Many natural ecosystems are periodically exposed to fire.  After a fire, there is often reduced competition and increased nutrient availability (from ash etc.).  The plants and flowers that grow after a fire are visited more often by pollinators, such as bees and other insects.  This can result in increased production of fruits and seeds. Bushfires have been part of certain australian ecosystems for thousands of years and some native species are ‘fire adapted’.  They have come to 'rely' on fires as a means of reproduction and / or  dispersal. Whilst no one fire can be attributed to climate change alone, rising temperatures and aridity, lengthening of the ‘fire season’, combined with bursts of extreme ‘fire weather’, all combine to suggest climate change is implicated. As the frequency of fires increases, the possible benefits of fire to such ecosystems / species are being lost. Fire can help with the physical dispersal of seeds from the parent plant.  In some parts of the world, such as South Africa and Australia, fire and / or smoke can be the stimulus for seed dispersal and subsequent germination.  Plants such as some species of Protea, Banksia, certain members of the myrtle family (e.g. some Eucalypts), and some Pines and Sequoias 'make use' of fire to disperse their seeds. Seed dispersal involving fire is termed serotiny.  Many of these plants produce woody fruits or cones in which the seeds are held.  The mechanism underlying seed release varies but can be due to a resin that ‘seals’ the seeds inside the fruit or cone.  The resin ‘melts’ / liquefies on exposure to heat releasing the seed or there may be a structure called a seed separator (as in Banksia).  Serotinous conifers (like lodgepole pine), have mature cones in which the cone scales are naturally sealed shut with resin.   Most of the seeds stay in the canopy until the cones reach 122-140o F  (i.e 50 to 60oC).  At these temperatures, heat / fire  melts the resin and  the cone scales open to expose the seed. The seed can then drop or drift to a burned but cooling ash-rich soil bed. The seeds do well on the burnt soil available to them as the site offers reduced competition, more light, warmth plus the nutrients from the burning of leaves and litter.  Some species align their germination to immediate post-fire conditions - stimulated by chemicals present in the smoke.  The organic compounds karrikins,  products of the degradation of cellulose are  a germination ‘cue’ for some species.  Karrikins are thought to be present on the soil surface after a fire.  When it rains,  the karrikins are 'washed' into the soil, and seeds present in the soil seed bank are then stimulated to germinate. Thanks to Steve Sangster and John Cameron for images of woodland fire.  

The period since WW2 has seen urban areas and, indeed farms, expand across the UK. The number of places where wildlife can thrive has been eroded.  Gardens and lawns have been changed to provide parking for cars, lawns are mowed and ‘weed-killered’, or worst still replaced with artificial grass so there is not a weed in sight.  Fortunately there are now initiatives like No Mow May that promote the growing of wild flowers in lawns and public spaces, like roadsides and verges.  Many common weeds are simply wildflowers by another name. Wild flowers / weeds (like dandelions, ragworts, clovers) are a lifeline for bees and bumblebees - who are facing so many threats [pesticides, habitat loss, invasive species] so adequate food is important. The flowers of these wild flowers / weeds offer food for a wide range of endangered bees, and at times when other resources are limited.  Dandelions, for example, offer an abundant source of nectar and pollen for bees & bumblebees when other options are limited - especially in urban settings. They produce their flowers (and therefore nectar and pollen) from early Spring right through to the onset of Winter. Recent studies have shown that the diet of bees has changed over the years.   In the past, the bees were able to forage and collect pollen and nectar from a wide variety of plants but with the loss of ‘natural’ wild areas their diet is now often dominated by brambles, clover and dandelions.  In the case of dandelions, their simple, open flowers makes for ease of collection.  They are visited by honey bees, bumblebees and carder bees.   Some studies have indicated that dandelion pollen, whilst it is rich in the amino acid proline,  has low levels or lacks certain amino acids (such as valine and isoleucine).  Bees need the same ten essential amino acids as us.  Without a supply of these particular amino acids, the development and growth of bees is impaired, as is their disease resistance and ability to raise the brood.  So, it is important to find ways to offer our pollinators a range of plants / pollen to provide all their essential nutrients. interesting related papers Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0158117 Shifts in honeybee foraging reveal historical changes in floral resources: https://www.nature.com/articles/s42003-020-01562-4

Forests, woodlands, trees are vital to life.  They absorb carbon dioxide, they release oxygen, they offer food and shelter to countless species (including us).  The global forests (equatorial to boreal) play an important role in mitigating climate change due to fossil fuel emissions.  However, many forests and their particular tree species are being  threatened by the world’s warming climate.  Recent years have seen catastrophic fires in many parts of the world, from Canada, Siberia, Sweden to Australia. In 2019/20, intense fires caused extensive damage to the Eucalypt forests in Australia.  Eucalypt rich woodland / forest is likely candidate for fire because the leaves of Eucalypts produce volatile and highly combustible oils.  The litter underneath such trees is rich in organic compounds such as phenols, which slow down the microbial breakdown of the dead leaves.   Consequently,  a layer of dry, eminently burnable material builds up. In Eastern Australia, some 40+% of the native eucalypt forests suffered severe canopy damage.   Trees on the west coast of America have also been subject to intense fires.  Their susceptibility to fire has been accentuated by drought across the region.  Analysis of the growth rings of trees, such as the Red Cedar (in areas such as Oregon) show that trees suffered reduced growth in the years prior to their death.  Drought stress increases the probability of attack by bark beetles and pathogens.  In California, many native species such as white fir, red fir and ponderosa pine have died and provided material for the fires that were to follow.  Fires in 2020/21 swept across the region, destroying vast swathes of forest.  The fires were of such an intensity that even Giant Sequoias were killed.   [caption id="attachment_40596" align="aligncenter" width="675"] Forest Fire in Canada[/caption] Sequoias had been thought ‘indestructible’ as they have a thick bark, which protects the inner living tissue, plus their canopy is usually well above the flames on the forest floor.  In the past, the fires burned litter on the ground, removing competitors, and releasing nutrients.  The heat would also open up the cones of the Sequoias releasing their seeds, so young trees could establish. Some of the Sequoias that died in these recent fires had stood for centuries and survived many wildfires.   In the past, the amount of litter / dead material was limited.  Indigenous people managed these forests (reducing the fuel load) to create forage for game animals, so that wildfires were of mild to moderate intensity.  Now, the fires are different - they are intense. There is more material to burn - including the trees that have already died from drought and disease. The fires can now reach into the canopies of the Sequoias. One of the Sequoias that died was the King Arthur tree - the 8th largest giant redwood in the world; it died in the Castle Fire of 2020. The drought driven deaths of many tree species is probably the start of a longer lasting shift in the growing range of the affected trees.  Temperature and water availability are two of the major determinants of the range of a given species.  It is possible that trees may ‘move’ northward and upward (grow at higher elevations).  Trees will begin to ‘die off’ at the edge of their range / lower elevations as drought / warming increases.  Die offs may also affect commercial plantations of species such as Douglas fir.

We had been looking for a wood preferably with a open area for sometime.   We had a look at a few that were not right for us, thinking it was never going to happen.   One day I opened an email and there it was - in September 2022.  Golden Hill Wood, I immediately called Stuart, the area manager, and we arranged to view it.   Well,  it was just perfect and literally five minutes away from our home, so the ball started to roll. It was time for some research on equipment, we got some good advice locally, so a chainsaw, brushcutter, and other equipment was purchased.  Having a walk around with Stuart, taking on some good advice, we then started to work on our new heaven. Golden Hill Wood has some old broadleaf trees but mainly spruce, fur and a few Douglas Firs amongst others.  The wood not been cared for in many years, so I set to taking lower branches off to head height, a few had to be removed including a couple of tactical removals with trees broken half way up, removing the many brambles that had stored from the ground to the canopy in a web like manner.  I found myself pulling brambles from one tree only to see I'm pulling a tree further away as there was so much of it.   Patience is a virtue and I got there.   It is not the end, but everything is now manageable so I have a few hours work and then a chill out. I have a couple of tarpaulin areas which the granddaughters just love and embrace and lend their little hands.   When Roe or Red Deer are about, we have two sets of Buzzards along with Red Kite and. of course, Bunnies.  We spent New Years Eve 2022-23 there and I've made a wild camp under a basher. I'd recommend anyone taking a wood on.  It is so peaceful and calming.

Solar farms have sprung up across the country with hundreds or thousands of solar panels, linked together in fields.  Now, researchers in the States have shown that sowing grasses and wild flowers in-between the panels on solar farms resulted in: A significant increase in the number of beneficial insects (bees in particular benefitted) An increase in insect diversity beneficial 'spillover effects' on adjacent farmland. The solar farms under study were sown with specially designed seed mixes. See also the previous woodlands  blog on solar panels and wildlife The seeding of solar farms would seem to offer support to : Renewable Energy Generation: Biodiversity Pollination services Habitat restoration: in fields that may have been damaged by intensive agriculture and / or development. They can also act as a refuge for native plants and wildlife. Erosion control: the root systems of native plant species (which penetrate to different depths) help prevent soil erosion. Reduced maintenance costs: as less mowing / weed control needed. The cabbage white butterfly is generally regarded as the enemy by the keen vegetable gardener.  If you are growing brassicas - cabbages, cauliflowers, brussels sprouts, broccoli, kale or pak choi, it is likely that you will have these butterflies as summer visitors.  The butterfly is white with black spots on the wings.  Males have a single spot on each of the forewings, whereas the females have paired spots. The butterflies are attracted to the plants as they produce the chemical - glucobrassicin. The butterflies can sense the glucobrassicin through the hairs on their front legs (they have three pairs of legs, a pair on each segment of the thorax). This chemical, glucobrassin, stimulates them to lay their eggs on the leaves of cabbage and other brassicas.  A female can lay up to 800 yellow eggs. These eggs may hatch and the green / black caterpillars emerge.  These caterpillars can double their mass in a day through their voracious feeding.  The adults are attracted to the glucobrassicin in the brassicas just as the caterpillars ‘enjoy’ the chemical - SINIGRIN.   When leaf tissue is damaged, the sinigrin is broken down into a mustard oil, responsible for the pungent taste of Cruciferous vegetables. There are a number of strategies that may help keep the butterfliess away from your crops, and reduce the damage by the caterpillars. Cover the plants with an insect proof mesh Offer ‘sacrificial brassicas’ away from the main crop Use companion / mixed planting, so that beneficial insects have 'hiding places' and it is more difficult for the female cabbage whites to find the brassicas.  Also, by mixing up the planting with herbs and other veg, it makes it a bit more difficult for the caterpillars to move from cabbage to cabbage etc. If you do need to use an insecticide, consider using the products derived from Bacillus thuringiensis.

To see the forests of  The Fens,  you would need to be a time traveller, as they were ‘lost’ some four thousand years ago.  Today, The Fens are a low lying agricultural region that forms part of Norfolk, Lincolnshire and Cambridgeshire.    The Fens contain some of the best agricultural land in the U.K., growing potatoes, sugar beet, and wheat.  A naturally marshy area, it was drained centuries ago and is now maintained through a complex system of drainage canals, dykes and pumping stations.  As a result of the drainage, the level of the land in many places has shrunk.  Indeed, in places, the land level is below sea level.  There are occasional ‘hills’ or islands, which have remained dry even when the surrounding area has been flooded.  The city of Ely and its cathedral was built on such a clay island. Deeper ploughing (e.g. for potatoes) in this area has over the years exposed  ’bog oaks’, large logs between two and eight metres in length.  The trunks were sometimes piled up in so-called clearance  cairns on the edges of a field, or allowed to dry out and later used for fuel.  Recently, ‘oaks’ from a number of farms across the region have been examined by researchers at Cambridge University and many have been identified as the remains of ancient yew trees.  The various logs were often well preserved in the peaty soils of the area, and this allowed detailed analysis of the annual rings (dendrochronology). The rings showed that some of the Yews were 400 years old, when they died.  Tree ring analysis plus examination of the pollen grains* (found in the peat), suggests that the area had dense yew (and oak) woodlands some 4500 years ago.  However, these woods were lost about 4200 years before today, probably due to an abrupt rise in sea level.   The trees would have been unable to tolerate the salt water (nor salt spray) when the area around The Wash was inundated.  Quite what was responsible for the rise in sea level is not clear, though other significant climatic events in different parts of the world have been recorded at this time. the 'wall' of pollen grains  [the exine] is made from a chemical [sporopollenin] that is extremely resistant to decay / degradation, so the grains  retain their shape / markings for thousands of years;  this means that plant species can be identified [palynology].  

Every now and then, some trees produce massive numbers of their fruits and seeds.  This sudden ‘excess’ of seeds / fruits, mens that the various animals that feed on the fruits / seeds cannot eat all of them - so many will survive to germinate, and go on to develop into seedlings and saplings. This excess of fruits [such as acorns, beech nuts] is known as masting.  Whilst it is thought to help with the long term survival of tree species, it is not without certain risks.  Masting uses up considerable nutritional and energy resources to produce flowers and fruit, which can affect the long term viability of the tree and the growth / reproductive capacity in subsequent years.  It is also possible that the abundance of food for animals could lead to an increase in small mammals (rodents?) and other animals, some of which might be vectors for disease. Masting has seemed to be a random process.  However, researchers at Hokkaido University have now developed a computer based model of masting - by studying the Japanese Oak (Quercus crispula).  The model considers such factors as : the resource budget of the tree pollen limitation weather patterns The researchers hope that apart from predicting the likelihood of masting that the model will also help predict : ‘the effects of climate change on woodlands and forests’ ‘long term trend availability of  food for animals’.   Though the model is currently based on the Japanese Oak, it is hoped to extend the model to include other species through collaboration with workers across the globe.     [caption id="attachment_41085" align="aligncenter" width="675"] Woodland path covered with mast[/caption]

Bees and light Honey bees need to sleep.  Unlike us, they do not sleep for long periods but they take ‘naps’ during the day and the night - within the hive where it is dark.   If the hive becomes over heated, then bees will move outside the hive and beat their wings to fan cooler air into the hive.  If the bees are exposed to artificial light during the night then there is evidence that their ability to perform the ‘waggle dance’ is impaired.   The dance is important as it tells other bees where to source pollen and nectar.   Cooling of the hive may become increasingly necessary with climate warming (and heat spells), which in turn might expose bees to artificial light at night.  Hives might need to placed away from road sides (hence car lights) and street lights.  An ancient pine. The Wollemi pine is rightly described as a living fossil.  It is a plant that has remained unchanged for millions of years.    An almost identical fossil form dates to the Cretaceous period , some 145 million to 66 million years ago.  Whilst the trees were abundant some 8 to 6 million years ago, now only 60 trees exist in the wild (in a canyon northwest of Sydney) and they are at risk of wild fires. The population of these pines has dwindled as the climate in Australia became drier and warmer.   The genetic make-up of the species has recently been analysed.  It turns out that the tree's 26 chromosomes contain some 12.2 billion base pairs; by comparison, the human genome has 3.4 billion base pairs.  The research also indicated there was very limited genetic diversity within the Wollemi pine population.  The existing trees appear to  have abandoned sexual reproduction, and now reproduce mainly by cloning, suckers emerge from the base of a tree and then grow on to become ‘new’ trees. Whether this remnant population of the Wollemi pine will survive ongoing climate change (and increasing risk of fire) remains to be seen.  The wollemi pine also appears to be susceptible to disease, in particular to Phytophthora cinnamomi, a pathogenic water mold that causes dieback.