[Crusty]

Well said Ibon.
+1

[SeaGypsy]

The areas shown in these http://www.google.com.au/search?hl=en&c ... 19&bih=425
were drowned in volcanic ash 20 years ago. The Pinutubo ash cloud created opportunity for nature to flourish in one of the densest populated parts of the planet. New rainforests appearing 100km from a city of 17 million people, in a near to lawless country.

[rockdoc123]

SeaGypsy has a great point. You can't look at the world as one big complex, there are numerous climatic zones that behave differently. I remember a number of years ago trying to plan an exploration well in the outskirts of the Amazon. We found that stripping the vegetation down to the ground over the area we had identified for the well and all the related stuff (flare pits, accommodation, etc) was only good for 3 months...after that you were back clearing the vegetation again.
I was down to see the devastation of Mt St Helens about a week after it happened, amazing. If you went there now you would have a hard time realizing something devastating had gone on.
That being said in areas where there is less rain, almost certainly it will be bad. One only has to learn from history...dirty thirties. All it took was poor agricultural practices coupled with a bit of drought and winds to turn most of central North America into a dust bowl. But low and behold it came back, North America didn't disappear into some sort of Mad Max scenario, it was a very short period in history.
I mentioned it on a post quite awhile ago but I'll repeat it once again. Man is a mere blink of the eye in the history of the world. Our concept of time (tens of years) can't even be recognized in the scale of even the period man and his predecessor have been around. The Earth is amazingly resilient and to think that the fleas (us) who currently are genera domina are going to somehow destroy it is hard to rationalize in the context of what has happened in the past.
Natures power is beyond most peoples contemplation.

[SeaGypsy]

I also find other 'kudzu' type species very interesting.

As it turns out, cats of the common variety are a devastating predator capable of survival in waterless desert, better than any other mammal or marsupial.

Buffel grass is creating grazing lands in previous unpruductive dry lands, simultaneously wiping out native competition with raging extremely hot fires which occur each year.

Cane toads are rapidly devouring thousands of species a year across the entire great savannah of northern Australia.

There are examples locally everywhere of these kinds of introduced species effects, many of which will likely outlive their carrier, us.

[Alan Cain]

Sorry to be so cheery, but the idea that the moment we are gone, everything will go back to pristine paradise is unprovable and lets us all collectively off the hook a bit too easily.

Can you say, "Easter Island?"

[Plantagenet]

We found that stripping the vegetation down to the ground over the area we had identified for the well and all the related stuff (flare pits, accommodation, etc) was only good for 3 months...after that you were back clearing the vegetation again.

Thats interesting but it has absolutely nothing to do with wilderness.

Wilderness is defined as "an unsettled, uncultivated region left in its natural condition."

The fact that kudzu grows over formerly cultivated fields or jungles grow back in areas cleared for oil exploration or egrets live in highway median strips doesn't make those areas "wilderness."

Wilderness, by definition, is land that has NEVER been disturbed and has always been in a natural, pristine state.

There isn't a lot of wilderness left in the world.

We are lucky here in Alaska. The vast majority of Alaska is still wilderness.

[Alan Cain]

We found that stripping the vegetation down to the ground over the area we had identified for the well and all the related stuff (flare pits, accommodation, etc) was only good for 3 months...after that you were back clearing the vegetation again.

Thats interesting but it has absolutely nothing to do with wilderness.

<<SNIP>>

There isn't a lot of wilderness left in the world.

We are lucky here in Alaska. The vast majority of Alaska is still wilderness.

As is most of Canada north of Highway One. Some exceptions but not many - mmmm, beautiful precambrian shield... I know you are defining wilderness as undisturbed, but whenever I hear the word, "wilderness", I think about how many roving feet have covered the planet over the last 50,000 or so years. I frequently find things like arrowheads and shards in places that quite surprise me.

[Ibon]

Wilderness, by definition, is land that has NEVER been disturbed and has always been in a natural, pristine state.

There isn't a lot of wilderness left in the world.

This thread is not about the definition of wilderness, but the question of how fast a state of wilderness will return post crash. As Sea Gypsy pointed out this will vary depending on habitat.

Just as there are fragile environments like Easter Island which may never see the original forests before human impact there will be other environments like in the lowland forests of Mexico where Mayan ruins were discovered underneath pristine old growth forest.

The theme here is resilience. And fortunately these designated wilderness areas around the planet represent the sinks from which
wilderness will return to areas of human impact.

Tropical areas have greater bio diversity and in these very areas the protected areas are smaller and under greater pressure than what you find in Canada or Alaska. In fact at one time in North AMerica east of the Mississippi there was less than 1% of forests remaining. There were very few extinctions considering this vast area; Passenger pigeons, Carolina Parakeets, Ivory billed Woodpeckers, American Chestnut etc.

IF you look at Canada north of Highway 1 there is vast wilderness areas but species diversity is low. In a square mile of boreal forest you may only have a dozen tree species vs the same area in the Amazon yielding 200.

There are many tropical ecologists who have worked decades in the field who would argue that if a crash in inevitable better sooner than later so that the integrity of these remaining sinks remains intact.

Tropical lowland forests of Southeast Asia are the most endangered in having the smallest protected areas and most under threat. Equatorial Africa once the Chinese invest their billions may soon follow. The neotropics are in better shape with significant sinks of preserved habitats in biodiversity hotspots throughout the tropical Americas.

The next couple of decades will be critical as the rate of extinctions will surely rise.

[SeaGypsy]

The most practical definition of wilderness is 'large areas unaccessible by wheeled vehicles/ ordinary transport, uncontrolled by man'.
Given looming curtailment of said transport, many more regions will become just this, the basis of this thread.

[ritter]

I think climate change is the big wild card. If it's gradual, wilderness as we now know it will return in areas, provided there is a reduction in human numbers, which seems inevitable. If it's rapid, wilderness as we now know it won't recover. There will be establishment of biomass, but it will be some hodgepodge of transient and opportunistic colonizer species in new latitudes that will support them as climate bands shift north/south. It may someday become wilderness, but I think it is highly unlikely we would recognize it as an ecological community today.

One thing that is often left out of the human population equation is disease. Without cheap energy, we lose access to cheap food and medicines, both leaving humans in a weaker condition. Disease is soon to follow.

[davep]

One thing that is often left out of the human population equation is disease. Without cheap energy, we lose access to cheap food and medicines, both leaving humans in a weaker condition. Disease is soon to follow.

I'm not so sure. We're not going to unlearn germ theory, so basic hygiene should not change too much. Modern medicine's ability to keep us healthy has ridden on the coat-tails of germ theory to a large extent.

[SeaGypsy]

There will be establishment of biomass, but it will be some hodgepodge of transient and opportunistic colonizer species in new latitudes that will support them as climate bands shift north/south. It may someday become wilderness, but I think it is highly unlikely we would recognize it as an ecological community today.

Who is 'we'?
I and anyone familiar with wilderness, know that only an expert can tell the difference between true virginal ecology (almost non existent) and 100 year old regrowth. Given a seedbank 'lifeboat' amazing recovery can be seen in 20, 40 and 100 year regrowth. Often introduced species begin as a pest, establish a nitrogen and phosphorus base then are gradually outgrown, starved of light and replaced by low light understory natives/ all of which aids native animals recolonization. Little native pests, like ticks for instance, can gradually spread among and wipe out feral cats.

[Newfie]

Diamond talks about how rich cultures can save their own resources and uses Japan as an example. The US is another. The forests in the NorthEast have been reestablishing since the advent of large commercial farming. You can see old stone fences in what, to our eye, looks like a mature forest. For one thing we don't really know what 'wilderness' looks like. Dad took me to Cook State Park near Erie once. That is a small patch that missed the loggers saw. Huge trees here on the East Coast, really changes your sense of scale.

Try driving from NYC to Chicago and realize that every single tree over your entire vista was cut, by hand saw.

Now however the US is loosing its wealth, in the sense of PO. Cheap calories have allowed us to develop the temperate zones where heat is a necessity. And we have a large housing investment that was designed for a time of cheap calories, inefficient at heating. While we CAN build houses that are very efficient we CAN NOT replace our existing housing stock.

As PO gains ground I fear we will see a return to natural wood for heating, which will further pollute the air and destroy the forests and the ground there under. Think Haiti on steroids. The only alternative is if something else thins the population first.

In any case the population will thin drastically. But then will it thin enough to allow Nature to recover? Or will we have enough marginal population to keep the ground stripped? Or, perhaps, we will create a Venus atmosphere where both sides are loosers as Hansen fears.

[Keith_McClary]

Columbus blamed for Little Ice Age

By the end of the 15th century, between 40 million and 80 million people are thought to have been living in the Americas. Many of them burned trees to make room for crops, leaving behind charcoal deposits that have been found in the soils of Mexico, Nicaragua and other countries.

About 500 years ago, this charcoal accumulation plummeted as the people themselves disappeared. Smallpox, diphtheria and other diseases from Europe ultimately wiped out as much as 90 percent of the indigenous population.

Trees returned, reforesting an area at least the size of California, Nevle estimated. This new growth could have soaked up between 2 billion and 17 billion tons of carbon dioxide from the air.

Ice cores from Antarctica contain air bubbles that show a drop in carbon dioxide around this time. These bubbles suggest that levels of the greenhouse gas decreased by 6 to 10 parts per million between 1525 and the early 1600s.

“There’s nothing else happening in the rest of the world at this time, in terms of human land use, that could explain this rapid carbon uptake,” says Jed Kaplan, an earth systems scientist at the Federal Polytechnic School of Lausanne in Switzerland.

[Newfie]

Interesting idea.

It would also go a long way to supporting modern AWG by showing how sensitive our climate is.

[SeaGypsy]

...suggesting a rapid end to AGW is very possible also...

[Margarethe]

In medicine, some of the worst wounds a body can sustain is best healed and cured by leaving it alone. And I mean alone - no chemicals, antibiotics, no pills. You'd be surprised. I know I was. Nature seems to have its own secrets when it comes to restoring balance and equilibrium - in a single organism's body or in the biosphere itself. Reports like these give me hope as well as food for thought.

[dolanbaker]

In medicine, some of the worst wounds a body can sustain is best healed and cured by leaving it alone. And I mean alone - no chemicals, antibiotics, no pills. You'd be surprised. I know I was. Nature seems to have its own secrets when it comes to restoring balance and equilibrium - in a single organism's body or in the biosphere itself. Reports like these give me hope as well as food for thought.

Only true if there is no infection!

[Margarethe]

Not in every case. I'm talking injuries sustained in remote places with no equipment or medicine. Some of these do get infected but wrap them up and leave them alone, and miraculously they heal. Again, I repeat, not in every case.
Anyway it's just a metaphor for what I'm saying. Thanks for that piece of thought anyway. =)

[KingM]

If humans disappeared today, the earth would return to a primeval state within a hundred years. Even large predator species would spread across the land within a few decades. Look at how quickly the wolves spread when reintroduced to Yellowstone. Even large predators like the tiger would quickly establish numbers in the hundreds of thousands or even millions.

Of course, in another twenty years most of these apex predators will be extinct in the wild, as will rhinos and possibly elephants. In another hundred years we'll probably manage to eliminate dozens of large species. Once that happens, there will be no return except on the million-year time frame.

Over the next billion years, until the sun boils off the earth's oceans, we'll see countless rises and collapses of ecosystems. It's a safe bet that we won't be the last intelligent life to evolve on this planet. Some future civilization of highly-evolved wombats will get a lot of enjoyment out of excavating the fossilized remains of human civilization.