Biological balance. Fact? Myth? The goal of our plans?

What do appeals to underfeed seagulls on beaches have in common with algal blooms in Dzierzgon Wielki and Dzierzgon? What do misguided fishing patterns have to do with changes in algal biomass or river baffling? All these questions revolve around biological balance (ecological balance, ecosystem homeostasis). It is commonly believed that stable ecosystems, exploited in a moderate way, remain in a state of dynamic equilibrium. Does this centuries-old accepted paradigm really exist in nature?

Mistakes must be paid for

The seagulls of our Baltic Sea feed on small fish and invertebrates, which brings some benefits to tourists in the form of less blood-sucking insect activity. Feeding these noisy birds and condoning the plundering of garbage cans upsets this delicate balance. Obese, sometimes waste-poisoned seagulls are unable to regulate the number or activity of fish and insects, not to mention the fact that they litter, increasing the threat of disease among humans. Even more dangerous can be erroneous fishing models, which we have already written about in Water Matters. They lead to the setting of incorrect fishing quotas, and this means overfishing more stocks, resulting in shortages on store shelves and unemployment among fishermen.

The natural effects of such mistakes are sometimes algal blooms, invasions of steaming jellyfish in fashionable bathing areas, or the complete reconstruction of successive marine ecosystems. On the other hand, interrupting the continuity of a lowland river with powerful dams means replacing the natural balance of the basin with a new anthropogenic order. A watercourse so shredded will turn into a series of flowing lakes and connecting rivers, with flora and fauna devoid of many native species, but with an increasing proportion of alien species. And often the waters gradually turning into sewage or brine. All these can be cited as examples of ecological imbalance of the ecosystem.

Moderation above all

We have been learning about the self-regulation of ecosystems for decades at successive stages of education. For example, the Integrated Education Platform of the Ministry of Education instructs us that a stabilized ecosystem has the ability to compensate for various disturbances associated with its open nature, changes in environmental factors or human activity [19]. Ecosystems are seen as a kind of superorganism endowed with the ability to self-regulate, otherwise known as ecosystem homeostasis. Already in elementary school we hear that this ecological balance is associated with the diversity of components of a given environment, that is, the number and permanence of interactions between living and non-living elements. That’s why the most diverse habitats, such as coral reefs and equatorial rainforests, regulate themselves brilliantly as long as they remain uninhabited or poorly explored by few natives and rational scientists.

At the opposite extreme are maximally simplified, completely artificial ecosystems, such as tree plantations and grain fields, which exhibit essentially no homeostasis. Here even constant human care cannot prevent pest hailstorms or natural disasters, every now and then destroying to the core such species-poor and poorly integrated biological systems [2, 9, 10, 11, 19].

Most habitats are somewhere between these two extremes. Anthropogenic forms of use are gradually depriving them of more species and self-regulating abilities. On the other hand, the protection of certain parts of them and selected species (especially keystone species) can reverse the decline in biodiversity and restore lost feedbacks between different groups of organisms and/or between living beings and their abiotic environment [9, 10, 11, 19].

Every action causes a reaction

Balance in nature is maintained by both positive and negative feedback. Positive feedback increases the deviation. The effect sustains the cause, leading to further amplification of the effect. An example of this in the world of biotopes and biocoenoses is supposed to be primary succession, according to textbooks. The encroachment of the first living organisms, usually lichens and mosses, into a new biotope gradually fertilizes it, forms a layer of soil. Vascular plants appear, followed by animals and mycorrhizal fungi.

Negative feedback reduces the deviation. The effect extinguishes its own cause. The response inhibits the impulse that triggers it. This is how the presence of a predator, especially an apex predator, works. An increase in the population of a carnivore reduces the population of its prey. Shrinking food availability leads to starvation and disease in the predator’s population. As a result, the size of its population also decreases [2, 9, 10, 11, 19].

Balance in the wolf-deer-axe triangle?

The processes of feedback and disruption of ecosystem homeostasis are often illustrated with the example of wolves, wapiti deer, and the willows and aspens of Yellowstone’s riparian forests. For millennia, all of these species, as representatives of the three trophic levels, have remained there in dynamic equilibrium, and their abundance and biomass have remained more or less constant. The scarcity of apex predators, due to their excessive extermination, has significantly increased the number of their prey, deer. Willows and aspens stopped recovering, and many more species suffered as a result.

The reintroduction of Canis lupus in 1995 was supposed to save pioneer tree species, and consequently many other plants and animals. Unfortunately, the beautiful theory about the salutary effect of wolves on the ecological balance in Yellowstone did not work, and American scientists themselves have challenged it. There is a growing body of work proving that in the presence of carnivores, wapiti pressure on willows even increases, as herbivores give up grazing grasses in clearings. The regeneration of aspen depends on wapiti abundance, and the latter is determined by several factors, not least the absence or presence of the wolf [12].

The image of primary succession disseminated in textbooks and encyclopedias also has its challengers. Botanists-pollinists and mountaineers do not need to be reminded that a significant part of the pioneer “mosses and lichens” are in fact rockeries, moorhens or drab, therefore cushion plants, but floral (angiosperms). Those who have inventoried the flora of damp pits know that, simultaneously with bryophytes, light-seeded trees, reeds, coneflowers or even certain orchids (in Poland, for example, foxgloves and linden trees) often enter there. Traces of cooperation between birch and pine or between Cladium and brown mosses are absent. Where is there room for any feedback here?

Averted view: is biological balance just an illusion?

The doyen of Polish ecology (and world tropical ecology) Prof. January Weiner-father has been preaching for decades that biological balance is a pernicious myth. Moreover, it has long since been debunked by science. Researchers agree that no overall balance in nature there is not and cannot be. All modern ecology textbooks are unanimous on this point, clear and full of evocative illustrations. And yet, the myth of balance in nature is perfectly fine, with many people preferring to believe that nature maintains itself in an equilibrium that is good for it, all organisms work for the common good, and only man shatters this balance. Psychologists and sociologists know well that beliefs instilled by culture can hinder the teaching and learning of scientific concepts, a The balance in nature is a clear example of this [17].

Is there or isn’t there?

According to Weiner, there is no balance in nature:

• thermodynamic disequilibrium, as it would imply a maximum of entropy, i.e., total necrosis achieved long after the self-commissioning of the ecosystem [15, 16, 18];
• the imbalance between the rate of speciation and the rate of extinction of species, because full equilibrium would mean a zero rate of both evolutionary processes. We have empirical evidence that the rate of extinction of species now exceeds the rate of speciation. There have been epochs with opposite trends – times of mass speciation, so-called adaptive radiations [4];
• The imbalance of the balance of the circulation of elements in nature. The carbon cycle does not balance on a geological scale. 2 billion years ago, cyanobacteria thoroughly and irreversibly changed the composition of the atmosphere and hydrosphere, causing a great extinction of anaerobes. In the Carboniferous it was the other way around: reduction prevailed, hence the huge coal deposits and the subsequent increase in atmospheric oxygen concentration. Also, the calcium and phosphorus cycles remain unstable on the paleontological scale, since we have deposits of limestone and gypsum [4];
• imbalance in local ecosystems (biocenoses). According to Weiner, they have neither a constant species composition nor a constant biomass. The constancy of biocoenoses and biomass was a paradigm for a long time, but was rejected a few decades ago [2, 9, 10, 11, 16].

To draw an analogy between an organism and an ecosystem, comparing biocoenoses to superorganisms, makes no sense, according to Weiner-father. The ecosystem as a whole does not have a purpose, and therefore no set parameters. A biocenosis consists of individuals selected fairly randomly. Even if some interact with individuals of other species, creating astonishing mutualisms, each is either driven by its own selfish purpose or is merely a puppet in the hand of its parasites. All communities of organisms are transient, and remain in disequilibrium because external conditions are constantly subject to random, sometimes strong and violent, fluctuations. Careful enough tracking of specific populations has almost always shown huge fluctuations in abundance [15, 16, 18].

Dawkins went even further in his criticism of the organismal approach. In his view, even a single individual is not fully integrated in itself (by itself) since the interests of some genes collide with the interests of others, and cancerous processes arise spontaneously, ending the life of a given specimen in agony [3]. Regardless, the ecology of biological invasions provides plenty of examples of successful invasions and their consequences as manifestations of imbalance [5, 7, 17, 18].

Fact or myth? Perhaps an age-old dream?

Prof. In his textbooks and lectures, Weiner devoted much space to trying to explain the persistence of the belief in biological balance. In his view, the two intertwined beliefs (the first about the occurrence of equilibrium and the second about the benefits to wildlife and humans from it) are as old as European culture [16, 17, 18]. Already the ancient Greeks, led by Herodotus, believed that predators remain in equilibrium with their prey, that is, they kill only as much as they need to [8]. According to the Stoics, nature was governed by cosmic Reason (Logos), so there had to be purposefulness and harmony in it [1].

Later, Russowski reinforced the notion of balance in nature with the myth of the paradisiacal life of good savages in the bosom of primordial nature, unspoiled by agriculture and industry [13, 14]. One of the founders of limnology, and early promoters of Darwinism, Stephen A. Forbes (1844-1930) dwelt on ecological balance as a benevolent order created by natural selection, and operating through predation and competition. In his classic article, he postulated a community of interest, uniting all organisms of a given microcosm (ecosystem). The paper was unique in Forbes’ career. It dealt with algal blooms and massive fish die-offs in Lake Mendota in Wisconsin, not with terrestrial flora and insects, to which he paid most attention. Nevertheless, it proved so influential that it initiated the establishment of lake ecology and river ecology as separate departments of biology [1, 6, 15, 16].

Can such polar opposite visions of ecological balance be reconciled? Perhaps yes, as long as we assume, following the latest lexicons, that ecosystem homeostasis is something short-lived and not very stable, disappearing after each stronger disturbance. Or it is a certain linguistic usus, like sunrises and sunsets. We use the terms sunrise and sunset although at the same time we recognize the validity of Copernicus’ heliocentric theory with later modifications by Kepler and Newton. For us, lovers of water and all things aquatic, this is especially important.

After all, the concept of biological equilibrium was born out of reflection on cyanobacterial blooms [1, 6] and still serves to explain them. The most popular examples of these self-regulating abilities remain equilibriums: in an aquarium, in a fish pond, in a lake undergoing biomanipulation, and finally in a river serving as a sewage receiver (which was already regulated by the REGULATION OF THE MINISTER OF MUNICIPAL GOSPODARKI OF September 2, 1950 on determining the conditions to which sewage discharged into surface water bodies and into the ground should conform). Biological balance, conceived in one way or another, remains the goal of most of us.

In the article, I used, among other things. z:

1. Bowler P. 2007 A history of environmental science. Published. Univ. of Warsaw, W-wa.
2. Czachorowski S. 2006 Describing biocenosis – zoocenology. Electronic script for master’s students (version 2, completed and revised). Published. UWM, Olsztyn.
3. Dawkins R. 2024 The Selfish Gene, Proszynski i S-ka, W-wa.
4. Boar J. 2023 The history of life on Earth. An introduction to paleobiology. Published. Naukowe PWN, Warsaw.
5. Elton C. 1967. the ecology of animal and plant invasions. PWRiL, Warsaw.
6. Forbes S.A.. 1887 The Lake as a Microcosm. Bulletin of the Scientific Association of Peoria, Illinois, pp. 77-87. Reprint: Illinois Natural History Survey Bulletin 15(9), 537-550.
7. Głowaciński Z., Okarma H., Pawłowski J., Solarz W. (eds.). 2011. alien species in the fauna of Poland. Volume I. Overview and status assessment. Published. Institute of Nature Conservation of the Polish Academy of Sciences. (Online edition: www.iop.krakow.pl/gatunkiobce).
8. Herodotus. 2024 History. Czytelnik, W-wa.
9. Krebs Ch. 2009 Ecology. Published. Naukowe PWN, Warsaw.
10. Mayr E. 2002 This is biology. The science of the animate world. Proszynski i S-ka, W-wa.
11. Odum E. 1977. fundamentals of ecology. PWRiL, Warsaw.
12. Okarma H. 2020. impact of wolves on populations of large ungulates. Let’s Protect Native Nature, 76(3), 24-36.
13. Rousseau J.J. [brak daty] Social contract https://wolnelektury.pl/katalog/lektura/rousseau-umowa-spoleczna.html [dostęp 05.10.2024]
14. Sady W. 2010 History of science, philosophy and religion. Published. Marek Derewiecki, Kęty.
15. Weiner J. 1999 Life and evolution of the biosphere. Handbook of general ecology. Published. Naukowe PWN, W-wa.
16. Weiner J. 2020 Life and evolution of the biosphere. Handbook of general ecology. Published. Naukowe PWN, W-wa.
17. Weiner J. 2009 Is there a balance in nature? Facts and myths. Universe 7: 4-9.
18. Weiner J. 1998. slogans Ecosystem, Homeostasis, Equilibrium, Stability, etc. in: Jura C., Krzanowska H. et al. (eds.) Encyclopedia of biology: all fields of natural sciences. Opres, Krakow.
19. Integrated Education Platform of the Ministry of Education. [brak daty] What is an ecosystem? https://zpe.gov.pl/a/przeczytaj/DqrqfJmC6 [dostęp 05.10.2024]