I have been watching with interest across the past few weeks of this heatwave, the behaviour of the carrion crow population in a part of Seaford that I frequent.
The local crow population near the seafront area (who appear to be rather benign, urban relations of the rural hunting type that I’m more familiar with) and seem very social together. They number up to some 15 birds and here is the point of interest, spend much of the hotter part of the day on neighbouring roofs and ridges in an attempt to stay cooler in the slight breeze that these higher vantage points presumably provide.
I feel that it’s now pertinent to reappraise, to question, why and how we move forward with conserving our iconic chalk grasslands. So, two questions come to mind for me and I shall here attempt to answer them.
1) Where does the conservation of chalk grassland fit into a much broader, evolving view of nature conservation in today’s Britain of the 21st century?
2) Can we, and how do we justify the expenditure of the currently very limited amounts of funding and resources, in dealing with the threats to conserving our chalk grasslands?
To try and answer the first question we need to begin by looking backwards… The latest cutting-edge research is very much pointing to the following scenario: that it was likely that the chalk grasslands of southern England following the retreat of the last Ice Age, were fairly open – perhaps a mosaic of grassland and scrub with occasional stands of woodland on the deeper soils. With the arrival of Man some 10,000 years ago, who practiced ‘intentional’ hunting, followed by approximately 5,000 years later the introduction of farming, it was likely that this open, grassland habitat on these lighter soils of the chalk would have been encouraged by the increased grazing with the occasional breaking-up of relatively small areas of grassland by effectively shallow, ‘organic’ tillage, this soon being recolonised by the large wild seedbank, once cultivation had been moved on. Chalk grassland was further enhanced over millennia peaking during the medieval period and again during the 18th and 19th centuries, with the arable element waxing and waning according to the demands of the market place.
Chalk grasslands are today, largely an inconvenience on most farms that include such areas; they are just somewhere to hold some livestock during the occasional pinch-point or in some cases, are simply disregarded, several unacceptable examples to be found on the Firle Estate in the BoPeep area, pictured below. Other sites are simply badly managed, for example, the Seven Sisters Country Park at Exceat. However, chalk grassland forms one of this country’s great biodiversity assemblages, rich in both flora and fauna and comparable in this respect to tropical rain forests. We have though, regrettably lost during the past century somewhere in the region of 97% of this treasured habitat. (Incidentally, the UK ranks as 29th from the bottom out of 218 countries assessed upon their remaining richness of biodiversity!).
As to the answering of the second question… We are now conditioned by some 70 years or more of interventionist conservation or ‘gardening,’ of our prize wildlife habitats including the one under discussion. Oddly, nearly all our designated landscapes (National Parks, Areas of Outstanding Natural Beauty) are valued primarily for their cultural value and not for their true potential wildness. Challenges faced by chalk grassland have been: the slump in agricultural production (grazing) during the first half of the twentieth century and following hard in its heels, the demise of the rabbit population and the fragmentation of farmland from the post-war industrialisation of farming. Then more latterly there are the repercussions of bovine Tb restricting where cattle can safely graze. All four challenges have led in general, to courser and ranker chalk grassland vegetation and also in places, to its loss.
But there are more recent, more sinister threats to chalk grassland which a century ago would have been virtually unheard of: nitrogen pollution; destruction from the use of pesticides and lastly, climate change. To briefly explain: nitrogen compounds emanate from the various types of exhaust emissions released into the atmosphere. These have almost certainly led to soil enrichment (most wild flora requiring nutrient-poor soils) aiding the spread of the rampant, native tor grass (Brachypodium rupestre) across much of the chalk grasslands and now possibly the increasing occurrence of soft brome grass (Brachypodium sylvaticum). These grasses are of little use to modern breeds of farm livestock. Then there has been the use, often indiscriminately, of artificial fertilizers. Also affecting chalk grassland is the diffuse drift of spray from the widespread use of a whole host of chemicals. Finally, there is the enormity of climate change which we’re increasingly being affected by and can only guess at what impact this will have in the future on this habitat.
So, we as a nation – national and local government (I castigate national government for their emasculation of Natural England!), NGO’s, (I here single out the National Trust’s achievements as being exemplary), with assistance and encouragement from the public, must continue to fight for and safeguard our chalk grasslands. Continued, sympathetic grazing by farmers and land managers together with well-considered control of scrub where thought necessary, are vital to safeguarding this much threatened and very finite wonder of the natural world here in the UK. Education too of course of our younger generations also has a vital part to play in the longer-term struggle.
Saturday, July 7th. Had a beautiful, enjoyable afternoon, including a trip down Memory Lane! Went to an Open Garden event in aid of the Family Support Group at The Long House in West Dean near Seaford. The owners have over the past six years created an extensive, beautiful but compartmentalised cottage garden containing a wide variety of plants.
Part of the garden at The Long house.
After, we visited the nearby churchyard and church. I used to know the village well and a number of its then inhabitants when I lived and worked over the hill at Exceat during the 1970’s and 1980’s.
Upon leaving the village spotted one of the last fair-sized elms in the area starting to die from Dutch Elm Disease. Further up the valley at Lullington and especially sad for me, one of the last sizable elms has at last surrendered to this dreadful disease. It is the only example in the area of a Smooth-leaved Elm of the variety diversafolia.
Variety ssp. diversafolia back in 2012.
I managed the East Sussex Dutch Elm Control project between 1997 and 2004. Due to mis-management and cost-cutting, it unraveled two years later and failed, after a total of some 30 something years and the expenditure of millions of pounds of public money.
As I drive about here in Sussex and further afield, I often notice dying ash trees and from time to time whole groups – especially of smaller semi-mature trees: the wooded downland escarpment above Eastbourne; Filching, Glynde, Jevington; even west Wales. Judging from the large numbers, I can only assume ash dieback is the cause. Added to this is the stress being caused by the current hot, dry weather exasperating many diseased and weakly trees of other species.
https://www.forestry.gov.uk/chalara. (You can also report diseased ash trees via this link). Confirmed findings as at midday on 1st June 2018:
10-kilometre grid squares with one or more Hymenoscyphus fraxineus (Chalara) infections confirmed in the wider environment:
The progression of numbers and appearance of new grid squares over time should not be interpreted as an indication of the rate of spread of the disease. It only indicates when infection sites were found, not when the fungus first arrived at the site, which in many cases cannot be known.
Because ash trees have many genetic variants and occur right across the UK, they come into leaf at different times. Ash is also one of the last tree species to flush, sometimes taking as long as six weeks to do so, and can often occur as late as the end of May. Trees in the colder north flush later than trees in the warmer south. Some ash trees will break-bud, or flush, earlier than others, and some buds will produce flowers rather than new shoots. Some variation will be more apparent in older trees.
Some shoots on ash trees will fail to flush altogether, while others will flush normally before showing signs of ill-health or dieback later. These events might mean that the trees are damaged in some way, but shoot death and dieback in ash trees can have a number of causes.
So if an ash tree does not have any leaves on it in April and May, it does not necessarily mean that it is diseased or dying, but by mid-June all healthy ash should be in full leaf.
Mid- to late summer (August and September) is a good time of year to undertake surveys, because once autumn has begun, visual symptoms can be confused with leaves that are naturally changing colour.
In the autumn you might see clumps of sometimes dark-coloured ash keys (seeds), retained on the trees after the leaves have fallen. This is quite normal, but from a distance they can be mistaken for the blackened leaves which can be a symptom of the disease.
Reporting suspected cases
If you think you have spotted the disease, please check our symptoms section before reporting it using Tree Alert or one of the Further Information contact points below.
Chalara is caused by a fungus called Hymenoscyphus fraxineus. This fungus has two phases to its life-cycle: sexual and asexual. The asexual stage, which grows in affected trees, attacking the bark and girdling twigs and branches, was the first to be described by science, and was originally called Chalara fraxinea. This gave rise to the common name of the disease which it causes.
The sexual, reproductive stage, which was only discovered some years later, occurs as tiny, mushroom-like fruiting bodies on infected rachises, or stalks, of the previous year’s fallen leaves. Infective spores from these fruiting bodies are spread by the wind on to the leaves of healthy trees in summer. This sexual stage was initially called Hymenoscyphus pseudoalbidus (H. pseudoalbidus) before a taxonomic revision suggested the name should be Hymenoscyphus fraxineus. The International Botanical Congress has also agreed that a single fungus should have only one name, even if different stages of the organism have previously been given separate names. Therefore Hymenoscyphus fraxineus is now widely accepted as the name to use.
Government scientists have set out the most up-to-date understanding of the disease. Their assessment concluded that:
the spores are unlikely to survive for more than a few days;
spore dispersal on the wind is possible from mainland Europe;
trees need a high dose of spores to become infected;
spores are produced from infected dead leaves during June to September;
there is a low probability of dispersal on clothing or animals and birds;
the disease will attack any species of ash;
the disease becomes obvious within months rather than years;
wood products would not spread the disease if treated properly;
once infected, trees cannot be cured; and
not all trees die of the infection – some are likely to have genetic factors which give them tolerance of, or resistance to, the disease.
Preliminary results from testing of selected fungicides for treating ash trees with Chalara dieback of ash for their efficacy in laboratory tests and field trials are now available on the Defra website.
The fungus is believed to have originated in Asia, where Asian species of ash are able to tolerate it after of thousands of years of co-evolution.
It entered Britain on ash plants imported from nurseries in continental Europe. However, now that infected, older trees have been found in South-East England with no apparent association with plants supplied by nurseries, it is thought possible that it also entered by natural means. These include being carried on the wind or on birds coming across the North Sea and English Channel, or on items such as footwear, clothing or vehicles of people who had been in infected sites in Continental Europe.
Meet Geoff Derbyshire’s Swift Champion. He has 10 pairs of breeding swifts in his roof in Chesterfield and it’s a suburban semi! He’s created holes for his swifts in his roof and they love it! Geoff, you’re a real wildlife champion, for making a home for so many swifts!
There are lots of really good, relevant news stories and up to date research to be found on the RSPB’s Martin Harper’s Blog. Here are some of the latest articles from this source which is to be found at: https://ww2.rspb.org.uk/community/ourwork/b/martinharper/default.aspx
Recent fires on the Pennines. https://ww2.rspb.org.uk/community/ourwork/b/martinharper/archive/2018/06/29/wildfire-at-dove-stone.aspx