One of the things I think the United Kingdom got "right" regarding protecting the enviroment is that they list several "sensitive" ecosystems that were created (or extended) by the hand-of-man.
Examples include Ancient Hedgerows, Old Apple Orchards, Woodland Parks and Heath.
Some of the motivation is emotional. Scottish Heaths evoke strong feeling of connection with the past.
Ecosystems are dynamic
Ecosystems are dynamic systems. They change in response to the pressures put on them. Since pressures are rarely evenly distributed, the larger ecosystem is a mosaic of smaller systems. Even fires tend to run in paths that run down-wind and up hill. In some places faster and in others more slowly and burning down to mineral soil.
The successional endpoint is highly related to where the system is when it is allowed to go ballistic. Simply "letting Mother Nature take her course" is not going to return the land to the primordial, pre-human state. For one thing, there was no single state before man arrived because there were multiple stressors before we showed up.
There were fires from lightning strikes. There were glaciers, wind-storms, droughts, bugs, diseases, new species expanding into areas where they had not existed, legacy species being expatriated and so on.
Another thing those funny-talking island people got right
It only takes a few trees in a pasture or heath to make it biologically much more interesting. Old trees have cavities that can host kestrels, small owls, bats, squirrels and serve as caches for nuts and acorns.
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Those islands-of-diversity are often found in cemeteries, church-yards, farm yards and railroad right-of-ways.
Get rid of man and the enclosed spaces that protect young saplings from grazing animals go away and the next generations of trees will never happen.
30 years ago, when we first moved into our home, there was a huge ol' box elder (ash leaf maple) in our backyard. It was gnarly, with branches bigger around than some trees, multiple cavities, dead parts, live parts, and rotted parts, a vertiable condo for critters, chipmunks, squirrels, raccoons, birds, etc. I didn't realize how rotted the tree was until a windstorm knocked it down. The entire tree, whose trunk was just over 4 foot in diameter, broke off cleanly about 4 inches above ground level. Gone went the critter condo, and the critters. Planted a small river birch, with three trunks, in its place.
ReplyDeleteNothing like being 30' up with a chainsaw and having a squirrel run up across and down you to prove it. True story, 14 years ago, Schenectady NY.
ReplyDeleteA colleague here in Texas executed a snake with a chainsaw in a tree.
I've never seen a snake with a chainsaw.
ReplyDeleteIt was probably a Burmese Poulan. Much more common in South Florida
DeleteI've never seen a snake with a chainsaw either, but I saw a crab with a knife. And I've seen a horse fly.
ReplyDeleteDown this way, we have this mountain juniper. It came in after overgrazing. They were supposed to be no drain on water tables, etc. Back in the early 90's a rumor started that the EPA was going to list it as protected due to it being home to some s--tweasel or something. Bulldozers went into overtime, and suddenly, springs that were written about in old documents came back. They were pulling a lot of water out. I don't think the EPA ever did anything, probably was a rumor started by Holt, or an owner needing work!
Without them, the Hill country is nice. Native grassland with oak motts. With them, it's a sneeze fest at certain times of the year. Rough stuff....
Ooops. they didn't exist in any numbers before the late 1800's. Overgrazing gave them a foothold. Now they are ubiquitous. (five dollar word used by a two bit Texian)
DeleteThe Jefferies provide migration paths for all sorts of creatures that would be picked off by predators if they had to cross open ground between tree coppices. Plus nesting, plant variety.
ReplyDeleteThe age of a hedge can be estimated as one century per different woody species in 30 yards.
The dry stone walls in Britain are another wonder.
It takes a few days for a man to build a few yards and we must have thousands of miles of them. With all the gaps between stones they are home refuge and highway for many species.