Over the past few weeks, we’ve been hosting an interesting debate on our website, between US-based Charlie (who’s commented here before) and Gov Pavlicek , a climatologist from the Netherlands (NL).  We think this conversation is interesting enough for its own posts. (In fact, it’s so long – currently about 12,000 words – it will be multiple posts. We’ve slightly edited all the posts for readability and focus, we believe without losing the argument.) When we post them all, we’ll link them here.

It started mid-April 2011, when Gov commented on a comment by someone who introduced himself as an Australian familiar with invasion ecology and practice, and said he would regard “eucalypts in the Sutro as not part of the ecosystem of the landscape.”

GOV: INVASION BIOLOGY HAS BECOME AN IDEOLOGY

Gov responded to that, and his response is given below.

“This is the basis for all clear-cutting of so-called nonnative trees. Ecology, conservation biology, restoration ecology and invasion ecology are different from most scientific fields in that they have become an ideology themselves, rather than used only in support of(nativist) nature organizations. Many ecologists actively support, or even work within, conservation groups.

“If you pick up any 5 books on invasion ecology used in Universities, and you realize 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 climatologists often have their own values 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, also tries to tell us what we should think about it and what we should do. That is up to society, not the views of a climatologist who cannot claim that his personal preference is somehow more valid than anyone else’s, just because he studied climatology.

“In ecology, the story is quite different. Apart from constant negative terminology about newcomers (such as: invaders, pests, plagues, unnatural, deviant, prolific, overcrowding)  that cannot be proven in a unbiased, sound scientific way, they also tell us what we should do. The word “eradication” is used constantly in many scholarly books.  This indoctrinates students with the same vision of newcomers in nature. It is difficult to talk to them ( as I have done) without judgmental wording on their side. In my view, this is highly unscientific and reflects an ideology. 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 eucalyptus is not a part of the ecosystem. It clearly is part of the ecosystem–  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 at least, not heavily influenced by man. There’s a name for these ecosystems: novel ecosystems.  Conservation biologists seem to hate this, 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 certain 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 cover of some native plant, compared to some invasive. I rarely see any model that can predict 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.

“I think most ecologists et al. should get rid of their ideological 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 rather than [repeating the biases of their mentors].

“Also they should change their terminology. For example:

• No more “invaders”, but instead neophytes (if it is a plant).  
• “Pests” cannot be defined, it’s subjective. One calls a Eucalyptus a pest, the other calls it a beautiful and desirable tree.
• “Unnatural” should be “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 like 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.

“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 are not bad and I get along very well with them 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.”

CHARLIE: BEING COMPLETELY UNBIASED IS IMPOSSIBLE AND SILLY

Charlie (who is not the Australian invasion biologist whose comments sparked the discussion) responded to Gov’s comment:

“You mention global warming and think that ecologists, unlike climate scientists, have some racism-based bias and are secretly conservatives. In fact the story is very similar to that of climate change and with a few words changed, these sorts of comments look like something right off of a global warming denialist’s computer. As with climate change, the science is very clear. CO2 warms the climate. Smoking causes lung cancer. Coal mining pollutes watersheds. Invasive  (not necessarily non-native) species are very, very clearly linked with ecosystem service loss and decreased biodiversity during initial invasion.

“This is not true for Sutro any more because it is a very old introduced forest and the ecosystem it replaced is already lost forever. I [personally] 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 cherry-picking data. If you have anecdotal evidence, by all means share that. Science isn’t the answer to anything. My anecdotal 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 agree with.
• Yes, there are issues with Monsanto and herbicide, and it is understandable to oppose 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.

“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.”

[Edited to Add: The discussion continues here.]