Highfield Wood is a place of magnificent old trees in a grassy, almost park-like setting. It was marked on the earliest detailed map of Cumberland, in 1774, and one or two of the trees seen today could have been around then. There is no physical boundary between the wood and the surrounding pasture; cattle wander at leisure. It is a very attractive feature of the landscape and a lovely place to wander on the way to the ancient church and the lake shore.
The two arrows on the photo of Highfield Wood below indicate an interesting phenomenon affecting the smaller trees. Whereas the foliage on the larger trees makes a fairly rounded shape at both top and bottom, that on the smaller trees is cut off in almost a straight line at the bottom. The foliage below this line has all been eaten. In fact, every green shoot of any kind between ground level and neck-stretch height has been eaten. That neat grassy floor exists because, as any lawnmower owner knows, grass has evolved to cope (indeed thrive) when cropped very short.
If everything green below a certain height gets eaten, a problem arises. Those big old trees had to start off as little young trees, and when they eventually die, there should be younger trees to replace them. So how do the little trees survive those early years when every leaf and shoot is within browsing range? In this wood, without human intervention, they wouldn't. The young trees would never grow, the old trees would eventually die and rot, just the grass and other specialised low-growing plants would survive. In Highfield Wood, each young tree has to be enclosed in a big cage, to protect it from browsing until most of its branches are above the crucial height.
Right: Protecting young trees with cages
Church Plantation is very different. There are hardly any big trees, and although it was shown as woodland on the first Ordnance Survey map in 1867, it was shown as heathland on Ordnance Survey maps in the mid-20th century. The two multi-stemmed trees in the forground of the picture below probably explain why- they have been "coppiced". Like grass, trees can also benefit from being cut down to the ground; they spring up again with multiple straight stems (and such cutting had probably been recently done in Church Plantation when the mapmakers came by making revisions). When these stems have grown to a convenient length or thickness, they can be cut again, for fuel, broom handles, chair legs, all sorts of uses. And the trees will regrow, with even more stems, again and again and again- some coppiced trees are thousands of years old, with stems forming a ring several metres acoss. But even coppiced trees don't grow vigorously enough to cope with having all their young shoots and leaves eaten. They could be grown in big cages, as at Highfield Wood, but instead, the whole of Church Plantation has always been fenced to keep out large herbivores.
Church Plantation is, frankly, rather an untidy wood. Not in the plastic bags and old tyres sense, but just in the way it has naturally grown. As the pictures above (taken on the same day as the main Highfield picture) show, the restriction on browsing animals has allowed all sorts of plants to flourish, from wild flowers to bushes, and young un-coppiced trees grow willy-nilly. But all those extra plants mean food and shelter to countless small creatures. Although pasture woodland contains some very interesting and rare species, specially adapted to survive in that environment, unbrowsed woodland contains a much greater number of species, both plant and animal.
Go round to the east flank of Skiddaw and you'll see what happens when no attempt is made to protect the trees- once upon a time, the fells of the Lake District would mostly have been clothed in woodland, but now few plants other than bracken can grow more than a few inches high, because the sheep (with a little help from other herbivores) keep eating them. On this picture, the only trees are those growing within the fence of Skiddaw House, the former shepherds' residence. As it happens, I like the bare "wilderness" appearance of Britain's mountains- but I'm happy to see woods as well, and without them we'd lose an awful lot of wildlife.Right, here's a real paradox. Because browsing and grazing do have significant effects on an ecosystem, at fairly low levels they actually serve to increase the variety of habitats within that ecosystem. For example, an open area within a wood (perhaps where some trees have been uprooted in a winter storm) will become a favoured spot for large herbivores, as all sorts of plants take advantage of the increased sunlight. If a reasonable number of plants are able to reproduce before being eaten (trees being at a disadvantage in this respect because of their long life-cycles), a specialised ecosystem will form- a woodland glade. Even the dung of large animals is an important addition to the resources of the wood. All in all, a wood containing a limited number of large browsing animals is likely to contain an even greater number of species, both plant and animal, than unbrowsed woodland.
At the opposite extreme, the Skiddaw wilderness is not as bad as it gets; even there the hungry herbivores are subject to a form of control, and the grass is quite a bit longer than in Highfield Wood. Given that the principal drive of any living thing is to reproduce, what (apart from walls and fences) stops populations of herbivores increasing until they take over the planet?