Category Archives: Charley Krebs’ blogs

On Global Science and Local Science

Leave a reply

I suggest that the field of ecology is fragmenting into two large visions of the science which for the sake of simplicity I will call Global Science and Local Science. This fragmentation is not entirely new, and some history might be in order.

Local Science deals with local problems, and while it aspires to develop conclusions that apply to a broader area than the small study area, it has always been tied to useful answers for practical questions. Are predators the major control of caribou declines in northern Canada? Can rats on islands reduce ground-nesting birds to extinction? Does phosphate limit primary production in temperate lakes? Historically Local Science has arisen from the practical problems of pest control and wildlife and fisheries management with a strong focus on understanding how populations and communities work and how humans might solve the ecological problems they have largely produced (Kingsland 2005). The focus of Local Science was always on a set of few species that were key to the problem being studied. As more and more wisdom accumulated on local problems, ecologists turned to broadening the scope of enquiry, asking for example if solutions discovered in Minnesota might also be useful in England or vice versa. Consequently, Local Science began to be amalgamated into a broader program of Global Science.

Global Science can be defined in several ways. One is purely financial and big dollars; this not what I will discuss here. I want to discuss Global Science in terms of ecological syntheses, and Global Science papers can often be recognized by having dozens to hundreds of authors, all with data to share, and with meta-analysis as the major tool of analysis. Global Science is now in my opinion moving away from the experimental approach that was a triumph of Local Science. The prelude to Global Science was the International Biological Program (IBP) of the 1970s that attempted to produce large-scale systems analyses of communities and ecosystems but had little effect in convincing many ecologists that this was the way to the future. At the time the problem was largely the development of a theory of stability, a property barely visible in most ecological systems.

Global Science depends on describing patterns that occur across large spatial scales. These patterns can be discovered only by having an extensive, reliable set of local studies and this leads to two problems. The first is that there may be too few reliable local studies. This may occur because different ecologists use different methods of measurement, do not use a statistically reliable sampling design, or may be constrained by a lack of funding or time. The second problem is that different areas may show different patterns of the variables under measurement or have confounding causes that are not recognized. The approach through meta-analysis is fraught with the decisions that must be made to include or exclude specific studies. For example, a recent meta-analysis of the global insect decline surveyed 5100 papers and used 166 of them for analysis (van Klink et al. 2020). It is not that the strengths and limitations of meta-analysis have been missed (Gurevitch et al. 2018) but rather the question of whether they are increasing our understanding of the Earth’s ecology. Meta-analyses can be useful in suggesting patterns that require more detailed analyses. In effect they violate many of the rules of conventional science in not having an experimental design, so that they suggest patterns but can be validated only by a repeat of the observations. So, in the best situations meta-analyses lead us back to Local Science. In some situations, meta-analyses lead to no clear understanding at all, as illustrated in the conclusions of Geary et al. (2020) who investigated the response of terrestrial vertebrate predators to fire:

“There were no clear, general responses of predators to fire, nor relationships with geographic area, biome or life-history traits (e.g. body mass, hunting strategy and diet). Responses varied considerably between species.” (page 955)

Note that this study is informative in that it indicates that ecologists have not yet identified the variables that determine the response of predators to fire. In other cases, meta-analysis has been useful in redirecting ecological questions because the current global model does not fit the facts very well (Szuwalski et al. 2015).

The result of this movement within both ecological and conservation science toward Global Science has been a shift in the amount of field work being done. Rios-Saldana et al. (2018) surveyed the conservation literature over the last 35 years and found that fieldwork-based publications decreased by 20% in comparison to a rise of 600% and 800% in modelling and data analysis studies. This conclusion could be interpreted that ecologists now realize that less fieldwork is needed at this time, or perhaps the opposite. 

In an overview of ecological science David Currie (2019) described an approach to understanding how progress in ecology has differed from that in the physical sciences. He suggests that the physical sciences focused on a set of properties of nature whose variation they analyzed. They developed ‘laws’ Like Newton’s laws or motion that could be tested in simple or complex systems. By contrast ecology has developed largely by asking how processes like competition or predation work, and not by asking questions about the properties of natural systems, which is what interests the general public trying to solve problems in conservation or pest or fisheries management. Currie (2019) summarized his approach as follows:

“Successful disciplines identify specific goals and measure progress toward those goals. Predictive accuracy of properties of nature is a measure of that progress in ecology. Predictive accuracy is the objective evidence of understanding. It is the most useful tool that science can offer society.” (page 18)

Many of these same questions underlay the critical appraisal of ecology by Peters (1991).

There is no one approach to ecological science, but we need to continue to ask what progress is being made with every approach. These are key questions for the future of ecological research, and they are worthy of much more discussion because they determine what students will be taught and what kinds of research will be favoured for funding in the future.

Currie, D.J. (2019). Where Newton might have taken ecology. Global Ecology and Biogeography 28, 18-27. doi: 10.1111/geb.12842.

Geary, W.L., Doherty, T.S., Nimmo, D.G., Tulloch, A.I.T., and Ritchie, E.G. (2020). Predator responses to fire: A global systematic review and meta-analysis. Journal of Animal Ecology 89, 955-971. doi: 10.1111/1365-2656.13153.

Gurevitch, J., Koricheva, J., Nakagawa, S., and Stewart, G. (2018). Meta-analysis and the science of research synthesis. Nature 555, 175-182. doi: 10.1038/nature25753.

Kingsland, Sharon .E. (2005) ‘The Evolution of American Ecology, 1890-2000  ‘ (Johns Hopkins University Press: Baltimore.) ISBN: 0801881714

Peters, R.H. (1991) ‘A Critique for Ecology.’ (Cambridge University Press: Cambridge, England.) ISBN: 0521400171

Ríos-Saldaña, C. Antonio, Delibes-Mateos, Miguel, and Ferreira, Catarina C. (2018). Are fieldwork studies being relegated to second place in conservation science? Global Ecology and Conservation 14: e00389. doi: 10.1016/j.gecco.2018.e00389.

Szuwalski, C.S., Vert-Pre, K.A., Punt, A.E., Branch, T.A., and Hilborn, R. (2015). Examining common assumptions about recruitment: a meta-analysis of recruitment dynamics for worldwide marine fisheries. Fish and Fisheries 16, 633-648. doi: 10.1111/faf.12083.

van Klink, R., Bowler, D.E., Gongalsky, K.B., Swengel, A.B., Gentile, A. and Chase, J.M. (2020). Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances. Science 368, 417-420. doi: 10.1126/science.aax9931.

On Cats and Birds and Policy Gaps

1 Reply

Many people in western societies like to keep cats as pets, and with that simple observation we run into two problems that require resolution. First, cats are killers of wildlife, particularly birds but also an array of other small prey. Most people do not believe this, because cats are adored and make good, if somewhat disinterested pets. So, my first point might be that if you think cats are not killers, I invite you to keep another cat like a mountain lion for a pet. But we need some data on the kill rate of cats. Before we begin this search, we should note that cats can be kept inside dwellings or in cat runs with no access to birds or other prey. If this is the case, no problem exists for wildlife, and you can skip to the bottom of this blog for one other issue to recognize.

How much mortality can be traced to cats roaming out of doors? This will include normal house cats let out to roam at night, as well as wild cats that have been discarded by their owners into the wild. There is extensive literature on cats killing birds. If you want a brief introduction Greenwall et al. (2019) discuss a nesting colony of Fairy Terns, a threatened species of Australian seabird, along a beach in southwestern Australia. With detailed observations and photographic data, they recorded the complete failure of all 111 nests in this colony with the loss of all tern chicks in the early summer of 2018. The predator was a single desexed feral cat. Many local governments allow the capture of feral cats with the protocol that they are desexed and then released back into the environment. Clearly desexing and release does not remove the problem.

The domestic cat has been spread world-wide, so that the cat problem is not a local one. Li et al. (2021) completed a survey of feral cat kill rates in the eastern part of China and found that the minimum annual loss of wildlife to feral cats was in the range of 2.7-5.5 billion birds, and 3.6-9.8 billion mammals, as well as large numbers of amphibians, reptiles, and fish. In gardens in Western Europe cat predation on ringed birds studied with precise data showed that up to 25% of dead birds were killed by cats, but these data varied greatly among species (Pavisse et al. 2019). For the European Robin which often feeds on the ground 40% of all ringed birds were killed by cats, for the European Greenfinch the figure was 56% of ringed birds killed. These are just two examples of an extensive literature on cat kills going back many years (Calvert et al. 2013).

What can we do about this predation? As with too many conservation issues the answer is simple but difficult to implement: Ban all cats from free-ranging unless they are on a leash and under control. Keep cats in the house or in special cat runs that are confined outdoors. Ban completely stupid programs of catching feral cats, sterilizing them, and releasing them back to the wild to continue their killing. Cats may make marvellous pets but need to be kept indoors. Many people would support these measures but many cat owners would disagree about such measures. Some progress is being made in urban environments in which some suburbs do not permit cats to roam freely.

Feral cats are a serious issue in Australia because they attack many threatened birds and reptiles (Doherty et al. 2019). In this case a federal environmental policy to kill 2 million cats is popular but from a conservation viewpoint still a poor policy. We do not know if killing 2 million cats is too much or too few, and without specific goals for conservation and careful monitoring of bird populations widespread killing my not achieve the goal of protection for threatened species. Eradications of cats on islands is often feasible, but no mainland eradication is currently possible.

As conservation biologists know too well, when humans are the problem, wise policies may not be implemented. So, the second issue and the bottom line might be to consider the human costs of cat ownership. Adhikari et al. (2020) report a highly significant association between the risk of dying from colon cancer and cat ownership. These results are not confounded by sedentary lifestyle, cigarette smoking or socio-economic status. In a similar study Adhikari et al. (2019) found that living with a cat significantly increased the death rate from lung cancer among women. The cause of these associations cannot yet be deciphered but are postulated to result from mycotoxins, toxic secondary metabolites produced by fungi (moulds) in cereal crops used in cat food. Aflatoxin is a mycotoxin that produces well-known chemicals that are seriously toxic to animals and humans.

These kinds of studies of associations arising from surveys can be tossed off by the typical comments ‘these-things-do-not-concern-my cats’ or ‘that there is no proof of the exact cause’ so if you are concerned you might investigate the literature on both mycotoxins and the diseases that cats carry.

It is up to humans to solve human problems, but up to conservation biologists to point out the detrimental effects of household pets and their feral cousins on wildlife. The present situation is a complete policy failure by governments at all levels. Good science is relatively easy, good policy is very difficult.

Adhikari, Atin, Adhikari, A., Jacob, N. K., and Zhang, J. (2019). Pet ownership and the risk of dying from lung cancer, findings from an 18 year follow-up of a US national cohort. Environmental Research 173, 379-386. doi: 10.1016/j.envres.2019.01.037.

Adhikari, Atin, Adhikari, A., Wei, Y. D., and Zhang, J. (2020). Association between pet ownership and the risk of dying from colorectal cancer: an 18-year follow-up of a national cohort. Journal of Public Health 28, 555-562. doi: 10.1007/s10389-019-01069-1.

Calvert, A.M., Bishop, C.A., Elliot, R.D., Krebs, E.A., Kydd, T.M., Machtans, C.S., Robertson, G.J., 2013. A synthesis of human-related avian mortality in Canada. Avian Conservation and Ecology 8: 11. doi 10.5751/ACE-00581-080211.

Doherty, T.S., Driscoll, D.A., Nimmo, D.G., Ritchie, E.G., and Spencer, R. (2019). Conservation or politics? Australia’s target to kill 2 million cats. Conservation Letters 12, e12633. doi: 10.1111/conl.12633.

Li, Yuhang, Wan, Yue, Shen, Hua, Loss, S.R., Marra, P.P., and Li, Zhongqiu (2021). Estimates of wildlife killed by free-ranging cats in China. Biological Conservation 253, 108929. doi: 10.1016/j.biocon.2020.108929.

Greenwell, C.N., Calver, M.C., and Loneragan, N.R. (2019). Cat Gets Its Tern: A Case Study of Predation on a Threatened Coastal Seabird. Animals 9, 445. doi: 10.3390/ani9070445.

Pavisse, R., Vangeluwe, D., and Clergeau, P. (2019). Domestic Cat Predation on Garden Birds: An Analysis from European Ringing Programmes. Ardea 107, 103-109. doi: 10.5253/arde.v107i1.a6.

Ecology for Now or the Future

Leave a reply

With the general belief that the climate is changing and that these changes must continue for at least 100 years due to the atmospheric physics of greenhouse gases, ecologists of all stripes face a difficult decision. The optimist says to continue with current studies, with due analysis of data from the past getting published, with the assumption that the future will be like the past. We know that the future will not be like the past so our belief in the future is a projection not a prediction. Does this mean that ecologists today should really be in the History Department of the Faculty of Arts?

Well, no one would allow this to happen, since we are scientists not the connivers of untestable stories of past events that masquerade as history, a caricature of the scientific method. The general problem is applicable to all the sciences. The physical sciences of physics and chemistry are fixed for all eternity, so physicists do not have to worry. The geological sciences are a mix of history and applied physics with hypotheses that are partly testable in the current time but with an overall view of future predictions that have a time scale of hundreds to thousands of years. One way to look at this problem is to imagine what a textbook of Physics would look like in 100 years, compared to a textbook of Geology or Biology or Ecology.

Ecological science is burdened by the assumption of equilibrium systems which we all know to be false since we have the long-term evidence of evolution staring at us as well as the short-term evidence of climate change. Ecologists have only two options under these constraints: assume equilibrium conditions over short time-frames or model the system to provide future projections of change. First, assume we are dealing with equilibrium systems within a defined time frame so that we can define clear hypotheses and test them on a short time scale of 10 to perhaps 20 years so we reach a 10–20-year time scale understanding of ecological processes. This is how most of our ecological work is currently carried out. If we wish to study the pollination of a particular set of plants or a crop, we work now to find out which species pollinate, and then hopefully in a short time frame try to monitor if these species are increasing or declining over our 10–20-year time span. But we do this research with the knowledge that the time frame of our ecological information is at most 100 years and mostly much less. So, we panic with bird declines over a 48 year time span (Rosenberg et al. 2019) with an analysis based on unreliable population data, and we fail to ask what the pattern might look like if we had data for the last 100 years or what it might look like in the next 100 years. We have the same problem with insect declines (Wagner et al. 2021, Warren et al. 2021).

If we wish to improve these studies we need much better monitoring programs, and with some notable exceptions there is little sign yet that this is happening (Lindenmayer et al. 2018, 2020). But the real question must come back to the time frame and how we can make future projections. We cannot do this with a 3-year funding cycle. If most of our conservation problems can be traced to human alterations of the biosphere then we must document these carefully with the usual scientific methods. At present I would hazard a guess that 95% of all endangered species are due directly to human meddling, even if we remove the effect of climate change.  

One way to make future projections is to model the population or community under study. A great deal of modelling is being done and has been done but there is little follow-through of how accurate the model predictions have been and little plan to test these projections. We may be successful with models that predict next year’s population or community dynamics, given much background data but that is only a tiny step to estimating what will be there in even 20 or 30 years. We need testable models more than panic calls about declining species with no efforts to discover if and why.

Where does that leave us? We must continue to analyse the ecological state of our current populations and communities and beware of the assumption that they are equilibrium systems. While physics for the future is rather well settled, ecological questions are not.

Lindenmayer, D.B., Likens, G.E., and Franklin, J.F. (2018). Earth Observation Networks (EONs): Finding the Right Balance. Trends in Ecology & Evolution 33, 1-3. doi: 10.1016/j.tree.2017.10.008.

Lindenmayer, D.B., Kooyman, R.M., Taylor, C., Ward, M., and Watson, J.E.M. (2020). Recent Australian wildfires made worse by logging and associated forest management. Nature Ecology & Evolution 4, 898-900. doi: 10.1038/s41559-020-1195-5.

Rosenberg, K.V., et al. (2019). Decline of the North American avifauna. Science 366, 120-124. doi: 10.1126/science.aaw1313.

Wagner, D.L., Grames, E.M., Forister, M.L., Berenbaum, M.R., and Stopak, D. (2021). Insect decline in the Anthropocene: Death by a thousand cuts. Proceedings of the National Academy of Sciences 118, e2023989118. doi: 10.1073/pnas.2023989118.

Warren, M.S., et al. (2021). The decline of butterflies in Europe: Problems, significance, and possible solutions. Proceedings of the National Academy of Sciences 118 (2), e2002551117. doi: 10.1073/pnas.2002551117.

On Biodiversity Science

Leave a reply

With David Attenborough and all the amazing picture books on biodiversity there can be few people in the world who have not been alerted to the array of beautiful and interesting species on Earth. Until recently the subject of biodiversity, known to First Nations since long, long ago, had not entered the western world of automobiles, industry, farming, fishing, music, theatres, and movies. Biodiversity is now greatly appreciated by most people, but perhaps more as entertainment for western societies and more for subsistence food in less wealthy parts of our world.

There are many different measures of ‘biodiversity’ and when discussing how we should protect biodiversity we should be careful about exactly how this word is being used. The number of different species in an area is one simple measure of biodiversity. But often the types of organisms being considered are less well defined. Forest ecologists attempt to protect forest biodiversity, but logging companies are more concerned only with trees and tree size for commercial use. Bird watchers are concerned with birds and have developed much citizen science in counting birds. Mushroom connoisseurs may worry about what edible mushrooms will be available this summer. But in many cases biodiversity scientists recognize that the community of organisms and the ecosystem that contains them would be a more appropriate unit of analysis. But as the number of species in an ecosystem increases, the complexity of the ecosystem becomes unmanageable. A single ecosystem may have hundreds to thousands of species, and we are in the infant stage of trying to determine how to study these biological systems.

One result is that, given that there are perhaps 10 million species on Earth and only perhaps 10,000 biologists who study biodiversity, where do we begin? The first and most popular way to answer this question is to pick a single species and concentrate on understanding its ecology. This makes are researcher’s life fairly simple. If elephants in Africa are under threat, find out all about the ecology of elephants. If a particular butterfly in England is very rare, try to find out why and how to protect them. This kind of research is very valuable for conservation because it provides a detailed background for understanding the requirements of each species. But the single species approaches lead into at least two quagmires. First, all species exist in a web of other species and understanding this web greatly expands the problem. It is possible in many cases to decipher the effects other species have on our elephants or butterflies, but this requires many more scientists to assist in analysing the species’ food chain, its diseases, its predators and parasites, and that is only a start. The second quagmire is that one of the general rules of ecology is that most species on Earth are rare, and few are common. So that we must concentrate our person-power on the common species because they are easier to find and study. But it is often the rare species that are of conservation concern, and so we should focus on them rather than the common species. In particular, given that only about 10% of the species on Earth have been described scientifically, we may often be assigned a species that does not have any information on its food habits or habitat requirements, its distribution, and how its abundance might be changing over time, a lifetime research program.

The result of this general overview is that the mantra of our day – Protect Biodiversity – begins as a compelling slogan and ends in enormous scientific complexity. As such it falls into the category of slogans like ‘Reduce Poverty’ and ‘Peace on Earth’, something we can all agree on, but the devil is in the details of how to achieve that particular goal.

One way to avoid all these pitfalls has been to jump over the problems of individual species and analyse communities of species or entire ecosystems. The result of this approach is to boil down all the species in the community to a number that estimates “biodiversity” and then use that number in relating ‘biodiversity’ to community attributes like ‘productivity’ or ‘stability’. This approach leads to testing hypotheses like ‘Higher biodiversity leads to greater stability’. There are serious problems with this approach if it is used to test any such hypothesis. First, biodiversity in this example must be rigorously defined as well as stability. The fact that higher biodiversity of butterflies in a particular region is associated with a more stable abundance of these butterflies over time is worthy of note but not of generalization to global communities or ecosystems. And as in all ecological studies we do not know if this is a generalization applicable to all butterfly populations everywhere until many more studies have been done.

A second problem is that this community or ecosystem approach to address ecological questions about biodiversity is not very useful in promoting conservation which boils down to particular species in particular environments. It should force us back to looking at the population ecology of species that are of conservation concern. It is population ecologists who must push forward the main goals of the conservation of the Earth’s biota, as Caughley (1994) recognized long ago.

The practical goals of conservation have always been local, and this constraint is mostly ignored in papers that demand some global research priorities and global ecological rules. The broad problem is that the conservation of biodiversity is a gigantic scientific and political problem that is currently underfunded and in its scientific infancy. At the present too much biodiversity research is short-term and not structured in a comprehensive framework that identifies critical problems and concentrates research efforts on these problems (Nichols et al. 2019, Sutherland et al. 2018). One more important issue for a seminar discussion group. 

Caughley, G. (1994). Directions in conservation biology. Journal of Animal Ecology 63, 215-244. doi: 10.2307/5542

Nichols, J.D., Kendall, W.L., and Boomer, G.S. (2019). Accumulating evidence in ecology: Once is not enough. Ecology and Evolution 9, 13991-14004. doi: 10.1002/ece3.5836.

Sutherland, W.J., Butchart, Stuart H.M., Connor, B., Culshaw, C., Dicks, L.V., et al. (2018). A 2018 Horizon Scan of Emerging Issues for Global Conservation and Biological Diversity. Trends in Ecology & Evolution 33, 47-58. doi: 10.1016/j.tree.2017.11.006.

A Poem on the State of Agriculture in 1935

Leave a reply

After listening to me rant about the state of modern agriculture in the Anthropocene, a colleague in Australia sent me this poem by C.J. Dennis (1876 – 1938) written long before most of us were born. I reprint it here as a reminder that many of our ecological problems are not new, that we have perhaps made progress on some but that in many areas Dennis’s poem about agriculture could have been published today. A powerful poem that in a classroom discussion might lead us to second thoughts that we now live in the best of all possible worlds. Vale C.J. Dennis.

C.J. Dennis in the Herald in 1935 in Australia
THE SPOILERS

“Because overstocking and continuous grazing have denuded the land of vegetation and removed all resistance to wind and flood, it has now been suddenly realised that erosion in the Western districts of N.S.W. has reduced thousands of acres to little better than desert. A descendant of the original black inhabitants of this country might regard this as just retribution.

Ye are the Great White People, masters and lords of the earth,
Spreading your stern dominion over the world’s wide girth.
Here, where my fathers hunted since Time’s primordial morn,
To our land’s sweet, fecund places, you came with your kine and corn.
Mouthing your creed of Culture to cover a baser creed,
Your talk was of White Man’s magic, but your secret god was Greed.
And now that your generations to the second, the third have run,
White Man, what of my country?  Answer, what have you done?

Now the God of my Simple People was a simple, kindly God,
Meting his treasure wisely that sprang from this generous sod,
With never a beast too many and never a beast too few,
Thro’ the lean years and the fruitful, he held the balance true.
Then the White Lords came in their glory; and their cry was: “More!  Yet more!”
And to make them rich for a season they filched Earth’s age-old store,
And they hunted my Simple People — hunters of yester-year —
And they drove us into the desert — while they wrought fresh deserts here.

They ravaged the verdant uplands and spoiled wealth ages old,
Laid waste with their pumps and sluices for a gunny-bag of gold;
They raided the primal forests and the kind, rain-bringing trees
That poured wealth over the lowlands thro’ countless centuries;
They fed their kine on the grasslands, crowding them over the land,
Till blade and root in the lean years gave place to hungry sand.
Then, warned too late of their folly, the White Lords grew afraid,
And they cried to their great god Science; but Science could not aid.

This have you done to our country, lords of the air and the seas,
This to the hoarded riches of countless centuries —
Life-yielding loam, uncovered, unsheltered in the drought,
In the floods your hand unbridled, to the age-old sea drifts out.
You have sold man’s one true birthright for a White Man’s holiday,
And the smothering sands drift over where once green fields turn grey —
Filched by the White Man’s folly to pamper the White Lords’ vice;
And leave to your sons a desert where you found a paradise.”

Herald, 6 December 1935, page 6

http://www.middlemiss.org/lit/authors/denniscj/newspapers/herald/1935/works/spoilers.html

Ecological Science: Monitoring vs. Stamp Collecting

Leave a reply

Ecology as a science is deeply divided by two views of the natural world. First is the view that we need to monitor changes in the distribution and abundance of the biota and try to explain why these changes are occurring through experiments. The second view is that we need to understand ecosystems as complex systems, and this can be done only by models with a tenuous link to data. It is worth discussing the strengths and weaknesses of each of these views of our science.

The first view could be described as the here-and-now approach, studies of how the populations, communities, and ecosystems are changing in all the biomes on Earth. It is clearly impossible to do this properly because of a lack of funding and person-power. Because of this impossibility we change our focus to short-term studies of populations, species, or communities and try to grasp what is happening in the time scale of our lifetime. This had led to a literature of confusing short-term studies of problems that are long-term. Experiments must be short term because of funding. Any long-term studies such of those highlighted in textbooks are woefully inadequate to support the conclusions reached. Why is this? It is the baffling complexity of even the simplest ecological community. The number of species involved is too large to study all of them, so we concentrate on the more abundant species, assuming all the rare species are of little consequence. This has led to a further division within the monitoring community between conservation ecologists who worry about the extinction of larger, dominant species and those that worry about the loss of rare species.

The first approach is further compromised by climate change and human exploitation of the Earth. You could invest in the study of a grassland ecosystem for 15 years only to find it turned into a subdivision of houses in year 16. We try to draw conclusions in this hypothetical case by the data of the 15 years of study. But if physiological ecologists and climate change models are even approximately correct, the structure of similar grassland ecosystems will change due to rainfall and temperature shifts associated with greenhouse gases. Our only recourse is to hope that evolution of physiological tolerances will change fast enough to rescue our species of interest. But there is no way to know this without further empirical studies that monitor climate and the details of physiological ecology. And we talk now about understanding only single species and are back to the complexity problem of species interactions in communities.

The second approach is to leap over all this complexity as stamp-collecting and concentrate on the larger issues. Are our ecological communities resilient to climate change and species invasions? Part of this approach comes from paleoecology and questions of what has happened during the last 10,000 or one million years. But the details that emerge from paleoecology are very large scale, very interesting but perhaps not a good guide to our future under climate change. If a forward-looking forestry company wishes to make sure it has 100-year-old trees to harvest in 100 years’ time, what species should they plant now in central Canada? Or if a desert community in Chile is to be protected in a national park, what should the management plan involve? These kinds of questions are much harder to answer than simpler ones like how many dingoes will we have in central Australia next year.

Long-term experiments could bridge the gap between these two approaches to ecological understanding, but this would mean proper funding and person-power support for numerous experiments that would have a lifetime of 25 to 100 years or more. This will never happen until we recognize that the Earth is more important than our GDP, and that economics is the king of the sciences.

Where does all this lead ecological scientists? Both approaches have been important to pursue in what has been the first 100 years of ecological studies and they will continue to be important as our ecological understanding improves. We need good experimental science on a small scale and good broad thinking on long time scales with extensive studies of everything from coral reefs to the Alaskan tundra. We need to make use of the insights of behavioural ecology and physiological ecology in reaching our tentative conclusions. And if anyone tells you what will happen in your lifetime in all our forests and all the biodiversity on Earth, you should be very careful to ask for strong evidence before you commit to a future scenario.

Beller, E.E., McClenachan, L., Zavaleta, E.S., and Larsen, L.G. (2020). Past forward: Recommendations from historical ecology for ecosystem management. Global Ecology and Conservation 21, e00836. doi: 10.1016/j.gecco.2019.e00836.

Bro-Jørgensen, J., Franks, D.W., and Meise, K. (2019). Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation. Philosophical Transactions of the Royal Society, B.  Biological Sciences 374: 20190008.  doi: 10.1098/rstb.2019.0008.

Lidicker, W.Z. (2020). A Scientist’s Warning to humanity on human population growth. Global Ecology and Conservation 24, e01232. doi: 10.1016/j.gecco.2020.e01232.

McGowan, D. W., Goldstein, E. D., and Zador, S. (2020). Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management. Marine Ecology. Progress Series 637, 117-140. doi: 10.3354/meps13211.

Tsujimoto, M., Kajikawa, Y., and Matsumoto, Y. (2018). A review of the ecosystem concept — Towards coherent ecosystem design. Technological Forecasting & Social Change 136, 49-58. doi: 10.1016/j.techfore.2017.06.032.

Wolfe, Kennedy, Kenyon, Tania M., and Mumby, Peter J. (2021). The biology and ecology of coral rubble and implications for the future of coral reefs. Coral Reefs 40, 1769-1806. doi: 10.1007/s00338-021-02185-9.

Yu, Zicheng, Loisel, J., Brosseau, D.P., Beilman, D.W., and Hunt, S.J. (2010). Global peatland dynamics since the Last Glacial Maximum. Geophysical Research Letters 37, L13402. doi: 10.1029/2010GL043584.

Why Ecology Fails to Prosper

2 Replies

The general science of Ecology has changed dramatically during the last 60 years and my perception is that at present it is failing its critical role in developing science for the good of the Earth. I ask here if this pessimistic view is correct, why that might be, and if it is possible to change our trajectory. Every science must focus on major problems and these problems are too often lost as time progresses. The causes of these changes are rarely due to the competence of the scientists involved and more typically are found in the social milieu.  

The most obvious problem is science funding. You will appreciate that some sciences are funded very extravagantly and others very poorly. It is a decision of most societies that the sciences of medicine, economics and law are the kings of the hill. More funding probably flows to medical science than to all the other sciences combined. You can argue that this is what should occur, since humans are the most dominant and most important species in the Earth’s ecosystems. The confound here is the ethical one – are the poor of the world to be helped or not? Such a question seems outrageous, but just look at the distribution of Covid vaccines at different countries around the world. Economics is a strange bedfellow of medicine in the apparent view of society and its governments. The result is that there are more economists in the world today than non-medical scientists. We will not change this in our day.

The sciences that are most highly regarded are those that achieve two goals: first, rapid developments that improve our wealth, economic, and social goals, and second, developments that enable Earth as a planet to be exploited for human welfare. The physical sciences and engineering permit us to travel quickly, to fight wars against our enemies, and as a spinoff provide us with better automobiles and kitchen appliances. Geology helps us to find oil, iron ore, and lithium while it maps the Earth to help us understand its history. Zoology and Botany are different. They are supported strongly when they interface with the medical sciences and agriculture at a very practical level but otherwise are low in the funding order.

Ecology differs in that it proposes to understand how the populations of animals and plants, the biological communities, and ecosystems operate and what forces cause these to change. The first problem that arises with this mandate it that ecological understanding requires time frames that exceed human lifespans. So, ecology faces the same problem as geology but is not easily able to be useful in telling us where to build dams, where to mine gold and coal. We face an impossible barrier. To describe the biota of the Earth with its millions of species will occupy us for hundreds of years, assuming the funding is there. To understand why communities and ecosystems change will require an equal time span. But since ecological elements are driven in many ways by weather, climate change forces us to analyse an ever-changing network of species interactions.  

A consequence of this dilemma for ecologists is that they must study how humans are destroying the Earth and suggest a resolution of these problems. We are squeezed between our original objective of understanding how ecological interactions structure our world and serious immediate problems. An introduced pest is killing our trees – do something about this. Deer populations are too high so fix that. Fisheries are in difficulty, manage that. Some iconic species are declining in abundance, so citizens push to have more funding for biodiversity conservation. These are all short-term problems, while the need for ecological understanding is almost entirely long term. This takes us back to funding. For the past 30 or more years governments around the world have been reducing funding for ecological investigations. Government biologists have not increased in number given the urgent problems of the day. University funding of ecological sciences and ecological faculty members has declined partly because ecologists do not increase economic growth. Private funding has not come to the rescue because it is largely directed to social and economic issues, partly because of the feeling that it is the government’s job to deal with long-term issues in research.

The only solution is for ecologists to work together on important large-scale ecological problems with minimal funding. But this is impossible within the university system in which teaching is a focus and research can only be short-term. Attempts to address the large-scale ecological issues have resulted in many publications that use meta-analyses to resolve ecological questions. I doubt that these have achieved the resolution of ecological issues that we need (e.g. Geary et al. 2020).

What can we do about this relatively gloomy situation? One suggestion is to continue as we are, addressing short-term questions with limited funding. The advantage of this approach is that it allows individuals freedom from group constraints. One disadvantage is that two studies of the same problem may not be comparable unless the methods used were the same (e.g. Christie et al. 2019). The argument that climate change is happening so everything will change, and the past will not be relevant to the present is an argument of a broad uncoordinated approach to ecological issues.

Another approach can be to identify the critical ecological questions that we need answered now. Few have been brave enough to attempt this (Sutherland et al. 2010, 2013, 2018) for the broad area of conservation biology. An attempt to judge how much progress had been made on the issues listed in these three papers would be profitable in order to determine if this approach is useful in coordinating research programs. We might hope that ecological discord would be reduced if critical ecological questions were attacked with a consistent experimental design.

This discussion of ecology fits under the ‘empirical ecological studies’ framework of Fulton et al. (2019), and the expansive belief that theoretical models and system models will drive ecology into a successful science is illustrated in this recent review (O’Connor et al. 2020) and the accompanying articles. My concern is that these approaches have gotten us very little ahead in understanding ecological systems to date, and that until empirical ecological studies are increased in scope, duration, and precision we will not know whether models and systems analysis are leading us to a better understanding of the Earth’s ecosystems and the drivers of change or not. There is much left to be done.  

Christie, A.P.et al. (2019). Simple study designs in ecology produce inaccurate estimates of biodiversity responses Journal of Applied Ecology 56, 2742-2754. doi: 10.1111/1365-2664.13499.

Fulton, E.A.et al. (2019). Where the ecological gaps remain, a modelers’ perspective. Frontiers in Ecology and Evolution 7. doi: 10.3389/fevo.2019.00424.

Geary, W.L., et al. (2020). Predator responses to fire: A global systematic review and meta-analysis. Journal of Animal Ecology 89, 955-971. doi: 10.1111/1365-2656.13153.

O’Connor, M.I.et al. (2020). Editorial: Unifying ecology Across scales: Progress, challenges and opportunities. Frontiers in Ecology and Evolution 8, 610459. doi: 10.3389/fevo.2020.610459.

Sutherland, W.J. et al. (2010). A horizon scan of global conservation issues for 2010. Trends in Ecology & Evolution 25, 1-7. doi: 10.1016/j.tree.2009.10.003.

Sutherland, W.J. et al. (2013). Identification of 100 fundamental ecological questions. Journal of Ecology 101, 58-67. doi: 10.1111/1365-2745.12025.

Sutherland, W.J et al. (2018). A 2018 Horizon Scan of Emerging Issues for Global Conservation and Biological Diversity. Trends in Ecology & Evolution 33, 47-58. doi: 10.1016/j.tree.2017.11.006.

Have We Lost the Plot?

Leave a reply

The decisions we make as a society depend directly on what knowledge we have achieved through our educational system. Two major problems the Earth faces occupy the day – the Covid epidemic and climate change. In both major emergencies, a significant fraction of humanity seems to have completely missed the plot and I would like to ask a few simple questions about why this might be.

The Covid epidemic is indeed a global emergency, and if you do not recognize this you should stop reading here. We have had major human epidemics in the last 1000 years so we might start by asking what knowledge we have garnered from past events. Epidemics occur because a particular disease is transmissible among people, and the three most obvious observations that could be made from previous epidemics are that large groups of people should not congregate, travel should be restricted, and that people should always wear a mask, a point made very clearly in the 1918 flu epidemic. More recent medical studies since the 1940s have shown conclusively that immunity to any particular disease can be achieved by vaccination programs, and many people have been vaccinated over their lifespan to reduce greatly the chance of infection. So, to make the point simple, many people are alive today because of the vaccinations they have received over time.

Vaccine hesitancy at this time with respect to the Covid epidemic has been decreasing, and as more of the population becomes vaccinated, disease incidence should decline. My question is how did many people become educated in our schools about these general points and then join the anti-vaxxers? I do not know the answer to this, but at least part of the answer might be a failure of our education systems.

A second emergency over climate change will probably be with us for a much longer time than the Covid pandemic, so we need to think very clearly about it. The problem in part is that climate change is long term (10-100+ years) and it is difficult to change human behaviour in a short time. Consequently, advances like renewable energy, solar panels on roofs, electric cars, and good insulation in houses need to be pushed by government policies. Since governments are too often concerned only about the next 4 years, and all the good policies will result in rising taxes, there is much talking but little action. Longer term issues like population control are too often swept under the table as too hot to handle. News outlets push panic buttons over reduced birth rates in the world today and translate this into immediate population collapse. Elementary issues of human demography that ought to be part of any curriculum are not understood, and the failure to appreciate the consequences of continued growth seem lost on much of the population. Consequently, part of our current problems involving action on the climate emergency must be laid to poor education about these simple matters.

We have gone through a long period when economics triumphed over ecology and sustainability, but that problem is rapidly being rectified. More people are recognizing that a single country cannot ignore global problems, conservation is strong on the agenda of many governments, although again these issues emit more talk than actions.

I certainly do not know the solution to these current issues but the polarization in the world today is strong enough to prohibit many policies being achieved that would improve and overcome our present emergencies. Unless we can achieve agreement on sustainable goals for all of society these emergencies will continue to build. Thinking that I could fly to Mars and get away from these problems is something even the British royalty recognize as ridiculous.

A few possible ideas:

  1. Call out and protest as much as you can about uninformed pseudo-scientific comments on ecology, economics, medical science, and sustainability. Demand political action on these two global emergencies now.
  2. Improve our education systems to demand a curriculum that addresses current problems of climate change and agriculture, population growth, medical history, disease, and the history of the biosphere.
  3. Get accurate data on global change and Covid from reliable sources.
  4. Never give up. Present scientific truth to counteract nonsense.
  5. And use social media effectively to improve communication of the science that speaks to the solution of these major problems.

Kolata, Gina B. (2019) Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus that caused it.’ Atria Books: New York. 352 pp. ISBN: 978-0743203982

MacKenzie, Debora (2020) COVID-19: The Pandemic that Never Should Have Happened and How to Stop the Next One. Hachette Books: New York. 304 pp. IBN: 978-0306924248  (Published in North America in 2021 as Stopping the Next Pandemic, 339 pp. ISBN 978-036924224.)

Piketty, Thomas (2021). Time for Socialism: Dispatches from a World on Fire, 2016-2021
Yale University Press: New Haven, Connecticut. 360 pp. ISBN: 978-0300259667

Salamon, Margaret Klein (2020). Facing the Climate Emergency: How to Transform Yourself with Climate Truth. New Society Publishers: Gabriola Island, B.C. Canada. 160 pp. ISBN: 978-0865719415

A Few Problems Ecologists Need to Face

Leave a reply

This is an overly simple attempt to look ahead, after a summer of extreme heat, extensive forest fires, overheated crops, and excessive flooding, to ask where we ecologists might be going in the next century. 

The first and most important point is that these disasters of the last several months can all be blamed on climate change, and despite what you hear, there is no stopping these changes in the next hundred years. CO2 enrichment is turning Earth into a hot planet. This is a simple fact of physics that the CO2 we have already emitted into our atmosphere will be there for hundreds to thousands of years. The politicians and the media will tell you that carbon-capture is coming soon to solve all our emission problems and cleanse the atmosphere of excess greenhouse gases. If you believe that, ask yourself if you would invest your capital and retirement account in a poker game for a decline in CO2 during the next 20 years.

The critical question for we ecologists is this: How much of the accumulated ecological wisdom will be unchanged in 100 years? If we have only to deal with changing climate, we could develop an understanding of what the limiting factors are and express the anticipated changes in the climatic units of the future. But that becomes a problem when we recognize that food webs have many interactions in them that are climate affected but perhaps not climatically determined. So, for example if we have a simple food web of polar bears feeding on seals, both of which require an ice pack for survival at the present time, what should we expect in 100 years when there is virtually no polar ice to be found. A simple model will predict that the polar bear will go extinct and perhaps seals will learn to use land instead of ice packs, but the fish that are the main food of the seals may also change if they depend on zooplankton that have a water temperature niche boundary that is exceeded. So exactly what will happen to this simple food web cannot be easily understood from current ecological wisdom or models.

Another example is from the current changing dynamics of Stellar sea lions of the North Pacific, summarized in an excellent review by Andrew Trites (2021). Stellar sea lions occupy the coastlines of the North Pacific from the Sea of Okhotsk and the Bering Sea eastward down the west coast of North America to southern California. Forty years ago, scientists noted a decline beginning in the western sea lion populations in the Bering Sea and the Gulf of Alaska and at the same time an increase in sea lion numbers from Southeast Alaska to California. Two explanations compete among seal experts to explain this pattern. The ‘overfishing hypothesis’ suggested that the Alaskan and Russian fishery has removed too much of the sea lion’s favourite food items and thus caused starvation among western sea lions. The alternative to this explanation, the ‘junk-food-hypothesis’ suggested that sea lions in the west were consuming too many fish species of low fat and fewer calories, and that their starvation was self-limited and not caused by the human fisheries.

Here is a “simple” ecological problem with 2 competing hypotheses or explanations that has not yet been resolved after many years of research. Empirical ecologists will possibly argue that we need to monitor the sea lions and their prey and the fishing catches over this extensive area for the next decade or two to find the answer as to which of the two competing hypothesis is closest to being correct. But given climate change and ocean warming, neither of which are uniform over all parts of the Earth, we would expect large changes in the abundance and distribution of many fish species and consequently also in the predators that depend on them. But exactly which ones, and exactly where? Conservation ecology is dogged by this problem and subsists largely by ignoring it in favour of short-term studies in small areas and the effects of human population growth, and perhaps this is all we can do at present. So, should “watch and wait, look and see” become our model? Wildlife and fisheries management thus become short-term ‘watch and wait’ sciences, like passengers on the Titanic long ago, wondering what the future holds.

One way to suggest future paths is to model the various communities and ecosystems that we study, and this activity is now strong in ecology and conservation. But there are many difficulties with this approach boiling down to a ‘wait-and-see’ method of empirical investigation. A review by Furtado (2020) of two books on fisheries management provides an up-to-date view of progress in fisheries ecology and illustrates problems with bluefin tuna management and the modelling approach to fish ecosystems in general. The problem in assuming the modelling approach as an answer to our dilemma is shown clearly by the current Covid pandemic and the reversals in modelling and alternative views that have caused much confusion despite much important research. Whither ecology from this point in time?

Furtado, Miguel (2020). The Future of Bluefin Tunas: Ecology, Fisheries Management and Conservation. Conservation Biology 34, 1600-1602.

Trites, A.W. (2021). Behavioral Insights into the Decline and Natural History of Steller Sea Lions. In ‘Ethology and Behavioral Ecology of Otariids and the Odobenid, Ethology and Behavioral Ecology of Marine Mammals,’. (Ed. C. Campagna and R. Harcourt), pp. 489-518. (Springer Nature Switzerland.)  doi: 10.1007/978-3-030-59184-7_23  

Whither the Big Questions in Ecology?

2 Replies

The science of ecology grows and grows and perhaps it is time to recognize the subcultures of the discipline which operate as nearly independent areas of science. Few people today would talk of the science of physics or the science of chemistry, but rather the subcultures of physics or chemistry in which critical problems are defined and tested. In a sense this has already been recognized in ecology by the increase in specific journals. No one goes to Conservation Biology to look up recent studies in insect pest control, and no one goes to Limnology and Oceanography to research progress in theoretical ecology. So, by default we ecologists have already subdivided the overall broad science of ecology into subcultures, and the problem then arises when we must consider major issues or big questions like the ecological impacts of climate change that encompass multiple subcultures, and the more specific issue of how we educate students of all ages about the broad problems of ecology and the environment.

The education issue ought to be the easiest part of this conundrum to deal with. The simple rule – Teach the Principles – is what textbook writers try to do. But this is easier said than done. Jim Hone et al. (2015) took on the problem of defining the principles of applied ecology and consolidated these into 22 prescriptive and 3 empirical principles that could serve as a starter for this area of general ecology. The same compilation could be done in many subdisciplines of ecology and there are many good examples of this (e.g., Lidicker, 2020, Ryo et al. 2019). A plethora of ecology textbooks exist to pull the broad subject together, and they are interesting themselves in what they emphasize.  

The larger problem is in the primary literature of ecology, and I pick here four big questions in ecology in which communication could be improved that would be useful both to educators and to the public.

  1. Sustainability of the Earth’s Ecosystems. This broad area covers human population dynamics, which can be generalized to many other species by the principles of population ecology. It would include agricultural issues and the consequences of soil erosion and degradation and cover the basics of atmospheric chemistry at least to question whether everyone going to Mars is particularly useful. Where relevant, every ecological publication should address how this research addresses the large issue of sustainability.
  2. Climate Change Effects. There is a general understanding of the geographic distribution of vegetation communities on Earth, how these have changed in geologic time and are changing now but projections for the future are vague. Much research is ongoing, but the ecological time frame of research is still too short (Hagerman and Pelai 2018). Teaching what we know now would include the essential physics and chemistry of sea level rise, changes in the distribution of good and bad species, including human diseases, and simple warnings about investing in real estate in Miami Beach. Every prediction about climate change effects should include a time frame at which the predictions could be accepted or rejected. If ecologists are to affect government policies, a testable action plan must be specified lest we keep barking up the wrong tree.
  3. Current conflicts in managing the Earth’s natural resources. The concern here is the social and economic drivers of why we continue overfishing and overharvesting resources that result in damage to local environments, and how we can manage conflicts over these resources. To manage intelligently we need to understand the interactions of the major species involved in the ecological community. Ecosystem dynamics will be the central set of concepts here, and the large topic of the resilience of our Earth’s ecosystems. Ecologists are clear that the resilience of ecosystems is limited but exactly where those limits are is far from clear at the present time.
  4. Conservation of Biodiversity. The ecological factors that limit biodiversity, and the consequences of biodiversity loss are major areas of current research and communication to the public. While the volume of concern is high in this subdiscipline, advances in understanding lag far behind. We operate now with only the vaguest of principles of how to achieve conservation results. The set of conservation principles (Prober et al. 2019) interacts strongly with the 3 big questions listed above and should cover advances in paleoecology and the methods of defining ancient environments as well as current conservation problems. Understanding how social conflict resolution can be achieved in many conservation controversies links across to the social sciences here. 

The key here is that all these big questions contain hundreds of scientific problems that need investigation, and the background of all these questions should include the principles by which ecological science advances, as well as the consequences of ignoring scientific advice. For educators, all these big questions can be analysed by examples from your favourite birds, or large mammals, or conifer trees, or fishes so that as scientific progress continues, we will have increased precision in our ecological understanding of the Earth. And more than enough material to keep David Attenborough busy.

For ecologists one recommendation of looking at ecology through the lens of big questions should be to include in your communications how your findings illuminate the road to improved understanding and further insights into how the Earth’s biodiversity supports us and how we need to support it. Ecology is not the science of the total environment, but it is an essential component of it.

Hagerman, S.M. and Pelai, R. (2018). Responding to climate change in forest management: two decades of recommendations. Frontiers in Ecology and the Environment 16, 579-587. doi: 10.1002/fee.1974.

Hone, J., Drake, A., and Krebs, C.J. (2015). Prescriptive and empirical principles of applied ecology. Environmental Reviews 23, 170-176. doi: 10.1139/er-2014-0076.

Lidicker, W.Z. (2020). A Scientist’s Warning to humanity on human population growth. Global Ecology and Conservation 24, e01232. doi: 10.1016/j.gecco.2020.e01232.

Prober, S.M., Doerr, V.A.J., Broadhurst, L.M., Williams, K.J., and Dickson, F. (2019). Shifting the conservation paradigm: a synthesis of options for renovating nature under climate change. Ecological Monographs 89, e01333. doi: 10.1002/ecm.1333.

Ryo, M., Aguilar-Trigueros, C.A., Pinek, L., Muller, L.A.H., and Rillig, M.C. (2019). Basic Principles of Temporal Dynamics. Trends in Ecology & Evolution 34, 723-733. doi: 10.1016/j.tree.2019.03.007.