Half Earth: Our Planet's Fight for Life by Edward O. Wilson

I give this book 9 out of 10 acorns.

This book should be read and properly digested by everyone who works with living organisms outside a laboratory (and probably most people in one): this especially means those of us working with “novel ecosystems”. If you are hanging out on permies.com, that means you!

I read this book seeking an answer to what might be called the Zone 5 Problem. In Permaculture our habitats are defined, in part, by their distance from the zone of habitation, typically some sort of housing. While these habitats are, in their ideal, managed in part for wildlife, the further one gets from the zone of habitation, the less management is involved and the more wildlife is left to its own devices.

To put it another way, how do we protect the biosphere?

I see this as something intrinsically valuable, and not something that exists to fulfil perceived human (Homo sapiens stultus-materfututor) “needs”. I know it's not a universal viewpoint, even around here, and it doesn't seem to be shared even by the author, but there is a difference between a forest garden and natural forest, just as there is a difference between mob-grazed “improved” grassland and prairie. These need to be kept conceptually separate, lest we lose intrinsically valuable biodiversity. The extent to which they need to be kept physically separate is a more complex question.

This can present problems. Some large herbivores – even some small ones, in sufficient numbers – can devastate a crop. This can mean fencing “them” out, although with a sense of being part of an ecosystem the sense of a “them” and “us” can become increasingly blurred. Equally, these individuals exist for their own reasons, not defined purely in relation to humans.

I'd learned that E. O. Wilson, a biologist I consider only a few steps below Darwin and Wallace, has proposed an answer to the land required for the preservation of biodiversity, and I was keen to read his thoughts on the matter. I like to think I know a bit about ecology. When E. O. Wilson speaks on the subject, I shut up and listen. For good reasons, he's angry. I'm angry too, for much the same reasons.

In doing so, I also found a response to another fraught question: that of the introduction of non-native species.

The first part of this book is given over to a brief but heart-rending overview of the ongoing losses in the Anthropocene extinction, otherwise known as the Sixth Great Extinction, the one we are now entering. Make no mistake: this is an environmental cataclysm, we are responsible, we are making things worse and we are out of non-radical options.

This matters to us because some of the radical options used by the Permaculture movement may do more harm than good.

I'm going to link to this review from another thread on non-native species, because Wilson speaks directly to it. I quote:

“It is contrary to all evidence to suppose, as a few writers have, that in time invasive species will settle down with native species into stable “new ecosystems.”

So, what constitutes an invasive species?

There are authors who have overgeneralised from some island ecosystems (such as Ascension Island), where there is evidence that, in some places where initial diversity is low and there are many niches to fill species will evolve to fit, but this is the exception, not the rule. This is where authors like Fred Pearce (https://permies.com/t/53346/books/Wild-Invasive-Species-Nature-Salvation ) are wrong. This can happen – it can even be encouraged – but it should not be overgeneralised. This may be useful where we take over a habitat degraded by overgrazing or monoculture in terms of creating a productive garden, but it would certainly be inappropriate when converting semi-natural habitat for food production. It is also less likely to support the functional interspecies connections seen between organisms that evolved in that ecoregion.

Wilson explains the Law of Tens. One in ten introduced species will jump the fence and become what I call a garden escape. One in ten of those will become a problem. Wilson compares this to playing Russian roulette. For our purposes, let's say we have a diverse forest garden with anything up to 400 species per hectare. Let's assume half of those are introduced. Those are not good odds for not shooting the local ecosystems somewhere that it will do a great deal of damage.

If we are serious about “planet care” we need to be very serious about making sure this doesn't happen! Each loss is a loss on the tree of life billions of years in the making, yet too many humans treat this the same way they treat kitchen vermin. I came to Permaculture to get away from that!

Wilson is quite clear: invasive species are one of (not the only, but one of) the main drivers of species extinction. It's fair to argue that other factors are involved (habitat destruction, pollution, population growth and hunting being the main ones), and invasive species often get the blame, but it's also fair to observe that invasive species are often the clinching factor. Many may not have occurred without them. Most extinctions are multifactorial, and to point to other causes at the exclusion of invasive species is unreasonable. We are in a good position to do something about some of the other causes by, for example, eating further down the food chain (including not eating bushmeat – i.e. hunting), cutting pollution, using less stuff, and, crucially, using contraception, but that does not excuse us from being very careful about introducing potentially invasive species.

The point is that these factors are synergistic. Each one compounds the effects of the others:

“Clearing a forest for agriculture reduces habitat, diminishes carbon capture, and introduces pollutants that are carried downstream to degrade otherwise pure aquatic habitats en route. With the disappearance of any native predator or herbivore species, the remainder of the ecosystem is altered, sometimes catastrophically. The same is true of the addition of an invasive species.” (my emphasis).

Natural selection is predicated upon an organism's adaptation to its environment. We are the ones responsible for most of the major changes to the environment, and an introduced invasive species is one crucial part of that picture.

The author is deeply critical, and I think rightly so, of those in the “conservation” movement who believe that, since there are no “pristine” “wildernesses” left, we might as well turn the whole lot over to human use, with these spaces carefully managed to meet our needs and our ideals. He calls this “well-intentioned ignorance”. In terms of Permaculture this might well be true of, say, a forest garden. For the rest of the world, Wilson has a better plan.

One mistake, one I'm prone to making, is the “emphasis on ecosystems as the key level of biological organization, to the near exclusion of species and genes.” This may surprise some coming from E. O. Wilson, of all people, but it's fair comment. Part of the problem is that the science of ecology is still, in many ways, in its infancy. Meanwhile, we are trying to mimic ecosystems when we don't even properly understand what an ecosystem is. To some degree, when “rewilding” it may be possible to replace one extinct species with another similar one, but only to some degree. In general, however, treating different species as interchangeable pieces in a jigsaw is scientifically bankrupt (Wilson compares this to phrenology).

Grazing cattle where there were once bison and wolves and calling the result “prairie” is a dangerous fantasy.

When we plant a forest garden we need to be very clear what it is we are mimicking – and what we are not. That's not the question addressed by this book, however. Wilson is more concerned with not causing damage in the first place, and much of part 2 is dedicated to explaining why.

Wilson spends much time discussing what he and his colleagues consider the “best” ecosystems on the planet, and I would treat this as a bucket list had I the resources and was indifferent about the consequences of all that travel. One, in particular, bears quoting at length for our purposes:

"HAWAII. The Hawaiian archipelago, like the equally far-flung Easter, Pitcairn, and Marquesas archipelagoes, deserves mention in part for what it once was. Its tropical climate, relatively large size, and mountainous terrain with multitudinous habitats promoted the genesis of a large diversity of land-dwelling plants and animals. A high percentage of these originated as products of adaptive radiations. Dramatic examples of such species swarms include the honeycreepers among the smaller birds, tree crickets among the insects, and lobelias among the flowering plants. The beautiful assemblage has been largely wiped out or pushed into the remote uplands of the central mountains by agricultural conversion and semiwild gardens of invasive species. Perversely, the latter have become a poster child for the “novel ecosystems” celebrated by Anthropocene supporters." - My emphasis

Rather than picking a species to solve a problem Wilson views it as crucial that we engage in a deeper understanding of what species we are engaging with, what they do, and how they fit into an ecosystem. In fact, the observation and monitoring we are always advised to engage in could be an important part of this ongoing effort. I've reviewed one book on this subject here: https://permies.com/t/55688/books/Studying-Invertebrates-Philip-Wheater-Penny#464356

So, what is Wilson's solution to the unfolding ecological disaster? This can be summed up in one sentence:

The only solution to the “Sixth Extinction” is to increase the area of inviolable natural reserves to half the surface of the Earth or greater. 

Personally, I would go for greater, simply on the basis of fairness: half for us and half for everything else strikes me as human exceptionalism.

He goes on:  

it also requires a fundamental shift in moral reasoning concerning our relation to the living environment.

He begins by spelling out the water crisis. Much of our food is dependent on it, but the drawdown of aquifers and the draining of entire rivers is reaching crisis point (in some places it already has, driving migration, which is in turn seized upon by demagogues for political gain). One quarter of the world's photosynthetic productivity goes to feed one species, leaving the remainder for the millions of others.

The first part of his answer is restoration. Wilson advocates that half the planet (the Half Earth of the title) needs to be returned to the wild, including wildlife corridors at a continental scale. There are wilderness areas remaining in the world, and these need to be protected. Some others can be restored by the reintroduction of keystone species, such as wolves, the removal of some invasive species, or both. This chapter is worth a read on its own, but key to what we need to be thinking about is not making things worse: one of these ways is by being very careful when it comes to introducing species that might be invasive, and the Law of Tens problem above is worth bearing in mind here. We need to be very careful about plants going over the fence, which means we need to avoid having our novel ecosystems too close to wilderness ones (Hawaii being an obvious case in point).

What this also implies is that some areas of relatively low productivity – grazing being low-hanging fruit here – need to be taken out of production and turned back over to wildlife in a massive rewilding effort, and if we are serious about planet care I think this is worth supporting.

Things get messy in the final couple of chapters as the author steps away from his field of expertise. I disagree fundamentally about his support for the free market, which is not free at all and is predicated upon exploitation: this is what got us into this mess in the first place. Comparing economics to ecology is a dangerous fantasy: Wilson knows ecology, but I have to wonder whether he knows economics. I'm far from convinced we're going to see decoupling of the economy from “resource use”. I think we need social changes encouraging us all to make do with less. To be fair, Wilson sees an end to commodification of the biosphere, but I think he's being far too optimistic, about this and other matters. Modern economics is dependent upon the commodification and exploitation of the biosphere. That's not about to change. His is a technophile vision as much as a biophilic one, and the former relies far too much on exploitation of the natural world, and will continue to do so. It's also an anthropocentric vision, and I'm not happy with that, either. I think he's right about the change in moral reasoning, but I think we need a more ecocentric one than he does.

There is another reason this makes me uncomfortable. As other authors have pointed out, much work on habitat restoration has been linked to agrochemical companies selling product to wipe out invasive species. I'm all for the eradication of certain invasive species in certain circumstances, but not at the cost of pollution. To be fair, Wilson mentions pollution elsewhere, but I don't want to be allied to the vested interests that caused many of the problems in the first place. To me the free market and its advocates are the enemy, and I don't want a system beholden to them.

I think he's right to observe, and here he is speaking from expertise, that humans are capable of altruism towards others, even towards other species, but I think it's going to take a massive shift in how we conceptualise our relationships with the rest of Nature, so I don't share his sense of optimism.

What are the lessons for us?

* It's clear to me that, if we accept the principle of novel ecosystems for agricultural purposes, this needs to be kept separate from conservation. They are not the solution: we need the massive spaces for conservation first and foremost: if we are going to accept novel ecosystems for food production, this needs to be separate. There needs to be a clear distinction between novel ecosytems used for food production (probably okay, within the limits outlined here) and novel ecosystems accepted as wildlife habitat (not okay at all). There will be wildlife in the former, and this seems to me to be fine, but habitat restoration is something else entirely: one is not a replacement for the other. If we get it right, we can lower our ecological footprint and yes, this does mean a shift down the food chain. If we get it wrong, we can do more damage, which leads me to:

* We need to be very careful not to allow any invasive species to jump the fence, and this could be very difficult, to the point where I wonder if it's even possible.

* We need to ensure that that space for wildlife is space for wildlife, not space for us to harvest or go hunting.

* We need to ensure that we are not destroying existing rich habitats, as Hawaii once was and to a point still is in order to convert them into what we have to be clear are gardens and farms. Existing natural and semi-natural habitat needs to be left alone, if not actively protected.

* We, as a species, need to be taking up less space. Were humans in the US to raise their meat on pasture, even mob-grazed pasture, they're need to use half the available land area to do it (and, if they want to improve the soil, they need imported inputs). Clearly this is not compatible with space for Nature.

I strongly encourage you to get hold of this book, read it, digest it, and lend it to your friends.

I'm certain you have researched this and feel much more strongly about it than I do, but some of these things to me are outright guesses.

"Wilson explains the Law of Tens. One in ten introduced species will jump the fence and become what I call a garden escape. One in ten of those will become a problem. "

Is there any evidence at all that one in ten introduced species that escape will become a problem? Also, in my mind, no one has clearly defined "introduced species", so any possible number that a person can come up with is worse than a guess. There isn't even a basis to guess from.

Rather than debate every part of the book since I haven't read it and would be taking things out of context, I would like to jump to your lessons.

How can you possibly keep plants from "novel ecosystems" from spreading into wildlife habitats?

I don't believe it is possible to ensure that no "invasive species" can ever "jump the fence". None of us lives in a bubble, and keeping a perfectly clear delineation between the areas we cultivate and wild areas is just not possible.

I fully agree that humans need to be taking up less space on the planet. This can only be done by population control. I'm all for that, but I believe it isn't a viable solution until things get far worse than they are now, simply because you would never get people to agree to it.

"Permaculture" seems to me to be trying to go in the direction of rebuilding areas that have been destroyed, or nearly so, by planting very diversely, minimizing outside inputs into the area, and trying to create an place that is as self-sustaining as possible. If planting food forests, conserving as much water as possible, minimizing or eliminating chemical use, etc., aren't the answer, someone needs to come up with a better one, rather than telling everyone that their best effort is just making everything worse and anything we plant that isn't strictly "native" is going to cause another great extinction.

I think people tend to skip over the part in the Designers Manual where Bill Mollison mentions that if we meet our needs by permaculture and adhere to the third ethic (Mollison's version, which is "Setting limits to population and consumption: By governing our own needs, we can set resources aside to further the above principles [first and second ethics].") most land could be returned to what Mollison calls "wild nature." Instead of most land being for human use, most land would be for the use of non-humans, that is, everyone else.

"Although initially we can see how helping our family and friends assists us in our own survival, we may evolve the mature ethic that sees all humankind as family and all life as allied associations. Thus, we expand people care to species care, for all life has common origins. All are our 'family'."

reference Chapter 1, Permaculture the Designers Manual

I see Mollison's idea of most land being returned to wild nature as not meant to be some land somewhere that somebody is setting aside or preserving, but that all of us with land have the responsibility to set as much of it aside as possible for non-humans. So Zone 5 would be the largest zone, not the smallest, and care of non-domestic non-humans would inform our use of all the other zones.

Todd Parr wrote:
I fully agree that humans need to be taking up less space on the planet. This can only be done by population control. I'm all for that, but I believe it isn't a viable solution until things get far worse than they are now, simply because you would never get people to agree to it.

You mean you would never get men to agree to it. The most effective method of population control is full human rights for women including the right to her own body and reproduction. http://www.populationconnection.org/resources/health-human-rights/

Tyler Ludens wrote:

You mean you would never get men to agree to it. The most effective method of population control is full human rights for women including the right to her own body and reproduction. http://www.populationconnection.org/resources/health-human-rights/

I haven't looked into the issue, but I know one man that you can certainly get to agree to it.

Todd Parr wrote:I'm certain you have researched this and feel much more strongly about it than I do, but some of these things to me are outright guesses.

"Wilson explains the Law of Tens. One in ten introduced species will jump the fence and become what I call a garden escape. One in ten of those will become a problem. "

Is there any evidence at all that one in ten introduced species that escape will become a problem? Also, in my mind, no one has clearly defined "introduced species", so any possible number that a person can come up with is worse than a guess. There isn't even a basis to guess from.

See, for example, here for a discussion, with more references for you to follow up: http://www.reabic.net/publ/Williamson_Fitter_1996.pdf

Todd Parr wrote:

How can you possibly keep plants from "novel ecosystems" from spreading into wildlife habitats?

I don't believe it is possible to ensure that no "invasive species" can ever "jump the fence". None of us lives in a bubble, and keeping a perfectly clear delineation between the areas we cultivate and wild areas is just not possible.

You can't, which comes back to sensible locations and good management. I was talking to someone earlier, who describes:

So much of the surrounding land is already down to eucalyptus, and it's hard to imagine much being worse than that stuff. ... The bits that are screaming out for modifying are bits that are smothered in cistus, growing around the edges, preparing the land for tree cover. ... There is loads of acacia growing wild here, which I think was introduced for land restoration purposes. ... But it's illegal to plant it, so I don't know how you balance all that up. It also shoots up from the roots in great thickets if you try to cut it down.

In other words, not Hawaii.

Todd Parr wrote:
I fully agree that humans need to be taking up less space on the planet. This can only be done by population control. I'm all for that, but I believe it isn't a viable solution until things get far worse than they are now, simply because you would never get people to agree to it.

I think he dodges this one. He acknowledges that we're heading for ten billion, and parts of his solution strike me as unworkable. That's not to say it wouldn't work overall, but I think it needs some modification.

Todd Parr wrote:
"Permaculture" seems to me to be trying to go in the direction of rebuilding areas that have been destroyed, or nearly so, by planting very diversely, minimizing outside inputs into the area, and trying to create an place that is as self-sustaining as possible. If planting food forests, conserving as much water as possible, minimizing or eliminating chemical use, etc., aren't the answer, someone needs to come up with a better one, rather than telling everyone that their best effort is just making everything worse and anything we plant that isn't strictly "native" is going to cause another great extinction.

Which is precisely why I'm advocating a more measured response: not to outlaw novel ecosystems as gardens, but be very careful where we put them and what we put in them.

Todd Parr wrote:

Tyler Ludens wrote:

You mean you would never get men to agree to it. The most effective method of population control is full human rights for women including the right to her own body and reproduction. http://www.populationconnection.org/resources/health-human-rights/

I haven't looked into the issue, but I know one man that you can certainly get to agree to it.

Two, but Tyler's point is well made. A lot of women are crying out for decent family planning, and it's being actively blocked by rather too many men. It would be dirt cheap by international aid standards, but it's being blocked by the Christian patriarchy. The whole thing stinks.

I'm not totally convinced by the agrument about one in ten mainly because in the UK the number of new species imported to fill the gardens of Britain over the past one hundered and fifty years must run into thousands yet invasives causing problems not sure how many . Do all invasives cause problems ? ( penny wort , knot weed , balsam , rhodadenrum ) ( I'm just talking plants animals for me are a different discussion )
Some invasives came hitching a ride and the only way to stop them would be to outlaw travel
As for turning over 50% of the world to nature this to me harks to the idea that nature is static - try telling that to the dinosaurs - that we know what a prestine wilderness un touched by man looks like - we dont - that the things we do dont have effects at a distance -they do and the real biggy what are we going to do with the folks who live there at the moment ?
I think the role of mankind in the bioshere need to be debated . Are we pointed haired boss of the planet (https://en.wikipedia.org/wiki/Pointy-haired_Boss ) ? Some days it feels like that .......

David Livingston wrote:
As for turning over 50% of the world to nature this to me harks to the idea that nature is static

I'm not seeing why letting non-humans have 50% of the world has to do with the idea that nature is static. Can you explain how leaving nature to its own devices is "static"?

well, late again to the conversation.....

diversity, ecology, natives, invasives, .... versus evolution



Forests in the olden days

which is "better"?

abandoning "worn out" fields to nature
or improving them with missing nutrients and species first

abandoned farmland won't return to prairie
without the required animal components
so should we continue commercial industrial agriculture on this land
because without grazing the land will degrade
and cattle will only create cattle prairie
rather than the "original" bison prairies?
(which were probably only several hundred years old)

or we could go back to the mammoth prairies
that existed before those invasive humans
crossed over from Asia

nature isn't a preset grouping of plants and animals

nature doesn't care if the grouping of organisms
occurs by accident, storms, disasters, or humans

dinosaurs disrupted nature and directed evolution
for a long time

evolution is the increased efficiency of the energy flow
through a given set of organisms

Okay, let me simplify this.

Organisms live in communities. They are often co-adapted to live in these communities (natural selection is driven by the organism's adaptation to its environment, not some "survival of the fittest" bollocks invented by an economist to justify his discredited ideas).

You cannot just switch out one species for another species without consequences for the rest of the community.

Now, I'm no "nativist" (I can't even sensibly define the word "native"), and I flat out oppose any alliance with agrochemical corporations, and there are plenty of species that can enter a community and develop relationships with the species already living in it. There are others that will simply die out as a result of not being able to develop those relationships. There are a few - and this is only predictable to a point and depends on many factors, mostly having to do with the existing community - that take over, become a monoculture and cause extinctions. This is why, the further from its evolved ecological area a species originated in the greater the likelihood of it tending to monoculture - which is effectively moonscaping from an environmental perspective in any case.

To suggest that these are going to settle down and develop some fluffy bunny new ecosystem without wrecking the diversity of the community is contrary to all experience. I know that there are people out there who believe in this "balance of Nature" stuff (although part of the definition of "ecosystem" involves the word "dynamic"), but if you push that balance far enough, you get a tipping point, and tipping points are where you get widespread extinctions.

We are now entering what looks like the Sixth Great Extinction on this planet, and humans are responsible. Personally, I find this very frightening, and think that we as individuals and as a species need to be taking responsibility for that as a matter of extreme urgency.

Duane,

By introducing invasive species, we can very quickly drive a lot of species to extinction and reduce the diversity (and therefore resilience) of ecosystems, just as all ecosystems on the planet are under increasing stress from other factors (especially climate change). For macroscopic life forms, evolution is too slow to catch up to this kind of damage. Suggesting that evolution will sort it all out doesn't seem to fit the evidence. Wilson's argument that we try to set aside much more land (and sea, hopefully) that we try not to mess with too much makes sense to me.

EDIT: posted simultaneously with Neil's post, which is much more eloquent.

Also, anyone who thinks that introducing invasive species is a good idea is welcome to come pull goutweed and porcelainberry on my property.

Neil Layton wrote:

We are now entering what looks like the Sixth Great Extinction on this planet, and humans are responsible. I'm horrified to discover people here who are not only indifferent but seem to want to make the problem worse.

I don't think you are giving the people here enough credit if you think anyone "wants to make the problem worse". The very nature of this forum assures me that the people here are far from even being indifferent. My own thoughts are that the plants I use on my land, including things like Autumn Olive that are classified as invasive, are not causing the problem, are not adding to it, and in some ways may be helping stop the problem. I think most of our end goals are very similar, and as strongly as you feel that you and a handful of others have the correct answer, not everyone agrees, as evidenced by much writing by "experts" on either side of the issue that can't come to an agreement.

Steven Kovacs wrote:Suggesting that evolution will sort it all out doesn't seem to fit the evidence.

Evolution has done a pretty good job of supporting life for millions, if not billions, of years on this planet. I believe it will continue to do so, long after humans are gone.

Todd Parr wrote:

Steven Kovacs wrote:Suggesting that evolution will sort it all out doesn't seem to fit the evidence.

Evolution has done a pretty good job of supporting life for millions, if not billions, of years on this planet. I believe it will continue to do so, long after humans are gone.

On shorter timeframes than "long after humans are gone," the fact that extinctions are vastly outpacing speciation is a serious problem. I don't know about you, but I care quite a bit about the next few decades and centuries.

This will be my last post on this subject, largely because it's beginning to make me angry and I don't like that. People in this thread and others insinuating that there are people on here that don't care about the planet or the species on it is simply ridiculous at face value. How many people come to a permaculture forum because they don't care about these things? It may just be possible that some of us don't agree that planting something that is "invasive" or not "native" is going to bring the world crashing down around our ears. Man is no doubt causing extinctions, but telling people that the answer is to never plant anything that isn't "native" is nonsense.

Neil Layton wrote:Organisms live in communities. They are often co-adapted to live in these communities (natural selection is driven by the organism's adaptation to its environment, not some "survival of the fittest"

It seems to me, like "Adaptation" and "Survival of the fittest" are exact synonyms... The plants that are most adapted to my farm are the ones that survive best and are most likely to produce seeds. And those seeds are more likely to be well adapted to my farm.

Neil Layton wrote:You cannot just switch out one species for another species without consequences for the rest of the community.

I don't have any reason to believe that there are either good consequences or bad consequences. I'm certainly not smart enough to be able to do that sort of evaluation. I believe that no human, and no civilization is capable of making those types of determinations. We can observe that changes may occur in species distribution, but we have no way of evaluating whether those changes are good or bad. I'm certainly not willing to live my life in fear: What if some plant is introduced, and it destroys all life on Earth? I know that it's a silly example, but that's so often how the rhetoric comes across. Destroying an ecosystem? I can't envision any way in which it is possible for that to happen. The bulldozers, fires, and poisons do more damage to an ecosystem than any plant, animal, or insect ever could. And yet, even then, the ecosystem just keeps plugging along, managing as best as possible.

Neil Layton wrote:there are plenty of species that can enter a community and develop relationships with the species already living in it.

As far as I can observe with my own eyes, there is no species that ever enters an ecosystem without developing many relationships with many other species... At the least, every species of plant and animal eats something from the environment, and it dies and returns nutrients to the environment.

Neil Layton wrote:There are a few - and this is only predictable to a point and depends on many factors, mostly having to do with the existing community - that take over, become a monoculture and cause extinctions.

I have never observed a monoculture anywhere on Earth, even in the most herbicide-poisoned and cultivated fields. Even in the most carefully selected Internet photo. And especially not in the wildlands. When I see a species that is growing very well someplace, it is only growing in a niche micro-environment. There are plenty of other micro-environments in close proximity where it is not growing. I have no reason to believe that in continental settings that any species of introduced plant has ever caused the extinction of any species.

Neil Layton wrote:This is why, the further from its evolved ecological area a species originated in the greater the likelihood of it tending to monoculture

With my own eyes, I observe just the opposite... Corn from Oaxaca won't grow in my garden. No tropical plants grow on my farm. No water-loving plants grow on my farm. If I want a foreign wildflower to grow in the wildlands of my farm, It pretty much has to have originated from someplace like the badlands of continental Asia. And when it gets here, it is competing with all the plants that are already here that thrive in a similar ecological area.

Neil Layton wrote:To suggest that these are going to settle down and develop some fluffy bunny new ecosystem without wrecking the diversity of the community is contrary to all experience.

When I go into the wildlands around here, and count species, the diversity is much higher when the non-historical species are counted. I observe the non-historical species providing tremendous ecosystem services. When I counted species in a Willow/Tamarisk setting, the tamarisk (non-historical) was supporting 8 times more species of birds, and 2 to 5 times more forbs, grasses, insects, and etc... With both willows and tamarisk in the ecosystem, the diversity was even better.

I think that people tend to believe that nearly all of the species they see in the wildlands are historical species. I bet that if a careful accounting were done, that less than half of the species around here were growing in this area in 1492. And none of the species currently living on my farm were here 15,000 years ago.

Neil Layton wrote:I know that there are people out there who believe in this "balance of Nature" stuff (although part of the definition of "ecosystem" involves the word "dynamic"), but if you push that balance far enough, you get a tipping point, and tipping points are where you get widespread extinctions.

I don't have any reason to believe that widespread extinctions are occurring. One or two per year is something to yawn about when there might be something like 100 million species on Earth. And even if they are, I believe that the best way to combat extinctions is to spread as many genes around from as many species as possible into as many novel environments as possible. That will foster the ex-situ preservation of species, and will offer the long-term opportunity for the creation of many more species as they adapt to their new ecosystems and co-habitants. I am working on my farm towards creating a few new species. It's slow going, but it's certainly within the capability of amateur plant breeders using low tech methods. I'm already smiling at the thought: Helianthus lofthousii.

Steven Kovacs wrote:the fact that extinctions are vastly outpacing speciation is a serious problem. .

We don't even know how many species exist. I think that we don't have the data necessary to determine how many species are becoming extinct. We certainly don't have the data to speculate about how many species are being generated... And in any case, it seems to me like the best way to generate new species is to move old species into new environments.

are we trying to flow with evolution or to prevent it?
are we hung up with angst over human actions ?
ecosystems are made up of both plants and animals
the more diverse both are, the further the ecosystem can evolve
restricting inputs into an ecosystem restricts the options evolution has
saying "no humans allowed" to an ecosystem
limits its potential

and yes, common sense and restraint should apply

trying to "hold" an ecosystem in time
thinking it is the best that it can get
is like holding water in you hands
it will slip away without progressing

I live near a state park here in Pa
the State has a policy of "returning to nature"
the park was created from old worn-out farmland
the existing forested land is slowly dying
as the trees die and none are planted
great habitat for woodpeckers
the fields are full of russian olive and multiflora rose
deer eat every shoot that tries to sprout
in a few hundred years a new forest should evolve
this could be shortened by giving nature and evolution
more elements (plants and animals) to work with in a
degraded ecosystem

evolution has only the goal of improving the flow of energy through an ecosystem
and is not concerned about the name of the components, just the number and variety of them
All organisms, however cute and fluffy, are just temporary assemblages that only last
until the next "New!, Improve!" version comes along

99%+ of all species that ever lived are extinct
the "Antropocene" is just a politically correct guilt trip
there was no "forest primeval"
Nature and Evolution have no "preferred" model
They are blind and preference is in the eye of the beholder

"those damn eucaryotes have ruined it for us procaryotes"

Tyler
I find the idea that we can leave half the world alone impractical and neive . It is not static and for better or worse we are part of the system -we are the pointy haired bosses of the ecosystem ,there is no ecosystem we are not part of in some way - we even effect the Antartic . People who think if we abandon the ec osystem to its own devices have in my experiance the idea it will revert to pristine wilderness - what ever that is/was . This I believe will not happen - things will change , change is a constant I make no value judgement like evolution their is not good or bad .
For myself Permaculture or something dervived from it offers hope that we stop being pointy haired bosses and learn to manage out world for all life.

David

I'm not talking about "abandonment." I'm talking about not appropriating most of the land to human purposes. Please read what Bill Mollison has to say about this in the Designers Manual.

Human purposes - I don't see any none human purposes ? Do we leave spaces for Bears for instance and not for gluttons ?I see everything we do as a human purpose it might not be food production but it's at our whim .For me it's all a matter of degree. We either manage or neglect .

David

Primarily for use by non-humans. Zone 5 as per Mollison. Many animals evolved before humans appeared, and some of them don't like to be around humans (the big cats, other large primates). The presence of these large non-humans often indicates a healthy ecosystem, and their removal often causes a cascade of failure within an ecosystem. I think one indication of permaculture success will be the return of apex predators and other large non-humans to regions where they have been mostly eliminated. This will prove the ecosystem is sufficiently healthy to support the large animals and all the other smaller animals, as well as plants, etc, associated with them.

I suspect all animals apart from "pets " and I am not even sure about all of them ( domestic cats )dont like being around humans :
The point I am trying to make is that even in this area humans will have some imput. It will be managed therefore subject to human intervention based on human value judgements . Its not that I think this a bad idea but I feel we need to recognise our role. We are the point haired managers and I feel we need to recognise this if we are to become better at it . Including agreeing what " better" and "it" actually are . For instance do I manage where I live to be a haven for Wild Boar ? knowing that there is only one preditor for them in this area ? however wild boar are in no danger of extinction or do I cut the grass in sutch a way to encourage hares which I think are not so common and much cuter ? Or I could neglect the park and soon most of it would be an overgrown jungle of bamboo , bramble, cherry Laurel, Laurel and larch . Three of these providing little in the way of food for local wild life . I dont think I know if there is an answer or even if I am asking the "right " questions .

Hi all. I think it's an interesting idea (half earth) and it's something i've contemplated at times. While i'm not against it, i do think its impractical in a world full of needy people. And unfortunately i think Wilson is right about the rule of tens. My way of thinking about the problem of ecological destruction is that its kind of like pandora's box moxed with midas' touch. Once you start trying to control the world you can't go back to how it was before. Also, attempts to control the world are inevitably bumbling and unpredictable. And inevitably destructive, at least to some extent. Destructive of the old, certainly. Constructive of something new that is perhaps also something good.

Preservation of wildlands is important. So is creation of forest gardens and other anthropocentric habitat. We can't go back. With luck we can go forward and it won't suck so much as it has been sucking.

Edit-- after looking at this thread i'm a bit concerned by what appears to be a lot of ignorance about evolution and biodiversity as well as misunderstanding what eo wilson is saying. Human created forest gardens are very different from efforts to restore a wildland to a more natural state. Further, natural processes in and of themselves have their own logic and their own timetable. So human meddling is inevitably at best a poor substitute for the hand of mother nature-- at least in an ideal sense. Simply because we don't actually understand ecosystems with any depth. So trying to manage them is inevitably fraught with peril of messing them up by accident. I just think wilson is fretting about this a bit too much, and letting it get in the way of trying to make things better, even if imperfectly so.

How has everyone overlooked the appropriation of half the earth???

Like literally how did you all get so distracted that you didn't stop to ask. "Who will be making sure that half of the earth is not used by people?"..."Who will be enforcing this plan?"

Because to me this seems more like a half-baked "Half Earth" idea.

I appreciate the conversations above, good points were made, but it frustrates me a little not to hear anyone clearly espouse the pattern of individuals (re)connecting more deeply with nature(with their ecosystems).
Which stands in stark contrast to government protecting nature from people(or massive movements to "protect" nature).

This is the overarching pattern to think on and choose a path from. Either individuals are the solution(and power/freedom belongs with the people), or "government" is the solution(and those individuals should be empowered to control even more).
Take your stance and then don't get lost in details(like how we are gonna transition, or who will stop the Kudzu, or what will keep people from letting their African Clawed Frog go in the sewer...)

Either you think that a group of people controlling other people is most natural(is best for nature), or you think that individuals controlling themselves is most natural(is best for nature).

Either you think that a small group holding power over a massive amount of the Earth is best for living things, or you think that individuals connected to and interacting with their local ecosystem is best for living things.

Lastly, I find a lot of value in the questions,

"Should I be 'in charge' of the movement of organisms in nature?"

"Should anyone be 'in charge' of nature"?

The idea of something, be it market or government, making sure that nobody uses half the (land?) surface of the earth is rather scary to me. However, I have not read the book! And I am certainly not going to criticize I book I haven't read! But that is soon to change; I'm ordering the book now. Thanks everyone for the discussion!

Sorry. I became very, very angry about what still seems to me to be indifference towards extinction in this thread.

This is one of the few things guaranteed to really piss me off.

The figure being thrown around of one to two species a year being driven to extinction is simply not accurate. That's the general background rate of extinction. The current rate is estimated to be at least a thousand times that: http://www.biologicaldiversity.org/programs/biodiversity/elements_of_biodiversity/extinction_crisis/

In some cases an introduced species can actually add to the number of species locally. In other cases it's a matter of moving one that can't persist in its original habitat due to climate disruption and that can't move because of habitat destruction, also usually caused by humans.

In a minority of cases, but a big enough minority to cause concern, it may be responsible, usually jointly in the case of plants, for driving other species to the edge. The introduced species is still, in all but a few cases, doing fine in its original habitat. Those that used to live in its new habitat are gone for ever. Hawaii is a terrible case in point. The actual number of species has increased, but most of them live elsewhere. They have replaced species that are extinct, and people creating "novel ecosystems" (like us) are partly - not wholly, but partly - responsible for those extinctions, and Wilson (as one of the world's top biologists) is clear about this.

That doesn't just make me sad. It's right to mourn them. It makes me angry, because members of what are apparently my species are responsible. It makes me ashamed, too.

"..we also need a nature-centred ethic for wilderness conservation. We cannot, however, do much for nature if we do not govern our greed, and if we do not supply our needs from our existing settlements. If we can achieve this aim, we can withdraw from much of the agricultural landscape, and allow natural systems to flourish...Our own survival demands that we preserve all existing species, and allow them a place to live." Bill Mollison

"As will be clear in other chapters of this book, the end result of the adoption of permaculture strategies in any country or region will be to dramatically reduce the area of the agricultural environment needed by the households and settlements of people, and to release much of the landscape for the sole use of wildlife and for re-occupation by endemic flora. Respect for all life forms is a basic, and in fact essential, ethic for all people." Bill Mollison, Chapter 1, Permaculture A Designers Manual

here are some possible zone 5 sites we can leave to Nature

http://managingwholes.com/photos/erosion/pictures/slide01.htm

without our input to improve them, what good are they?

wouldn't it make more sense to fix them before giving them back?

http://managingwholes.com/photos/erosion/pictures2/slide01.htm

I've got the book, and am most of the way through it. I will have more to say shortly, but one thing I want to point out now; the rule of tens on invasive plants. He says that out of every ten plants introduced to an area, 1 in 10 will escape to the wild, and 1 in 10 of those will become a "pest." No doubt. But what does "pest" mean? I'm not sure that solely means driving other plants to extinction. There are 41 plants on the legally noxious plant list in Colorado. 2 of these are native to Colorado, so we will leave those out. So, 39 plants. Some of these will probably not take over an intact Colorado ecosystem. For instance, tansy is on the list. From studying the literature, it seems to favor degraded and overgrazed areas; it is attractive and palatable to animals; it is an herbaceous, non-vining perennial. It may be on the list because it can taint cow's milk, as can various native plants. Chicory is on the list; again, a plant that favors open ground near human habitation, edible. Burdock is on the list, another classic plant of waste areas and human cultivation; so are many thistles. How many of these 39 plants actually can drive another species extinct without previous clearing, tilling, etc.? Russian olive, maybe, salt-cedar maybe. Let's just say 20 of them. In that case, have only 2000 plants be introduced to Colorado? I wonder.

I think in most cases invasive plants are a symptom, not a cause. This does not directly refer to the main premise of Wilson's book, but he does spend a lot of time and rhetoric on invasive plants. We shouldn't forget that certain entities have vested interests in controlling the genetic resources of the world, and the application of herbicides.

I think part of the problem is that people tend to look at it in a reductionist sense.

This is related to the problem that there is no clear definition of "invasive".

You have those species that reach plague proportions and/or at least tend to monoculture (think rabbits, gorse, kudzu and so on).

Then you have those that become a problem in concert with others, and push out not just individual species but those that depend on them.

Tansy, burdock, thistles, broom and so on may not be a problem on their own (and all of them are functional parts of a semi-natural ecosystem here), but together with those other 39 species in Colorado the picture becomes more complicated. That seems to be what's happened on Hawaii.

There are vested interests involved, and I marked the book down for the last few pages because of Wilson's implicit support for the system they depend on and which I regard as part of the problem, but that doesn't mean there's not an issue.

More from Bill Mollison:

“In a world where we are losing forests, species, and whole ecosystems, there are three concurrent and parallel responses to the environment:

1.Care for surviving natural assemblies, to leave wilderness to heal itself.
2. Rehabilitate degraded or eroded land using complex pioneer species and long term plant assemblies (trees, shrubs, ground covers)
3. Create our own complex living environment with as many species as we can save, or have need for, from where ever on earth they come."

"It is my belief that we have two responsibilities to pursue.

Primarily, it is to get our house and garden, our place of living, in order so that it supports us.

Secondarily, it is to limit our population on earth, or we ourselves become the final plague.

We create our own life conditions, now and for the future.

In permaculture, this means that all of us have some part in identifying, supporting, recommending, investing in, or creating wilderness habitats and species refuges. The practical way to proceed (outside of the home garden) is to form or subscribe to institutes or organisations whose aims under their legal charter are to carry out conservation activities. While the costs are low, in sum total the effects are profound. Even the smallest garden can reserve off a few square meters of insect, lizard, frog, or butterfly habitat, while large gardens and farms can fence off forest and wetland areas of critical value to local species. Such areas should only be for the conservation of local species."

Indeed, Tyler.

I mean, I think it's perfectly legitimate to disagree with Mollison (the are issues over which I disagree with Mollison) and I think it's perfectly legitimate to innovate (it's not a religion), but if you are going to disagree with Mollison I think it's incumbent on you to say why, and demonstrate that your practice conforms to at least the spirit of permaculture's underlying principles, or it isn't permaculture, but something else (which is also fair enough, but you have to ask whether it belongs here).

If your practices degrades existing natural or semi-natural ecosystems, or are liable to contribute to extinctions, then it seems to me that it's clearly counter to the underlying principles of permaculture.

In this sense Mollison seems to be consistent with Wilson, at least up until the last bit of the book, where Wilson is speaking from outside his realm of expertise anyway.