Tag Archives: conservation ecology

Is Conservation Ecology a Science?

Now this is certainly a silly question. To be sure conservation ecologists collect much data, use rigorous statistical models, and do their best to achieve the general goal of protecting the Earth’s biodiversity, so clearly what they do must be the foundations of a science. But a look through some of the recent literature could give you second thoughts.

Consider for example – what are the hallmarks of science? Collecting data is one hallmark of science but is clearly not a distinguishing feature. Collecting data on the prices of breakfast cereals in several supermarkets may be useful for some purposes but it would not be confused with science. The newspapers are full of economic statistics about this and that and again no one would confuse that with science. We commonly remark that ‘this is a good scientific way to go about doing things” without thinking too much about what this means.

Back to basics. Science is a way of knowing, of accumulating knowledge to answer questions or problems in an independently verifiable way. Science deals with questions or problems that require some explanation, and the explanation is a hypothesis that needs to be tested. If the test is retrospective, the explanation may be useful for understanding the past. But science at its best is predictive about what will happen in the future, given a set of assumptions. And science always has alternative explanations or hypotheses in case the first one fails. So much everyone knows.

Conservation ecology is akin to history in having a great deal of information about the past but wishing to use that information to inform the future. In a certain sense it has a lot of the problems of history. History, according to many historians (Spinney 2012) is “just one damn thing after another”, so that there can be no science of history. But Turchin disagrees (2003, 2012) and claims that general laws can be recognized in history and general mathematical models developed. He predicts from these historical models that unrest will break out in the USA around 2020 as cycles of violence have broken out in the past every 30-50 years in this country (Spinney 2012). This is a testable prediction in a reasonable time frame.

If we look at the literature of conservation ecology and conservation genetics, we can find many observations of species declines, of geographical range shifts, and many predictions of general deterioration in the Earth’s biota. Virtually all of these predictions are not testable in any realistic time frame. We can extrapolate linear trends in population size to zero but there are so many assumptions that have to be incorporated to make these predictions, few would put money on them. For the most part the concern is rather to do something now to prevent these losses and that is very useful research. But since the major drivers of potential extinctions are habitat loss and climate change, two forces that conservation biologists have no direct control over, it is not at all clear how optimistic or pessimistic we should be when we see negative trends. Are we becoming biological historians?

There are unfortunately too few general ‘laws’ in conservation ecology to make specific predictions about the protection of biodiversity. Every one of the “ecological theory predicts…” statements I have seen in conservation papers refer to theory with so many exceptions that it ought not to be called theory at all. There are some certain predictions – if we eliminate all the habitat a species occupies, it will certainly go extinct. But exactly how much can we get rid of is an open question that there are no general rules about. “Protect genetic diversity” is another general rule of conservation biology, but the consequences of the loss of genetic diversity cannot be estimated except for controlled laboratory populations that bear little relationship to the real world.

The problems of conservation genetics are even more severe. I am amazed that conservation geneticists think they can decide what species are most ‘important’ for future evolution so that we should protect certain clades (Vane-Wright et al. 1991, Redding et al. 2014 and much additional literature). Again this is largely a guess based on so many assumptions that who knows what we would have chosen if we were in the time of the dinosaurs. The overarching problem of conservation biology is the temptation to play God. We should do this, we should do that. Who will be around to pick up the pieces when the assumptions are all wrong? Who should play God?

Redding, D.W., Mazel, F. & Mooers, A.Ø. (2014) Measuring evolutionary isolation for conservation. PLoS ONE, 9, e113490.

Spinney, L. (2012) History as science. Nature, 488, 24-26.

Turchin, P. (2003) Historical dynamics : why states rise and fall. Princeton University Press, Princeton, New Jersey.

Turchin, P. (2012) Dynamics of political instability in the United States, 1780–2010. Journal of Peace Research, 49, 577-591.

Vane-Wright, R.I., Humphries, C.J. & Williams, P.H. (1991) What to protect?—Systematics and the agony of choice. Biological Conservation, 55, 235-254.

The Anatomy of an Ecological Controversy – Dingos and Conservation in Australia

Conservation is a most contentious discipline, partly because it is ecology plus a moral stance. As such you might compare it to discussions about religious truths in the last several centuries but it is a discussion among scientists who accept the priority of scientific evidence. In Australia for the past few years there has been much discussion of the role of the dingo in protecting biodiversity via mesopredator release of foxes and cats (Allen et al. 2013; Colman et al. 2014; Hayward and Marlow 2014; Letnic et al. 2011, and many more papers). I do not propose here to declare a winner in this controversy but I want to dissect it as an example of an ecological issue with so many dimensions it could continue for a long time.

Dingos in Australia are viewed like wolves in North America – the ultimate enemy that must be reduced or eradicated if possible. When in doubt about what to do, killing dingos or wolves has become the first commandment of wildlife management and conservation. The ecologist would like to know, given this socially determined goal, what are the ecological consequences of reduction or eradication of dingos or wolves. How do we determine that?

The experimentalist suggests doing a removal experiment (or conversely a re-introduction experiment) so we have ecosystems with and without dingos (Newsome et al. 2015). This would have to be carried out on a large scale dependent on the home range size of the dingo and for a number of years so that the benefits or the costs of the removal would be clear. Here is the first hurdle, this kind of experiment cannot be done, and only a quasi-experiment is possible by finding areas that have dingos and others that do not have any (or a reduced population) and comparing ecosystems. This decision immediately introduces 5 problems:

  1. The areas with- and without- the dingo are not comparable in many respects. Areas with dingos for example may be national parks placed in the mountains or in areas that humans cannot use for agriculture, while areas with dingo control are in fertile agricultural landscapes with farming subsidies.
  2. Even given areas with and without dingos there is the problem of validating the usual dingo reduction carried out by poison baits or shooting. This is an important methodological issue.
  3. One has to census the mesopredators, in Australia foxes and cats, with further methodological issues of how to achieve that with accuracy.
  4. In addition one has to census the smaller vertebrates presumed to be possibly affected by the mesopredator offtake.
  5. Finally one has to do this for several years, possibly 5-10 years, particularly in variable environments, and in several pairs of areas chosen to represent the range of ecosystems of interest.

All in all this is a formidable research program, and one that has been carried out in part by the researchers working on dingos. And we owe them our congratulations for their hard work. The major part of the current controversy has been how one measures population abundance of all the species involved. The larger the organism, paradoxically the more difficult and expensive the methods of estimating abundance. Indirect measures, often from predator tracks in sand plots, are forced on researchers because of a lack of funding and the landscape scale of the problem. The essence of the problem is that tracks in sand or mud measure both abundance and activity. If movements increase in the breeding season, tracks may indicate activity more than abundance. If old roads are the main sampling sites, the measurements are not a random sample of the landscape.

This monumental sampling headache can be eliminated by the bold stroke of concluding with Nimmo et al. (2015) and Stephens et al. (2015) that indirect measures of abundance are sufficient for guiding actions in conservation management. They may be, they may not be, and we fall back into the ecological dilemma that different ecosystems may give different answers. And the background question is what level of accuracy do you need in your study? We are all in a hurry now and want action for conservation. If you need to know only whether you have “few” or “many” dingos or tigers in your area, indirect methods may well serve the purpose. We are rushing now into the “Era of the Camera” in wildlife management because the cost is low and the volume of data is large. Camera ecology may be sufficient for occupancy questions, but may not be enough for demographic analysis without detailed studies.

The moral issue that emerges from this particular dingo controversy is similar to the one that bedevils wolf control in North America and Eurasia – should we remove large predators from ecosystems? The ecologist’s job is to determine the biodiversity costs and benefits of such actions. But in the end we are moral beings as well as ecologists, and for the record, not the scientific record but the moral one, I think it is poor policy to remove dingos, wolves, and all large predators from ecosystems. Society however seems to disagree.

 

Allen, B.L., Allen, L.R., Engeman, R.M., and Leung, L.K.P. 2013. Intraguild relationships between sympatric predators exposed to lethal control: predator manipulation experiments. Frontiers in Zoology 10(39): 1-18. doi:10.1186/1742-9994-10-39.

Colman, N.J., Gordon, C.E., Crowther, M.S., and Letnic, M. 2014. Lethal control of an apex predator has unintended cascading effects on forest mammal assemblages. Proceedings of the Royal Society of London, Series B 281(1803): 20133094. doi:DOI: 10.1098/rspb.2013.3094.

Hayward, M.W., and Marlow, N. 2014. Will dingoes really conserve wildlife and can our methods tell? Journal of Applied Ecology 51(4): 835-838. doi:10.1111/1365-2664.12250.

Letnic, M., Greenville, A., Denny, E., Dickman, C.R., Tischler, M., Gordon, C., and Koch, F. 2011. Does a top predator suppress the abundance of an invasive mesopredator at a continental scale? Global Ecology and Biogeography 20(2): 343-353. doi:10.1111/j.1466-8238.2010.00600.x.

Newsome, T.M., et al. (2015) Resolving the value of the dingo in ecological restoration. Restoration Ecology, 23 (in press). doi: 10.1111/rec.12186

Nimmo, D.G., Watson, S.J., Forsyth, D.M., and Bradshaw, C.J.A. 2015. Dingoes can help conserve wildlife and our methods can tell. Journal of Applied Ecology 52. (in press, 27 Jan. 2015). doi:10.1111/1365-2664.12369.

Stephens, P.A., Pettorelli, N., Barlow, J., Whittingham, M.J., and Cadotte, M.W. 2015. Management by proxy? The use of indices in applied ecology. Journal of Applied Ecology 52(1): 1-6. doi:10.1111/1365-2664.12383.

Ecosystem Science to the Rescue

What can ecologists do to become useful in the mess that is currently the 21st Century? In Australia we have a set of guidelines now available as “Foundations for the Future: A Long Term Plan for Australian Ecosystem Science” (http://www.ecosystemscienceplan.org.au ) It is a useful overall plan in many respects and the only question I wish to discuss here is how we ecologists come to such plans and whether or not they are realistic.

We should begin by treating this plan as an excellent example of political ecology – a well presented, glossy brochure, with punch lines carved out and highlighted so that newspaper reporters and sympathetic politicians can present sound bites on air or in Parliament. One example: “Healthy ecosystems are the cornerstone of our social and economic wellbeing”. No arguments there.

Six key directions are indicated:

  1. Delivering maximum impact for Australia: Enhancing relationships between scientists and end-users
  2. Supporting long-term research
  3. Enabling ecosystem surveillance
  4. Making the most of data resources
  5. Inspiring a generation: Empowering the public with knowledge and opportunities
  6. Facilitating coordination, collaboration and leadership

Most ecologists would agree with all 6 key directions, but perhaps only 2 and 3 are scientific goals that are key to research planning. Everyone supports 2, but how do we achieve this without adequate funding? Similarly 3 is an admirable direction but how is it to be accomplished? Could we argue that most ecologists have been trying to achieve these 6 goals for 75 years, and particularly goals 2 and 3 for at least 35 years?

As a snapshot of the importance of ecosystem science, the example of the Great Barrier Reef is presented, and in particular understanding reef condition and its changes over time.

“Australia’s Great Barrier Reef is one of the seven wonders of the natural world, an Australian icon that makes an economic contribution of over $5 billion annually. Ongoing monitoring of the reef and its condition by ecosystem scientists plays a vital role in understanding pressures and informing the development of management strategies. Annual surveys to measure coral cover across the Great Barrier Reef since 1985 have built the world’s most extensive time series data on reef condition across 214 reefs. Researchers have used this long-term data to assess patterns of change and to determine the causes of change.”

The paper they cite (De’ath et al. 2012) shows a coral cover decline on the Great Barrier Reef of 50% over 27 years, with three main causes: cyclones (48% of total), crown-of-thorns starfish (43%) and coral bleaching (10%). From a management perspective, controlling the starfish would help recovery but only on the assumption that the climate is held stable lest cyclones and bleaching increase in future. It is not clear at all to me how ecosystem science can assist reef recovery, and we have in this case another good example of excellent ecological understanding with near-zero ability to rectify the main causes of reef degradation – climate change and water pollution.

The long-term plan presented in this report suggests many useful activities by which ecosystem studies could be more integrated. Exactly which ecosystem studies should be considered high priority are left for future considerations, as is the critical question of who will do these studies. Given that many of the originators of this ecosystem plan are from universities, one worries whether universities have the resources or the time frame or the mandate to accomplish all these goals which are essentially government services. With many governments backing out of serious ecosystem research because of budget cuts, the immediate future does not look good. Nearly 10 years ago Sutherland et al. (2006) gathered together a list of 100 ecological questions of high policy relevance for the United Kingdom. We should now go back to see if these became a blueprint for success or not.

De’ath, G., Fabricius, K.E., Sweatman, H., and Puotinen, M. (2012). The 27–year decline of coral cover on the Great Barrier Reef and its causes. Proceedings of the National Academy of Sciences 109(44): 17995-17999. doi:10.1073/pnas.1208909109.

Sutherland, W.J., et al. (2006). The identification of 100 ecological questions of high policy relevance in the UK. Journal of Applied Ecology 43(4): 617-627. doi: 10.1111/j.1365-2664.2006.01188.x

 

The Naïve Ecologist

I confess to being a member of the Naïve Ecologist Society. I began research when Zoology and Botany Departments typically consisted of a great mix of scientists working at different levels of biological organization from cells and molecules to ecosystems. As far as I can remember no one thought that it was our job to save the Earth or even a part of it. Our job was to do good science to help understand the processes we see in front of us. Physiologists studied ion transfer in the gills of fish, and muscle energetics, geneticists tried to unravel the genetics of protozoa, and developmental biologists tried to understand the embryology and endocrinology of sex determination. We thought that it was the universities’ job to do excellent teaching and research, and the government’s job to take care of the society and to protect and enhance our natural environment.

Now time warp about 40-50 years later. As far as I can see the molecular and cellular physiologists and geneticists are doing the same thing now as they did then. The tools of course are much improved, their knowledge base has vastly expanded, and modern genetic technology has provided insights into how things work that no one could have imagined long ago. But still (in my experience) if you talk to these sub-organismal biologists in general they will still not tell you they are trying to save the Earth by doing science. They will certainly twist and turn to convince the granting agencies that their work is critical to solving all the problems of humanity, but everyone knows that this is fluff and will be immediately tossed off when the money is delivered. But somehow at the present time it has become the job of the ecologist to save the Earth from human destruction. There is no time left to do pure ecological research to try to find out how ecosystems work and how species interact. We must have answers now to all the pressing questions of conservation biology, and if you wish to get funding for your research you had best try to bend your goals to the solution of climate change, ecosystem services, adaptation, and evolution in the days ahead. There is no time to think and study and observe, we must know now what to do. So we build models of unknown validity and speculate with little data about plans to save the Earth based on untested theory. No other postgraduate student or scientist in a university will operate under this imperative.

This would not be a serious problem if we had a better division between more basic ecologists in universities and more applied ecologists in government labs. Some of this division still exists in some countries, but in many cases governments have cut applied ecology research programs to save money and have turned their applied ecologists into paper pushers assigned to stamp approval on environmental impact statements they have no time or resources to evaluate. So a partial solution to this problem would be to fund more applied ecology positions in government with the resources and regulatory authority to protect as much ecological integrity as possible. State of the Environment glossy brochures are not a substitute for ecological information on environmental impacts, and when you read them carefully you can begin to appreciate how little is truly known about the state of our planet.

I enjoy listening to science programs on the radio as it provides a tiny window into what the radio stations think we need to know about science in action. Science broadcasters usually concentrate on the physical sciences because since they have the big money, they must be very important, then on the space sciences, since no one wants to think about how things are on earth, and finally on behavioural ecology, nice stories that warm our hearts about how bees and birds and orchids make a living. The overall mantra is relatively simple: avoid population ecology lest you have to think about the problems of eternal growth and the human population, and avoid community and ecosystem ecology lest you have to provide more bad news about collapsing coral reefs and the impacts of climate change. Keep the Pablum flowing and hope that the Hadron Collider will save us all.

There is a certain irony is the vast expenditures now being used in medicine to make sure humans live a few more years versus the tiny expenditures being given to environmental science to check on the state of natural world. If the human population collapses in the near future, it will not be because they have not made enough progress in medicine to make us all live to be 95 instead of 85. It will be more likely be due to the inability to appreciate the twin juggernauts of overpopulation and pollution that will render the globe a less nice place for us. By that time the gated communities of Los Angeles will be passé and we will be looking for someone to blame.

Is Community Ecology Impossible?

John Lawton writing in 1999 about general laws in ecological studies stated:

“…. ecological patterns and the laws, rules and mechanisms that underpin them are contingent on the organisms involved, and their environment…. The contingency [due to different species’ attributes] becomes overwhelmingly complicated at intermediate scales, characteristic of community ecology, where there are a large number of case histories, and very little other than weak, fuzzy generalizations….. To discover general patterns, laws and rules in nature, ecology may need to pay less attention to the ‘middle ground’ of community ecology, relying less on reductionism and experimental manipulation, but increasing research efforts into macroecology.” (Lawton 1999, page 177)

There are two generalizations here to consider: first that macroecology is the way forward, and second that community ecology is a difficult area that can lead only to fuzzy generalizations. I will leave the macroecology issue to later, and concentrate on the idea that community ecology can never develop general laws.

The last 15 years of ecological research has partly justified Lawton’s skepticism because progress in community ecology has largely rested on local studies and local generalizations. One illustration of the difficulty of devising generalities is the controversy over the intermediate disturbance hypothesis (Schwilk, Keeley & Bond 1997; Wilkinson 1999; Fox 2013a; Fox 2013b; Kershaw & Mallik 2013; Sheil & Burslem 2013). In their recent review Kershaw and Mallik (2013) concluded that confirmation of the intermediate disturbance hypothesis for all studies was around 20%. For terrestrial ecosystems only, support was about 50%. What should we do with hypotheses that fail as often as succeed? That is perhaps a key question in community ecology. Kershaw and Mallik (2013) adopt the approach that states that the intermediate disturbance hypothesis will apply only to grassland communities of moderate productivity. The details here are not important, the strategy of limiting a supposedly general hypothesis to a small set of communities is critical. We are back to the issue of generality. It is certainly progress to set limits on particular hypotheses, but it does leave the land managers hanging. Kershaw and Mallik (2013) state that the rationale for current forest harvesting models in the boreal forest relies on the intermediate disturbance hypothesis being correct for this ecosystem. Does this matter or not? I am not sure.

Prins and Gordon (2014) evaluated a whole series of hypotheses that represented the conventional wisdom in community ecology and concluded that much of what is accepted as well supported community ecological theory has only limited support. If this is accepted (and Simberloff (2014) does not accept it) we are left in an era of chaos in which practical ecosystem management has few clear models for how to proceed unless studies are available at the local level.

Should we conclude that community ecology is impossible? Certainly not, but it may be much more difficult than our simple models suggest, and the results of studies may be more local in application than our current general overarching theories like the intermediate disturbance hypothesis.

The devil is in the details again, and the most successful community ecological studies have essentially been population ecology studies writ large for the major species in the community. Evolution rears its ugly head to confound generalization. There is not, for example, a generalized large mammal predator in every community, and the species of predators that have evolved on different continents do not all follow the same ecological rules. Ecology may be more local than we would like to believe. Perhaps Lawton (1999) was right about community ecology.

Fox, J.W. (2013a) The intermediate disturbance hypothesis is broadly defined, substantive issues are key: a reply to Sheil and Burslem. Trends in Ecology & Evolution, 28, 572-573.

Fox, J.W. (2013b) The intermediate disturbance hypothesis should be abandoned. Trends in Ecology & Evolution, 28, 86-92.

Kershaw, H.M. & Mallik, A.U. (2013) Predicting plant diversity response to disturbance: Applicability of the Intermediate Disturbance Hypothesis and Mass Ratio Hypothesis. Critical Reviews in Plant Sciences, 32, 383-395.

Lawton, J.H. (1999) Are there general laws in ecology? Oikos, 84, 177-192.

Prins, H.H.T. & Gordon, I.J. (eds.) (2014) Invasion Biology and Ecological Theory: Insights from a Continent in Transformation.  Cambridge University Press, Cambridge. 540 pp.

Schwilk, D.W., Keeley, J.E. & Bond, W.J. (1997) The intermediate disturbance hypothesis does not explain fire and diversity pattern in fynbos. Plant Ecology, 132, 77-84.

Sheil, D. & Burslem, D.F.R.P. (2013) Defining and defending Connell’s intermediate disturbance hypothesis: a response to Fox. Trends in Ecology & Evolution, 28, 571-572.

Simberloff, D. (2014) Book Review: Herbert H. T. Prins and Iain J. Gordon (eds.): Invasion biology and ecological theory. Insights from a continent in transformation. Biological Invasions, 16, 2757-2759.

Wilkinson, D.M. (1999) The disturbing history of intermediate disturbance. Oikos, 84, 145-147.

On Repeatability in Ecology

One of the elementary lessons of statistics is that every measurement must be repeatable so that differences or changes in some ecological variable can be interpreted with respect to some ecological or environmental mechanism. So if we count 40 elephants in one year and count 80 in the following year, we know that population abundance has changed and we do not have to consider the possibility that the repeatability of our counting method is so poor that 40 and 80 could refer to the same population size. Both precision and bias come into the discussion at this point. Much of the elaboration of ecological methods involves the attempt to improve the precision of methods such as those for estimating abundance or species richness. There is less discussion of the problem of bias.

The repeatability that is most crucial in forging a solid science is that associated with experiments. We should not simply do an important experiment in a single place and then assume the results apply world-wide. Of course we do this, but we should always remember that this is a gigantic leap of faith. Ecologists are often not willing to repeat critical experiments, in contrast to scientists in chemistry or molecular biology. Part of this reluctance is understandable because the costs associated with many important field experiments is large and funding committees must then judge whether to repeat the old or fund the new. But if we do not repeat the old, we never can discover the limits to our hypotheses or generalizations. Given a limited amount of money, experimental designs often limit the potential generality of the conclusions. Should you have 2 or 4 or 6 replicates? Should you have more replicates and fewer treatment sites or levels of manipulation? When we can, we try one way and then another to see if we get similar results.

A looming issue now is climate change which means that the ecosystem studied in 1980 is possibly rather different than the one you now study in 2014, or the place someone manipulated in 1970 is not the same community you manipulated this year. The worst case scenario would be to find out that you have to do the same experiment every ten years to check if the whole response system has changed. Impossible with current funding levels. How can we develop a robust set of generalizations or ‘theories’ in ecology if the world is changing so that the food webs we so carefully described have now broken down? I am not sure what the answers are to these difficult questions.

And then you pile evolution into this mix and wonder if organisms can change like Donelson et al.’s (2012) tropical reef fish, so that climate changes might be less significant than we currently think, at least for some species. The frustration that ecologists now face over these issues with respect to ecosystem management boils over in many verbal discussions like those on “novel ecosystems” (Hobbs et al. 2014, Aronson et al. 2014) that can be viewed as critical decisions about how to think about environmental change or a discussion about angels on pinheads.

Underlying all of this is the global issue of repeatability, and whether our current perceptions of how to manage ecosystems is sufficiently reliable to sidestep the adaptive management scenarios that seem so useful in theory (Conroy et al. 2011) but are at present rare in practice (Keith et al. 2011). The need for action in conservation biology seems to trump the need for repeatability to test the generalizations on which we base our management recommendations. This need is apparent in all our sciences that affect humans directly. In agriculture we release new varieties of crops with minimal long term studies of their effects on the ecosystem, or we introduce new methods such as no till agriculture without adequate studies of its impacts on soil structure and pest species. This kind of hubris does guarantee long term employment in mitigating adverse consequences, but is perhaps not an optimal way to proceed in environmental management. We cannot follow the Hippocratic Oath in applied ecology because all our management actions create winners and losers, and ‘harm’ then becomes an opinion about how we designate ‘winners’ and ‘losers’. Using social science is one way out of this dilemma, but history gives sparse support for the idea of ‘expert’ opinion for good environmental action.

Aronson, J., Murcia, C., Kattan, G.H., Moreno-Mateos, D., Dixon, K. & Simberloff, D. (2014) The road to confusion is paved with novel ecosystem labels: a reply to Hobbs et al. Trends in Ecology & Evolution, 29, 646-647.

Conroy, M.J., Runge, M.C., Nichols, J.D., Stodola, K.W. & Cooper, R.J. (2011) Conservation in the face of climate change: The roles of alternative models, monitoring, and adaptation in confronting and reducing uncertainty. Biological Conservation, 144, 1204-1213.

Donelson, J.M., Munday, P.L., McCormick, M.I. & Pitcher, C.R. (2012) Rapid transgenerational acclimation of a tropical reef fish to climate change. Nature Climate Change, 2, 30-32.

Hobbs, R.J., Higgs, E.S. & Harris, J.A. (2014) Novel ecosystems: concept or inconvenient reality? A response to Murcia et al. Trends in Ecology & Evolution, 29, 645-646.

Keith, D.A., Martin, T.G., McDonald-Madden, E. & Walters, C. (2011) Uncertainty and adaptive management for biodiversity conservation. Biological Conservation, 144, 1175-1178.

On Political Ecology

When I give a general lecture now, I typically have to inform the audience that I am talking about scientific ecology not political ecology. What is the difference? Scientific ecology is classical boring science, stating hypotheses, doing experiments or observations to gather the data, testing the idea, and accepting or rejecting it, outlined clearly in many papers (Platt 1963, Wolff and Krebs (2008), and illustrated in this diagram:

Scientific ecology is clearly out-of-date, and no longer ‘cool’ when compared to the new political ecology.

Political ecology is a curious mix of traditional ecology added to the advocacy issue of protecting biodiversity. Political ecology is aimed at convincing society in general and politicians in particular to protect the Earth’s biodiversity. This is a noble cause, and my complaint is only that when we advocate and use scientific ecology in pursuit of a political agenda we should be scientifically rigorous. Yet much of biodiversity science is a mix of belief and evidence, with unsuitable evidence used in support of what is a noble belief. If we believe that the end justifies the means, we would be happy with this. But I am not.

One example will illustrate my frustration with political ecology. Dirzo et al. (2014) in a recent Science paper give an illustration of the effects of removing large animals from an ecosystem. In their Figure 4, page 404, a set of 4 graphs purport to show experimentally what happens when you remove large wildlife species in Kenya, the Kenya Long-term Exclosure Experiment (Young et al. 1997). But this experiment is hopelessly flawed in being carried out on a set of plots of 4 ha, a postage stamp of habitat relative to large mammal movements and ecosystem processes. But the fact that this particular experiment was not properly designed for the questions it is now being used to address is not a problem if this is political ecology rather than scientific ecology. The overall goal of the Dirzo et al. (2014) paper is admirable, but it is achieved by quoting a whole series of questionable extrapolations given in other papers. The counter-argument in conservation biology has always been that we do not have time to do proper research and we must act now. The consequence is the elevation of expert opinion in conservation science to the realm of truth without going through the proper scientific process.

We are left with this prediction from Dirzo et al. (2014):

“Cumulatively, systematic defaunation clearly threatens to fundamentally alter basic ecological functions and is contributing to push us toward global-scale “tipping points” from which we may not be able to return ……. If unchecked, Anthropocene defaunation will become not only a characteristic of the planet’s sixth mass extinction, but also a driver of fundamental global transformations in ecosystem functioning.”

I fear that statements like this are more akin to something like a religion of conservation fundamentalism, while we proclaim to be scientists.

Dirzo, R., Young, H.S., Galetti, M., Ceballos, G., Isaac, N.J.B. & Collen, B. (2014) Defaunation in the Anthropocene. Science, 345, 401-406.

Platt, J.R. (1964) Strong inference. Science, 146, 347-353.

Wolff, J.O. & Krebs, C.J. (2008) Hypothesis testing and the scientific method revisited. Acta Zoologica Sinica, 54, 383-386.

Young, T.P., Okello, B.D., Kinyua, D. & Palmer, T.M. (1997) KLEE: A long‐term multi‐species herbivore exclusion experiment in Laikipia, Kenya. African Journal of Range & Forage Science, 14, 94-102.

Should All Ecologists Become Social Scientists or Politicians?

Two items this week have stirred me to write about the state of ecology. The first was a talk by an eminent biologist, who must remain nameless, about how scientists should operate. All very good, we should be evidence-based, open to falsification of hypotheses, and we should work as best we can to counter media misinformation. He/she talked about the future of biology in optimistic terms and in the entire one hour talk the word ‘biodiversity’ occurred once and the word ‘environment’ once. So my conclusion was that to this eminent biologist ecology was not on the radar as anything very important. We should be principally concerned about improving the health and wealth of humanity, and increasing economic growth.

This got me to thinking about why ecology falls at the bottom of the totem pole of science so that even though we work hard to understand the functioning of nature, ecologists seem to have value only to ourselves rather than to society. Perhaps society as a whole appreciates us for light entertainment about birds and bees, but when ecologists investigate problems and offer solutions they seem to be sidelined rapidly. Perhaps this is because taking care of the biosphere will cost money, and while we happily spend money on cars and new airplanes and guns, we can afford little for the natural world. One possible explanation for this is that many people and most politicians believe that “Mother Nature will take care of herself” at no financial cost.

If this is even partly correct, we need to change society’s view. There are several ways to do this, perhaps most importantly via education, but a more direct way is for ecologists to become social scientists and perhaps politicians. My experience with this recommendation is not terribly good. Social scientists have in my experience accomplished little for all their work on the human foibles of our time. Perhaps going into politics would be useful for our science if anyone wishes to cross that Rubicon, but there are few role models that we can put up.

So we continue in a political world where few ecologists sit in high places to challenge the modern paradigm of economic growth fuelled by non-renewable resources, and many of our national leaders see no human footprint on climatic warming. Short-term thinking is one element of this puzzle for we ecologists who take a longer view of life on Earth, but it must really rankle our paleo-ecologists who take a very long term look at changes in the Earth’s environment.

The second item this week that has encapsulated all of this was the announcement from a developed country that a new institute with over 1000 scientists was to be set up to study molecular biology for the improvement of human health. Now this is a noble cause that I do not wish to cast aspersions on, but it occurred to me that this was possibly a number greater than the total number of ecologists working in Canada or Australia or New Zealand. The numbers are hard to document, but I have not seen anything like this kind of announcement for a new institute that would address any of our many ecological problems. There is money for many things but very little for ecology.

None of this is terribly new but I am puzzled why this is the case. We live in a world of inequality in which the rich squander the wealth of the Earth while the future of the planet seems of little concern. Luckily ecologists are a happy lot once they get a job because they can work in the laboratory or in the field on interesting problems and issues (if they can get the money). And to quote the latest Nature (March 13, 2014, p. 140) “If ecologists want to produce work useful to conservation, they might do better to spend their days sitting quietly in ecosystems with waterproof notebooks and hand lenses, writing everything down.” That will cost little money fortunately.

On Biodiversity Science

Biodiversity science features heavily in articles in Science and Nature and it is a good idea to look at the accumulated wisdom to date. We can begin with the Cardinale et al. (2012) paper in Nature (“Biodiversity Loss and Its Impact on Humanity”) which gives us six consensus statements:

Consensus statement one: There is now unequivocal evidence that biodiversity loss reduces the efficiency by which ecological communities capture biologically essential resources, produce biomass, decompose and recycle biologically essential nutrients.

Consensus statement two: There is mounting evidence that biodiversity increases the stability of ecosystem functions through time.

Consensus statement three: The impact of biodiversity on any single ecosystem process is nonlinear and saturating, such that change accelerates as biodiversity loss increases.

Consensus statement four: Diverse communities are more productive because they contain key species that have a large influence on productivity, and differences in functional traits among organisms increase total resource capture.

Consensus statement five: Loss of diversity across trophic levels has the potential to influence ecosystem functions even more strongly than diversity loss within trophic levels.

Consensus statement six: Functional traits of organisms have large impacts on the magnitude of ecosystem functions, which give rise to a wide range of plausible impacts of extinction on ecosystem function.

followed by four emerging trends:

Emerging trend one: The impacts of diversity loss on ecological processes might be sufficiently large to rival the impacts of many other global drivers of environmental change.

Emerging trend two: Diversity effects grow stronger with time, and may increase at larger spatial scales.

Emerging trend three: Maintaining multiple ecosystem processes at multiple places and time requires higher levels of biodiversity than does a single process at a single place and time.

Emerging trend four: The ecological consequences of biodiversity loss can be predicted from evolutionary history.

I encourage you to read this paper and consider how well it describes a blueprint of past and future research on biodiversity. Here I offer a few thoughts on why I think it consists of a set of worrisome generalizations.

First of all every biologist would like to think that biodiversity is important. But we should consider what the equivalent statement might be for chemistry – chemicals are important. Surely this is both true and of little use, since we can never define scientifically the word ‘important’. Biodiversity is so broadly defined as to be a rather poor noun to use in scientific statements unless it is strictly defined. But you can take any kind of biodiversity measure – species number (richness) for example, and you might find that species X is a terrible weed that is not desirable for farmers but is beautiful in your home garden or useful food for butterflies. Malaria-carrying mosquitoes are not particularly desirable members of the local biological community. But let us all agree that biodiversity is important because it is an ethical belief but not a scientific statement as it stands.

If we look at the consensus statements as scientific hypotheses (I note the word ‘hypothesis’ appears only once in this article), we can ask how you could test them and what the alternative hypotheses would be. For consensus 1 for example, what would be the result of finding a community that increased productivity if certain species were lost from the system? This finding would not be viewed as contrary to consensus one because it would be said that the increased productivity was not done efficiently. It is probably best to assume these statements are not hypotheses to be tested.

As we work our way through the consensus statements, we find they are filled with weasel words that are useful in eliminating contrary evidence. Thus for consensus statement 2 we can stop at biodiversity (many definitions) and then stability (perhaps 70 different metrics) and finally ecosystem functions (of which there are many) and time (weeks?, years?, centuries?). The consensus which sounds so solid is empirically rather empty as any guide to the world.

I am left with many questions. Could not all of these consensus statements have been written 30 years ago? All of them have contrary instances that could be given from the literature, if the terms were rigorously defined. But this many not matter. Let us concede that these generalizations may be right 90% of the time. The bottom line is that we should conserve biodiversity. But this is what everybody has been saying for decades so we are no farther ahead.

The singular problem that concerns me the most is that these kinds of consensus statements are of little use to the land manager or the wildlife manager or the politician who has to make applied decisions at the local level. If we wish to arrest the decline of a particular songbird, what is the utility of these kind of statements? I have concluded that these kinds of papers about biodiversity are a kind of pablum for conservation ecologists to show that Nature and Science really are concerned about conservation issues while at the same time they devote 97% of their issues to the technological fixes that will ‘solve’ all the problems conservation biologists continually point out. As such these kinds of papers are useful statements for political ecology.

The four emerging trends are themselves worthy of another blog. They are vague ideas expressing beliefs that cannot be considered scientific hypotheses without rigorous definitions, and in their present form are almost quasi-religious statements of belief. How they might ever be tested is unclear. I particularly enjoyed the fourth emerging trend since I think that one of the evolutionary laws is that evolutionary history is exactly that – history – not a predictive map of future changes. There is a certain irony of our time that some of the world’s most prestigious evolutionary biologists are anti-religion while biodiversity scientists are trying hard to set up a new religion of biodiversity beliefs.

Cardinale, B. J.et al. 2012. Biodiversity loss and its impact on humanity. Nature 486:59-67.