Sunday, February 26, 2012

Pithy Python Ponderings: Invasive Species are Wickedly Inconvenient

               Invasive species are a wicked inconvenience to those concerned and to those unaware. Invasion biology is the study of an ecological wicked problem.[1] The intentional or accidental release due to human activities and subsequent establishment of a new species into an ecosystem, in which the novel species has no co-evolutionary interactions, impacts the system irrevocably. Burmese pythons are a charismatic example of an ecosystem undergoing human induced change. The pythons are also an example of the complexities of the issue of invasive species and the wicked nature of any conversation. 
                In 2009 I wrote about the larger than life snake [Thompson. Pythons, People & Pathways: Invasive Species Slither In. Invasive Notes. August 22, 2012] and my up-close and personal controlled encounter with it. Now almost three years later, the saga continues inextricably towards a logical end.  In a recent study reported by Craig Pittman,  "... a lot of animals that used to be seen in the Everglades are gone — apparently  gobbled up by the invading snakes." [Pittman. When pythons take over Everglades, raccoons, rabbits and other small mammals vanish. Tampa Bay Times. January 31, 2012]  The study published by the National Academy of Sciences (PNAS) and referred to by Pittman in some detail states in its discussion that "[n]umerous lines of evidence implicate introduced Burmese pythons as the primary cause of dramatic declines of several species of once-abundant mammals in ENP."[2]

               In the current misunderstanding of what science is and the confusion between fact, value and opinion, we feel obliged to present all points of views equally neatly confusing each component and producing an homogenized miasma of beliefs. Because science is about the repeated testing of hypothesis and not about absolute facts as received dogma, we are treated to a system that equates fairness with science. We feel obligated to closely inspect occasional hyper-opinions as fact. And so we get today's extra-ordinary journalistically bombastic headline: "Are pythons overrunning the Everglades? Some experts now say no."[3] On the face of it, the report simply notes that there are more opinions in the world than those in the reviewed study from the National Academy of Sciences. The problem is that in the PNAS paper we have a proposition that can be tested and either sustained or proved wrong, and in the two opinions from the Tribune article we have un-testable value statements which may or may not be testable. 

                  But as surely as tweets can fly and hogs have legs, we will hear that there is no consensus on any measurable impact of the establishment of a novel species in the Everglades.   This balance in the name of fairness results in logical fallacies of the 2 = 11 type. What is really called for if some feel the study is problematic is a testable model of their position with their methodology explained and their conclusions stated. To this we throw in the empirical  evidence debate that occupies dark corners of controversy. As my friend John  Waugh points out that " Most of us lack any empirical evidence that the light bulb goes off when the fridge is shut either."[4] We then use journalism to stir the pot of controversy until there is a virtual public sector boiling that serves to attract more and more uninformed opinion creating a congress of expectations.

               That non-indigenous pythons as a top predator or keystone species may be dramatically altering an ecosystem should come as no surprise. According to a Science Codex article   "it is predator/prey relationships (not competitor or mutualistic relationships) that provide the necessary stability for almost infinite numbers of species to exist in ecosystems. They do so by keeping the size of species populations in check at supportable levels. ..When prey are high, predators increase and reduce the number of prey by predation. When predators are low, prey decrease and thus reduce the number of predators by starvation. These predator/prey relationships thereby promote stability in ecosystems and enable them to maintain large numbers of species."[5] This strongly supports the study and of course is never mentioned when competing opinions are submitted for consideration as science construed in terms of journalism.

               Because invasive species issues are a form of a wicked problem we tend to skip the science when a testable conclusion does not fit our value system or our a priori desired outcomes. Because the issues of invasion biology and ecology are so complex, by the time we absolutely know we have a problem, we no longer have the resources to actually do anything about the resulting alteration of the ecosystem itself. When I was involved directly in the nursery industry and managed fields and green houses, I did not need to be overwhelmed by a new weed or insect in my production to react, and if my very small managed system began to yield unexpected results, I would identify the usual suspects of physical change as well as take immediate steps to eradicate or control the new species without waiting for the complete loss of the crops. So while it is true that our ecosystems are complex adaptive systems with many internal signals that create the great and small cycles, they are because of their very chaotic nature extremely sensitive to small novel perturbations which can quickly change the character of the system. If farmers awoke every morning and decided to wait and see what novelty might do to their harvests we would all starve.

               There is a tendency to overreact in the other direction and misunderstand the nature of science based papers and the information therein. Invasive species problems rarely if ever have a linear solution. Once the cat is out of the bag it can almost never be stuffed back in having at the very least scratched a hole in the bag in the re-stuffing attempt and therefore altering the bag (the system) forever.  Driving a solution that depends upon human activity disappearing in a world of 7 billion souls achieves little in the long run. And most importantly invasive species are considered from a human-centered point of view mostly because the people writing about and living in the ecosystems are human. One can perhaps wish there were no humanity, but the exercise is an adventure into the null space of human reality. We are here and we are part of nature; and for now we must find ways to live in nature and with it. The Dorcas et al. paper is a form of early warning, and may actually come too late to affect any significant reversal of the process of integration of a novel species into south Florida. We may actually be in the control and management phase adjusting our expectations of local ecosystems services that we can recover from the resources that are being altered.

               Buried way down in the philosophical basement of all invasive species debates is the concept of ecological systems and the services the resources provide. In the cellar of ideas where few bother to tread, are value systems that state that ecosystem services are infinite, that ecosystem resources can be owned and dispensed on a who can pay basis, and that ecosystem services are separate from human activities, needs and wants. It is here that the idea that the Everglades is a vast other just waiting to be processed by human industry and intellect resides; and implicit in this is the idea that nothing is sacred, that everything exists to be subservient to the desires of humankind today. If there is nothing of value that we think we need in the Everglades with pythons then it is clear that diverting scarce resources to their control is problematic . Because banks do not put a value on the spirit of place, of what concern are a few less rodents and mammals to us? In other words why worry about the introduction of a new species to an old ecosystem when change is all around us.  


[1] Thompson. 2011. The Wicked Inconvenience of Invasive Species: A Reader in Complexities. InvasiveNotes.
The discussion of invasive species issues may be framed by the planning theory of “wicked” problems. Rittel & Webber's formulation of wicked problems specifies ten characteristics, perhaps best considered in the context of social policy planning, 1- 10. Jeff Conklin Ph.D., a computer scientist expanded, or rather refined the definition, with 11-14, below.

1. There is no definitive formulation of a wicked problem.

2. Wicked problems have no stopping rule.

3. Solutions to wicked problems are not true-or-false, but instead better, worse, or good enough.

4. There is no immediate and no ultimate test of a solution to a wicked problem.

5. Every solution to a wicked problem is a "one-shot operation"; because there is no opportunity to learn by trial-and-error, every attempt counts significantly.

6. Wicked problems do not have an enumerable (or an exhaustively describable) set of potential solutions, nor is there a well-described set of permissible operations that may be incorporated into the plan.

7. Every wicked problem is essentially unique.

8. Every wicked problem can be considered to be a symptom of another problem.

9. The existence of a discrepancy representing a wicked problem can be explained in numerous ways. The choice of explanation determines the nature of the problem's resolution.

10. The planner has no right to be wrong (Planners are liable for the consequences of the actions they generate). Further, the planner or designer (solving the problem) has no inherent right to solve the problem, and no permission to make mistakes.

11. The problem is not understood until after formulation of a solution.
Stakeholders have radically different world views and different frames for understanding the problem

12. Constraints and resources to solve the problem change over time.

13. The problem is never solved.

14. Wicked problems are often "solved" (as well as they can be...) through group efforts.

15. Wicked problems require inventive/creative solutions.

16. Every implemented solution to a wicked problem has consequences, and may cause additional problems.

[2] Dorcas et al. 2012. Severe mammal declines coincide with proliferation of
invasive Burmese pythons in Everglades National Park. PNAS. accessed February 26, 2012]
Received for review in September of 2011, the paper has eleven authors. Given the point I shall try to make today, I think it important to list them by name and their institutions of record:  Michael E. Dorcas, Department of Biology, Davidson College, Davidson, NC 28035; John D. Willson, Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Robert N. Reed, Fort Collins Science Center, US Geological Survey, Fort Collins, CO 80526; Ray W. Snow, Everglades National Park, National Park Service, Homestead, FL 33034; Michael R. Rochford, Fort Lauderdale Research and Education Center, University of Florida, Davie, FL 33314; Melissa A. Miller, Department of Biological Sciences, Auburn University, Auburn, AL 36849; Walter E. Meshaka, Jr., State Museum of Pennsylvania, Harrisburg, PA 17120; Paul T. Andreadis, Department of Biology, Denison University, Granville, OH 43023; Frank J. Mazzotti , Fort Lauderdale Research and Education Center, University of Florida, Davie, FL 33314; Christina M. Romagos, Department of Biology, Davidson College, Davidson, NC 28035; and Kristen M. Hart. Southeast Ecological Science Center, US Geological Survey, Davie, FL 33314. The study was edited by Peter M. Vitousek, Stanford University, Stanford, CA, and approved December 21, 2011.

[3] Barbara Liston. Are pythons overrunning the Everglades? Some experts now say no. Chicago Tribune. February 24, 2012. [accessed February 26, 2012],0,5920161.story?page=1
"Do I think we have an impending disaster? I don't think so," said Scott Hardin, exotic species coordinator for the Florida Fish and Wildlife Conservation Commission.
"That study should have never made it to the light of day,"

[4] personal communication email February 26, 2012

[5] Solved! Mystery that stumped ecosystem modelers. ScienceCodex {Source: National Science Foundation} February 22, 2012. [accessed February 26, 2012]

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