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.

NaturScot is Scotland’s nature agency.  It monitors and reports on all aspects of the natural environment.  It has published a report on its terrestrial bird breeding species and it is a somewhat mixed report. Some of the most ‘famous’ species associated with Scotland, such as the black grouse have declined significantly during the period of study (1994 - 2019).  The grouse population has halved, and the kestrel, greenfinch and lapwing populations are also in decline.  Woodland populations of Capercaillie have also fallen.  The largest grouse in the world, the capercaillie was once widespread but suffered local extinction in the eighteenth century and was reintroduced in the C19th. It is now only found in old pine forests and mainly in the Cairngorms National Park. The Capercaillie are now red-listed and protected in the UK. [The Pine Marten which feeds in part on the eggs of game birds was almost lost in the nineteenth century, due to farmers and gamekeepers trapping them.] The fall in bird numbers has been associated with changes in climate, notably warmer and wetter weather coupled with extreme events (such as flooding and heat waves).  Whilst some species have suffered as a result of the changing weather, others seem to have prospered, including some that do not ‘traditonally’ make their way to Scotland.  The great spotted woodpecker is one such species, its numbers have increase by 500%, bullfinch and red numbers have also increased.  Gold finches and magpies are now more common on farmlands in Scotland. various measures could help offset some of these declines,.such as  the diversification of woodland (more tree species) restoration of peatlands Creation of habitats on farmland legal predator control deer exclusion to allow regeneration removal of deer fencing, (where feasible) as capercaillie and black grouse are known to fly into this and injured as a result. One example of the benefits of deer fencing is to be seen in the Glen Lyone woodlands.  Historically, this area was part of the royal hunting grounds of Cluanie and was home to capercaillies, wildcats and lynx.    Nineteenth century maps show a significant area of woodland, but by the 1990’s less than a hundred of the ancient pines were left.  The oldest pine in the area dates back to the C14th century, and many others are several centuries old.  However, the area was heavily grazed by deer, which reduces regeneration as young seedlings / saplings get eaten.  Now “Trees for Life” have erected new deer fencing, which hopefully will allow natural regeneration of pine forest in the area.  Calendonian Forest once covered much of the Highlands but now less than 2% of it survives.  Full details of this project (and a video) may be found here ; https://treesforlife.org.uk/scotlands-oldest-wild-pine-saved/

Just as many animal species are threatened with extinction, so are many species of tree.  In fact, one estimate suggests that up to a third of tree species are under threat - that is more than 17,000 species.  This equates to more that the number of endangered mammals, birds, reptiles and amphibians put together.  In 2021, the IUCN (the International Union for the Conservation of Nature) produced a report on some 58,497 tree species which identified 17,510 species as being threatened (and 142 extinct in the wild). In Mauritius, some 57% of tree species are at risk of extinction! Ideally, no single tree species should be lost, a single species can be an integral part of an ecological network. Its loss could result in the disappearance of many species and even an ecosystem collapse.  Some tree species are now represented by single numbers of specimens.  The ‘lonesome palm’ (Hyophorbe amaricaulis) is probably the last surviving member of its species. It is to be found in a botanic garden in Mauritius. It is an old, damaged and spindly specimen. It has problems with fruit formation; each of its fruits contains but one seed and the seeds are difficult to germinate (even the botanists at Kew could not persuade them to grow). The best approach to saving vulnerable trees is to protect their natural habitats.  This might mean controlling grazing by herbivores, or banning logging in sensitive areas.  Sometimes a change in cultivation techniques can make a difference.  The Lansan Tree produces a valuable, aromatic resin.  It is endemic to the Windward Islands and its fleshy fruits provide for native pigeons and other wildlife.  The resin is collected (tapped) from the tree by slashing the bark every one-to-two weeks. However, over-tapping for the resin can lead to the trees becoming infected with pathogens, then rotting, or subject to termite attack. The pathogens may spread to untapped trees.  Unregulated tapping and conversion of land from rainforest to agriculture have led to Lansan Tree populations all but disappearing in places. On Saint Lucia, where there is a large but threatened population of Lansan Trees, there is hope after the introduction of a sustainable resin harvesting technique.  This technique does not damage the tree but still allows a good yield of the resin.  This,  coupled with training of licensed resin tappers should protect the trees. Some species have reduced populations because their pollinators have been lost, so fruit and seed production has ceased.  Other species have separate male and female plants (dioecism) and the small populations that remain are represented by only one sex.  This was true for the catkin yew population in Hong Kong, where all the trees were males.  A global search found a female specimen in the Royal Botanic Garden in Edinburgh.  Cuttings from the Edinburgh tree have now been planted in a managed site in Hong Kong.  Hopefully when they flower, fruit and seed production will occur;  but it may be a long wait for the young trees to reach sexual maturity.  Another species, the oleander podocarp (Podocarpus neriifolius) has been nursed back to viability by similar techniques. Some rare and isolated trees produce seeds but getting them to germinate is another matter.  Many seeds enter a state of dormancy and have extremely specific requirements for them to germinate and grow on.  In many cases, their needs are simply not known.  The seeds may need a particular temperature regime, or exposure to cold, fire, smoke or light of a particular wavelength. Some seeds may need to travel through the gut of a particular animal before they will germinate.  Sometimes, scientists have used to embryo culture. The embryonic radicle (root) and plumule (shoot) is extracted from a seed and then grown in a sterile nutrient culture medium.  This technique was used at Kew with the ‘lonesome palm’ as attempts to grow its seeds had failed.   Embryo culture resulted in plantlets forming but after a while their roots turned brown and the young plants died.  There are success stories.  A Cypress species Widdringtonia whytei, was reduced to a few trees in Malawi, as a result of illegal logging for timber. Many seedlings have been  planted on Mount Mulanje and  a good number of these have survived. [caption id="attachment_25196" align="aligncenter" width="675"] Entrance to the Millennium Seed Bank[/caption] When and where seeds are actually available, they can be dried or frozen (cryopreservation) and placed in seed banks, for example the Millennium Seed Bank at Wakehurst Place.   We have to hope that through various interventions, the use of seed banks, botanic gardens and arboreta that we will be able to save many rare and threatened tree species,  you never know when one might be needed.

Rapid onset climate change, and the spread of new pests and diseases are creating unprecedented challenges to the long-term survivability of UK woodlands.  This looming threat is becoming ever more tangible, and the need for strategies of resilience building is urgent. Promoting diversification within and amongst woodlands has been identified as one such strategy with the potential for significant, positive impact. DiversiTree is a UKRI-funded project led by the James Hutton Institute which is measuring the impact a more diverse mixture of tree species has on building resilient woodland ecosystems, as well as how woodland managers and others understand woodland diversity, and what they are CURRENTLY doing to promote resilient woodlands. The project also hopes to generate practical advice and results which managers can use to make better informed decisions regarding the species mix of their woodlands, especially with regard to conifers. A key question which often accompanies discussions of woodland diversity is the planting of non-native species within British woodlands. The DiversiTree project is taking an evidence-focussed approach to its assessment and are investigating how ecological resilience interacts with woodlands with different priorities or objectives and what this might mean for the longer-term ecological sustainability of the forests of the UK. In actuality, many native woodlands are rather species poor, and could potentially benefit from a period of managed diversification with native species, non-natives, or a mixture depending on local objectives and context. What is critical here, is understanding the ecological role ANY tree can serve in a complex landscape, and planting in a manner which enhances and strengthens a woodland’s biodiversity.   If you’d like to learn more about our work and keep updated with our progress, please follow us on Twitter @DiversiTree_UK (https://twitter.com/DiversiTree_UK?s=20) or email [email protected] with any questions.  Seumas Bates (Environmental Anthropologist, Bangor University)  

Lichens are plant-like organisms that are rather unusual in that they are an amalgam of two (or occasionally three) organisms : a fungus and algae (or cyanobacterium). They are symbiotic systems, where the partners of the association work together for mutual benefit.  The fungus makes up the bulk of the lichen's form (known as the thallus), it is a complex network of fungal hyphae that surround the algal cells.  The algae (green algae or cyanobacteria) are essential to the association as they can photosynthesise, fixing carbon dioxide and providing both partners with organic carbon compounds (often in the form of sugar alcohols). Some lichen species are brightly coloured. The colour may vary from a golden yellow to a deep red. The pigments responsible for these colours belong to the anthraquinones.  However, these insoluble, phenolic pigments can have toxic effects. To avoid harm by these pigments, the lichen exports* the pigment from the fungal component of the symbiosis. The pigment then accumulates / crystallises on the surface of the lichen. The layer of pigment crystals reflects harmful radiation (in the form of UV light) and also blue light, whilst still allowing enough light to pass through for photosynthesis by the algae / cyanobacteria. Exposure to UV light can damage DNA, inducing mutations.  The pigmentl layer is effectively a ‘sunscreen’ for the lichen. * Recent work at Imperial College and RBG, Kew has identified the genes responsible for pigment production, and the transport of the pigment out of the fungal tissue. In the past, certain lichen pigments were often used to dye clothing materials.    Parmelia saxatilis, also known as grey crottle, was used to dye wool for Harris Tweed.  This lichen is often found growing on tree trunks and gives a red / brown colour to the material. [caption id="attachment_39793" align="aligncenter" width="700"] Lichen and moss growing together  (thanks to Art for photos)[/caption] Woodlands TV has produced two short videos on the biology of lichens :- https://youtu.be/XQ_ZY57MY64     https://youtu.be/0djrOgKtGlk

The onset of Spring brings a variety of blue flowered plants such a bluebells, hyacinths and squills in our gardens, parks and woodlands. The bluebell is ‘easily’ recognisable.  However, there are two or three different types of bluebells. The bluebell that is native to the UK has the Latin or Linnaean name of Hyacinthoides non scripta. Its deep blue and scented flowers hang from an elegantly arching stem. It is found in abundance in many deciduous woodlands and hedgerows across the UK, though it is unusual or rare in parts of East Anglia and Scotland.  The Spanish bluebell (H. hispanica) is also to be found. It is possible to distinguish between the two species – some of the differences are listed in the table below: Native Bluebell Spanish Bluebell Leaves are narrow by comparison to Spanish Bluebell, about half an inch or so wide Leaves broader, often an inch or more wide The flowers at the top of the stem droop to one side The top of the stem is much more erect The flowers hang from one side of the stem The flowers are arranged around the stem The flowers are deep violet blue The flowers are a pale or mid blue, and white and pink ones are also found The flowers have parallel or straight sides and have a narrow bell shape The flowers are more ‘open’ with a cone shaped bell The tips of the petals roll back somewhat as though they ‘want’ to touch the tube of the flower Not such obvious curving The pollen is a pale cream colour Pollen is a blue colour Flowers are scented No scent detectable The spanish bluebell can hybridise with the native bluebell, giving rise to types that have a mixture of the above characteristics.     The Natural History Museum is trying to map the distribution of these different bluebells and it is asking people to complete an online questionnaire about the bluebells in their gardens, local parks, hedgerows and woodlands. If you can help, go to: http://www.nhm.ac.uk/nature-online/british-natural-history/survey-bluebells/recording/index.html Since this was first posted in 2006, there have been various updates, but the bluebell survey link does not seem to be active now. See : https://www.nhm.ac.uk/take-part/citizen-science/bluebell-survey.html

Some years back, the Woodlands blog posted various articles about hedgerows,  noting the loss of many - due to the increased mechanisation of farming in the mid C20th.  Now, there is greater recognition of the importance of hedgerows, and there are initiatives to promote the maintenance and expansion of hedgerows. But what is a hedgerow? Natural England offers a definition as follows : A hedgerow is defined as any boundary line of trees or shrubs over 20m long and less than 5m wide, and where any gaps between the trees or shrub species are less that 20m wide (Bickmore, 2002). Any bank, wall, ditch or tree within 2m of the centre of the hedgerow is considered to be part of the hedgerow habitat, as is the herbaceous vegetation within 2m of the centre of the hedgerow.  This differs from the definition in the  Biodiversity Action Plan, which included references to ancient hedges / species-rich hedges.  The definition now includes all hedgerows consisting of at least one native woody species of tree or shrub (mainly), but it does exclude bramble and honeysuckle as ‘woody species’.  According to one source, there are some 550,000km of hedgerow in England, with over 400,000 km being actively managed.  Hedgerows are an important semi-natural habitat in what is otherwise a managed agricultural landscape. They are found across the country but there are more in lowland regions. Hedgerows in the south east are associated with large fields and fewer trees, the proportion of trees in hedgerows increases as one goes north and west.   The nature of hedgerows varies across the country but all are important as : They provide a habitat, shelter (micro-climate provision) and resources for many different species (from plants to insects, birds and mammals). Hedgerows are particularly important as nesting sites for birds. They support animals that have key roles within the broader ecosystem, for example pollinators and predators of pests. They offer an important source of nectar that helps support wild bees - adjacent farmland can be a poor source of nectar Hedgerows are known to support threatened (red listed) species Hedgerows capture and store carbon (above and below ground) Hedgerows offer ecosystem services eg. mitigation of water flux and availability, landscape connectivity, soil conservation / stabilisation. A number of studies indicate that increasing the number of hedgerows would help with landscape connectivity (for example, for hedgehogs) and that planting of blackthorn and hawthorn in association with later flowering species would help support a number of wild bee species.  Expanding the number of hedgerows could have some negative effects as they might offer a home to invasive species and / or pathogens; but one study has indicated that ash trees in hedgerows suffer less impact from ash dieback than trees in forests.  To date there does not appear to be any detailed research on whether increasing hedgerow coverage would have any impact on tree disease / pathogen spread. Hedgerows, like woodlands themselves, face a number of challenges due to climate change.  Warmer winters may mean that the ‘winter chill’ requirements of some shrubs / trees will not be met; this may mean flowers and fruits fail to form properly which in turn means less food for birds, small mammals etc.  Drier summers may stress some species, trees like Beech are susceptible to drought.  Extreme weather events (like Storm Arwen) can inflict damage on hedgerow trees.  If a hedgerow is next to farmland, then it may experience drift from pesticide and / or herbicide spraying  nutrient enrichment (eutrophication) due to the use of fertilisers. Hedgerows with a diverse structure, with plants, shrubs and trees of varying ages and heights provide the widest range of niches / microhabitats for wildlife.  The inclusion of dead / decaying wood offers opportunities for various fungi, saproxylic beetles, woodlice etc.  Some hedgerows are managed / reduced with a mechanical flail (see above !!!). If this is done annually, it can result in a loss of biodiversity. Trimming should be done on a 2 or 3 year cycle; and some sections of the hedge might be left for longer " see (https://www.hedgelink.org.uk/cms/cms_content/files/76_ne_hedgecutting.pdf).  Thousands of tree and hedgerow plants are being planted to create a flood defence project at Castlehill, East Hull.   The plan is to create some seven hectares of woodland and over five kilometres of new hedgerow, as part of a flood defence project (to store floodwater east of the city).  Trees such as field maple, downy birch, English oak, and black alder are being planted along with species of willow, dog rose, guelder rose and blackthorn and hawthorn to create hedgerows and scrubland.  Other species will be allowed to naturally develop in the area and the habitat is expected to reach ‘maturity in some fifteen to twenty years. There is a citizen science project that involves surveying hedgerows.  It is organised by the People’s Trust for Endangered Species [PTES].  The Great British Hedgerow Survey guidelines can be found here : https://hedgerowsurvey.ptes.org/survey-guidelines Some times hedges offer a home to other things         

Woodlands.co.uk is 'republishing' this blog, as contact details for the Jones family are now available and several people have expressed an interest in having a walking stick 'custom made'.  The blog originally appeared in 2014. Contact email address is pj451324(at)gmail.com Peter Jones and his sons make walking sticks on a serious scale using sticks they come across in the woods, where they do their forestry work.  They use chestnut, silver birch, oak and hazel.  But they avoid using willow, as it goes brittle once it's aged.  Apart from finding the right stick to work on they need a steamer for bending the tops of the walking sticks and a good supply of sealant and varnish for protecting the finished sticks. "Honeysuckle makes the best twist sticks" advises out Peter Jones, who comes across a lot of twisted stems in Kent and East Sussex.  As a result, he is able to trade these with fellow stick makers in more northern English areas - they give him carved tops for walking sticks in exchange for good twisted shanks.  But even among twisted sticks there is variety: the slower growing trees such as holly and oak twist more slowly whilst the fast-growing chestnut twists quickly.  Though he also corrected me pointing out that the maker of walking sticks should really be called a "stick dresser" Read more...