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.  

Monks Wood is an area of woodland in Cambridgeshire.   It has been subject to extensive and intensive ecological studies for many years.  The site is described by Natural England as one of our essential lowland woods with ash and field maple trees; also to be found is the rather rare wild service tree.  The ground flora is typical of that of ancient woodland, within the wood there are also ponds and streams.  Monks Wood is a National Nature Reserve. Next to the reserve there is former agricultural land.  Two fields have been studied to understand the process of natural woodland development.  One field was formerly two acres of grassland that was ‘abandoned’ (in 1996), the other was a four acre barley field (that was left to stand in 1961).  For natural regeneration of woodland to occur there needs to be existing woodland nearby.  The transition of these fields to ‘new’ woodland has been monitored over the intervening years - through field surveys of trees, measurement of vegetation height, remote sensing via LIDAR.  Read more...

Australia has experienced some of the most dramatic effects of climate change - with the unprecedented burning of vast areas of its countryside (see previous blogs).  Recently, the weather turned to another extreme - thunderstorms, hailstorms and rain.  Large hailstones (the size of golf balls or bigger) have bombarded cities like Sydney, Melbourne and Canberra, damaging roofs, cars, trees, and infrastructure.  Flash flooding has occurred in some places due to heavy rain, plus there have been high winds and dust storms. Whilst rain has been welcomed in that it has helped to ‘damp down’ some of the fires that have been raging, the intensity of the rain is not without problems in places. Heavy rainfall can result in further damage to ecosystems. Read more...

What do the seeds of ash, sycamore and maple trees have in common?  They all are enclosed in a wing-like structure that helps them disperse - away from the parent plant and indeed each other.  Wind dispersal is also known as anemochory.  Effective fruit / seed dispersal provides a tree's offspring with the chance to colonise a new area, and reduces competition for resources with their parent and siblings; it also reduces the likelihood of infection with pests and pathogens.  A single Ash tree (Fraxinus excelsior) can produce thousands of fruits (also  known as keys) in large clusters attached to the tips of its branches. Read more...

In early Spring this year, both Norway and Sweden reported wild fires in their forests, due in part to a run of dry weather. More recently, fires have been reported in many parts of the world - particularly in the Amazonian Forest,  parts of Africa, Siberia,  Canada and even within the Arctic Circle. A few years back, the Russian authorities initiated a policy of allowing remote forest fires to burn - unless the trees / areas were of economic importance.  However, the fires this summer affected thousands of square miles of boreal forest and strong winds spread the smoke and ash across the country; it affected cities such as Novosibirsk and Krasnoyarsk (each home to a million people). Read more...

 Some years back, the blog talked about a 5000 year old ‘mummy’ - called Otzi.   Otzi was a Neolithic man, and was found frozen, high in the mountains between Austria and Italy.   Careful examination of his body, clothing and possessions gives us some insights into his daily life and diet.  Otzi and, we presume, his contemporaries made good use of the plants and natural materials around them. Thus,  His bow was made from Yew  Ash provided his dagger handle  Woven grass and bast for his cloak (bast is made from the fibres of the linden tree) goats hide for his leggings and jerkin,  bear skin for his cap deer skin for shoes  arrows from a wayfaring tree and dogwood Read more...

Members of the kingdom of the fungi can essentially be divided into the two basic categories of basidiomycetes and ascomycetes. The basidiomycetes form and release their spores on specialised cells called basidia, which can be found on the underside gills of our more familiar mushroom and toadstool-shaped types, or within the pores of boletes and brackets and suchlike.  Ascomycetes, however, produce their spores in the elongated cells known as asci that cover their spore releasing surface. Each individual ascus can contain usually around 8 spores, like snooker balls in a sock, which then get released out of the end when ready: the word is derived from the Greek for wineskin or sac. Typically we might think of cup fungi, such as the various members of the Peziza genus, like the Blistered Cup (Peziza vesiculosa) depicted here, whose favoured substrates of well-rotted manure or compost heaps lends has led to its alternate common name of the Common Dung Cup.  Read more...

Having put in place the basic infrastructure so that I can store tools, equipment and firewood and have somewhere for shelter and to work, my attention turned to the top two priorities on my ‘to do’ list – well actually, numbers 2 and 3, number one will always remain ‘relax, do nothing and just enjoy it’. Firstly there is a semi-circular clearing near the eastern side of what is essentially a triangular plot. I have planted a ‘family copse’ Read more...