About the role of the species Homo Sapiens in environment. The postulate of human ecology can help us to better understand the connections between Homo Sapiens as a key species and its natural environment in order to ensure the sustainability of ecological systems.

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Is Homo Sapiens a key species in an ecological System?
In the 20th century, several scientists went to the most remote areas of
the earth to explore the complexities of different ecological systems. Their
findings provide answers to the greatest challenges of our time. Biologists
such as Charles Elton, Robert T. Paine, Mary E. Power, Jim Estes, Tony
Sinclair and John Terborgh were pioneers in the study of certain animal
species and their importance for the preservation of complex ecological
systems. They coined the term "Keystone species” (key species) and
demonstrated that the absence of a single species can destroy an entire
community of species. The role of key species is both relevant and
surprising: otters help kelp forests bloom and support everything from
salmon to eagles; Wolves allow rivers to remain clear and thrive in
forests; and the humble wildebeest controls the number of trees,
butterflies, elephants and even giraffes on the savannah. Based on the
discoveries of these scientists, Sean B. Carroll writes the book "The
Serengeti Rules", and places a monument to these pioneers of ecology.
In the documentary of Nicolas Browns, "The Serengeti Rules", based on
the book with the same name of Sean B. Carroll, Jim Estes says that man
as Homo Sapiens has become a mega key species, which cannot be
contradicted. In ecological systems, each species has its usefulness and a
certain function. If only one species is wiped out regionally, such as the
predatory starfish, an intact network of biological cycles of a large area is
destroyed. In the case of the starfish, for example, uncontrolled growing
shell banks remain, which eventually lead to the death of an underwater
flora and fauna. When humans are considered a key species, it is not
difficult to understand how important the number and behaviour of people
is in a particular ecological system. The postulate of human ecology lets
us know what happens when humans on a limited area of the earth, with
limited natural resources, under certain climatic conditions, come together
with a certain behaviour (defined by culture, mentality and technology),
with a certain standard of living and with a certain quality of the
environment. The postulate allows us a qualitative analysis of a particular
ecological system, and the function could look like this below, namely:
REV = f (s, n, k, b, l, q, t)
where:
- REV is the multidimensional Regional Ecological Value;
- s - is the number of people per square kilometre on the considered

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earth surface;
- n - defines the natural resources taken into account (including
minerals and the biological environment, i.e. animals and plants);
- k - defines the climate conditions;
- b - defines the behaviour of human beings on the above-e.g. earth
surface;
- l - defines living standards;
- q - defines environmental quality;
- t - a date as a time stamp.
To avoid comparing pears with apples or to get a consistency, REV should
be considered for earth surfaces with similar climatic conditions, etc. This
means that, for example, you cannot directly represent a REV for the
whole of Canada, but only for parts of Canada. This is the only way to
estimate what impact a particular ecological system could have on the
whole. In this analysis, the stability of the geological and cosmic
environment should not be disregarded.
The loss of top predators around the world has a profound impact on
nature. There are cascade effects after the disappearance of top
predators. These "top-down constraints" (causes of variability) have
unexpected effects, such as increase in disease, forest fires, losses in
carbon sequestration, occurrence of invasive species and disruption of
biogeochemical cycles. In the 4.5 billion years of its existence, our planet
has experienced several mass extinctions, with an enormous loss of
biodiversity, followed by novel changes. We are now in the early to mid-
stage of a sixth mass extinction. And as we estimate today, humans, as a
key species, largely influenced this recent extinction, intentionally or
unintentionally. This process of extinction is started by the removal of top
predators. This extinction could be the most profound human impact on
the natural world.
The extinction obviously means a permanent disappearance of these
animals, which in turn often has a ripple effect and causes many other
changes in the entire ecological system. These widespread changes are
referred to by scientists as "trophic cascades". Some of the end results of
"trophic cascades" are: forest fires, disease, climate change, habitat
loss for various living beings and pollution.
The role of the species Homo Sapiens in all these developments is no
longer negligible. Human ecology and socioecology as interdisciplinary
sciences can help us to better understand the connections between the
key human species and its natural environment in order to ensure the
sustainability of ecological systems.

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Webographie:
1. Carroll, Sean B. - The Serengeti Rules: The Quest to Discover How
Life Works and Why It Matters - With a new Q&A with the author -
Scribd
2. Center for Biological Diversity - Halting the extinction crisis
3. Eisner, K. - Stunning doc explains how ecosystems are governed by
The Serengeti Rules - Straight
4. Film - The Serengeti Rules – Die Macht des Gleichgewichts
5. Estes, J. A., Terborgh, J., Brashares, J. S., Power, M. E., Berger, J.,
Bond, W. J., Carpenter, S. R., Essington, T. E., Holt, R. D., Jackson,
J. B. C., Marquis, R, J., Oksanen, L., Oksanen, T., Paine, R. T.,
Pikitch, E. K., Ripple, W. J., Sandin, S. A., Scheffer, M., Schoener, T.
W., Shurin, J. B., Sinclair, A. R. E., Soulé, M. E., Virtanen, R.,
Wardle, D. A. - Trophic Downgrading of Planet Earth - Science
6. Robert T. Paine - Keystone Species Hypothesis - Research Gate
7. Saltre, F., Bradshaw, C. J. A., - Are We Really in a 6th Mass
Extinction? Here's The Science - Science Alert
8. Satvanyi, E. - Das Postulat der Humanökologie - Satvanyi`s
Homepage
9. Satvanyi, E, - Ist der Mensch eine Schlüsselart in einem
ökologischen System? – Academia.edu
10. Satvanyi, E. - The Postulate of Human Ecology - Academia.edu
11. Stony Brook University - Loss of top animal predators has
massive ecological effects - Science Daily
12. Fischman, K. - Trophic Downgrading or Where Have All the
Predators Gone? - Ancient Pathways to a Sustainable Future
13. Kolbert, E. - Will Humans Survive the Sixth Great Extinction?
Species are disappearing at an alarming rate, a new study finds. -
National Geographic
14. Greshko, M. and National Geographic Staff - What are mass
extinctions, and what causes them? - National Geographic
15. Wallach, A. D., Dekker, A. H., Lurgi, M., Montoya, J. M.,
Fordham, D. A., Ritchie, E. G. - Trophic cascades in 3D: network
analysis reveals howapex predators structure ecosystems - Methods
in Ecology and Evolution
16. Wikipedia - Socioecology
17. Wikipedia - The Serengeti Rules
18. Wikipedia - Trophic cascade
19. Woodward, A., - 18 signs we're in the middle of a 6th mass
extinction - Business Insider