The base of a tree trunk is often covered with a ‘carpet’ of moss and lichens and the branches of the tree may bear ‘decorations’ of different mosses.  In shady areas, there may be a soft, spongey layer of moss underneath the tree.  Mosses are ‘simple’, non-vascular plants. They lack the sophisticated transporting tissues (phloem and xylem).  Nor do they have true roots, instead they have small structures called rhizoids, which help them attach to a surface. They ‘like’ moist places and are dependent on water for their reproduction.   The ancestors of mosses were probably some of the first plants to colonise land (previously there were only algae in the seas), possibly in the Ordovician Period. Mosses rarely grow to any great height, due to the absence of supporting mechanical tissue (lignified tissues, like xylem) but they can form extensive ‘mats’ in damp, shady places (as can liverworts).  Exposed to direct sunlight, they lose water rapidly.  Such mossy mats can, in some situations, help reduce soil erosion. The mats may also allow for the accumulation of humus and soil formation.  A particular example of the accumulation of mossy material is seen with the moss Sphagnum. Sphagnum grows in acidic, marshy conditions, often forming a bog. Low fertility and a cool climate result in slow growth of the Sphagnum (and other plants). The subsequent decay of dead plant material is even slower (due low oxygen levels). Hence, peat forms and accumulates.  Large areas of land can be covered to a depth of several metres with peat.  Bogs are a very effective means of locking up carbon for hundreds, if not thousands of years.   Sadly, many wetlands have been drained and allowed to dry out, then the peat cut from them as a form of fuel.  When peat areas are drained (channels are cut through the peat), they degrade and dry out. They are then at risk of  catching fire as has been seem in recent times:for example, the burning of  Slieve Beagh in Ireland and Langdale Moor in Yorkshire. The Interesting fact : Sphagnum has an interesting property in that can hold water  many times its own weight.  Because of this absorbency, Sphagnum was used as a wound dressing in WW1. https://earthobservatory.nasa.gov/images/150780/irelands-cutaway-peatlands https://www.bbc.co.uk/news/articles/cvg9n0j07epo .

Various Wildlife Trusts are experiencing financial problems as a result of Ash Dieback.  Dead and dying trees are to be found in woodlands up and down the country, (some of which are managed by local Wildlife Trusts).    The fungus has its origins in Asia and has spread across Europe for the last thirty years. It was seen in Denmark in 2002, and has spread across the country by 2005.  It  is now to be found in  Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Italy, Latvia, Lithuania, The Netherlands, Norway, Poland, Slovenia, Sweden and Switzerland. It probably arrived here on imported (and infected) plants, though its spores are easily spread on the wind.  Once infected, the fungus affects the movement of water, minerals and sugars as the vascular system (xylem and associated tissues) is impacted.  Once a tree has been infected with the fungus, it may then be colonised by another pathogen such as the honey fungus (Armillaria spp).  Symptoms of ash dieback may include Shoot tips become black and shrivel, side shoots on young trees may die. Dead and ‘black’ leaves can be seen, their veins and stalks of turned brown.  Leaves shed early. Branches begin to dieback Diamond-shaped dark lesions form on the trunk near to dead side shoots.  In late summer, small white fruiting bodies can be found on blackened leaf stalks (see Jasper’s detailed blog). [caption id="attachment_39049" align="aligncenter" width="600"] the fungus emerging from blackened dead ash petiole.[/caption]   The dead and decaying trees pose a threat (as they become weakened and brittle), and need to be removed.  Removal is an expensive process and takes money from the Wildlife Trusts that would otherwise be used for habitat restoration, new planting etc. Apart from affecting the beauty of our woodlands and hedgerows, the loss of these trees has ‘knock on’ effects for other species.  Brown eared bats and barbastelle bats are known to nest in ash trees, the trees also provide perches and nest sites for birds and act as a substrate for epiphytes such as lichens and mosses.  The loss of ash tree will also affect the plants beneath, plants that like damp shady conditions such as lady fern (Athyrium filix-femina) and dog’s mercury; these may be replaced by light loving species / grasses. Featured image : Ash in winter Detailed information of Ash Dieback : https://cdn.forestresearch.gov.uk/2017/06/fcrn029.pdf [note this link downloads a PDF].