Lowland Chalk Grassland

[zigzag_wanderer]

I found my oldest bit of pottery at archaeology up on the South Downs three weeks ago, a chunky piece of Middle Bronze Age bowl. That's the Amex Stadium a little to the right of it.

You can't help but get a bit reflective when you find something like that. To me it's as if the intervening 3,400 (ish) years vanish down to an instant, one person hacked off because they've broken a bowl and another very happy to find some of it.

It also got me thinking about the lowland chalk grassland habitat the Neolithic ancestors of the pot's owner had helped create and the many subsequent generations of farmers and their livestock have helped maintain, right up to the sterling present day efforts of people like Neil Hulme (and others on this site I'm sure) who put in hard scrub-bashing graft for the benefit of the many flora and fauna species who make this habitat their home and the people who enjoy seeing them.

Apologies then if this is a really daft question, but sticking just with butterflies were our current lowland chalk grassland specialists exactly that at the dawn of the major Neolithic woodland clearances / onset of livestock farming i.e. with colonies already established in pre-existing strips of chalk grassland along the coast and possibly other naturally occurring tree-free areas, who just followed their larval food plants into the rapidly expanding man-made landscape ? Or was there nowhere naturally scrub-free/short-turfed enough to support a Silver-spotted Skipper colony (for example) and we can say with some certainty that this species decided to take advantage of this newly cleared/grazed/maintained expansive man-made vista by making significant changes to its (presumably) erstwhile woodland edge existence ?

[essexbuzzard]

An interesting question. I’m not scientist but, to my knowledge, chalk downland, like all the best butterfly habitats ( lowland Heath, woodland clearings, etc), is entirely man-made. This is why, if not intensively managed, chalk downland will quickly revert to scrub, then woodland. When this country was covered in the ancient wildwood, it must have been very species poor. It was not until man started to cut down the trees and create enclosed farmland, that a diversity of species of flora and fauna became established.

[Wolfson]

Long before we created the modern landscape, mega fauna, meandering rivers, wild fires and other forces of nature created a diverse landscape over huge areas that would have supported great diversity.

[David Lazarus]

There are recent theories that speculate that the UK was not entirely wooded and that large wild herbivores, such as the aurochs, kept clearings open, moved through rides, and grazed on south-facing slopes from which habitats the habitat-specialist species evolved.

It also may be the case that habitat-specialists moved with humans from the continent within plants & plant litter such as hay and straw which is known to be a transporter of Essex Skipper, for instance.

We may not have had all the species we have now in ancient times. Some species may have come over during the history of man and how humanity has changed the landscape - the history of the changing landscape itself - which includes habitat development and the creation of new types of self-supporting ecosystems. They came to take advantage of these changes.

With the disappearance of large herds of aurochs and bison because of the over-hunting of man, the ecosystem service provided by large herbivores has had to be replaced by humans. Unfortunately, this means some of our habitat-specialist butterfly species are almost entirely dependent on humans to suspend ecological succession in their favour.

The change to intensive farming to support a growing population, and the habitat loss caused by new development, has not done that and so we see the loss of species and local extinction.

The way humanity manages the landscape including conservation work, the restoration and enhancement of habitats, and how the land is used, needs to change and change soon or all will be lost and this will be a crying shame. Unfortunately I will not see this in my lifetime and I will continue to be heartbroken

[Jack Harrison]

Thoughtful essay David.

Jack

[zigzag_wanderer]

Really appreciate the considered and heartfelt replies on this, chaps.

A lyric that's stuck with me since watching TOTP in early 1978, is from Shot By Both Sides by Magazine:

One thing follows another,
You live and learn....you have no choice.

I would regularly remind myself of this couplet after screwing up, but I guess it holds true for all living species who want to stay extant, you continually have to learn and adapt to changes in your environment or risk going under. But obviously if these changes happen too quickly then you may not have enough time to learn.

The dramatic change to Downland management with seasonal farming cycles continuing down the millennia must have had a massive effect on the surrounding flora and fauna for Chalk Grassland to become so richly biodiverse. Obviously, this bonus was mainly coincidental to our aims and there would certainly have been some losers locally in these woodland/scrub clearances, but it clearly indicates David's (and Howard Devoto / Pete Shelley's) point of how species live and learn by adapting/taking advantage.

I have no knowledge of the eating habits of our prehistoric grazing fauna but I presume our ancient large wild cattle species, while great at opening up grassland from scrub and generating plenty of scrapes for butterflies to bask on, would be twisters and pullers when eating, more akin to modern cows, rather than fine nibbling grazers like sheep who tend to give the sward a good Number 2 all over (in both the haircut and natural fertilisation senses) ? So in the very strict sense of my opening query, I still wonder if there was enough of the habitat currently favoured by some of our Chalk Grassland specialists, occurring naturally 6000 years ago ? Probably a moot point anyway !

[David Lazarus]

A lyric that's stuck with me since watching TOTP in early 1978, is from Shot By Both Sides by Magazine:

One thing follows another,
You live and learn....you have no choice.

I have no knowledge of the eating habits of our prehistoric grazing fauna but I presume our ancient large wild cattle species, while great at opening up grassland from scrub and generating plenty of scrapes for butterflies to bask on, would be twisters and pullers when eating, more akin to modern cows, rather than fine nibbling grazers like sheep who tend to give the sward a good Number 2 all over (in both the haircut and natural fertilisation senses) ? So in the very strict sense of my opening query, I still wonder if there was enough of the habitat currently favoured by some of our Chalk Grassland specialists, occurring naturally 6000 years ago ? Probably a moot point anyway !

One of my all time favourite songs. Obviously my first reply was influenced by post-punk evolutionary theory.

I suspect that the large herds of auroch would do all the hard graft and that there would be smaller herbivores that would provide the number 2(s).

I think we also have to remember that chalk is both alkaline and low in nutrient, being porous it is free draining. Therefore, stress tolerators such as the plants that we find on our chalk grasslands would benefit from these sun-baked, dry, nutrient-poor soils which would be open sward and rich in diversity of both fauna and flora. I’d imagine that butterflies would have evolved to take advantage of such habitats. When man came along and started to manage them, such butterflies took full advantage of the opportunities provided to them - probably expanding their range and increasing in numbers. The Victorians would therefore witness clouds of butterflies before the Industrial Revolution took hold and changed the landscape to the benefit of humans and disregarded the needs of the rest of nature.

Just a thought

[zigzag_wanderer]

You know what your trouble is David ? You have good taste and you've always got a bloomin' answer !

OK, I'll buy your smaller herbivores as the necessary nibblers, although I'm not sure what wild fine-grazers we had at that time (but I own that's totally down to my ignorance).

But in my mind's eye (a dangerously ignorant lens, I fully accept) I can see small herds of aurochs roaming over vast expanses (...so far, so Basil Fawlty...), moving freely through woodland and grassland finding new areas to munch on, albeit also having to avoid being hunted by us and possibly wolves (for the young and infirm at least). I'm sure they had seasonal preferences and may have formed larger groups at certain times of the year, probably in the same general localities, but these would have been fairly expansive I'm sure.

So I'm still not sure they were sedentary or predictable enough creatures for guaranteed short grass over a large enough area, at predictable and long-enough times of the year, every year, for an insect to rely on. And that's without this required camp-following army of smaller herbivores to get the required No. 2 sward height.

I appreciate you may, inconveniently for me, counter the above with actual facts. So I am more than happy to accept that this question is probably moot and try and walk away with a score draw.

I did have a sneaky shuftie at my Butterflies Of Europe book though and it does say that in other places Silver-spotted Skipper inhabits woodland/forest edges, where presumably it doesn't have quite such a reliance on the sward being as short as it is here ? So maybe its preference here is totally based on a need for high temperatures in which case it might only have settled here after the onset of Downland sheep farming...even dare I say it, after the introduction of rabbits ?

As I'm now conjecturing wildly from a basis of almost total ignorance I will stop !

But I will, if I may, leave you all with one more punk-era lyric that's stuck with me down the years, the opening lines from No Time To Be 21 by The Adverts:

Life's short....don't make a mess of it,
To the ends of the earth you look for sense in it.

I'm still trying and I'm still looking....but maybe in the wrong places !

[Wolfson]

It is difficult to imagine what the world would have looked like before bipedal apes started to hunt. Some of the many rewilding projects provide clues. The role of megafauna David refers to are well established and the reference below is as good a place to start as any, for those that are curious.

Ecological consequences of Late Quaternary extinctions of megafauna

C.N. Johnson
Published:18 March 2009
https://doi.org/10.1098/rspb.2008.1921

[David Lazarus]

You know what your trouble is David ? You have good taste and you've always got a bloomin' answer !

I appreciate you may, inconveniently for me, counter the above with actual facts. So I am more than happy to accept that this question is probably moot and try and walk away with a score draw.

As I'm now conjecturing wildly from a basis of almost total ignorance I will stop !

But I will, if I may, leave you all with one more punk-era lyric that's stuck with me down the years, the opening lines from No Time To Be 21 by The Adverts:

Life's short....don't make a mess of it,
To the ends of the earth you look for sense in it.

I'm still trying and I'm still looking....but maybe in the wrong places !

Another classic!!!!

And because of the well-thought out response to my clever-dick reply and for quoting the classics, definitely a score draw

[zigzag_wanderer]

Thanks David !

Thanks too for sharing that link, Wolfson. I think I definitely owe it to myself to read that.