Although Eucalyptus (and Monterey Cypress) are not native to this area, they serve as a windbreak and when mature, allow a variety of species to live in their understory (including oaks and toyons).

If anything, the forest might need a little thinning, but not clear cutting.

Hi Charlie,

Thanks again for the thorough response. It is much appreciated!

My question: what is “damage”? Give me a description that only is confined to invasive species, and why this IS damage, (and a scientific truth rather than a personal view).

You said: Can you provide cites? Some of these go directly against what I have observed!

Of course! In these papers or articles about papers you’ll find many, many of the assumptions and sometimes dismay of ecologists reading the new research.
They cannot cope with the thought that nonnative ecosystems are functioning very well, from an ecological point of view.

1) First, very on topic. Research from 2002 on species diversity in Euc forests in California. It says species richness is comparable at least with native forests [Webmaster: The provided link did not work, but the one substituted should be okay. This is Dov Sax's research in Berkeley, presumably.]

2) Conservation Magazine, “The New Normal”: http://www.conservationmagazine.org/2010/06/the-new-normal/
and from Nature News: http://www.nature.com/news/2009/090722/full/460450a.html

These links are essentially the same. They describe findings in Hawaii and Puerto Rico.

3) Glasgow Natural History: – http://www.glasgownaturalhistory.org.uk/abstracts.html
Somewhere in the middle of this, you’ll find that [non-native] Sitka spruce forests in Scotland, as it matures, provides more and more habitat for native wildlife…Also read that only 1-2% of SEMI natural
woodland has been preserved…So what is the problem here (again)? Not the neophytes.

4) From Reason.com, an article making the case that introduced species increase net biodiversity, even when they lead to some local extinctions.
– http://reason.com/archives/2010/08/10/invasion-of-the-invasive-speci
This is a compilation of short interviews with Dov Sax and Mark King.

5) – http://www.springerlink.com/content/4ku835810464h57g/
Not that spectacular but again it notes that nonnative Pine forests in Patagonia provide valuable habitat for native birdspecies

There are others, but this is enough for now.

Charles said: “By a ‘nonnative ecosystem’ is – do you mean an ecosystem dominated by one plant? Or do you mean an ecosystem that contains at least one non-native plants? (that includes almost every ecosystem!) Are you sure that non-native ecosystems (whatever they are) facilitate more diversity?”

Let’s call them novel ecosystems, as there are no ecosystems that solely consist of neophytes either. Indeed these are in general more species rich. There is ample evidence of that readily found on the internet.

Charlie said: “What if more diverse ecosystems are more likely to be invaded? Lastly, you say that no species invasion has ‘ever’ lead to an extinction, which you have not backed up with any science.”

I don’t believe I said that. I have stated that New Zealand lost 4 species of plants out of 2,069 and got 2,065 naturalised species in return, thus doubling the biodiversity.

It was meant in this discussion so let me clarify: no plants have outcompeted others to extinction on any continent. [Extinctions caused by invasive species are] still very rare, as can be seen in New Zealand on Island like habitats (which includes large inland lakes). Most extinctions by invasives are caused by predators or pathogens in those habitats. They still are exceptional, and pale in comparison to the current overall extinction rate. As we were constantly talking about plants in either the US or Europe, that’s what I referred to.

Charlie: “It seems patently false but even if it can’t be disproven, there is no way you can prove anything like that. Major extinction events occurred when vast numbers of new species were introduced, in South America by the connection of South America with North America; and Australia by human intervention.”

[Surely, the onus of proof is on the other side?] The assumption is that competition leads to extinctions and that this is a big cause of global extinctions. The ones that assert that need to prove it. Not vice versa. The extinctions that HAVE happened have been researched, and competition in general does not lead to extinctions. Not on continents, anyway.

According to the research I know of, by James Brown, the fossil record does not support large mass extinctions through land-bridges either. Humans are exceptions on the rule of course, we know that. But scientists are excluding humans from the equation when talking about invasive species…. We have caused many extinctions. But this is about nonnative species.

http://www.nytimes.com/2008/09/09/science/09inva.html?pagewanted=2 It notes that there is a net increase in biodiversity after historical invasions, not a decrease. It is not there in the historical record.

Whether extirpation constitutes a gross loss depends. If the indigenous Lyme disease causing bacteria (Borrelia I believe) is wiped out by one that does not cause any disease, how is this a loss? Or the malaria in the third world? Less extreme: if I do not like the local weed, how is this a loss for me? I don’t like it and it is gone: to me we have gained a nicer ecosystems without the troublesome weed…You seem to imply that every native species is of value to the ecosystem. I can mention a few that add virtually nothing over here. Like English Holly or the Yew. If a newcomer provides more services to the ecosystem but is also the most abundant, does this constitute a valuable addition or is it still an invasive weed? Who can determine that? It is all based on what we see as value or not. It is again subjective.

Gov: “Apparently this is also true for Euc forests in California, not just the one on Mount Sutro.”

Charlie: “Have you ever been to a Euc forest in California? Have you ever BEEN to California? It seems like you are taking what you know about the ecology of Europe and applying it to California which may be why it isn’t accurate.”

We have been over this one. I read papers on the topic. I need not be there.

Charlie: “You bring up some valid points about problems with the current scientific/peer review system. I don’t disagree with those points at all. The thing is though that my personal observations strongly back up what the scientists here are saying about invasive plants, in most cases. All science has the potential for bias but what you are saying is that science you disagree with is biased but science you agree with is not.”

No, what I am saying is that there are no scientific works that have examined all the extinctions, but one. And that one was done by Dov Sax. It is clear and contradicts what ecologists have said (and still say over and over again). Meanwhile, [that study] is undisputed while it itself disputes the many assumptions about invasive species and extinctions.

Apart from that, I have read those invasion ecology books. They themselves, without reference to the Sax paper/s, say invasive plants haven’t caused any extinctions, nor are they expected to (for instance in germany)…

I have also read biased, value-laden words so many times — that is clearly not the way to get a student doing impartial research on neophytes and other immigrant species. It is quite obvious one leads to another…

I do not want to get into a personal argument, so let’s not go there. Let’s stick to the points we raise instead.

On climate change and translocation of species: there are many feedback effects, but there is no doubt that in many temperate zones on continents the 7 km/ year drift northwards of the isotherms is already real. No reason to think it will slow. The implication will be that a number of species (trees) cannot keep up. We can see that from the recolonisation of trees after the ice age. They travel at about 1/10 of that speed at most.

I am not against nonnative species at all, so I am not against translocation. However: if you consider introductions harmful, and yet consider global biodiversity extremely important — you will have a problem with climate change. [Because the trees that "belong" will no longer survive, and yet you cannot introduce species that *will* survive.]

You said “On to invasiveness. If I read what you say, I get the feeling you base your discussion on a lot of theory on imigrant species, neophytes in this case. ”

No, that is not what i am saying. I am saying that INVASIVE species cause damage to ecosystems, regardless to where they come from or why they are invasive. I do NOT dislike species because of where they are from, or advocate removal of species due to xenophobia. I ONLY advocate the management and removal of INVASIVE species.

“- The most biodiverse indigenous systems in general carry the most neophytes, which totally goes against the theory that niches are occupied. This does not seem to be the case at all.
- Nonnative ecosystems all over the world (US, UK, NL, SPain+Portugal, South Africa, Hawaii and Puerto Rico to name a few) are as biodiverse and in some case MORE biodiverse than the local native ecosystems.
- 50% of all species around us are not locally-evolved, but invasions
- Large invasions in the past have never led to mass extinctions”

Can you provide cites? Some of these go directly against what I have observed!

By a ‘nonnative ecosystem’ is – do you mean an ecosystem dominated by one plant? Or do you mean an ecosystem that contains at least one non-native plants? (that includes almost every ecosystem!) Are you sure that non-native ecosystems (whatever they are) facilitate more diversity? What if more diverse ecosystems are more likely to be invaded? Correlation does not imply causation. There is a difference between a species expanding in range, and an invasive species.

Lastly, you say that no species invasion has ‘ever’ lead to an extinction, which you have not backed up with any science. It seems patently false but even if it can’t be disproven, there is no way you can prove anything like that. Major extinction events occurred when vast numbers of new species were introduced, in South America by the connection of South America with North America; and Australia by human intervention. North America itself had mass extinctions when the land bridge connected it with Asia, though it may be due to humans. Finally, even if a species is not completely extinct, if an important species becomes rare, it still is a great loss to the ecosystem in general.

“Apparently this is also true for Euc forests in California, not just the one on Mount Sutro.”

Have you ever been to a Euc forest in California? Have you ever BEEN to California? I freely admit that I’ve never been to mainland Europe and don’t know much about the ecology there. It seems like you are taking what you know about the ecology of Europe and applying it to California which may be why it isn’t accurate.

You bring up some valid points about problems with the current scientific/peer review system. I don’t disagree with those points at all. The thing is though that my personal observations strongly back up what the scientists here are saying about invasive plants, in most cases. All science has the potential for bias but what you are saying is that science you disagree with is biased but science you agree with is not.

“In one case a researcher who again found the same conclusions (i.e., the introduced species of birds had no negative effects at all) was approached aggressively.”

Obviously this is unprofessional and totally uncalled for and that ecologist should not have acted that way! But, you seem to be assuming that every ecologist will act the same way. Please give me the benefit of the doubt rather than assuming I am a xenophobic racist in the guise of a biologist who secretly wants to commit ethnic cleansing on plants.

“I think the problem is that people who are interested in nature venture into it, see things and are told some things about them. Like in NL where little kids are brought with parents to rip out ["weeds"?] first because they do not belong here. They study things; some become ecologists/ biologists and read these value-laden, indoctrinating wording in their books. Then they go back and tell these things to the new generation. Etc etc…It is so firm in their minds that, on numerous occasions (which is my unsubstantiated view, but supported by some ecologists themselves) they cannot deal with another reality. And in the end, we see people like those over here, who have to fight for what they like [nonnative species] against a dogma that it is something that should be disliked…”

This describes a basic human problem, but it isn’t limited to people who want to remove invasive species. I’ve heard some pretty pro-invasive- species dogma also.

“- What is “native” in 560 ppm world? As I said: the climate change moves zones northward at 7 km/year. Virtually no tree can keep up with that pace, which leads to the following problem: we want the world to be very biodiverse AND we do not want to introduce any species anywhere (many ecologists think that way). These might very well not get together.”

This is a valid point… species are moving and maybe we do need to move species along. But, you said you were opposed to restoration earlier. Are you only in favor of introducing non-native species? This just doesn’t make sense at all.

[Webmaster: I read that to mean that plants that do well in a particular area should be allowed to continue in it, rather than being battled. Not that they should be introduced. ]

Also, while temperatures globally are going to warm, there is a LOT of variation in precipitation and temperature effects as well as a variety of positive and negative feedback loops we don’t understand yet. I fully agree that we need to stop burning fossil fuels, and that our doing so will harm us as well as natural ecosystems. But, I don’t think it is yet time to move plants and animals around to the extent you seem to be proposing.

“I do not think man is a steward of nature.”

I don’t think we act that way right now . But many different cultures have done different things in the past… and we need to do something differently in the future. Hopefully we choose correctly!

[@Charlie:]

We are on the same page when it comes to our personal preferences and so are the people here. You like what you see (or saw ), like those people over here who love the forest for their reasons.

On to invasiveness. If I read what you say, I get the feeling you base your discussion on a lot of theory on imigrant species, neophytes in this case. In short, these are the facts:
- The most biodiverse indigenous systems in general carry the most neophytes, which totally goes against the theory that niches are occupied. This does not seem to be the case at all.
- Nonnative ecosystems all over the world (US, UK, NL, SPain+Portugal, South Africa, Hawaii and Puerto Rico to name a few) are as biodiverse and in some case MORE biodiverse than the local native ecosystems.
- 50% of all species around us are not locally-evolved, but invasions
- Large invasions in the past have never led to mass extinctions

Apparently this is also true for Euc forests in California, not just the one on Mount Sutro. Exactly the same story is told in Spain and Portugal about Euc forests [i.e., that invasive eucalyptus is supplanting native species], and again it is not true. Especially in the Atlantic NW of Iberia, these forests are very lush. The limiting factor there seems to be not the species, but the rain or lack of it.

So how come we hear these stories over and over again? Well if you repeat something long enough, it becomes the accepted reality. How this develops in ecology is studied at the University of Leiden. Two nonnative birdspecies were (and are) perceived to be very invasive, aggresive and prolific; and a threat to local bird diversity. This is accepted by ecologists in the Netherlands as fact. But study revealed that there were no studies done (so they did one), and that in the various scientific works the same subjective material (from observations, not checked with any statistics) was used. At first, it was displayed correctly; but from the fifth scientific paper onwards, exactly the same observation was now cited as a scientific fact and used as such.

[Webmaster: I think we have an analogy for this in the "beak-gumming" myth -- the belief that birds' nostrils get blocked when they forage in eucalyptus.]

In reality, the nonnative species did not affect avian societies at all — or even supported it! Now I have had some discussions with ecologist on this, but they fail to acknowledge it. In one case a researcher who again found the same conclusions (i.e., the introduced species of birds had no negative effects at all) was approached aggressively. I was in this discussion and it was clear some ecologists could not deal with this information at all.

The same is true for research on forests in Puerto Rico. Nonnative trees supported a more diverse ecosystem than the native one. This peer-reviewed research did not get through the review system at first. Not because it was erroneous, but because of the conclusion. The peers, of course, were ecologists who said it was “difficult to make lemonade out of these lemons.”

I think the problem is that people who are interested in nature venture into it, see things and are told some things about them. Like in NL where little kids are brought with parents to rip out ["weeds"?] first because they do not belong here. They study things; some become ecologists/ biologists and read these value-laden, indoctrinating wording in their books. Then they go back and tell these things to the new generation. Etc etc…It is so firm in their minds that, on numerous occasions (which is my unsubstantiated view, but supported by some ecologists themselves) they cannot deal with another reality. And in the end, we see people like those over here, who have to fight for what they like [nonnative species] against a dogma that it is something that should be disliked…

Some points to restorations and our future:
- restorations just do not turn a nonnative based forest into a native one.
- What is “native” in 560 ppm world? As I said: the climate change moves zones northward at 7 km/year. Virtually no tree can keep up with that pace, which leads to the following problem: we want the world to be very biodiverse AND we do not want to introduce any species anywhere (many ecologists think that way). These might very well not get together.

Most of all that 560 ppm (3 K temperature rise) is not where it stops if the current trend of emission continues. On another side note: 21 Gigatons of emission instead of the current 7-8 is perfectly acceptable in 2050 (!). So temps will rise after 2100 too.

So habitats will change and many species will be unable to cope with their new climate. If you do not use translocation because of one dogma you won’t reach the other ideal…Many species will become extinct because of a dogmatic view on things.

I do not think man is a steward of nature. So our human view, for instance that invasives should be kept at bay, are only valid if it directly hurts us (economically). Well, personally I do not mind that much about economy, but it will go that way. If something directly hurts the economy people are willing to act. If not, they just have less interest.

Thanks for the thoughtful response.

I feel like we are in some ways on the same page. But, one of my most important points is one of the ones I seem to be having the most trouble communicating. I have been trying to say the whole time that I strongly believe the native vs non native dichotomy is not what we should be looking at…. but that you are going too far the other way and saying that invasive species should not be managed/dealt with either, because you feel most people want to get rid of them because they are often non-native… There are DEFINITELY native species that are invasive (though Chestnut blight is introduced to North America). Native species most frequently become invasive when something changes in the landscape that throws off the previous balance. When this happens, a native invasive acts the same was as a non-native invasive. I think we should manage/control ANY invasive species if we find that it is feasible. That was my whole point the whole time… I am not (to my knowledge) a xenophobe and am not opposed to ‘non-native’ organisms (I plant plenty in my yard though I avoid invasive ones or those inappropriate to a site) and my entire point was that I think we need to look at species (and people, if you want to continue that analogy) based on what they do, not where they are from.

The unusual assemblage of plants on Mt Sutro have obviously formed a complex ecosystem, despite the fact that they are from all over the world. I DO think it is really neat, and people should be spending more time studying ecosystems like this. How can an equilibrium form in just a century? Are the fungi, bacteria, etc, implemented and connected as strongly as a native ecosystem that has been similar for 100,000 years?

[Webmaster: Interrupting the conversation to say, maybe yes, maybe no. But if it were removed, the replacement ecology would not even be a century old. It would be brand new, and while it might mimic an older ecosystem, it wouldn't *be* a 100 thousand year old ecosystem. It would be a representation of one, maintained that way with ongoing effort.]

If so, what makes Sutro different from some of the other Euc groves I have seen with little diversity in the understory, or worse, an arundo or tamarisk stand with essentially NO diversity. There’s a lot we don’t understand here, and it’s really worth a closer look. I initially came to this site because I was concerned that the blackberry, etc, in the understory might infect other areas with more natural ecosystems, and cause ecosystem collapse. I think I do agree though that because it is in the center of a city, and because there is already blackberry all around the greater area, this may not be justification for removing the blackberry.

The native bark beetle problem is often blamed on climate change and I think that is a factor but it seems that the main reason is due to alteration of fire regimes. The trees are too dense, and in some cases too old, so they are more vulnerable to drought and beetle attack. So, they are all dying at once. In this case it is probably too late to solve this problem.

This brings up the point that many invasive organisms are that way due to larger scale management issues that need to be addressed. All land on Earth is being managed by humans (no-action is a management choice at this point) and most places have been managed by humans for at least 15,000 years. In Europe this history is much older. But, while we figure out the best way to manage the land, to allow the more complex ecosystems to persist, a variety of invasive species are causing extinctions all over California and other areas.

We may ultimately realize that if we use a more appropriate management regime the invasives will go away or ‘behave properly’ as an ecosystem component. But, it could take many decades to figure this out and if we do nothing about the symptom, by the time we figure out what to do about overall management of an ecosystem, most of the components will be extinct or reduced to such a small population size and genetic diversity that they are essentially lost together. What I propose is that we learn the systems, but we also deal with the symptoms before we lose too much to recover. It’s much like holistic medicine… eating well, exercise, mental/spiritual health, etc, etc, are essential to not getting sick, but if you have a potentially fatal disease caused by poor overall practices, it’s better for the patient to take a medicine with somewhat harmful side effects than to die. After we save the patient we can figure out what they can do to avoid getting sick again.

In any event, I apologize for any overdramatic or inflammatory contents that I may have made on this website. I also apologize that you have run across so-called ecologists who were racists, bigots, or xenophobes. I also, however, assure you that while we all have our own biases and shortcomings and irrational fears, mine are not the basis of the ecological management regimes I am advocating.

[Webmaster: Speaking for myself, I find your viewpoints interesting even in cases where we disagree. Thanks both to you and to Gov for stopping by here.]

[Well, this is really] about Mount Sutro and its value and, in a broader sense, about more of these kinds of habitats (let’s call them novel ecosystems) that are threatened because some people have an ideology. They use some scientific facts with personal preferences to come to sometimes some dogmatic (religious) views.

Charlie, you mention some facts (diseases spread and kill many trees — which is true), but add your personal preferences and views on what is a functioning ecosystem and what isn’t. Like, the Chestnut IS beautiful. Or that some species have been extirpated and are not a meaningful part of the landscape. Or that the ecosystem is collapsing.

Chestnut blight….no one likes it. But what does it prove? [Native organisms can also be invasive.] We know that the native Mountain Pine Beetle currently wreaks havoc from Colorado to British Columbia and Alberta. The current outbreak of mountain pine beetles is ten times larger than previous outbreaks. Huge swaths of central British Columbia and parts of Alberta have been hit badly, with over 40 million acres (160,000 km2) of BC’s forests affected. And that is just British Columbia. Some experts have predicted that if the problem is not eradicated, many of Colorado’s mature lodgepole pine forests will be killed within three to five years. Regeneration of decimated forests has begun as the US Forest Service hires loggers to remove the dead trees….

In Europe we have native badgers carrying Bovine TB, causing losses to farmers because cows are infected. We have Birch and Pine constantly invading heath and fields, and thereby limiting the number of red list species that cannot survive in forests…Etc etc…

You extrapolate to say that some species will almost become extinct in the next 50-100 years. First of all: extinction like you mention isn’t everything. You are right: it simply happens as long as there is life on this Earth. So the occasional extinction here and there, for whatever reason, is not that much of a deal. Most of all if you consider the current extinction rate because of us in a more direct sense (habitat loss for agriculture — which you mention as a side note).

But how sure are you that the current trend will continue? Can’t local species adapt? Can ecologists predict which species will become invasive and which won’t? No. Have they been able to predict the outcome of an ongoing invasion? Rarely. Many times, they have the same anwer if some asks if some species have become extinct: “Not yet.” As if it is inevitable….An example is the Argentinian ant that started to dominate all other ant species in Texas somewhere in the 1980s. It had the upper hand. 15 years later, you had to look for it, according to researchers. The ant is there, but behaves like every other ant….

You note the differences. Any chance of things getting back to how they were? At what cost? Who is going to pay that? Is it for the public good or is it to please the few? In The Netherlands, they have started campaigns to convince people their views are the right ones because currently people, as I have mentioned, do not support it.

How come ecologists (among others) do this? Is that something for a scientist to do? Seems again more like a religion.

Finally: in many cases the restoration of landscapes will become dependent on money. If the invaders are present, but kept at bay, they won’t be kept at bay once there is no money. At least in NL this is very much the case because with much rain and snow, you [naturally] get a forest in a rather cool climate. It could be broad-leaved, it could be coniferous or a mix. [Thus, keeping areas as open heaths requires human intervention.] I think that if this is the case, it is yet another reason to simply accept the reality.

Or how about sand dunes? These are just as good and natural as are sand dunes where once a rainforest grew in the Amazon or Africa. In The NL we have 800-1000 mm of rain per year. [Our] climate is a more continental variety of the Pacific North West in the US. Not a place for impoverished sand dunes. Or heath. As is clear if it’s let go: it would become a forest in a matter of decades.

Now Scots pine is native, Norway spruce is not considered native even though this is highly debatable. And indeed these forests as mentioned are full of rare species. They are as species-rich as other native forests, but have different species in them. So the best preserved spruce forest over here is considered a goldmine for mycologists who begged the Staats Bosbeheer (State forest service, which is all into getting rid of nonnatives), to save this forest (1000 ha on a scale of 10,000s). Okay, they said they would only thin it….End result: there are still some trees left. But not a forest. They destroyed it completely. The moist atmosphere is gone, because too much sun now penetrates the floor. This is not just an example. This is consistently done. The Dutch Mycological Society commented that this is one of many examples that show the blind hatred these Services and organisations have for non-native species.

Another one: Sitka spruce forests. Instead of fungi (although some now grow there since 2008 after becoming extinct in the NL), they are extremely rich in fern species. Compared to any native forest, the number of ferns and the number of species are literally off the scale –100 times more rich in places. Also it is full of lichens. Long story short: it didn’t matter. Even 400*400 metres of Sitka spruce had to leave to make way for….well…I don’t know what they wanted but I am positive they did not want it to become one big chunk of blackberry, which it is now….And some Sitka spruce seedlings in it. The ferns are gone. Thank you very much.

This also goes on despite uproar by the locals, who are proud of their forests. Not all policy makers are like that, but over here the extremists always seem to have the upper hand….

[Note from the Webmaster: Charlie notes he doesn't wish to be referred to as a 'nativist' because it usually references people with anti-immigration views.]

Have you ever been to California? I don’t mean this in a negative way at all, but unless you have spent a lot of time in California you aren’t going to understand how the ecosystems work. Europe has been occupied by agriculturalist humans for a really long time, and it is true that diversity there is a bit lower. It may very well be that introduced plants fill lost niches there and add diversity without any real loss. That just isn’t true in California. We are in the process of watching everything unravel… well, the end stages of that.

You say invasions rarely cause extinction.. well, I say extinction is not everything. Much of interior California was once covered in a bunchgrass and wildflower prairie. This is all gone. Granted much of this is due to factory farming but even in unfarmed areas, the bunchgrasses are quite rare now as are their wildflower cohort. In their place are just a few species: ripgut brome, yellow star thistle, wild oats, black mustard… There are millions of acres covered predominatly by those species and the bunchgrasses are now confined to a few places that the invasive plants can’t tolerate the soil – mostly clay or serpentine soils. They aren’t extinct but they are no longer a meaningful part of the landscape. They weren’t replaced by an equally diverse multicultural tapestry of prairie grasses and forbs selected from around the world. They were replaced by a handful of agricultural weeds. See, when invaders are introduced, we don’t introduce their whole ecosystem. If we plunked an intact California ecosystem and an intact South African ecosystem of a similar climate together, next to each other, on a space colony or something, you’d probably get some really neat mixes, the kind you are describing. Maybe that is even what you are getting in Europe and I could buy something similar happening in Sutro on a small scale. But, on the grasslands, what you have is the ruderal plants from several ecosystems completely crowding out the normal ecosystem process.

So you see what I mean about extinction not being everything? Having a bunchgrass clinging to life on a rock is not the same as a million acres of bunchgrass prairie.

A few more examples:

American chestnut was once the dominant tree in much of eastern North America. This huge, beautiful tree provided food for humans and wildlife, was a centerpiece of the ecosystem, and also had very nice wood. You are probably guessing they were all cut down but they weren’t. The chestnut blight, introduced from Europe, top-killed every chestnut with VERY few exceptions. The chestnut still exists as a coppiced shrub in a few places, so it isn’t extinct. But, the chestnut forest is gone.

American elm was decimated by Dutch Elm Disease in much the same way as the chestnut. Woolly adelgids, an insect, are currently killing off most of the Eastern Hemlocks in the same area, and the emerald ash borer may do in most of the ash trees.

[Webmaster: And for another example, Sudden Oak Death is killing California's oak trees. But how is this an argument for preventing those plants that can survive from doing so? These blights are almost impossible to stop, except by quarantines; we can't chop them down or garden them out. So if the oak goes, and we fell the eucalyptus, we have no forests?]

Sound like a diverse globalized ecosystem to you? To me it sounds like a collapsing ecosystem – that is exactly what it is.

Similarly, Joshua trees and sajuaro cactus will probably be banished to a few rocky outcroppings in the next 50 years because two grasses – buffelgrass and cheatgrass – are completely dismantling the desert ecosystems of the American Southwest by changing fire regimes.

The idea of blended ecosystems might sound nice when you write it down (though to me it sounds horrible because we lose the uniqueness of place!) but nonwithstanding that, it won’t work. There is no way to transport an entire ecosystem, with all of the insects, bacteria, fungi, etc, etc, to a new continent. You will only transfer a few plants.. some become invasive, most die off.

So, it seems like you are pushing for McDonalds and star thistle on every hill. I’m hoping we can retain some of the rich ecosystem diversity on the planet instead.

As for blurring of ecosystems and land managers, maybe sometimes that is true but all too often the opposite is true, they don’t talk, and poor management decisions are made. Again maybe in Europe it is different… but here in the US, it just isn’t a problem.

Okey Charlie, thanks again. I do understand that you feel a loss of what you love in nature and I wish, for you, things were different. I have stated on many other fora about this subject that the feeling of losing something is one of the things that seems to influence people. I understand it.

Of course our discussion does not have to be scientific solely although I feel that many of the things being said by nature-adepts come from the current ecological mainstream as can be seen in many organisations turning nativist. I’ll try to separate them.

You say: “I guess I don’t understand your point here. Are you saying you support globalization of ecosystems? I don’t understand why anyone would support converting every ecosystem with similar conditions across the world, into the same thing. That’s what happens if you mix up all the plants… the opportunistic ones take over, because their predators aren’t there also, and you lose a lot of diversity.”

I have no problem with it. Mankind to me is just a relative new dispersal factor, like the wind, landbridges etc. Regionally, biodiversity sharply rises, with the loss of almost no species. We are talking about thousands of new species at the expense of nearly zero….

So the homogenisation of biota. That is aesthetic. Are New York, Bangkok and Paris boring or the same because of cultural homogenisation? Because opportunists like McDonalds, Starbucks but also pizzerias etc can be found everywhere? I have never heard anyone who visits them complain. They remain unique, though they have changed and share more similarities than before.

For the locals, are they losing something with the addition of Starbucks and Mac? Could be. But most like them, otherwise they would not be there. I bring up this example because ecologists themselves bring it up regularly as to show how “bad” this is. They call it the “McDonaldisation” of nature. And as I said: this of course is presented as something we shouldn’t like, otherwise they wouldn’t bring it up. To who do they think they are talking? Not to the majority of people I am sure.

Now in nature there are no plants or animals that can establish themselves in any climate, unlike McDonalds. So this won’t happen, but some can be seen in more places. But like cities, these places will remain unique. Marine ecosystems are much more alike because dispersal is easier. Are these systems less interesting?? I don’t think so either.

Do you see the difference between the Russian and the Canadian Taiga? Or Tundra? The spruce trees are different but look much alike. Many animals are shared already; like the brown bear, the wolverine, the beaver, the wolf, the fox, the seal etc etc. Only a connoisseur would see the difference. Is any one complaining? Siberia is still very different from Canada, despite the similarities. Anyway: this is not a scientific argument. It is preference.

Who is going to notice the similarities? The lucky few. Others now have to travel 10,000 km instead of 100 to see a Sitka spruce forest….So for local people, [preserving native ecosystems means that] they lose biodiversity instead of winning anything.

You say: “I understand there is a division between invasive and exotic. I try to be very clear: I am not talking about ‘exotic’ plants but about invasive plants. Only 1 in 1000 introduced plants (or whatever) are invasive… this is true. How does this justify not doing anything about the [0.1%] that cause a problem?”
Because ‘invasion’ does not equal ‘problem.’ It equals ‘change.’ To you they are a problem, to me they are not, in general.

[Charlie:] “The thing is, you seem to equate ecosystems of plants with human culture. I reject this as completely unvalid. It is unfair to compare invasive plants with Muslims, or otherwise draw connections between human societies and botany. All humans are the same species, and biologically we are even all the same race. We diverged less than 100,000 years ago and since we have long lifetimes, we haven’t diverged enough to form separate species. Also, human societies do not act like plants. It is unfair to compare invasive plant ecology with xenophobia or racism.”
I have tried to explain that the way we think about these newcomers is similar. It is not based on science, it is based on our prejudice, fears etc. You fail to see the comparison, may be I am not clear also. Let me cite Dov Sax in a discussion with ecologists (and he himself does peer-reviewed research on invasions and extinction, and is not disputed by his collegues). I could not say it better myself:

“So the impacts of exotic species on native biodiversity and ecosystem processes vary widely in kind and magnitude. Whether these are considered to be positive or negative, good or bad is a subjective value judgement rather than an objective scientific finding.

“Scientists are no more uniquely qualified to make such ethical decisions than lay people. Scientists are uniquely qualified to collect the facts and interpret their consequences. It is entirely proper for private citizens, including scientists, to be advocates for positions that promote some combination of self-interest
and societal welfare. These positions may be based in part on scientific information, such as the documented
extent and likely consequences of global warming or a biological invasion. In their professional roles, however, scientists have the obligation to collect, analyse and communicate such information accurately and objectively. When scientists go further and try to impose their own ethical and moral imperatives on society as a whole, they embark on a slippery slope. They risk compromising the principles of unbiased, objective inquiry that are the essence of the scientific method – and the primary reason why society should support and pay attention to scientists.

“Don’t get us wrong. As private citizens we authors are enthusiastic supporters of actions and policies to reduce the ongoing loss of global biodiversity and homogenization of the earth’s biota. We also stand by
our comment, however, that many scientists, managers, policy makers and lay people have a deep-seated prejudice against exotic species that comes close to xenophobia. This is apparent in the adjectives used to describe non-native species and their impacts – invasive, alien, plague, foreign, aggressive, catastrophic, insidious, destructive, decimating, devastating, damaging,threatening, assaulting and flooding – to mention
just a few. But worse than such words are the unsubstantiated, unscientific tales, too often promulgated by scientists themselves, that biological invasions are somehow unnatural and that as a general rule invading species dominate ecosystems and cause economic losses, wholesale ecological changes and extinctions of native species. Sometimes they do, but the impacts vary enormously with the species of invader
and the environmental setting.

“Moreover, whether these impacts are perceived as positive or negative, good or bad, varies with the moral beliefs of societies and individuals. When scientists claim that their professional credentials uniquely qualify them to make such moral judgements, they exceed their special, time-honoured roles as unbiased collectors, interpreters and communicators of scientific information.”

Sax is not the only one. By myself, I came to almost the same conclusions.

You said: “If you ask 100 people if they like a tree, of course 60 will say they like it. If they understood that having this one species of tree means a loss of 40 other species [of plants], maybe they wouldn’t feel the same way. I don’t see how it is relevant anyway.”

Read again: they were told why [the trees] were cut down. This was rejected by 65%. Only 15% agreed. BTW exactly the same percentage of people support nativist politicians BTW…

You said: “I do not support or want anything to do with the Republican Party in the United States.”

Well, I can understand that!

[Charlie:] “Again, climatologists DO have emotional and personal responses to their findings. I don’t see the difference between them and ecologists. Both are dealing with complex systems that are difficult to define, but both have come to very overwhelming conclusions. The connection between INVASIVE species and biodiversity loss is really, really strongly established. I can’t find the list (many pages) of references on CAL-IPC that show this connection.”

Climatologists do so in private and not in papers nor in books for scholars. It ain’t so and I know so. I have done research myself on this matter…I know climatologists and I know those who had to testify for our government. They have not said the development is bad or good. It’s a scientific fact that the Earth warms. What politicans should think about it was up to them.

Climatologists in general behave like Dov Sax thinks ecologists should behave, and I agree.

[Webmaster: Okay, I'll try to make it clearer... It's easier on readers to do it this way with very long comments.]

To me the issue is not change in ecosystems, which is of course a constant, but loss of biodiversity by one ‘viral’ species that quickly outcompetes everything else because its natural controls are not present. This is not limited to species introductions, it also happens when a predator or other control is removed from an ecosystem. Either way, one species is thrown vastly out of equilibrium and takes off. Again I don’t like the human-ecosystem comparisons but in some ways it is a bit like a tumor… one component acting in its ‘short term best interest’ and not acting like an ecosystem component. As with chemotherapy, invasive species control is only treating the symptom, and it would be better to figure out why invasions are happening in the first place, but sometimes we can’t.

That’s all for now. I find that I get into long debates online when I am putting off working on my paper… but I need to get some work done.

Again, diversity may increase with some ‘exotic’ species but does it ever increase with ‘invasive’ species? I doubt it.

[Webmaster: How is "invasive" defined?
Even if you define it tautologically as a plant that expands into areas where it's not planted so as to reduce diversity, all sorts of broader possibilities exist. A species could invade, and reduce plant diversity but if it provides a good habitat, increase fauna diversity. It could reduce plant diversity temporarily, but then die back and make space for other plant species, possibly more than existed in the first place.

Really the issue of natives seems not so much the species-count of diversity, but the whole idea or "restoring" one of the earlier ecosystems.]

Sutro and the other euc forests are indeed complex and diverse right now, but we won’t ever know what they replaced because it was destroyed when the trees are planted. So, perhaps the trees shouldn’t be cut down, but there’s no need to deny that they replaced something else.

[Webmaster: Of course this ecosystem did replace another one. I expect that's true of every ecosystem, except a few in very extreme stable climates. There's disease, there's predation on plants, there's natural succession, and in a disturbed land of fire and earthquakes and storms, there are dynamic changes to the ecosystem.]

Also I wonder what was in the understory of the oak forest in Berkeley. Blackberry?

[Webmaster: Quite a few species, actually. Here's the story on another website, Death of a Million Trees.]

I guess I don’t understand your point here. Are you saying you support globalization of ecosystems? I don’t understand why anyone would support converting every ecosystem with similar conditions across the world, into the same thing. That’s what happens if you mix up all the plants… the opportunistic ones take over, because their predators aren’t there also, and you lose a lot of diversity.

I understand there is a division between invasive and exotic. I try to be very clear: I am not talking about ‘exotic’ plants but about invasive plants. Only 1 in 1000 introduced plants (or whatever) are invasive… this is true. How does this justify not doing anything about the [0.1%] that cause a problem?

The thing is, you seem to equate ecosystems of plants with human culture. I reject this as completely unvalid. It is unfair to compare invasive plants with Muslims, or otherwise draw connections between human societies and botany. All humans are the same species, and biologically we are even all the same race. We diverged less than 100,000 years ago and since we have long lifetimes, we haven’t diverged enough to form seperate species. Also, human societies do not act like plants. It is unfair to compare invasive plant ecology with xenophobia or racism.

If you ask 100 people if they like a tree, of course 60 will say they like it. If they understood that having this one species of tree means a loss of 40 other species [of plants], maybe they wouldn’t feel the same way. I don’t see how it is relevant anyway.

Yes, conservation has conservative characteristics and it is a bit odd that in the US it is perceived as a liberal cause. This has more to do with struggles over wilderness designation and regulation of access in the American West than anything. When I objected to being called a conservative, I should have been more specific. I do not support or want anything to do with the Republican Party in the United States.

Again, climatologists DO have emotional and personal responses to their findings. I don’t see the difference between them and ecologists. Both are dealing with complex systems that are difficult to define, but both have come to very overwhelming conclusions. The connection between INVASIVE species and biodiversity loss is really, really strongly established. I can’t find the list (many pages) of references on CAL-IPC that show this connection. I don’t know why you keep prodding the discussion towards ‘hatred of non-natives’ which is a straw man discussion you are creating… I am talking about INVASIVE organisms, most of which are introduced by humans.

[Webmaster: The CAL-IPC is not exactly unbiased in this matter; the fear of invasives is exactly why they exist. But perhaps you could link to one or two species relevant to Sutro Forest, like blackberry or black acacia?]

This is a personal issue for me because I have watched too many ecosystems in California be basically ‘crashed’ (like a computer freezing, or an economic collapse of sorts) from diverse, self sustaining ecosystems, to monocultures of 1 or 2 plants. I realize that in 10,000 years the ecosystems will organize into a much more complex form again, but me and anyone I know will be long, long dead before then.

[Webmaster: I think you underestimate nature, myself. Within a year, insects, birds and animals will find new niches within that habitat, and start to change it. Other plants will enter and compete. I don't think it's going to take 10,000 years to get there. There's change on a human scale, and change on a scale that's too small, too fast, too large, too slow. But creating stasis in an inherently dynamic system takes work.]

Essentially the ecosystems I love are being destroyed, and when I try to protect them I am compared to racists and xenophobes and the Tea Party. Why not recognize they [native plant advocates] are trying to protect places they love?

[Webmaster: Not the Tea Party!]

Thanks for the thorough reply. You know I was astonished by the ecologists I know. I’d say they are not secretly conservative on this issue, they don’t seem to know it or acknowledge it. Now I don’t want to play word games, but the term “conservation ecology” should at least be a clue. In all other aspects, like me, they are progressive and do not seem to have these traits when it comes to people and most of the time not culture. Otoh, I have read some comparisons between the homogenisation of nature and culture in a sense that the latter is also “bad”. McDonalds in Nepal would be awful. Like in nature, the locals seem to enjoy it. In The Netherlands the Uni of Wageningen did research on which woodland forests were liked the most in NL. These were all visitors of several forests. Out of 150 different pictures two clearly emerged as top favourites: one had beech in it, the other oak and both had a Douglas fir clearly visible. They concluded that people do not reject and indeed like these trees.

Another research by the same University asked the same visitors what they thought of exotic trees like Sitka spruce and Doug fir and other trees (native). Again these trees were highly valued. The idea of eradicating them because they somehow did not belong here was rejected. Even after an explanation of why they were removed in some woods, this idea again was rejected. People felt these trees had every right to be there.

In short: 65% of the people favour these trees, 20% was neutral and 15% was in favour. Not unlike McDonalds in Nepal or Mount Sutro forest in San Francisco. Should we get rid of things because 15% of a population thinks that is good?

I am not the only one finding the the resemblance between ecological and cultural xenophobia striking. Researchers like Dov Sax, James Brown, Steve Gaines and Mark King note the same thing. Kate Rawles, a British philosopher, notes the same xenophobic and illogical thinking within [some] large British conservation groups.

It is also quite obvious that someone can (and sometimes does) say the same thing about immigrants; and in both cases they base themselves on the exceptions and use examples to support their views. It just shows that (extreme) conservatism is not simply a rightwing thing. I have also found that the remark that it is xenophobic is rejected with anger by ecologists. But we can easily compare the two and come to that conclusion.

First: what is conservatism? It comes from conservare which means “to preserve”. In general we can say that most ecologist see it as a good thing to preserve global biodiversity, to preserve as many species as possible and reject the thought of extinctions and it is clear they want to preserve all kinds of habitats. Moreover, habitats that have changed over the last centuries are “restored” to how they supposedly looked. In what sense is this not conservative? How is that different from people who long for the good old days in culture?

Racist..I never used that word. Xenophobic. Never used it either, but indeed I find it xenophobic or at least [tending] to it. Simply because there are a lot of organisations, lead by ecologists who strongly are:
- against globalisation of nature
- against introduction of species by man (all other factors seem to be fine)
- where possible, the are strongly in favour of eradication of plants and species whenever they feel [it suitable].
- They, like you, feel that new trees are not members of a certain ecosystem and fail to acknowledge the fact that these species form a new kind of ecosystem.

That is the “xeno” part of it. Something that has entered at some randomly used point in time will always be a stranger. Everything before that time is no problem in general. There is no place for this stranger. He will always be a stranger. Sometimes they tolerate the stranger, but they wil rarely accept him.

The phobia (fear) comes from the many assumptions, demonisations and exaggerations we find in scientific and other literature by those ecologists. It is also clear in the value-laden wording [often considered okay]: Many words that tell us they see them as not belonging somewhere and causing harm simply by being there. Alien, pests, plagues, prolific etc to name a few.

Or the assumption that a new plant outcrowds another plant and will lead to extinctions. That competition is a major factor for extinctions. While research has shown this has never happened on a continent (Sax and Gaines, 2008, PNAS). Earlier research by others have noted the same. Other research by the University of Wageningen has shown that 1 of 1000 immigrant species become invasive. 999 do not. I see no difference in talking about Muslims as evil, threatening people when less than 1% has the potential of becoming a terrorist. BTW: how the newcomer enters the new habitat does not matter. So whether it is spread by itself or by man has no influence on the outcome.

Now the comparison between climatologists and ecologists is ill-chosen, I feel. You’ll find no peer-reviewed research over the last ten or fifteen years challenging the theory that a rise in CO2 causes a rise in global temperatures. The same is true for the cigarette comparison. In ecology, this is not the case. Like global warming denialists, it [is] ecologists who revert to examples, assumptions and who actively seek media attention to tell us how evil immigrant species are. They are vocal like climate change denialists while not giving us any proof for an “invasional meltdown”.

Climatologists in general are not nearly as vocal, even though their science is unchallanged. They also are quite clear where the uncertanties are and how uncertain these factors are and what their total influence is on global warming (for instance: cloudcover).

Conservation biology is not a science if it tells others what they seem to think of right and wrong. It is an ideology. It remains a science if it tells how you can restore somethings. Like some architects can tell you how to restore monumental buildings.

The biologists however on many occasions tell us why we should restore all sorts of habitats. In the end, it is for themselves and their personal and not scientific views.

But this scientific field is more than just conservation ecology. You can research all sorts of developments and changes without attributing any value to any change. In doing so, you also prevent others [from becoming] opiniated before they do research on their own, or becoming indoctrinated with some views on these changes. I think scientists should do everything not to be biased. If you become biased, the chance of your research being coloured by your personal preferences rather than scientific facts becomes quite large.

A final point is that ecology deals with life. And if we talk about life and death, certainly on a massive scale as is proposed by ecologists just like that in their work, we talk about ethics. And ethics are not defined by some gropup of scientists with some view on how the Earth should look like. This is done by a society as a whole and this is where ecology sometimes clashes with layman, animal right groups and others. Which is why the Grey Squirrel was not eradicated in Lombardia.

When we talk about our landscape this concerns all people who live in it. Who venture in it (or not). This is clear in Mount Sutro, but I can give you loads of examples from Europe as well. The best thing for ecology to do is not tell those what they should think, they are perfectly capable to decide for themselves. What ecology should do is just to give us sound science, science facts about these changes and let society decide.

This is not true for Sutro anymore because it is a very old introduced forest and the ecosystem it replaced is already lost forever. I believe it was a mistake to plant the Eucs but the damage is already long done. Sutro is very different from most other invaded ecosystems.

There are a few conflicting studies but you can’t build a compelling argument that invasive plants don’t reduce biodiversity and alter ecosystems without heavily cherrypicking data. If you have anecdotal evidence, by all means share that. Science isn’t the answer to anything. My anectotal evidence in pretty much every case strongly supports the science.

[Webmaster: Actually, there are studies showing that biodiversity can increase with the introduction of exotic species... and there's another showing that a eucalyptus forest and an oak forest in Berkeley California had the same number of species. "Invasive" plants are not invasive in all contexts. If you view ecosystems as static, then it may make sense to try to prevent the flora in a particular area from changing. If you view them as dynamic, then today's invader may be tomorrow's hanging-on-by-its-fingernails (or equivalent part) while something else takes over.]

Of course scientists are biased – they usually care about what they study. Those linking tobacco with cancer may have an anti-cigarette ‘bias’ because people they love are at risk of getting a horrible disease. Climate scientists are biased because they don’t want climate change to starve or drown people. Conservation biologists care about functioning ecosystems and are biased towards their protection. It is impossible to be completely unbiased but I would argue it is also silly.

There are plenty of valid arguments to be made against restoration of Sutro to native habitat, and most of them have already been gone over here. Sutro is a very established and complex forest, and even if it has replaced a unique ecosystem that is now mostly gone, it does have inherent value. It is a cultural resource used by people who live in the area. It does offer habitat value, filter rainfall, collect fog and reduce erosion. It may be impossible to recreate an ecosystem that has already been destroyed. Urban areas do not necessarily have anything ‘native’ to them except pigeons. The Eucs can’t spread to and destroy other habitat. Some feel that scrubland is not as appropriate or aesthetically desirable as euc forest. Some rightfully are concerned that some forms of conservation exclude humans as part of an ecosystem. Some people believe evolution and formation of ecosystems happens much faster than we think, a view I partially also agree with.

Yes there are issues with monsanto and herbicide, and it is understandable to be opposed to using these tools. In invasion biology, like in medicine, we are faced with ‘cures’ that also have negative side effects, and we have to balance the negatives with the positive.

This is the basis of all clearcutting of so called nonnative trees. Ecology, conservation biology, restoration ecology and invasion ecology are all different from most if not all scientific fields in the way that they have become an ideology themselves rather than used as support for (nativist) nature organisations only. Of course many ecologists actively support, or better, work within Nature conservation groups.
Just pick up 5 books on invasion ecology that are readily used on Universities and you understand how this will not change any time soon: they are full of value-laden words, constantly negative about newcomers in local natural reserves or even gardens. These books are also filled with assumptions rather than facts.

I have experience with climate change research, and you can imagine that climatologists have their own strong morals (at times) about the rising temperatures. Simply think of a polar bear drowning because he can’t find the next ice-shelf. It evokes a strong, emotional response. However, in the scientific literature you will not find remarks that the current warming is somehow unnatural. It is anthropogenic (caused by humans). And no peer-reviewed research that is about the rate of warming etc also tells us what we should think about it and what we should do. That is up to the society, not the personal preference of a climatologist who can never prove that his personal preference is somehow more valid than anyone else because he has studied climatology.

In ecology, the story is quite different. Apart from constant negative terminology about newcomers (invaders, pests, plagues, unnatural, deviant, prolific, overcrowding) and many more that cannot be proven in a unbiased, sound scientific way, they also tell us what we should do. The word “eradication” seems on the tip of the tongue constantly and is used constantly in many books for scholars.

In this way, students themselves get the same vision on newcomers in nature. They are indoctrinated and it is difficult not to talk to them (I have done so) without judgmental wording on their side. In my view, it is highly unscientific and much more ideologic. The basis seems to be fear of change and they experience a personal loss when something becomes extinct. It is their goal to go back in time instead of moving along and going with the flow.

The words of the Australian ecologist do not prove that the Eucalyptus is not a part of the ecosystem. It clearly is as it is growing there and indeed facilitating life of both old- and newcomers. It doesn’t fit his view of what an ecosystem should be. And that is: not influenced by man (I think). Or not heavily influenced by man. The name for these ecosystems you find mostly is that what conservation biologists seem to hate the most: novel ecosystems. Because with this new name comes credibility. If you read the scientific literature you’ll find they have big problems accepting these systems and it is really causing them to choke when it turns out that these new assemblages are more biodiverse than their “native” counterparts.

They constantly say that plants outcompete others. The question is: if this has never lead to any extinction (and on continents they never did), please tell us the scale. I rarely find the scale on which something is “outcompeted.” I rarely find clear numbers of the drop in percentage of cover of some native plant compared to some invasive. I rarely see any model that can predict on what will. What I see most is assumptions. Like “if this continues at this rate, the species will be extinct within x years”. So the key is: will it continue that way and why? No answer there.

It is just another term to evoke fear. The fear is of course that it finally will become extinct. But in plants, it never happened once…

I think most ecologists et al. should get rid of their strong moralistic and single-sided views and develop a more rational open mind to what happens to species in the world. So new ecologists can have their own views and new insights rahter than the same all over again.

Also they should change their terminology. So no more invaders, but neophytes (if it is a plant), pests: cannot be defined as it is personal. One calls a Eucalyptus a pest, the other calls it a beautiful and desirable tree, unnatural- anthropogenic. It is caused by humans but not therefore “unnatural”. And that is what you can prove: you can prove humans did something, of course. You cannot prove this is right or wrong in anyway. Biodiversity: applies to all species. So not only counting native species.
It would be as counting only true Native Americans as the people of the US and then saying that the population of the US is dwindling and the culture is impoverished, omitting the fact that there are almost 300 million Americans with a very diverse cultural life albeit not Native American.

And that is how I like to finish my long essay (sorry): do not fall into the trap of their wording, their ideologic views they call science, their extremely conservative view of the countryside. I’d say: be consistent and rephrase there words. Unnatural=anthropogenic etc.

Their view in general is rather similar to extreme conservative views in culture and the result is the same: killing things, eradicate things and trying to install a black-white thought-pattern in general towards newcomers. That is the mainstream in ecology. The people themselves BTW are not bad and I can get along very well actually. For instance: when it comes to humans they are not xenophobic at all and really hate the comparison. But the comparison is valid and Mount Sutro is not the only part of the world where this becomes clear. And like politicians they use soft words to cover up extreme things. In The Netherlands, there are loads of examples of that.

Good luck!

Stress-tolerant plants that are less tolerant of disturbance usually occur in really harsh areas like deserts and alpine areas. For instance, sajuaro cactus, joshua trees, and creosote bush are VERY tolerant of heat and drought stress. However, they do not tolerate fire, soil disturbance, or competition with weedy plants because they didn’t have to before modern humans came around. In fact, one creosote bush clone is over 10,000 years old! Soil disturbances can take years to recover in habitats dominated by these plants… sometimes even centuries. Combinations of invasive grasses and increased fire frequency are threatening the dominance or even existence of these species in many cases.

Another example of ‘stress tolerant’ plants is the ‘cushion’ plants that occur in alpine areas. These are extremely tough against cold, drought, wind, etc, but one stomp can kill a plant that is centuries old. Fast changes in climate can also do that.

Some of the chaparral plants act a bit like stress tolerants, albeit adapted to some types of disturbance (fire). Coast live partially fit the description, but not completely because they produce so many seeds. i’ll bet some Eucalyptus trees meet the characteristics too although the ones naturalized around Sutro and other parts of CA seem more like ‘competitive’ life strategy. The idea has been around in a while and I think was first proposed in this paper that is unfortunately unviewable if you don’t have a journal subscription:
http://www.jstor.org/pss/2460262

Can you give some examples of the stress tolerant plants you mean? I’m thinking if they can tolerate stress, but not disturbance, they must have interesting adaptations.

Although I am not always successful, I try to draw a distinction between ‘introduced’ and ‘invasive’. Certainly not all introduced plants are invasive. As you point out, we use a lot of them and in fact rely on introduced plants for most of our food and many other things. No one really understand why some plants become invasive in an ecosystem and others don’t. Or, at least, no one I know or have talked to understands it. Maybe someone does, or did in the past. It seems to me very similar to what is happening in the economy with a few large corporations gobbling up or outcompeting the small ones… or a bit like a disease that does not necessarily kill its host.

Obviously we can’t go back to hunter-gatherer ways with our current lifestyle. We seem to be ‘stuck’ with a lifestyle that is unsustainable in the long term, and hoping technology fixes things and moves us on to something new… hopefully that works out. Some days I think it will, others I don’t. I also think that around our cities, many areas are kept in a state of early succession… especially fire clearance areas and introduced native grasslands. Some of the chaparral, oak woodlands, and perhaps some eucalyptus forests have reached a more stable state (the ones I have seen less so, it will be interesting to someday see Sutro which sounds like it has a diverse understory!). Maybe there are ways we can live in cities to reduce our disturbance that sends ecosystems to early successional states, and perhaps invite more of nature into our cities. I think it is ‘crashing’ ecosystems to early successional states that bothers me, rather than which plants are native and which aren’t. I do, on a personal level, really love the CA native plants though. Somehow I feel more of a connection to them than most of the introduced plants…

I glanced at the mycorrhizal issue and it sure looks complex and poorly understood:
http://scholar.google.com/scholar?q=invasive+plant+mycorrhizae&hl=en&btnG=Search&as_sdt=1%2C46&as_sdtp=on

It seems that by definition early seral plants steal from or ignore the fungal network… From my brief glance though, many eucs are mycorrhizal too at least in their natural habitat. Maybe one day they will even form symbiotic veg communities with the oaks. I tend to think they won’t but i may be too pessimistic. Indeed there is so much we don’t understand, which is why it is so hard trying to make management decisions. In the end people try to use science, and it’s a good tool, but a lot of times our gut feelings end up giving better answers.

The stress tolerants have survived the many years of droughts, floods, heat waves, etc. They are not adapted to modern human society and with their slow generation times may die off before they can adapt to deal with urban disturbance and introduced plants. But like I said I am a pessimist. We’ll see…

I don’t know if I’d call introduced plants “weeds.” Humankind — in fact all migrating creatures — deliberately or inadvertently move plants around. Plants use that dispersal mechanism. Of course, the plants probably didn’t count on jet planes… but they probably did use the jet stream. I do think that one of the things many ignore is natural succession, as well as natural population booms and busts. Stable states are an exception rather than a rule. And our entire way of life depends on introduced plants, from the stuff we wear to the food we eat to the things we grow in our gardens or the lawns our kids play on. We couldn’t live in tepees of hide and poles, or eat acorn flour and fish as a staple diet. Some of the plants that were food — “Pigweed” for instance — are no longer edible in nitrogen-rich environments.

I would imagine that what stress-tolerant plants need is flexibility — the ability to withstand drought, temperature fluctuations, animal predation. It may be that ones that thrive in very marginal conditions invest in fewer seeds but make them hardier. If they are indeed more competitive, then they would not need our help. They would be around, and come right back when the population of the ruderals crashed. It’s interesting, though, that some of the native plants also need disturbed conditions — lupine is one.

Do you have a reference for the non-connection to the myco network? From what I could discover, it’s certainly not true of eucalyptus. I can’t imagine why that would happen, but if it does, I’d be interested. And yes, I’d love to know what’s happening in the century-old forest. (And if it were indeed “my forest” I would try to find out. It would be an amazing place for citizen science.)

The moderation definitely makes sense but there is no reply link at all on the messages with a lot of replies. I think it is just so they don’t get too squished to the right side of the page.

‘Invasion ecology’ is still a very poorly understood thing, so of course I can’t say that the lack of predators thing is certainly true. I have also heard the theory that invasive plants either don’t connect to the mycorrhizal network, or connect to ‘steal’ resources without contributing. It would be very interesting to see if the plants at Sutro have developed a similar mycorrhizal network to native habitat, since it has been there so long. Of course, it is extremely hard to study since it consists of tiny threadlike mycelium in the earth. It might be fun to see which fungi are in Sutro though. (On a side note, have you tried any of the new mobile citizen science programs like Project Noah? Pretty neat stuff)…

My gut feeling is that if plants with a million seeds always did better than plants with a thousand seeds, the former would be everywhere and the latter would not exist. There must be some evolutionary process that gives advantages to plants that produce less seed. Some say that stress-tolerant plants produce less seed than ruderals, and are in it for the ‘long run’. Perhaps the increase in human disturbance and impacts is why the ‘ruderal’ (‘weedy’) plants are doing so well near the city. In any event as it turns out evolution involves a lot more symbiosis, and a lot less direct ‘battling’ and competition, than originally thought. You’ve probably already noticed this intuitively since you’ve commented on the connectivity of the organisms of Sutro. And, like you said, the trophic web is just extremely complex. So much we don’t understand! It’s too bad people weren’t interested in doing science when they introduced the weeds. Of course the Native Americans had tremendous cultural ecological knowledge but alas most of that is now lost because they were either killed off or removed from the land.

I’ll look you up if I am out your way! After all this discussion, I am really curious about your forest now, I must admit.

Your reply came through fine, but we moderate comments here because like any popular and active site, it gets tons of spam. We don’t really want this website carrying ads for performance-enhancing pharmaceuticals… Sometimes comments take a while to show up. Especially because we do try to respond to comments here. So if there are a lot of them, it may take a few days.

I’ve come across the no-predator theory, but I’m not sure how accurate it is in this context. It may also be that the more successful plants evolved in a predator-rich environment, and responded by out-producing them. (Have you read Guns Germs and Steel?) A plant with a million seeds will have a better chance of passing on genes than a plant with only a thousand. And a plant that erupts early and stays longer will also have a better chance at populating the place. I haven’t heard that SF’s native plants do worse because they’re victims of predation. (Except the lupine – it got hit by a fungus one year. But then, the non-native fuchsia got hit by a mite and we can hardly grown them in SF any more. Fungal predators and mites seem to be more of a problem than megafauna — butterflies upward. Consider Sudden Oak Death.) I think the trophic web is a *lot* more complex than we suppose.

Spring has been lovely and rainy (which is also lovely!) by turns. If you come by SF any time, I’d love to show you the forest. If it still exists.

Anyway, we don’t honestly know every species that lived in bunchgrass stands because most of them were destroyed before people were paying attention. Certainly they didn’t support birds that live in tree habitat (except maybe some in oak savannahs). They did support a unique ecosystem that is now almost completely gone. I am not saying Sutro is the best place to restore this habitat type, but I think it is really sad if you aren’t valuing it as a unique and complex ecosystem, just beacuse it doesn’t have as much charismatic megafauna (well, coastal prairie did have lots of elk and antelope, but not anymore and no room in SF for them anyway…) If every part of the world had habitat with 50 species of birds, but it was the same 50 species of birds across the whole world, then we are still left with less biodiversity than if we have 1000s of habitat types, each with 20 species of bird.

The anise swallowtails are a neat story, and hopefully the fact that fennel has a new predator will help it move from invasive to a normal part of the ecosystem. As for coyotes, I love them, they are one of the most amazing and adaptable species on Earth, but they certainly don’t need our help. They will be fine regardless of what we do, even if we paved everything we’d still have coyotes. So they aren’t really an indicator of a healthy ecosystem per se.

The reason invasive plants produce more seed or plant material is probably largely because they don’t have as many predators. This in turn means they are contributing LESS to the trophic web, not more. Like you said, animals are more adaptable than us humans think, and they are adapting to use these invasive plants. Unfortunately the less adaptable animals – the specialists – may go extinct or severely decline rather than adapting. You are still left with a complex natural system, but less so if extinctions don’t occur.

Anyway, I hope you are enjoying the spring. I was just in CA and did enjoy being out in the canyons, even the ones with eucalyptus. Fog season is coming, make sure to get out there and enjoy the fog drip!

Also: wildlife is adaptable. Though it may have evolved over millions of years, it doesn’t mean that it’s tied to that specific habitat, because those change, too. Anise swallowtail butterflies (native) are adapted to non-native fennel… and it’s the same story with a number of other insects. Coyotes (native) use non-native bushes for cover, and hunt native gophers and non-native rats. Bandtail pigeons (native) happily eat non-native seeds and berries and dine on non-native grains at (non-native) bird feeders. Gophers (native) feed on the bulbils of yellow oxalis (non-native). Hawks and owls eat gophers (native) and rats and mice (some native, some not). And so on.

The reason I say that native vegetation is not that great: The reason why “weeds” get ahead in the competitive race is because they’re more prolific. They make more seed and fruit or they grow for a longer period or they can deal with more variation in soils and growing conditions. All this also makes them better habitat and better as a food source. The only exception are a few specific organisms (e.g. the Mission Blue butterfly) that is tied to a specific plant (lupine, in this case) for reproduction — though even those butterflies use non-native flowers as a nectar source.

Bunchgrasses support different animals than trees, no doubt. But, bunchgrass habitat has been destroyed at a much higher rate than woodland (though both have been destroyed). Remember that the animals that use the eucalyptus also can use the redwoods, the mixed evergreen forest, or any of the other eucalyptus groves in the area. Bunchgrass-reliant species just have nowhere left to go

Or read this description of the rich habitat of this forest.

Bunch grass is not that great for animals or birds. They need places to hide and nest and eat.

Thanks for commenting. I see (and respect) your strong preference for native plants.

What we love here is the whole amazing 125-year-old ecosystem, the dense cloud forest in an urban area and the wildlife — birds, insects, reptiles, mammals — that live there. (Ironically, in a comparison of oak-bay forest and eucalyptus forest near Berkeley, the biodiversity was equal in the two areas except that the eucalyptus forest had fewer rodents…)