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Invasion Biology

By Michael Ogden
Natural Systems International

An article by Mark Davis in Nature..this is all old hat to you, but I like his way of thinking (recently purchased a copy of “Invasion Biology, pub OUP, 2009), and every time I think about how many land managers never took a class on evolution and want to hang on to some notion of what’s native, and what’s not?

Unfortunately he doesn’t say much about Phragmites …but every time I ride the train from Newark International into NYC, I wonder what else could possible grow there?


  1. Kevin Heatley says:

    Davis jumps from descriptive science to normative statements about value and appropriate response actions without discussion of the underlying philosophical assumptions. Who are the beneficiaries and whose interests are being advanced? His focus is extremely narrow and his conclusions have more to do with unexamined personal bias than science.

    I do not dispute the science of invasion biology but normative statements require careful analysis and justification. Our response to the ecological stew we are creating is a matter of ethics not descriptive science. I have yet to hear any proponent of novel ecosystems fully address these fundamental issues. Instead, we hear that it is just the way nature works, these organisms supply some benefits and it is too big of a shit mess to fix anyway.

    Well, if I am an American Ash about to see my species whiped out by Emerald Ash Borer, or an American Dogwood dying of imported anthracnose fungus, I am not going to be convinced by arguments that EAB helps feed woodpeckers or that the pretty Korean Dogwood is a suitable alternative to my existence.

    The logical conclusion of the novel ecosystems argument is – why bother at all? If it holds the soil, provides food, helps clean the air, and we think it has pretty flowers in the spring, hell, let it displace organisms and systems that have existed for hundreds of thousands of years. Why should we care about species extinctions at all?

    Again, this is the realm of ethics not science.

  2. Peter May says:

    It is the realm of ecological science Kevin, which should serve to objectively inform the ethical debate. I dont see investigations into understanding novel ecosystems as giving up ethically. There is a lot to be learned there or I wouldn't have given a decade of my life up to study it. Scientifically understanding these systems (not just anecdotally) and how they function is key to making smart management decisions. This is not an either or situation. Novel ecosystems cover a lot of territory and while I believe some may be the best fit for a situation and relative effort to turn it back, I think efforts to counter EAB and especially efforts to prevent new invasions may be worthwhile.

    When a species is threatened with extinction it is always worth extreme efforts in my mind. Don't confuse those interested in scientific understanding of the matter with being ethically lacking. Science is supposed to be objective, but at the end of the day we use the information to hopefully make some decisions that are informed, and not based solely on our passions and what we "feel" is ethically right or wrong.

    I'm actually on the train to NYC pulling into Newark soon. Disturbance creates opportunity, tough living along the train lines although I saw my first grey fox walking the tracks in DC!

  3. Michael Ogden says:

    Yes…I love it …as we are in the beginning of the 6th mass extinction, and the Anthropocene, we are probably living in one of the most fascinating and interesting times in human history.

    Now that Christina and I have taken on two conservation easements – Black Oak and Wetlands (two endangered species) we (Wife and I) get to look at these issues in a very direct way. The Black Oak easement is fenced from the neighbors cows, but the turkeys come and eat the acorns..so there are no more oaks. We are adding some old limbs under the oaks so the acorns get started and eating the turkeys (introduced by Cal Fish and Game).

    There are northern cottonwood in the wetlands…California native plant people hate them..but there are also masses of Himalayan blackberries (introduced by Burbank)…we are removing blackberries (an attempt- its war) and planting elderberry, ash, Q. lobata, and buckthorn; and a fern….restoration? regeneration? The rushes that grow in the wetlands were established by the Pomo Indians – basket making material –

    There is a small patch of native grasses in the pasture, and a thistle , probably Cirsium vulgare that would puncture a bull's hide. Thistle is gone (temporarily?) after some aggressive hoeing…

    The deer are eating my strawberries and pomegranates so venison is on the menu… swallows are feeding voraciously (nesting sites are encouraged)

    What belongs? What goes? I never thought that I would think about a pasture so intently. And the very act of thinking about it suggests why this is the Anthropocene…till we are all gone.

    We expect visitors… all are welcome to contemplate what was oak/redwood forest with native grass savannahs, and a huge wetland which eventually drains into the Pacific (it floods every winter during the rainy season..incredible).

    And yes, grape vines go in this September. How's that for restoration effort?

  4. Michael Ogden says:

    This is great stuff for a conference to be hosted by the non-profit. Get all sides…"weeds of the west folks", native species enthusiasts (apparently we're going to lose most if not all of the frogs in the Darien – last remaining region in Central America), agriculturalists (how do we feed everybody?), fisheries folks, etc….Get Mark Davis there with Keith. What about EO Wilson and biophilia?

    Let's talk about BioRegions… are we becoming planetary managers with teams of people responsible for particular bioregions? What goes? What stays? What if a bird gets blown across the Atlantic and ends up in Florida? Do we xterminate the bird? Return it to Africa? What do we do with people like Johnny Appleseed? (Provided apples for cider because the water was undrinkable). Can I bring teosinte from Mexico to improve my corn? Can I take my disease resistant corn back to Mexico.?

    Nature asked a bunch of people – docs, entomologists, ecologists, limnologists..etc if they could eliminate the mosquito, would they? If you could eliminate the Asian Grass Carp would you? In the great lakes? Mississippi? What can the control folks tell us? Tamarisk was good in the 40's, bad in the 90's, and is now good again? What's going on here?

    How would you manage a bioregion? What do you do if a new species appears? If a Mexican appears do we send him back?

    Start the conference!!”

  5. Chris Streb says:

    Here is another line of conversation regarding the same article. Interesting counterpoints.


    I find perhaps the most compelling scientific rationale for native plant preference is the degree to which natives enhance insect biomass. Anyone want to argue that the quality of energy in simple sugars from fruiting plants is superior to insect protein? This points highlights for me the elaborate network of ecological relationships that are mostly unknown and unseen. The dynamic changes occurring in the world are no doubt upsetting relationships that evolved over centuries or millenia. In the case of the relationships between plants, insects and birds, some evidence suggests that migratory birds are declining in population and in weight. Is their starvation literally a canary in the coal mine for humanity? Are we in essence turning our world into simple sugars while the population explodes? Who wants to wait for research dollars to find out?

  6. Amy Nelson says:

    Biologist and author Mark Davis sent this comment to Rhizome's moderator to post in response to this discussion:

    A primary goal of our essay was to promote discussion and reflection on ideas that may have been taken for granted for some time. Nature imposed rather severe space and citation constraints on us. This prevented us from providing additional information and comments that would have addressed some of the concerns that have been raised. We told the Nature people that by not being able to include this material, we would be opening up doors for criticism, but they held firm. Who knows, they may have wanted to stir up controversy. All the authors certainly support efforts to manage the damage done by species causing great economic harm, e.g., the Emerald Ash Borer, or pathogens that threaten human health and/or crops and domesticated animals. However, we do think that we need to set a high bar for intervention for species that are not causing any significant economic or health harm. We cannot garden the earth and efforts to do so often end up causing more harm than good. We are being inundated with so many new species that clearly learning to live with most of them is our only realistic option. We want to be sure that we reserve scarce public monies so that we can use them against the truly highly damaging species. We need to be very careful that we do not apply the word ‘invasive’ too easily. Once a species is declared invasive, it means it’s harmful, and basically obligates society to do something to remedy the “problem”. None of the authors believe we should just open the borders and let everything come in. We definitely support screening efforts to try to keep out species likely to cause great harm. But, we must stop vilifying weeds and other non-native species in general. Once something is demonized, almost any remedy is considered justified, including extensive use of chemicals and other major environmental disruptions. There have been a number of citizen and environmental groups that have been formed to try to counter this ‘war on weeds’, which they believe has been very damaging. Here’s one that contacted me yesterday in support of the essay: Fearless Fund http://www.fearlessfund.info/about-fearless-fund/

  7. Kevin Heatley says:

    The idea that "nature doesn't care, we do" is really anthropocentrism on steroids. I reject the concept of "nature" as a false construct that perpetuates the illusion of our species as different from the rest of the biota. But, please, before anyone jumps on it, just because we are part of "nature" that does not justify any action as inherently "natural" and then therefore good. That is the naturalistic fallacy.

    In addition, the idea that all value resides in our species interpretation of worth is just silly. All organisms have interests and hence can be considered to "value" certain environmental conditions. Just because they may have varying levels of cognitive functioning does not invalidate their interests. If cognitive functioning were the criteria by which valuation hierarchy's were determined than most humans would be subservient to a privileged class of overlords. Oh wait, we already have that in our corporate nation states and under our current economic system.

    The central question is how we address the interests of other species. If we f**k up their environment by randomly mixing biota do we have a moral obligation to correct the situation as best as possible? Or do we just tell them' "too damn bad, evolve quickly or die off"?

    What is the proper scope of our moral concern? Is everything and everyone else on this planet just tools to meet our individual needs or do we define ourselves by our relationship to the rest of the biota and culture? Descartes was a jackass who tortured animals to show they were just machines. "I think, therefore I am." What a bunch of elitist crap. It should have been "I am because we are". Understand that and integrating the basic survival needs of other species into our decision making becomes more than just a matter of preference and the destruction of their habitat more than just "novel".

    But this is ethics, not science. Prescriptions for how we should behave can be informed by the science but the science does not determine the right or wrong of a response. (And yea, I know ethics is rooted in biochemistry and free will is an illusion, but that is a discussion that will definitely get the thought police swat team mobilized.)

  8. Kevin Heatley says:

    My last post was in response to an off-blog discussion with Dr. May and makes little sense without his comments also being posted. In fact, my comments may make little sense in general but that is for the blog lurkers to decide.

    I response to Mark's comments, it should be noted that they are all value judgements that fall outside of the science of biology. They fall within the scope of ethics and require an examination of the underlying ethical principles.

    In addition, while I am no fan of the agro-chemical industry the organization he mentions "Fearless Fund" appears on their website to be fanning the flames of chemophobia. This is a separate issue that is amendable to scientific analysis.

  9. Anonymous says:

    my problem with all this "novel" stuff is that their major premise is that we, ecologists should accept that it is a new world. As Kevin said, I too have not seen a lot of guidance on where we should draw the line invasive vs. super invasive? how we could best put our limited resources to best use. So, until I get more than a lot of rhetoric, I will continue to practice ecological restoration and to replace non-native and invasive species with native species to the best of my ability. I subscribe to the teachings of Doug Tallamy, who espouses the yet-to-be-fully discovered value of native plants.

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