches is typically, though not always, cited under the first reason.

People will probably only begin to properly care about trees when they become a novelty - as in, there aren't many left, and those that are lack age and size. Unless, of course, the education system stops teaching kids how to pass exams and immerses them into reality.

1. Landscape connectivity To get from A to B, organisms need to travel via certain means. For humans, this generally means roads. For birds and bats, this may often mean by using trees (particularly woodland birds). Trees need to be present within a landscape, in order for birds to successfully travel from A to B (assuming A and B are separated by a different type of landscape - imagine two woodlands with a large agricultural landscape in between both). With trees, birds and bats can 'stop off' (for feeding, roosting, hiding from predators, etc) along the way. Without trees, they cannot, and thus they essentially become trapped in their woodland site. For smaller organisms, such as saproxylic (deadwood-lovers) insects, if there aren't trees within a ~50m radius (or less) from their current host tree, they are wholly trapped. When that tree dies, the insect population goes with it. Here is the expanse of literature explaining how landscape connectivity works. 2. Heterogeneity of the landscape Agricultural fields + hedgerows + field trees = more diverse than just agricultural fields + hedgerows. Diversity is, by-and-large, good, when it comes to the natural environment. 3. Crop yields & soil ecology Trees shelter (individuals or shelterbelts) crops from desiccation (by wind). They support mycorrhizal associations. They improve nutrient recycling by supporting soil biota (organisms). They reduce rates of soil erosion.

With the greatest of respect, this is the sort of attitude that projects some sort of lack of responsibility for the problem at hand, by simply discarding the problem by stating that the trees can sort themselves out. We are losing agricultural trees, and fast. This has problems for landscape connectivity, the heterogeneity of habitat, crop yields, soil ecology, and so much more. They were once planted or retained for their mast, though times have changed and we're putting so many stresses upon our environments that we need to change approach. An economic pursuit once now becomes an ecological one.

I would also stress that we're saying that there is a tendency for the trees to decline / die. There will always be those that buck the trend. Of course, my point stands about some trees declining more slowly. It depends on many variables, including what radius of non-ploughed land surrounds the tree(s), what is grown on the land around the tree(s), what pesticides and fertilisers are applied around the tree(s), and how intensively-managed the farmland is around the tree(s).

Long term? Very likely so. Roots are being damaged / destroyed, mycorrhizal associations are being disrupted / destroyed (as a result of ploughing, fertilisation of the soil, and a monoculture beneath the tree), and the pH of the soil is changing (as a result of fertilisation, amongst other things I would expect). Just because the tree doesn't die overnight doesn't mean it is not dying - trees don't necessarily respnd immediately to a stressor. It may take years, if not decades. We really need to get out of this mindset of "well it didn't die the next year so it can't be that bad". Drive along the 414 from Chelmsford to Harlow and just weep at all the hammered oaks. Nasty.

The propspect of reading lacklustre sarcastic comments is equally as amusing.