In recent decades, extreme climate events such as tropical storms, droughts, floods, wildfires, heat waves, and cold snaps have increased in both frequency and intensity. These events have the potential to reshape human populations and ecosystems across nearly all regions of the world. According to the Intergovernmental Panel on Climate Change (IPCC), such events are projected to intensify further in the coming decades. Very strong hurricanes are expected to become more common, wildfires to burn hotter and spread farther, and heat waves to last longer. Extreme events pose severe risks not only to human populations but also to biodiversity and the structural integrity of ecosystems. They can reek changes in species in a number of ways. One of the earliest studies of the biological consequences of an extreme climate event was carried out by Hermon Bumpus at Brown University.  [caption id="attachment_42667" align="aligncenter" width="675"] Brown University campus[/caption] In February 1898, an unusually severe and prolonged storm brought snow, sleet, and rain to Providence, Rhode Island. After the storm, Bumpus collected a large number of incapacitated sparrows (Passer domesticus), of which 72 survived and 64 perished. He measured a range of body characteristics in both groups. The birds varied in length from 152 mm to 167 mm, with an average of 159.5 mm. Individuals whose body length was close to this average were more likely to survive, whereas those at the extremes were more likely to die. Very long-bodied birds were particularly vulnerable. In addition to body length, [caption id="attachment_42669" align="alignleft" width="300"] Elementary lessons in zoölogy, by Needham, James G. 1896[/caption] Bumpus measured traits such as weight, femur length, humerus length, sternum length, and skull width. Interestingly, he also noted that males were more likely to survive the storm than females. Bumpus’s work represents one of the earliest investigations of natural selection in the context of an extreme climate event. Since his study, relatively few investigations have directly examined the selective pressures imposed by such events.  However,  certain lizards on the Turks and Caicos Islands have been found to have larger sticky toe pads after experiencing Hurricanes Irma and Maria, when compared to ‘pre-hurricane’ lizards.  The next generation of lizards also had larger toe pads, which suggests a heritable feature and hurricane driven selection. Nevertheless, such research suggests that extreme climate events [such as high winds, extreme temperatures, flooding] can generate 'short lived' but strong episodes of natural selection, and may drive rapid evolutionary change.   [caption id="attachment_43023" align="aligncenter" width="675"] a sparrow[/caption] Further reading : https://www.cell.com/current-biology/fulltext/S0960-9822(25)00955-8 Sparrow leg anatomy from 'Elementary lessons in zoölogy, a guide in studying animal life and structure in field and laboratory' by Needham, James G, 1898. Accessed from Archive.org  

Scientists from the Meteorological Office use radar data to track approaching storms and changing weather patterns.   The radar works by sending out pulses of microwaves, these bounce off rain drops and other particles in the air.  The time that it takes for this signal to return, plus its intensity gives information about the approaching weather. Early radar [during the Second World War] also picked the movement of ‘angels’. These ‘angels’ were later recognised as the movement of birds, bats and insects.  Scientists then had to develop techniques to remove this ‘biological scatter / material’, so that they could accurately predict storms etc. By removing this ‘biological component’ of the signal, a lot of biological information about the movement of birds, bats and insects was being ‘discarded’.   Now, scientists from the University of Leeds have ‘repurposed’ the radar data (from many radar stations, which scan the skies many times each day & night) but this time they remove the data relating to the weather.  This leaves information about the insects moving at a height of some 500 / 700 metres above the ground.  The results showed that some 11.2 trillion insects are moving during the day, and that this reduces to some five trillion at night.   Some of these insects are actively flying, but some are being carried by the wind  / thermals.  Furthermore, there were more insects above areas such as woodlands, grasslands and even urban areas.  However, the numbers were lower over intensively farmed areas, where plant biodiversity was reduced as compared to woodland or natural grassland.  The numbers were also lower where artificial lighting was high.   Other work by the CEH, Newcastle University and Butterfly Conservation, has involved surveys of grassland and hedgerows in southern England (Thames Valley) some of which were lit by streetlamp, others were unlit. The areas that were exposed to night time lights had roughly half the number of caterpillars as compared to the unlit areas.   In another study, LED lighting was set up in fields, and caterpillars' numbers in these illuminated fields were reduced.  The lighting may :- [caption id="attachment_40185" align="alignleft" width="300"] Cinnabar moth caterpillar.[/caption]   Deter nocturnal moths from egg laying. Make the night flying moths ‘easier targets’ for predators (such as bats). Affect the feeding habits of moth caterpillars. Whilst it would seem that night time light affects insects and the feeding behaviour of caterpillars,  quite how and why is yet to be determined.

Woodlands provide us with number of benefits They supply softwoods and hardwoods, which have variety of uses. They provide a variety of habits for many species of wildlife, adding biodiversity to an area. They allow for a number of recreational pastimes. However, we and our woodlands need to prepare and adapt to a changing climate, one in which winters may be milder and summers hotter and drier.  Extreme weather events are also becoming more common.  So woodlands need to be resilient.  If they are resilient, then: They recover better from disturbances, like fire or disease Generally fare better when challenged by storms or floods. A number of government agencies have produced booklets / downloadable files (PDFs) on how to address the possible problems associated with the changing climate.  The advice seems to fall into three basic categories. Increase the range of trees in your woodland, promote diversity.  Look for trees that not only match your site (soil, aspect etc) but also might cope with future climate conditions.  If the climate is drier, then trees which have done well in the past might struggle in the new conditions.  For example, beech was noticeably affected by the drought in the summer of 1976.  Look for trees that can cope or unaffected by disease and insect pests and are from a reputable source and free of disease. Review the management of your woodland. For example, what and when to thin, create access and paths, openings or glades which can improve the diversity of the plants at ground level.  Paths and openings will also improve access within your woodland. [caption id="attachment_41085" align="aligncenter" width="674"] Woodland path covered with mast[/caption] When planting new trees, think about where the trees come from. What conditions do they are experience in their home environment, can they cope with drought. It may be that trees species that usually grow in more southerly areas of Europe will be better suited to the changing conditions. As mentioned above there are a number of publications / guides to help with increasing the resilience and diversity of your woodland.  Some of these are listed in the links below : The Climate Change Hub has a number of informative fact sheets and videos. Information about increasing species diversity from Natural Resources Wales. Improving structural diversity in woodlands from Natural resources Wales:  Forest Research has produced a detailed practice guide on woodland management and climate change. The Government website has numerous links and publications, eg. Advice of new trees and woodlands in light of climate change.

Since its formation, the earth has undergone change.  Life forms have come and gone.  There have been five major extinctions, the last being at the end of the Cretaceous Period; it killed off the dinosaurs and many other species.  This particular extinction event is thought to have been particularly rapid, due to an asteroid impact.  It caused a series of cataclysmic events and a rapid cooling of the Earth’s climate. Other changes, such as intense volcanic activity and tectonic uplift, may have pre-dated the asteroid impact but the event saw the elimination of many, many life forms. We are witnessing significant global change, that is also rapid in geological terms. Changes in the Earth’s climate and species composition usually take place over millennia, indeed over millions of years.  However, recent years have been very warm.  Global temperatures have changed noticeably. The warming that has been recorded “is exceptional relative to any period since before the last ice age, about 125,000 years ago”.  This warming has resulted in extreme and severe weather events in this country and across the world.  This year a record breaking January temperature of 19.9oC was recorded at Achfary, with storms Henk, Isha, and Jocelyn in the same month. The Earth’s warmest year on record (between 1850 to 2023) was 2023.  In early September 2023, the UK experienced a significant heatwave when daily maximum temperatures exceeded 30°C [somewhere in the UK] for seven consecutive days. [caption id="attachment_35526" align="aligncenter" width="675"] Drought![/caption] Such changes are not without effect. Phenology observations indicate that trees are producing their leaves earlier, woodland plants are coming into flower earlier. See the woodlands blog “Spring is on the move”.  A concern with these changing phenologies is that ‘mismatches’ can occur.  When trees come into leaf determines when caterpillars can feed and that, in turn, affects when birds can feed on the caterpillars and raise their young.  If these events do not occur in synchrony then the ‘functioning of the ecosystem’ is disturbed.  [caption id="attachment_25123" align="alignleft" width="300"] Leaf 'unfolding'[/caption] The agricultural and horticultural ecosystems that we have created are also affected by climate change. This year, heavy rainfall has meant that farmers in many parts of the UK have been unable to plant certain crops [such as potatoes, wheat and vegetables] during the key spring months. Some crops have rotted in the soil. In April, there was 111.4mm of rain, [the average for April is 71.9mm]; the sixth wettest April of the last 189 years.  Persistent wet weather also affects lambing, and can mean it is not possible to turn dairy cattle out onto grass / pasture, which in turn affects milk production. Monthly temperatures are more likely to be above average than below as climate change take effect.  This was true for the first three months of the year.  Warmer air holds more moisture and it can evaporate more water from the seas / oceans. A one degree (Celsius) rise in temperature adds 7% more moisture in the air.  Woodlands are affected by heavy rain as soil becomes waterlogged, which affects woodland flowers, and wet winters do no favours for animals that hibernate. The UK is not the only place to be affected by extremes of weather, be it rainfall and flooding, or high temperatures and drought.  India has recently experienced a period of extreme temperature, with temperatures approaching 50oC.  Such temperatures push human physiology to its limits.  Just as extreme rain is a problem for farmers, so is extreme heat and / or drought.  Brazil has been the main exporter of oranges for producing orange juice, but its recent crop has been substantially reduced as a result of flooding and drought; resulting in the worst harvest in decades. Spanish orange production has also been reduced due to drought. Like California, large parts of Florida ‘the Sunshine State’’ has seen its once-famous citrus industry reduced over the past two decades. Two diseases, greening and citrus canker have taken their toll, and then Hurricane Ian in September 2023, hit the citrus industry at the beginning of its growing season.  Large parts of the one famous citrus industry (oranges and grapefruit) have been lost and farmers are turning to the PONGAMIA tree to repurpose fallow land. [caption id="attachment_41381" align="alignleft" width="650"] Pongamia  : image thanks to Sarangib on Pixabay[/caption] This is a climate-resilient tree from India. They do not need fertiliser or pesticides.   It has been grown as a shade tree. As a member of the Fabaceae, it produces small, brown beans.  These are so bitter than not even wild hogs will eat them.  However, the beans are easily harvested by a machine that shakes the tree.  A San Francisco based company has found a way to remove the bitter tasting chemicals and use the beans in food production, as they yield a high quality protein and also an oil.  The bean (a legume) has been used to make a table oil, protein bars and a biofuel.   Orange juice production is not the only drink to be affected by changing climate.  Drought affects coffee plants and damages the quality of the soil, and excessive rainfall ‘favours’ fungal disease [e.g.coffee leaf rust and cherry rot], all of which will impact the yield and quality of the beans harvested.  Similarly, chocolate production is threatened. Cacao trees are impacted by global warming,  they can only grow and thrive within 10 degrees of the Equator, needing stable temperatures, high humidity, and ample rain.  However, temperatures are rising while rainfall has decreased. These changes lower the humidity. The trees are also under attack by a virus - cacao swollen shoot virus disease (CSSVD). Changing temperatures and rainfall patterns will influence what crops can be grown and where, it will also influence their cultivation and the working patterns associated with those crops.  Climate change is thus a factor contributing to food inflation and insecurity across the world.    

Winds are critical to our woodlands - they help to strengthen the trees and they spread seeds and pollen.  They are also sometimes the main reason a woodland is there, as a shelter-belt to protect housing or agriculture from prevailing winds.  But how much notice do we take of wind patterns?  Our history of urbanisation has also been a history of moving indoors and many people nowadays spend only a tiny proportion of their lives outdoors. Read more...

In 2010, the blog reported on the exceptional winter weather.  Back then, we had just ‘emerged’ from one of the coldest winters on record. Currently, we are experiencing one of the wettest winters ever. In December, the East Coast faced storms and a tidal surge (affecting communities from Scotland down to Essex), and then Christmas Eve saw high winds and the cancellation of flights from Gatwick.   January brought some 175 mm of rain in the South East.  The closest comparable January was that of 1948.  A summary of the winter so far can be found at the Met Office web site - here Read more...

On 16th October 1987, the Great Storm took away many mature trees from the landscape of southeast England, a great swathe of destruction was wreaked on our woodland and parkland trees.  Many trees and overlarge coppice still lie where they fell, the coppice more often than not growing up again but from a much larger base.  The mature trees have been gradually rotting. All the resources locked up in the wood being released and taken up by bacteria, fungi, invertebrates and so to higher organisms.  It was a major ecological disturbance,  that in some ways has been of considerable benefit to wildlife. Read more...