In 1820, John Keats famous poem “To Autumn’ was published.  Its opening line often serves to describe autumn as ‘The season of mists and mellow fruitfulness’.  Indeed, Autumn has arrived here.  Woodlands have been transformed into a 'tableau' of red, yellows, and oranges as the leaves are shed and the woodland floor has become a veritable fungal jungle, (as Jasper has described).  Hawthorn and other bushes are laden with berries, conkers and acorns are generously strewn across woodland floors, squirrels are eating hazelnuts (and hiding them as a winter food store).  But this cornucopia of fruits and seeds may be in response to the long, hot and very dry summer we have experienced.  Trees and shrubs have been stressed by the heat and drought. Some have responded by mobilising their reserves / efforts into producing more fruits and seeds, to ensure that they pass on their genes to the next generation.   Different trees are responding in other ways. Some are ‘holding on’ to their leaves for longer, whilst others (like some birches and rowans) have already shed theirs - in order to limit the damage from wilting and water loss during the intense heat and drought of summer.  [caption id="attachment_39130" align="aligncenter" width="675"] Autumnal colour[/caption] Blackberries appeared early this Summer and few are to be seen this Autumn, some animals (like the dormouse) will search in vain. [caption id="attachment_39026" align="aligncenter" width="675"] Black Bryony berries (photo by Art Symons)[/caption] Will this Autumn be long and mild? It may extend into the traditional winter months. There is also the threat of extreme weather events (like Storm Arwen that brought severe winds across the UK last November).  Whilst we might welcome mild weather (with the high price of gas and electricity), it could be mean an increase in bacterial and fungal infections, not only of plants but also affecting overwintering insects - tucked up in cocoons and pupal cases. Prolonged cold periods, coupled with frosts limit the spread of such infections.  The cold of winter is also the traditional signal for animals like hedgehogs to hibernate.  If they are still active in winter when food is scarce, then they will lose condition and possibly starve to death.  Milder weather in Autumn and Winter also affects the migratory behaviour of birds, some birds may choose to overwinter here.  Some seeds need to experience cold temperatures before they will germinate in the following Spring. Climate change and severe weather events are here to stay until there is a coordinated and concerted effort to reduce greenhouse emissions on a global scale.  On a local scale, our gardens (which represent some 400,000 hectares of land) can make a contribution by encouraging wildlife / pollinators and promoting biodiversity.  Gardens can also help to some extent with extreme rainfall.  During heavy rain, water runs off hard surfaces and into the drains, these may also deal with sewage.  When the drains are overwhelmed by storm water, sewage is discharged into our rivers (and the sea).   Gardens can help by  reducing hard landscaping, so that rain can soak into the soil instead of running off into the drains making use of water butts.  They capture water, so it does not enter the drainage system.  It is also there to use when the garden needs water (and there is a hose pipe ban) mulching the soil with a layer of plant material. It is an effective method of conserving water in the soil and it reduces surface runoff, increasing the infiltration / penetration of water into the soil.  It helps keep the soil moist in times of drought, and helps reduce run off during heavy rainfall.  Particularly important when planting young trees / shrubs. [caption id="attachment_38957" align="aligncenter" width="675"] a light mulch (in Art's garden)[/caption]  

Super fast poplar trees ? In theory, increasing the number of trees across the globe could help reduce the levels of atmospheric carbon dioxide that are so intimately associated with climate change.   As trees grow, they absorb carbon dioxide from the air turning into wood.  This effectively locks away the carbon for a period of time.  However, the growth of trees can be slow so if trees could be ‘persuaded’ to grow faster then more carbon could be ‘locked up’ A San Francisco based company called “Living Carbon” has genetically modified hybrid poplar trees to speed up photosynthesis so that they grow faster.  They picked on the poplar trees as their genome had already been sequenced. The work of Living Carbon is at early stage and further work is needed to see if the enhanced photosynthetic rates and growth are maintained over the life time of the modified trees.  Another possible benefit of these modified trees is that they might help restore damaged land as their roots also grow faster, helping to address soil erosion.  Further details are available on their website : https://www.livingcarbon.com/ A discussion about the value / usefulness of such trees in affecting climate change / carbon sequestration was featured in the BBC program Positive Thinking this week. Effects of climate change. Climate change is associated with extreme weather events, such as flooding, heat waves and prolonged periods of drought.  American scientists at Ohio State University have been looking at the effects of higher temperatures and lower water availability on fungal infection in Austrian pines. They found that within three days of infection (by certain fungi - Diplodia species),  the warmer and drier conditions resulted in  Reduced photosynthesis by the tree Enhanced removal of carbon resources of the tree to the fungus. This means that there are fewer sugars and other metabolites available to the tree for growth (and defence against infection).   It would seem that a warming climate will render many trees more susceptible to invasion by various pathogens.   Full details of this research here.    Stressed out plants. Thale cress or Arabidopsis thaliana is a small flowering plant, that is native to many parts of Europe and Asia.  It is generally viewed as a weed, found by roadsides and on disturbed land. It is an annual that has a short life cycle. Its genome was one of the first to be sequenced. It has become a popular plant in the researching of the biology of flowering, light sensing and understanding the molecular biology of many plant traits, including flower development and light sensing.   Recently it has been used to investigate the stress response to heat, intense sun and drought.  Such stresses result in the production of reactive oxygen species (ROS).  High levels of ROS are lethal but low level of ROS are a signal to the plant to protect itself.  This is done through the photosynetic machinery which generates an ‘alarm molecule’ (MEcPP).  As this molecules accumulates in the plant, it in turn triggers the production of salicylic acid (essentially a form of aspirin).  This helps protect the chloroplast from damage.  Salicyclic acid is involved in many plant systems, notably defence against infection but also germination and stomatal physiology.