Category Archives: Conservation Biology

In Praise of Long Term Studies

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I have been fortunate this week to have had a tour of the Konza Prairie Long Term Ecological Research (LTER) site in central Kansas. Kansas State University has run this LTER site for about the last 30 years with support from the National Science Foundation (NSF) of the USA. Whoever set up this program in NSF so many years ago deserves the praise of all ecologists for their foresight, and the staff of KSU who have managed the Konza site should be given our highest congratulations for their research plan and their hard work.

The tall grass prairie used to occupy much of the central part of the temperate zone of North America from Canada to Texas. There is almost none of it left, in Kansas about 1% of the original area with the rest given over to agriculture and grazing. The practical person sees this as progress through the lens of dollar bills, the ecologist sees it as a biodiversity catastrophe. The big questions for the tall-grass prairie are clear and apply to many ecosystems: What keeps this community going? Is it fire or grazing or both in some combination? If fire is too frequent, what are the consequences for the plant community of tall-grass prairie, not to mention the aquatic community of fishes in the streams and rivers? How can shrub and tree encroachment be prevented? All of these questions are under investigation, and the answers are clear in general but uncertain in many details about effects on particular species of birds or forbs.

It strikes me that ecology very much needs more LTER programs. To my knowledge Canada and Australia have nothing like this LTER program that NSF funds. We need to ask why this is, and whether this money could be used much better for other kinds of ecological research. To my mind ecology is unique among the hard sciences in requiring long term studies, and this is because the ecological world is not an equilibrial system in the way we thought 50 years ago. Environments change, species geographical ranges change, climate varies, and all of this on top of the major human impacts on the Earth. So we need to ask questions like why is the tall grass prairie so susceptible to shrub and tree encroachment now when it apparently was not this way 200 years ago? Or why are polar bears now threatened in Hudson’s Bay when they thrived there for the last 1000 or more years? The simple answer is that the ecosystem has changed, but the ecologist wants to know how and why, so that we have some idea if these changes can be managed.

By contrast with ecological systems, physics and chemistry deal with equilibrial systems. So nobody now would investigate whether the laws of gravitation have changed in the last 30 years, and you would be laughed out of the room by physical scientists for even asking such a question and trying to get a research grant to answer this question. Continuous system change is what makes ecology among the most difficult of the hard sciences. Understanding the ecosystem dynamics of the tall-grass prairie might have been simpler 200 years ago, but is now complicated by landscape alteration by agriculture, nitrogen deposition from air pollution, the introduction of weeds from overseas, and the loss of large herbivores like bison.

Long-term studies always lead us back to the question of when we can quit such studies. There are two aspects of this issue. One is scientific, and that question is relatively easy to answer – stop when you find there are no important questions left to pursue. But this means we must have some mental image of what ‘important’ questions are (itself another issue needing continuous discussion). Scientists typically answer this question with their intuition, but not everyone’s intuition is identical. The other aspect leads us into the monitoring question – should we monitor ecosystems? The irony of this question is that we monitor the weather, and we do so because we do not know the future. So the same justification can be made for ecosystem monitoring which should be as much a part of our science as weather monitoring, human health monitoring, or stock market monitoring are to our daily lives. The next level of discussion, once we agree that monitoring is necessary, is how much money should go into ecological monitoring? The current answer in general seems to be only a little, so we stumble on with too few LTER sites and inadequate knowledge of where we are headed, like cars driving at night with weak headlights. We should do better.

A few of the 186 papers listed in the Web of Science since 2010 that include reference to Konza Prairie data:

Raynor, E.J., Joern, A. & Briggs, J.M. (2014) Bison foraging responds to fire frequency in nutritionally heterogeneous grassland. Ecology, 96, 1586-1597. doi: 10.1890/14-2027.1

Sandercock, B.K., Alfaro-Barrios, M., Casey, A.E., Johnson, T.N. & Mong, T.W. (2015) Effects of grazing and prescribed fire on resource selection and nest survival of upland sandpipers in an experimental landscape. Landscape Ecology, 30, 325-337. doi: 10.1007/s10980-014-0133-9

Ungerer, M.C., Weitekamp, C.A., Joern, A., Towne, G. & Briggs, J.M. (2013) Genetic variation and mating success in managed American plains bison. Journal of Heredity, 104, 182-191. doi: 10.1093/jhered/ess095

Veach, A.M., Dodds, W.K. & Skibbe, A. (2014) Fire and grazing influences on rates of riparian woody plant expansion along grassland streams. PLoS ONE, 9, e106922. doi: 10.1371/journal.pone.0106922

Is Conservation Ecology a Science?

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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.

On Tipping Points and Regime Shifts in Ecosystems

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A new important paper raises red flags about our preoccupation with tipping points, alternative stable states and regime shifts (I’ll call them collectively sharp transitions) in ecosystems (Capon et al. 2015). I do not usually call attention to papers but this paper and a previous review (Mac Nally et al. 2014) seem to me to be critical for how we think about ecosystem changes in both aquatic and terrestrial ecosystems.

Consider an oversimplified example of how a sharp transition might work. Suppose we dumped fertilizer into a temperate clear-water lake. The clear water soon turns into pea soup with a new batch of algal species, a clear shift in the ecosystem, and this change is not good for many of the invertebrates or fish that were living there. Now suppose we stop dumping fertilizer into the lake. In time, and this could be a few years, the lake can either go back to its original state of clear water or it could remain as a pea soup lake for a very long time even though the pressure of added fertilizer was stopped. This second outcome would be a sharp transition, “you cannot go back from here” and the question for ecologists is how often does this happen? Clearly the answer is of great interest to natural resource managers and restoration ecologists.

The history of this idea for me was from the 1970s at UBC when Buzz Holling and Carl Walters were modelling the spruce budworm outbreak problem in eastern Canadian coniferous forests. They produced a model with a manifold surface that tipped the budworm from a regime of high abundance to one of low abundance (Holling 1973). We were all suitably amazed and began to wonder if this kind of thinking might be helpful in understanding snowshoe hare population cycles and lemming cycles. The evidence was very thin for the spruce budworm, but the model was fascinating. Then by the 1980s the bandwagon started to roll, and alternative stable states and regime change seemed to be everywhere. Many ideas about ecosystem change got entangled with sharp transition, and the following two reviews help to unravel them.

Of the 135 papers reviewed by Capon et al. (2015) very few showed good evidence of alternative stable states in freshwater ecosystems. They highlighted the use and potential misuse of ecological theory in trying to predict future ecosystem trajectories by managers, and emphasized the need of a detailed analysis of the mechanisms causing ecosystem change. In a similar paper for estuaries and near inshore marine ecosystems, Mac Nally et al. (2014) showed that of 376 papers that suggested sharp transitions, only 8 seemed to have sufficient data to satisfy the criteria needed to conclude that a transition had occurred and was linkable to an identifiable pressure. Most of the changes described in these studies are examples of gradual ecosystem changes rather than a dramatic shift; indeed, the timescale against which changes are assessed is critical. As always the devil is in the details.

All of this is to recognize that strong ecosystem changes do occur in response to human actions but they are not often sharp transitions that are closely linked to human actions, as far as we can tell now. And the general message is clearly to increase rigor in our ecological publications, and to carry out the long-term studies that provide a background of natural variation in ecosystems so that we have a ruler to measure human induced changes. Reviews such as these two papers go a long way to helping ecologists lift our game.

Perhaps it is best to end with part of the abstract in Capon et al. (2015):

“We found limited understanding of the subtleties of the relevant theoretical concepts and encountered few mechanistic studies that investigated or identified cause-and-effect relationships between ecological responses and nominal pressures. Our results mirror those of reviews for estuarine, nearshore and marine aquatic ecosystems, demonstrating that although the concepts of regime shifts and alternative stable states have become prominent in the scientific and management literature, their empirical underpinning is weak outside of a specific environmental setting. The application of these concepts in future research and management applications should include evidence on the mechanistic links between pressures and consequent ecological change. Explicit consideration should also be given to whether observed temporal dynamics represent variation along a continuum rather than categorically different states.”

 

Capon, S.J., Lynch, A.J.J., Bond, N., Chessman, B.C., Davis, J., Davidson, N., Finlayson, M., Gell, P.A., Hohnberg, D., Humphrey, C., Kingsford, R.T., Nielsen, D., Thomson, J.R., Ward, K., and Mac Nally, R. 2015. Regime shifts, thresholds and multiple stable states in freshwater ecosystems; a critical appraisal of the evidence. Science of The Total Environment 517(0): in press. doi:10.1016/j.scitotenv.2015.02.045.

Holling, C.S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology and Systematics 4: 1-23. doi:10.1146/annurev.es.04.110173.000245.

Mac Nally, R., Albano, C., and Fleishman, E. 2014. A scrutiny of the evidence for pressure-induced state shifts in estuarine and nearshore ecosystems. Austral Ecology 39: 898-906. doi:10.1111/aec.12162.

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

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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.

Why Do Physical Scientists Run Off with the Budget Pie?

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Take any developed country on Earth and analyse their science budget. Break it down into the amounts governments devote to physical science, biological science, and social science to keep the categories simple. You will find that the physical sciences gather the largest fraction of the budget-for-science pie, the biological sciences much less, and the social sciences even less. We can take Canada as an example. From the data released by the research councils, it is difficult to construct an exact comparison but within the Natural Sciences and Engineering Research Council of Canada the average research grant in Chemistry and Physics is 70% larger than the average in Ecology and Evolution, and this does not include supplementary funding for various infrastructure. By contrast the Social Sciences and Humanities Research Council reports research grants that appear to be approximately one-half those of Ecology and Evolution, on average. It seems clear in science in developed countries that the rank order is physical sciences > biological sciences > social sciences.

We might take two messages from this analysis. If you listen to the news or read the newspapers you will note that most of the problems discussed are social problems. Then you might wonder why social science funding is so low on our funding agenda in science. You might also note that environmental problems are growing in importance and yet funding for environmental research is also at the low end of our spending priority.

The second message you may wish to ask is: why should this be? In particular, why do physical scientists run off with the funding pie while ecologists and environmental scientists scratch through the crumbs? I do not know the answer to this question. I do know that it has been this way for at least the last 50 years, so it is not a recent trend. I can suggest several partial answers to this question.

  1. Physical scientists produce along with engineers the materials for war in splendid guns and aircraft and submarines that our governments believe will keep us safe.
  2. Physical scientists produce economic growth by their research so clearly they should be more important.
  3. Physical sciences produce scientific progress on a time scale of months while ecologists and environmental scientists produce research progress on a time scale of years and decades.
  4. Physical scientists do the research that produce good things like iPhones and computers while ecologists and environmental scientists produce mostly bad news about the deterioration in the earth’s ecosystem services.
  5. Physical scientists and engineers run the government and all the major corporations so they propagate the present system.

Clearly there are specific issues that are lost in this general analysis. Medical science produces progress in diagnosis and treatment as a result of the research of biochemists, molecular biologists, and engineers. Pharmaceutical companies produce compounds to control diseases with the help of molecular biologists and physiologists. So research in these specific areas must be supported well because they affect humans directly. Medical sciences are the recipient of much private money in the quest to avoid illness.

Lost in this are a whole other set of lessons. Why were multi-billions of dollars devoted to the Large Hadron Collider Project which had no practical value at all and has only led to the need for a Very Large Hadron Collider in future to waste even more money? The answer seems to lie somewhere in the interface of three points of view – it may be needed for military purposes, it is a technological marvel, and it is part of physics which is the only science that is important. The same kind of thinking seems to apply to space research which is wildly successful burning up large amounts of money while generating more military competition via satellites and in addition providing good movie images for the taxpayers.

While many people now support efforts on the conservation of biodiversity and the need for action on climate change, the funding is not given to achieve these goals either from public or private sources. One explanation is that these are long-term problems and so are difficult to get excited about when the lifespan of the people in power will not extend long enough to face the consequences of current decision making. Finally, many people are convinced that technological fixes will solve all environmental problems so that the problems environmental scientists worry about are trivial (National Research Council 2015, 2015a). Physics will fix climate change by putting chemicals into the stratosphere, endangered species will be resurrected by DNA, and fossil fuels will never run out. And as a bonus Canada and Scandinavia will be warmer and what is wrong with that?

An important adjunct to this discussion is the question of why economics has risen to the top of the heap along with physical sciences. As such the close triumvirate of physical sciences-engineering-economics seems to run the world. We should keep trying to change that if we have concern for the generations that follow.

 

National Research Council. 2015. Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration. The National Academies Press, Washington, DC. 140 pp. ISBN: 978-0-309-36818-6.

National Research Council. 2015a. Climate Intervention: Reflecting Sunlight to Cool Earth. The National Academies Press, Washington, DC. 234 pp. ISBN: 978-0-309-36821-6.

Ecosystem Science to the Rescue

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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

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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.

Are Birds of Any Consequence?

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We all love birds. They are colourful, interesting creatures and they entice many people to a love of nature and then hopefully the conservation of biodiversity. Thus we do not want to get rid of them. A great deal of effort goes into censusing birds and they are often thought of as indicator species of ecosystem health. No one is in favour of ‘Silent Spring’. But let us do a thought experiment.

The question I wish to ask is somewhat different than the important issue of bird conservation: are birds of any consequence to the operational integrity of communities and ecosystems? In the simplest case what would happen, say, to the eastern deciduous forest or the tall grass prairie or the arctic tundra if all the birds in those ecosystems went extinct? Predators that specialize on birds would clearly disappear but I do not know how many bird specialist predators exist. At the same time the parasites of these birds would be gone. But what about the integrity of existing ecosystems?

Can we dismiss the oceans because birds have a negligible effect on oceanic food webs and energy flow? I do not know the answer to this. In forests birds are often thought to keep insect pests of trees under control, but this seems to be unlikely in many systems in which defoliating insects damage trees of many sorts. Perhaps insect outbreaks would increase in frequency if there were no birds. I come away with the image that birds are for the most part of little consequence for terrestrial ecosystems because they are consumers operating at a very low quantitative level. An exception might be tropical forests in which birds are essential pollinators and seed dispersers, but again I am not sure how often they are necessary pollinators or seed dispersers.

All of this speculation is pretty useless, one might argue, because birds are not going to disappear. They may well be reduced in abundance if habitat is lost and habitat loss seems to be a global problem. But there are two aspects of current ecological research that these idle speculations touch on. First, are birds very good model systems for conservation biology? The answer the ecological world seems to have decided is that they are and very much research must be done on birds for this reason. If research time and money is limited, more research on birds means less on other aspects of community and ecosystem dynamics. Should we be concerned about this? Bird research is convenient and sexy, at least in university settings, but is it more of “Nero fiddling while Rome is burning”? One might in fact argue that many birds are the worst possible model system for understanding conservation problems except for those specific to birds. When I was producing a textbook section on population dynamics I tried to find a good solid example of a supposed decline in bird abundance for any species in which the mechanisms of decline were understood. While there are many data on declines, and much hand wringing, there were virtually no examples with hard data on mechanisms except for the vague idea of habitat loss. Maybe mechanisms are unimportant in conservation biology but it seems unlikely that they are superfluous to understanding the larger issues of population dynamics.

The second general question is the converse one of what kinds of organisms should ecologists be concentrating on if we are to make convincing arguments about biodiversity conservation? If changes in community and ecosystem dynamics are looming, so that the future will not look like the past, where should we put our energies to prevent ecosystem collapse? Are insects and invertebrates in general of greater importance that birds or mammals?

Hurlbert (1971, 1997) raised the question of how to determine the general functional importance of a species to a community, and he concluded that the only measure that has been put forward is ‘the sum over all species, of the changes in productivity which would occur on removal of the particular species from the community’. He pointed out that this definition of importance is clear and specific but could never be measured for even a single species in a community for practical reasons. Hurlbert (1997) also recognized that ‘importance’ had now morphed into ‘keystone’ for much of ecology (e.g. Daily et al. 1993), with all the problems associated with the keystone idea. He suggested, as did Walker (1992) that most species are redundant and of little consequence to ecosystem functioning. Much discussion has occurred since these papers and some has morphed into discussions of ‘functional groups’ instead of species. But plant ecologists have in general not addressed the challenges that Hurlbert (1999) asked, and we are far from being able to answer even the hypothetical question in the title of this blog.

Daily, G.C., Ehrlich, P.R., and Haddad, N.M. 1993. Double keystone bird in a keystone species complex. Proceedings of the National Academy of Sciences USA 90(2): 592-594. doi:10.2307/2361101.

Hurlbert, S.H. 1971. The non-concept of species diversity: a critique and alternative parameters. Ecology 52: 577-586.

Hurlbert, S.H. 1997. Functional importance vs. keystoneness: Reformulating some questions in theoretical biocenology. Australian Journal of Ecology 22(4): 369-382.

Walker, B.H. 1992. Biodiversity and ecological redundancy. Conservation Biology 6: 18-23.

On Adaptive Management

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I was fortunate to be on the sidelines at UBC in the 1970s when Carl Walters, Ray Hilborn, and Buzz Holling developed and refined the ideas of adaptive management. Working mostly in a fisheries context in which management is both possible and essential, they developed a new paradigm of how to proceed in the management of natural resources to reduce or avoid the mistakes of the past (Walters & Hilborn 1978). Somehow it was one of those times in science where everything worked because these three ecologists were a near perfect fit to one another, full of new ideas and inspired guesses about how to put their ideas into action. Many other scientists joined in, and Holling (1978) put this collaboration together in a book that can still be downloaded from the website of the International Institute for Applied Systems Analysis (IASA) in Vienna:
(http://www.iiasa.ac.at/publication/more_XB-78-103.php

Adaptive management became the new paradigm, now taken up with gusto by many natural resources and conservation agencies (Westgate, Likens & Lindenmayer 2013). Adaptive management can be carried out in two different ways. Passive adaptive management involves having a model of the system being managed and manipulating it in a series of ways that improve the model fit over time. Active adaptive management takes several different models and uses different management manipulations to decide which model best describes how the system operates. Both approaches intend to reduce the uncertainty about how the system works so as to define the limits of management options.

The message was (as they argued) nothing more than common sense, to learn by doing. But common sense is uncommonly used, as we see too often even in the 21st century. Adaptive management became very popular in the 1990s, but while many took up the banner of adaptive management, relatively few cases have been successfully completed (Walters 2007; Westgate, Likens & Lindenmayer 2013). There are many different reasons for this (discussed well in these two papers), not the least of which is the communication gap between research scientists and resource managers. Research scientists typically wish to test an ecological hypothesis by a management manipulation, but the resource manager may not be able to use this particular management manipulation in practice because it costs too much. To be useful in the real world any management experiment needs to have careful, long-term monitoring to map its outcome, and management agencies do not often have the opportunity to carry out extensive monitoring. The underlying cause then is mainly financial, and resource agencies rarely have an adequate budget to cover the important wildlife and fisheries issues they are supposed to manage.

If anything, reading this ‘old’ literature should remind ecologists that the problems discussed are inherent in management and will not go away as we move into the era of climate change. Let me stop with a few of the guideposts from Holling’s book:

Treat assessment as an ongoing process…
Remember that uncertainties are inherent…
Involve decision makers early in the analysis…
Establish a degree of belief for each of your alternative models…
Avoid facile and narcotic compression of indicators such as cost/benefit ratios that are generally inappropriate for environmental problems….

And probably remind yourself that there can be wisdom in the elders….

The take-home message for me in re-reading these older papers on adaptive management is that it is similar to the problem we have with models in ecology. We can produce simple models or in this case solutions to management problems on paper, but getting them to work properly in the real world where social viewpoints, political power, and scientific information collide is extremely difficult. This is no reason to stop doing the best science and to try to weld it into management agencies. But it is easier said than done.

Holling, C.S. (1978) Adaptive Environmental Assessment and Management. John Wiley and Sons, Chichester, UK.

Walters, C.J. (2007) Is adaptive management helping to solve fisheries problems? Ambio, 36, 304-307.

Walters, C.J. & Hilborn, R. (1978) Ecological optimization and adaptive management. Annual Review of Ecology and Systematics, 9, 157-188.

Westgate, M.J., Likens, G.E. & Lindenmayer, D.B. (2013) Adaptive management of biological systems: A review. Biological Conservation, 158, 128-139.

On Repeatability in Ecology

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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.